1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542
3543
3544
3545
3546
3547
3548
3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561
3562
3563
3564
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
3581
3582
3583
3584
3585
3586
3587
3588
3589
3590
3591
3592
3593
3594
3595
3596
3597
3598
3599
3600
3601
3602
3603
3604
3605
3606
3607
3608
3609
3610
3611
3612
3613
3614
3615
3616
3617
3618
3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660
3661
3662
3663
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
3748
3749
3750
3751
3752
3753
3754
3755
3756
3757
3758
3759
3760
3761
3762
3763
3764
3765
3766
3767
3768
3769
3770
3771
3772
3773
3774
3775
3776
3777
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
3800
3801
3802
3803
3804
3805
3806
3807
3808
3809
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
3836
3837
3838
3839
3840
3841
3842
3843
3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
3876
3877
3878
3879
3880
3881
3882
3883
3884
3885
3886
3887
3888
3889
3890
3891
3892
3893
3894
3895
3896
3897
3898
3899
3900
3901
3902
3903
3904
3905
3906
3907
3908
3909
3910
3911
3912
3913
3914
3915
3916
3917
3918
3919
3920
3921
3922
3923
3924
3925
3926
3927
3928
3929
3930
3931
3932
3933
3934
3935
3936
3937
3938
3939
3940
3941
3942
3943
3944
3945
3946
3947
3948
3949
3950
3951
3952
3953
3954
3955
3956
3957
3958
3959
3960
3961
3962
3963
3964
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
3978
3979
3980
3981
3982
3983
3984
3985
3986
3987
3988
3989
3990
3991
3992
3993
3994
3995
3996
3997
3998
3999
4000
4001
4002
4003
4004
4005
4006
4007
4008
4009
4010
4011
4012
4013
4014
4015
4016
4017
4018
4019
4020
4021
4022
4023
4024
4025
4026
4027
4028
4029
4030
4031
4032
4033
4034
4035
4036
4037
4038
4039
4040
4041
4042
4043
4044
4045
4046
4047
4048
4049
4050
4051
4052
4053
4054
4055
4056
4057
4058
4059
4060
4061
4062
4063
4064
4065
4066
4067
4068
4069
4070
4071
4072
4073
4074
4075
4076
4077
4078
4079
4080
4081
4082
4083
4084
4085
4086
4087
4088
4089
4090
4091
4092
4093
4094
4095
4096
4097
4098
4099
4100
4101
4102
4103
4104
4105
4106
4107
4108
4109
4110
4111
4112
4113
4114
4115
4116
4117
4118
4119
4120
4121
4122
4123
4124
4125
4126
4127
4128
4129
4130
4131
4132
4133
4134
4135
4136
4137
4138
4139
4140
4141
4142
4143
4144
4145
4146
4147
4148
4149
4150
4151
4152
4153
4154
4155
4156
4157
4158
4159
4160
4161
4162
4163
4164
4165
4166
4167
4168
4169
4170
4171
4172
4173
4174
4175
4176
4177
4178
4179
4180
4181
4182
4183
4184
4185
4186
4187
4188
4189
4190
4191
4192
4193
4194
4195
4196
4197
4198
4199
4200
4201
4202
4203
4204
4205
4206
4207
4208
4209
4210
4211
4212
4213
4214
4215
4216
4217
4218
4219
4220
4221
4222
4223
4224
4225
4226
4227
4228
4229
4230
4231
4232
4233
4234
4235
4236
4237
4238
4239
4240
4241
4242
4243
4244
4245
4246
4247
4248
4249
4250
4251
4252
4253
4254
4255
4256
4257
4258
4259
4260
4261
4262
4263
4264
4265
4266
4267
4268
4269
4270
4271
4272
4273
4274
4275
4276
4277
4278
4279
4280
4281
4282
4283
4284
4285
4286
4287
4288
4289
4290
4291
4292
4293
4294
4295
4296
4297
4298
4299
4300
4301
4302
4303
4304
4305
4306
4307
4308
4309
4310
4311
4312
4313
4314
4315
4316
4317
4318
4319
4320
4321
4322
4323
4324
4325
4326
4327
4328
4329
4330
4331
4332
4333
4334
4335
4336
4337
4338
4339
4340
4341
4342
4343
4344
4345
4346
4347
4348
4349
4350
4351
4352
4353
4354
4355
4356
4357
4358
4359
4360
4361
4362
4363
4364
4365
4366
4367
4368
4369
4370
4371
4372
4373
4374
4375
4376
4377
4378
4379
4380
4381
4382
4383
4384
4385
4386
4387
4388
4389
4390
4391
4392
4393
4394
4395
4396
4397
4398
4399
4400
4401
4402
4403
4404
4405
4406
4407
4408
4409
4410
4411
4412
4413
4414
4415
4416
4417
4418
4419
4420
4421
4422
4423
4424
4425
4426
4427
4428
4429
4430
4431
4432
4433
4434
4435
4436
4437
4438
4439
4440
4441
4442
4443
4444
4445
4446
4447
4448
4449
4450
4451
4452
4453
4454
4455
4456
4457
4458
4459
4460
4461
4462
4463
4464
4465
4466
4467
4468
4469
4470
4471
4472
4473
4474
4475
4476
4477
4478
4479
4480
4481
4482
4483
4484
4485
4486
4487
4488
4489
4490
4491
4492
4493
4494
4495
4496
4497
4498
4499
4500
4501
4502
4503
4504
4505
4506
4507
4508
4509
4510
4511
4512
4513
4514
4515
4516
4517
4518
4519
4520
4521
4522
4523
4524
4525
4526
4527
4528
4529
4530
4531
4532
4533
4534
4535
4536
4537
4538
4539
4540
4541
4542
4543
4544
4545
4546
4547
4548
4549
4550
4551
4552
4553
4554
4555
4556
4557
4558
4559
4560
4561
4562
4563
4564
4565
4566
4567
4568
4569
4570
4571
4572
4573
4574
4575
4576
4577
4578
4579
4580
4581
4582
4583
4584
4585
4586
4587
4588
4589
4590
4591
4592
4593
4594
4595
4596
4597
4598
4599
4600
4601
4602
4603
4604
4605
4606
4607
4608
4609
4610
4611
4612
4613
4614
4615
4616
4617
4618
4619
4620
4621
4622
4623
4624
4625
4626
4627
4628
4629
4630
4631
4632
4633
4634
4635
4636
4637
4638
4639
4640
4641
4642
4643
4644
4645
4646
4647
4648
4649
4650
4651
4652
4653
4654
4655
4656
4657
4658
4659
4660
4661
4662
4663
4664
4665
4666
4667
4668
4669
4670
4671
4672
4673
4674
4675
4676
4677
4678
4679
4680
4681
4682
4683
4684
4685
4686
4687
4688
4689
4690
4691
4692
4693
4694
4695
4696
4697
4698
4699
4700
4701
4702
4703
4704
4705
4706
4707
4708
4709
4710
4711
4712
4713
4714
4715
4716
4717
4718
4719
4720
4721
4722
4723
4724
4725
4726
4727
4728
4729
4730
4731
4732
4733
4734
4735
4736
4737
4738
4739
4740
4741
4742
4743
4744
4745
4746
4747
4748
4749
4750
4751
4752
4753
4754
4755
4756
4757
4758
4759
4760
4761
4762
4763
4764
4765
4766
4767
4768
4769
4770
4771
4772
4773
4774
4775
4776
4777
4778
4779
4780
4781
4782
4783
4784
4785
4786
4787
4788
4789
4790
4791
4792
4793
4794
4795
4796
4797
4798
4799
4800
4801
4802
4803
4804
4805
4806
4807
4808
4809
4810
4811
4812
4813
4814
4815
4816
4817
4818
4819
4820
4821
4822
4823
4824
4825
4826
4827
4828
4829
4830
4831
4832
4833
4834
4835
4836
4837
4838
4839
4840
4841
4842
4843
4844
4845
4846
4847
4848
4849
4850
4851
4852
4853
4854
4855
4856
4857
4858
4859
4860
4861
4862
4863
4864
4865
4866
4867
4868
4869
4870
4871
4872
4873
4874
4875
4876
4877
4878
4879
4880
4881
4882
4883
4884
4885
4886
4887
4888
4889
4890
4891
4892
4893
4894
4895
4896
4897
4898
4899
4900
4901
4902
4903
4904
4905
4906
4907
4908
4909
4910
4911
4912
4913
4914
4915
4916
4917
4918
4919
4920
4921
4922
4923
4924
4925
4926
4927
4928
4929
4930
4931
4932
4933
4934
4935
4936
4937
4938
4939
4940
4941
4942
4943
4944
4945
4946
4947
4948
4949
4950
4951
4952
4953
4954
4955
4956
4957
4958
4959
4960
4961
4962
4963
4964
4965
4966
4967
4968
4969
4970
4971
4972
4973
4974
4975
4976
4977
4978
4979
4980
4981
4982
4983
4984
4985
4986
4987
4988
4989
4990
4991
4992
4993
4994
4995
4996
4997
4998
4999
5000
5001
5002
5003
5004
5005
5006
5007
5008
5009
5010
5011
5012
5013
5014
5015
5016
5017
5018
5019
5020
5021
5022
5023
5024
5025
5026
5027
5028
5029
5030
5031
5032
5033
5034
5035
5036
5037
5038
5039
5040
5041
5042
5043
5044
5045
5046
5047
5048
5049
5050
5051
5052
5053
5054
5055
5056
5057
5058
5059
5060
5061
5062
5063
5064
5065
5066
5067
5068
5069
5070
5071
5072
5073
5074
5075
5076
5077
5078
5079
5080
5081
5082
5083
5084
5085
5086
5087
5088
5089
5090
5091
5092
5093
5094
5095
5096
5097
5098
5099
5100
5101
5102
5103
5104
5105
5106
5107
5108
5109
5110
5111
5112
5113
5114
5115
5116
5117
5118
5119
5120
5121
5122
5123
5124
5125
5126
5127
5128
5129
5130
5131
5132
5133
5134
5135
5136
5137
5138
5139
5140
5141
5142
5143
5144
5145
5146
5147
5148
5149
5150
5151
5152
5153
5154
5155
5156
5157
5158
5159
5160
5161
5162
5163
5164
5165
5166
5167
5168
5169
5170
5171
5172
5173
5174
5175
5176
5177
5178
5179
5180
5181
5182
5183
5184
5185
5186
5187
5188
5189
5190
5191
5192
5193
5194
5195
5196
5197
5198
5199
5200
5201
5202
5203
5204
5205
5206
5207
5208
5209
5210
5211
5212
5213
5214
5215
5216
5217
5218
5219
5220
5221
5222
5223
5224
5225
5226
5227
5228
5229
5230
5231
5232
5233
5234
5235
5236
5237
5238
5239
5240
5241
5242
5243
5244
5245
5246
5247
5248
5249
5250
5251
5252
5253
5254
5255
5256
5257
5258
5259
5260
5261
5262
5263
5264
5265
5266
5267
5268
5269
5270
5271
5272
5273
5274
5275
5276
5277
5278
5279
5280
5281
5282
5283
5284
5285
5286
5287
5288
5289
5290
5291
5292
5293
5294
5295
5296
5297
5298
5299
5300
5301
5302
5303
5304
5305
5306
5307
5308
5309
5310
5311
5312
5313
5314
5315
5316
5317
5318
5319
5320
5321
5322
5323
5324
5325
5326
5327
5328
5329
5330
5331
5332
5333
5334
5335
5336
5337
5338
5339
5340
5341
5342
5343
5344
5345
5346
5347
5348
5349
5350
5351
5352
5353
5354
5355
5356
5357
5358
5359
5360
5361
5362
5363
5364
5365
5366
5367
5368
5369
5370
5371
5372
5373
5374
5375
5376
5377
5378
5379
5380
5381
5382
5383
5384
5385
5386
5387
5388
5389
5390
5391
5392
5393
5394
5395
5396
5397
5398
5399
5400
5401
5402
5403
5404
5405
5406
5407
5408
5409
5410
5411
5412
5413
5414
5415
5416
5417
5418
5419
5420
5421
5422
5423
5424
5425
5426
5427
5428
5429
5430
5431
5432
5433
5434
5435
5436
5437
5438
5439
5440
5441
5442
5443
5444
5445
5446
5447
5448
5449
5450
5451
5452
5453
5454
5455
5456
5457
5458
5459
5460
5461
5462
5463
5464
5465
5466
5467
5468
5469
5470
5471
5472
5473
5474
5475
5476
5477
5478
5479
5480
5481
5482
5483
5484
5485
5486
5487
5488
5489
5490
5491
5492
5493
5494
5495
5496
5497
5498
5499
5500
|
/* xdelta 3 - delta compression tools and library
* Copyright (C) 2001, 2003, 2004, 2005, 2006, 2007,
* 2008, 2009, 2010. Joshua P. MacDonald
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
-------------------------------------------------------------------
Xdelta 3
The goal of this library is to to implement both the (stand-alone)
data-compression and delta-compression aspects of VCDIFF encoding, and
to support a programming interface that works like Zlib
(http://www.gzip.org/zlib.html). See RFC3284: The VCDIFF Generic
Differencing and Compression Data Format.
VCDIFF is a unified encoding that combines data-compression and
delta-encoding ("differencing").
VCDIFF has a detailed byte-code instruction set with many features.
The instruction format supports an immediate size operand for small
COPYs and ADDs (e.g., under 18 bytes). There are also instruction
"modes", which are used to compress COPY addresses by using two
address caches. An instruction mode refers to slots in the NEAR
and SAME caches for recent addresses. NEAR remembers the
previous 4 (by default) COPY addresses, and SAME catches
frequent re-uses of the same address using a 3-way (by default)
256-entry associative cache of [ADDR mod 256], the encoded byte.
A hit in the NEAR/SAME cache requires 0/1 ADDR bytes.
VCDIFF has a default instruction table, but an alternate
instruction tables may themselves be be delta-compressed and
included in the encoding header. This allows even more freedom.
There are 9 instruction modes in the default code table, 4 near, 3
same, VCD_SELF (absolute encoding) and VCD_HERE (relative to the
current position).
----------------------------------------------------------------------
Algorithms
Aside from the details of encoding and decoding, there are a bunch
of algorithms needed.
1. STRING-MATCH. A two-level fingerprinting approach is used. A
single loop computes the two checksums -- small and large -- at
successive offsets in the TARGET file. The large checksum is more
accurate and is used to discover SOURCE matches, which are
potentially very long. The small checksum is used to discover
copies within the TARGET. Small matching, which is more expensive,
usually dominates the large STRING-MATCH costs in this code - the
more exhaustive the search, the better the results. Either of the
two string-matching mechanisms may be disabled.
2. INSTRUCTION SELECTION. The IOPT buffer here represents a queue
used to store overlapping copy instructions. There are two possible
optimizations that go beyond a greedy search. Both of these fall
into the category of "non-greedy matching" optimizations.
The first optimization stems from backward SOURCE-COPY matching.
When a new SOURCE-COPY instruction covers a previous instruction in
the target completely, it is erased from the queue. Randal Burns
originally analyzed these algorithms and did a lot of related work
(\cite the 1.5-pass algorithm).
The second optimization comes by the encoding of common very-small
COPY and ADD instructions, for which there are special DOUBLE-code
instructions, which code two instructions in a single byte.
The cost of bad instruction-selection overhead is relatively high
for data-compression, relative to delta-compression, so this second
optimization is fairly important. With "lazy" matching (the name
used in Zlib for a similar optimization), the string-match
algorithm searches after a match for potential overlapping copy
instructions. In Xdelta and by default, VCDIFF, the minimum match
size is 4 bytes, whereas Zlib searches with a 3-byte minimum. This
feature, combined with double instructions, provides a nice
challenge. Search in this file for "black magic", a heuristic.
3. STREAM ALIGNMENT. Stream alignment is needed to compress large
inputs in constant space. See xd3_srcwin_move_point().
4. WINDOW SELECTION. When the IOPT buffer flushes, in the first call
to xd3_iopt_finish_encoding containing any kind of copy instruction,
the parameters of the source window must be decided: the offset into
the source and the length of the window. Since the IOPT buffer is
finite, the program may be forced to fix these values before knowing
the best offset/length.
5. SECONDARY COMPRESSION. VCDIFF supports a secondary encoding to
be applied to the individual sections of the data format, which are
ADDRess, INSTruction, and DATA. Several secondary compressor
variations are implemented here, although none is standardized yet.
One is an adaptive huffman algorithm -- the FGK algorithm (Faller,
Gallager, and Knuth, 1985). This compressor is extremely slow.
The other is a simple static Huffman routine, which is the base
case of a semi-adaptive scheme published by D.J. Wheeler and first
widely used in bzip2 (by Julian Seward). This is a very
interesting algorithm, originally published in nearly cryptic form
by D.J. Wheeler. !!!NOTE!!! Because these are not standardized,
secondary compression remains off by default.
ftp://ftp.cl.cam.ac.uk/users/djw3/bred3.{c,ps}
--------------------------------------------------------------------
Other Features
1. USER CONVENIENCE
For user convenience, it is essential to recognize Gzip-compressed
files and automatically Gzip-decompress them prior to
delta-compression (or else no delta-compression will be achieved
unless the user manually decompresses the inputs). The compressed
represention competes with Xdelta, and this must be hidden from the
command-line user interface. The Xdelta-1.x encoding was simple, not
compressed itself, so Xdelta-1.x uses Zlib internally to compress the
representation.
This implementation supports external compression, which implements
the necessary fork() and pipe() mechanics. There is a tricky step
involved to support automatic detection of a compressed input in a
non-seekable input. First you read a bit of the input to detect
magic headers. When a compressed format is recognized, exec() the
external compression program and create a second child process to
copy the original input stream. [Footnote: There is a difficulty
related to using Gzip externally. It is not possible to decompress
and recompress a Gzip file transparently. If FILE.GZ had a
cryptographic signature, then, after: (1) Gzip-decompression, (2)
Xdelta-encoding, (3) Gzip-compression the signature could be
broken. The only way to solve this problem is to guess at Gzip's
compression level or control it by other means. I recommend that
specific implementations of any compression scheme store
information needed to exactly re-compress the input, that way
external compression is transparent - however, this won't happen
here until it has stabilized.]
2. APPLICATION-HEADER
This feature was introduced in RFC3284. It allows any application
to include a header within the VCDIFF file format. This allows
general inter-application data exchange with support for
application-specific extensions to communicate metadata.
3. VCDIFF CHECKSUM
An optional checksum value is included with each window, which can
be used to validate the final result. This verifies the correct source
file was used for decompression as well as the obvious advantage:
checking the implementation (and underlying) correctness.
4. LIGHT WEIGHT
The code makes efforts to avoid copying data more than necessary.
The code delays many initialization tasks until the first use, it
optimizes for identical (perfectly matching) inputs. It does not
compute any checksums until the first lookup misses. Memory usage
is reduced. String-matching is templatized (by slightly gross use
of CPP) to hard-code alternative compile-time defaults. The code
has few outside dependencies.
----------------------------------------------------------------------
The default rfc3284 instruction table:
(see RFC for the explanation)
TYPE SIZE MODE TYPE SIZE MODE INDEX
--------------------------------------------------------------------
1. Run 0 0 Noop 0 0 0
2. Add 0, [1,17] 0 Noop 0 0 [1,18]
3. Copy 0, [4,18] 0 Noop 0 0 [19,34]
4. Copy 0, [4,18] 1 Noop 0 0 [35,50]
5. Copy 0, [4,18] 2 Noop 0 0 [51,66]
6. Copy 0, [4,18] 3 Noop 0 0 [67,82]
7. Copy 0, [4,18] 4 Noop 0 0 [83,98]
8. Copy 0, [4,18] 5 Noop 0 0 [99,114]
9. Copy 0, [4,18] 6 Noop 0 0 [115,130]
10. Copy 0, [4,18] 7 Noop 0 0 [131,146]
11. Copy 0, [4,18] 8 Noop 0 0 [147,162]
12. Add [1,4] 0 Copy [4,6] 0 [163,174]
13. Add [1,4] 0 Copy [4,6] 1 [175,186]
14. Add [1,4] 0 Copy [4,6] 2 [187,198]
15. Add [1,4] 0 Copy [4,6] 3 [199,210]
16. Add [1,4] 0 Copy [4,6] 4 [211,222]
17. Add [1,4] 0 Copy [4,6] 5 [223,234]
18. Add [1,4] 0 Copy 4 6 [235,238]
19. Add [1,4] 0 Copy 4 7 [239,242]
20. Add [1,4] 0 Copy 4 8 [243,246]
21. Copy 4 [0,8] Add 1 0 [247,255]
--------------------------------------------------------------------
Reading the source: Overview
This file includes itself in several passes to macro-expand certain
sections with variable forms. Just read ahead, there's only a
little confusion. I know this sounds ugly, but hard-coding some of
the string-matching parameters results in a 10-15% increase in
string-match performance. The only time this hurts is when you have
unbalanced #if/endifs.
A single compilation unit tames the Makefile. In short, this is to
allow the above-described hack without an explodingMakefile. The
single compilation unit includes the core library features,
configurable string-match templates, optional main() command-line
tool, misc optional features, and a regression test. Features are
controled with CPP #defines, see Makefile.am.
The initial __XDELTA3_C_HEADER_PASS__ starts first, the _INLINE_ and
_TEMPLATE_ sections follow. Easy stuff first, hard stuff last.
Optional features include:
xdelta3-main.h The command-line interface, external compression
support, POSIX-specific, info & VCDIFF-debug tools.
xdelta3-second.h The common secondary compression routines.
xdelta3-decoder.h All decoding routines.
xdelta3-djw.h The semi-adaptive huffman secondary encoder.
xdelta3-fgk.h The adaptive huffman secondary encoder.
xdelta3-test.h The unit test covers major algorithms,
encoding and decoding. There are single-bit
error decoding tests. There are 32/64-bit file size
boundary tests. There are command-line tests.
There are compression tests. There are external
compression tests. There are string-matching tests.
There should be more tests...
Additional headers include:
xdelta3.h The public header file.
xdelta3-cfgs.h The default settings for default, built-in
encoders. These are hard-coded at
compile-time. There is also a single
soft-coded string matcher for experimenting
with arbitrary values.
xdelta3-list.h A cyclic list template
Misc little debug utilities:
badcopy.c Randomly modifies an input file based on two
parameters: (1) the probability that a byte in
the file is replaced with a pseudo-random value,
and (2) the mean change size. Changes are
generated using an expoential distribution
which approximates the expected error_prob
distribution.
--------------------------------------------------------------------
This file itself is unusually large. I hope to defend this layout
with lots of comments. Everything in this file is related to
encoding and decoding. I like it all together - the template stuff
is just a hack. */
#ifndef __XDELTA3_C_HEADER_PASS__
#define __XDELTA3_C_HEADER_PASS__
#include "xdelta3.h"
/***********************************************************************
STATIC CONFIGURATION
***********************************************************************/
#ifndef XD3_MAIN /* the main application */
#define XD3_MAIN 0
#endif
#ifndef VCDIFF_TOOLS
#define VCDIFF_TOOLS XD3_MAIN
#endif
#ifndef SECONDARY_FGK /* one from the algorithm preservation department: */
#define SECONDARY_FGK 0 /* adaptive Huffman routines */
#endif
#ifndef SECONDARY_DJW /* semi-adaptive/static Huffman for the eventual */
#define SECONDARY_DJW 0 /* standardization, off by default until such time. */
#endif
#ifdef HAVE_LZMA_H
#define SECONDARY_LZMA 1
#else
#define SECONDARY_LZMA 0
#endif
#ifndef GENERIC_ENCODE_TABLES /* These three are the RFC-spec app-specific */
#define GENERIC_ENCODE_TABLES 0 /* code features. This is tested but not */
#endif /* recommended unless there's a real use. */
#ifndef GENERIC_ENCODE_TABLES_COMPUTE
#define GENERIC_ENCODE_TABLES_COMPUTE 0
#endif
#ifndef GENERIC_ENCODE_TABLES_COMPUTE_PRINT
#define GENERIC_ENCODE_TABLES_COMPUTE_PRINT 0
#endif
#if XD3_ENCODER
#define IF_ENCODER(x) x
#else
#define IF_ENCODER(x)
#endif
/***********************************************************************/
/* header indicator bits */
#define VCD_SECONDARY (1U << 0) /* uses secondary compressor */
#define VCD_CODETABLE (1U << 1) /* supplies code table data */
#define VCD_APPHEADER (1U << 2) /* supplies application data */
#define VCD_INVHDR (~0x7U)
/* window indicator bits */
#define VCD_SOURCE (1U << 0) /* copy window in source file */
#define VCD_TARGET (1U << 1) /* copy window in target file */
#define VCD_ADLER32 (1U << 2) /* has adler32 checksum */
#define VCD_INVWIN (~0x7U)
#define VCD_SRCORTGT (VCD_SOURCE | VCD_TARGET)
/* delta indicator bits */
#define VCD_DATACOMP (1U << 0)
#define VCD_INSTCOMP (1U << 1)
#define VCD_ADDRCOMP (1U << 2)
#define VCD_INVDEL (~0x7U)
typedef enum {
VCD_DJW_ID = 1,
VCD_LZMA_ID = 2,
VCD_FGK_ID = 16 /* Note: these are not standard IANA-allocated IDs! */
} xd3_secondary_ids;
typedef enum {
SEC_NOFLAGS = 0,
/* Note: SEC_COUNT_FREQS Not implemented (to eliminate 1st Huffman pass) */
SEC_COUNT_FREQS = (1 << 0)
} xd3_secondary_flags;
typedef enum {
DATA_SECTION, /* These indicate which section to the secondary
* compressor. */
INST_SECTION, /* The header section is not compressed, therefore not
* listed here. */
ADDR_SECTION
} xd3_section_type;
typedef unsigned int xd3_rtype;
/***********************************************************************/
#include "xdelta3-list.h"
XD3_MAKELIST(xd3_rlist, xd3_rinst, link);
/***********************************************************************/
#define SECONDARY_MIN_SAVINGS 2 /* Secondary compression has to save
at least this many bytes. */
#define SECONDARY_MIN_INPUT 10 /* Secondary compression needs at
least this many bytes. */
#define VCDIFF_MAGIC1 0xd6 /* 1st file byte */
#define VCDIFF_MAGIC2 0xc3 /* 2nd file byte */
#define VCDIFF_MAGIC3 0xc4 /* 3rd file byte */
#define VCDIFF_VERSION 0x00 /* 4th file byte */
#define VCD_SELF 0 /* 1st address mode */
#define VCD_HERE 1 /* 2nd address mode */
#define CODE_TABLE_STRING_SIZE (6 * 256) /* Should fit a code table string. */
#define CODE_TABLE_VCDIFF_SIZE (6 * 256) /* Should fit a compressed code
* table string */
#define SECONDARY_ANY (SECONDARY_DJW || SECONDARY_FGK || SECONDARY_LZMA)
#define ALPHABET_SIZE 256 /* Used in test code--size of the secondary
* compressor alphabet. */
#define HASH_PERMUTE 1 /* The input is permuted by random nums */
#define ADLER_LARGE_CKSUM 1 /* Adler checksum vs. RK checksum */
#define HASH_CKOFFSET 1U /* Table entries distinguish "no-entry" from
* offset 0 using this offset. */
#define MIN_SMALL_LOOK 2U /* Match-optimization stuff. */
#define MIN_LARGE_LOOK 2U
#define MIN_MATCH_OFFSET 1U
#define MAX_MATCH_SPLIT 18U /* VCDIFF code table: 18 is the default limit
* for direct-coded ADD sizes */
#define LEAST_MATCH_INCR 0 /* The least number of bytes an overlapping
* match must beat the preceding match by. This
* is a bias for the lazy match optimization. A
* non-zero value means that an adjacent match
* has to be better by more than the step
* between them. 0. */
#define MIN_MATCH 4U /* VCDIFF code table: MIN_MATCH=4 */
#define MIN_ADD 1U /* 1 */
#define MIN_RUN 8U /* The shortest run, if it is shorter than this
* an immediate add/copy will be just as good.
* ADD1/COPY6 = 1I+1D+1A bytes, RUN18 =
* 1I+1D+1A. */
#define MAX_MODES 9 /* Maximum number of nodes used for
* compression--does not limit decompression. */
#define ENC_SECTS 4 /* Number of separate output sections. */
#define HDR_TAIL(s) ((s)->enc_tails[0])
#define DATA_TAIL(s) ((s)->enc_tails[1])
#define INST_TAIL(s) ((s)->enc_tails[2])
#define ADDR_TAIL(s) ((s)->enc_tails[3])
#define HDR_HEAD(s) ((s)->enc_heads[0])
#define DATA_HEAD(s) ((s)->enc_heads[1])
#define INST_HEAD(s) ((s)->enc_heads[2])
#define ADDR_HEAD(s) ((s)->enc_heads[3])
#define TOTAL_MODES(x) (2+(x)->acache.s_same+(x)->acache.s_near)
/* Template instances. */
#if XD3_BUILD_SLOW
#define IF_BUILD_SLOW(x) x
#else
#define IF_BUILD_SLOW(x)
#endif
#if XD3_BUILD_FAST
#define IF_BUILD_FAST(x) x
#else
#define IF_BUILD_FAST(x)
#endif
#if XD3_BUILD_FASTER
#define IF_BUILD_FASTER(x) x
#else
#define IF_BUILD_FASTER(x)
#endif
#if XD3_BUILD_FASTEST
#define IF_BUILD_FASTEST(x) x
#else
#define IF_BUILD_FASTEST(x)
#endif
#if XD3_BUILD_SOFT
#define IF_BUILD_SOFT(x) x
#else
#define IF_BUILD_SOFT(x)
#endif
#if XD3_BUILD_DEFAULT
#define IF_BUILD_DEFAULT(x) x
#else
#define IF_BUILD_DEFAULT(x)
#endif
/* Consume N bytes of input, only used by the decoder. */
#define DECODE_INPUT(n) \
do { \
stream->total_in += (xoff_t) (n); \
stream->avail_in -= (n); \
stream->next_in += (n); \
} while (0)
/* Update the run-length state */
#define NEXTRUN(c) do { if ((c) == run_c) { run_l += 1; } \
else { run_c = (c); run_l = 1; } } while (0)
/* This CPP-conditional stuff can be cleaned up... */
#if REGRESSION_TEST
#define IF_REGRESSION(x) x
#else
#define IF_REGRESSION(x)
#endif
/***********************************************************************/
#if XD3_ENCODER
static void* xd3_alloc0 (xd3_stream *stream,
usize_t elts,
usize_t size);
static xd3_output* xd3_alloc_output (xd3_stream *stream,
xd3_output *old_output);
static int xd3_alloc_iopt (xd3_stream *stream, usize_t elts);
static void xd3_free_output (xd3_stream *stream,
xd3_output *output);
static int xd3_emit_byte (xd3_stream *stream,
xd3_output **outputp,
uint8_t code);
static int xd3_emit_bytes (xd3_stream *stream,
xd3_output **outputp,
const uint8_t *base,
usize_t size);
static int xd3_emit_double (xd3_stream *stream, xd3_rinst *first,
xd3_rinst *second, usize_t code);
static int xd3_emit_single (xd3_stream *stream, xd3_rinst *single,
usize_t code);
static usize_t xd3_sizeof_output (xd3_output *output);
static void xd3_encode_reset (xd3_stream *stream);
static int xd3_source_match_setup (xd3_stream *stream, xoff_t srcpos);
static int xd3_source_extend_match (xd3_stream *stream);
static int xd3_srcwin_setup (xd3_stream *stream);
static usize_t xd3_iopt_last_matched (xd3_stream *stream);
static int xd3_emit_uint32_t (xd3_stream *stream, xd3_output **output,
uint32_t num);
static usize_t xd3_smatch (xd3_stream *stream,
usize_t base,
usize_t scksum,
usize_t *match_offset);
static int xd3_string_match_init (xd3_stream *stream);
static uint32_t xd3_scksum (uint32_t *state, const uint8_t *seg,
const usize_t ln);
static usize_t xd3_comprun (const uint8_t *seg, usize_t slook, uint8_t *run_cp);
static int xd3_srcwin_move_point (xd3_stream *stream,
usize_t *next_move_point);
static int xd3_emit_run (xd3_stream *stream, usize_t pos,
usize_t size, uint8_t *run_c);
static usize_t xd3_checksum_hash (const xd3_hash_cfg *cfg,
const usize_t cksum);
static xoff_t xd3_source_cksum_offset(xd3_stream *stream, usize_t low);
static void xd3_scksum_insert (xd3_stream *stream,
usize_t inx,
usize_t scksum,
usize_t pos);
#if XD3_DEBUG
static void xd3_verify_run_state (xd3_stream *stream,
const uint8_t *inp,
usize_t x_run_l,
uint8_t *x_run_c);
static void xd3_verify_large_state (xd3_stream *stream,
const uint8_t *inp,
uint32_t x_cksum);
static void xd3_verify_small_state (xd3_stream *stream,
const uint8_t *inp,
uint32_t x_cksum);
#endif /* XD3_DEBUG */
#endif /* XD3_ENCODER */
static int xd3_decode_allocate (xd3_stream *stream, usize_t size,
uint8_t **copied1, usize_t *alloc1);
static void xd3_compute_code_table_string (const xd3_dinst *code_table,
uint8_t *str);
static void* xd3_alloc (xd3_stream *stream, usize_t elts, usize_t size);
static void xd3_free (xd3_stream *stream, void *ptr);
static int xd3_read_uint32_t (xd3_stream *stream, const uint8_t **inpp,
const uint8_t *max, uint32_t *valp);
#if REGRESSION_TEST
static int xd3_selftest (void);
#endif
/***********************************************************************/
#define UINT32_OFLOW_MASK 0xfe000000U
#define UINT64_OFLOW_MASK 0xfe00000000000000ULL
#if SIZEOF_USIZE_T == 4
#define USIZE_T_MAX UINT32_MAX
#define xd3_decode_size xd3_decode_uint32_t
#define xd3_emit_size xd3_emit_uint32_t
#define xd3_sizeof_size xd3_sizeof_uint32_t
#define xd3_read_size xd3_read_uint32_t
#elif SIZEOF_USIZE_T == 8
#define USIZE_T_MAX UINT64_MAX
#define xd3_decode_size xd3_decode_uint64_t
#define xd3_emit_size xd3_emit_uint64_t
#define xd3_sizeof_size xd3_sizeof_uint64_t
#define xd3_read_size xd3_read_uint64_t
#endif
#if SIZEOF_XOFF_T == 4
#define XOFF_T_MAX UINT32_MAX
#define xd3_decode_offset xd3_decode_uint32_t
#define xd3_emit_offset xd3_emit_uint32_t
#elif SIZEOF_XOFF_T == 8
#define XOFF_T_MAX UINT64_MAX
#define xd3_decode_offset xd3_decode_uint64_t
#define xd3_emit_offset xd3_emit_uint64_t
#endif
#define USIZE_T_OVERFLOW(a,b) ((USIZE_T_MAX - (usize_t) (a)) < (usize_t) (b))
#define XOFF_T_OVERFLOW(a,b) ((XOFF_T_MAX - (xoff_t) (a)) < (xoff_t) (b))
const char* xd3_strerror (int ret)
{
switch (ret)
{
case XD3_INPUT: return "XD3_INPUT";
case XD3_OUTPUT: return "XD3_OUTPUT";
case XD3_GETSRCBLK: return "XD3_GETSRCBLK";
case XD3_GOTHEADER: return "XD3_GOTHEADER";
case XD3_WINSTART: return "XD3_WINSTART";
case XD3_WINFINISH: return "XD3_WINFINISH";
case XD3_TOOFARBACK: return "XD3_TOOFARBACK";
case XD3_INTERNAL: return "XD3_INTERNAL";
case XD3_INVALID: return "XD3_INVALID";
case XD3_INVALID_INPUT: return "XD3_INVALID_INPUT";
case XD3_NOSECOND: return "XD3_NOSECOND";
case XD3_UNIMPLEMENTED: return "XD3_UNIMPLEMENTED";
}
return NULL;
}
/***********************************************************************/
#define xd3_sec_data(s) ((s)->sec_stream_d)
#define xd3_sec_inst(s) ((s)->sec_stream_i)
#define xd3_sec_addr(s) ((s)->sec_stream_a)
struct _xd3_sec_type
{
int id;
const char *name;
xd3_secondary_flags flags;
/* xd3_sec_stream is opaque to the generic code */
xd3_sec_stream* (*alloc) (xd3_stream *stream);
void (*destroy) (xd3_stream *stream,
xd3_sec_stream *sec);
int (*init) (xd3_stream *stream,
xd3_sec_stream *sec_stream,
int is_encode);
int (*decode) (xd3_stream *stream,
xd3_sec_stream *sec_stream,
const uint8_t **input,
const uint8_t *input_end,
uint8_t **output,
const uint8_t *output_end);
#if XD3_ENCODER
int (*encode) (xd3_stream *stream,
xd3_sec_stream *sec_stream,
xd3_output *input,
xd3_output *output,
xd3_sec_cfg *cfg);
#endif
};
#define BIT_STATE_ENCODE_INIT { 0, 1 }
#define BIT_STATE_DECODE_INIT { 0, 0x100 }
typedef struct _bit_state bit_state;
struct _bit_state
{
usize_t cur_byte;
usize_t cur_mask;
};
#if SECONDARY_ANY == 0
#define IF_SEC(x)
#define IF_NSEC(x) x
#else /* yuck */
#define IF_SEC(x) x
#define IF_NSEC(x)
static int
xd3_decode_secondary (xd3_stream *stream,
xd3_desect *sect,
xd3_sec_stream **sec_streamp);
#if XD3_ENCODER
static int
xd3_encode_secondary (xd3_stream *stream,
xd3_output **head,
xd3_output **tail,
xd3_sec_stream **sec_streamp,
xd3_sec_cfg *cfg,
int *did_it);
#endif
#endif /* SECONDARY_ANY */
#if SECONDARY_FGK
extern const xd3_sec_type fgk_sec_type;
#define IF_FGK(x) x
#define FGK_CASE(s) \
s->sec_type = & fgk_sec_type; \
break;
#else
#define IF_FGK(x)
#define FGK_CASE(s) \
s->msg = "unavailable secondary compressor: FGK Adaptive Huffman"; \
return XD3_INTERNAL;
#endif
#if SECONDARY_DJW
extern const xd3_sec_type djw_sec_type;
#define IF_DJW(x) x
#define DJW_CASE(s) \
s->sec_type = & djw_sec_type; \
break;
#else
#define IF_DJW(x)
#define DJW_CASE(s) \
s->msg = "unavailable secondary compressor: DJW Static Huffman"; \
return XD3_INTERNAL;
#endif
#if SECONDARY_LZMA
extern const xd3_sec_type lzma_sec_type;
#define IF_LZMA(x) x
#define LZMA_CASE(s) \
s->sec_type = & lzma_sec_type; \
break;
#else
#define IF_LZMA(x)
#define LZMA_CASE(s) \
s->msg = "unavailable secondary compressor: LZMA"; \
return XD3_INTERNAL;
#endif
/***********************************************************************/
#include "xdelta3-hash.h"
/* Process template passes - this includes xdelta3.c several times. */
#define __XDELTA3_C_TEMPLATE_PASS__
#include "xdelta3-cfgs.h"
#undef __XDELTA3_C_TEMPLATE_PASS__
/* Process the inline pass. */
#define __XDELTA3_C_INLINE_PASS__
#include "xdelta3.c"
#undef __XDELTA3_C_INLINE_PASS__
/* Secondary compression */
#if SECONDARY_ANY
#include "xdelta3-second.h"
#endif
#if SECONDARY_FGK
#include "xdelta3-fgk.h"
const xd3_sec_type fgk_sec_type =
{
VCD_FGK_ID,
"FGK Adaptive Huffman",
SEC_NOFLAGS,
(xd3_sec_stream* (*)(xd3_stream*)) fgk_alloc,
(void (*)(xd3_stream*, xd3_sec_stream*)) fgk_destroy,
(int (*)(xd3_stream*, xd3_sec_stream*, int)) fgk_init,
(int (*)(xd3_stream*, xd3_sec_stream*, const uint8_t**, const uint8_t*,
uint8_t**, const uint8_t*)) xd3_decode_fgk,
IF_ENCODER((int (*)(xd3_stream*, xd3_sec_stream*, xd3_output*,
xd3_output*, xd3_sec_cfg*)) xd3_encode_fgk)
};
#endif
#if SECONDARY_DJW
#include "xdelta3-djw.h"
const xd3_sec_type djw_sec_type =
{
VCD_DJW_ID,
"Static Huffman",
SEC_COUNT_FREQS,
(xd3_sec_stream* (*)(xd3_stream*)) djw_alloc,
(void (*)(xd3_stream*, xd3_sec_stream*)) djw_destroy,
(int (*)(xd3_stream*, xd3_sec_stream*, int)) djw_init,
(int (*)(xd3_stream*, xd3_sec_stream*, const uint8_t**, const uint8_t*,
uint8_t**, const uint8_t*)) xd3_decode_huff,
IF_ENCODER((int (*)(xd3_stream*, xd3_sec_stream*, xd3_output*,
xd3_output*, xd3_sec_cfg*)) xd3_encode_huff)
};
#endif
#if SECONDARY_LZMA
#include "xdelta3-lzma.h"
const xd3_sec_type lzma_sec_type =
{
VCD_LZMA_ID,
"lzma",
SEC_NOFLAGS,
(xd3_sec_stream* (*)(xd3_stream*)) xd3_lzma_alloc,
(void (*)(xd3_stream*, xd3_sec_stream*)) xd3_lzma_destroy,
(int (*)(xd3_stream*, xd3_sec_stream*, int)) xd3_lzma_init,
(int (*)(xd3_stream*, xd3_sec_stream*, const uint8_t**, const uint8_t*,
uint8_t**, const uint8_t*)) xd3_decode_lzma,
IF_ENCODER((int (*)(xd3_stream*, xd3_sec_stream*, xd3_output*,
xd3_output*, xd3_sec_cfg*)) xd3_encode_lzma)
};
#endif
#if XD3_MAIN || PYTHON_MODULE || SWIG_MODULE || NOT_MAIN
#include "xdelta3-main.h"
#endif
#if REGRESSION_TEST
#include "xdelta3-test.h"
#endif
#endif /* __XDELTA3_C_HEADER_PASS__ */
#ifdef __XDELTA3_C_INLINE_PASS__
const uint16_t __single_hash[256] =
{
/* Random numbers generated using SLIB's pseudo-random number generator.
* This hashes the input alphabet. */
0xbcd1, 0xbb65, 0x42c2, 0xdffe, 0x9666, 0x431b, 0x8504, 0xeb46,
0x6379, 0xd460, 0xcf14, 0x53cf, 0xdb51, 0xdb08, 0x12c8, 0xf602,
0xe766, 0x2394, 0x250d, 0xdcbb, 0xa678, 0x02af, 0xa5c6, 0x7ea6,
0xb645, 0xcb4d, 0xc44b, 0xe5dc, 0x9fe6, 0x5b5c, 0x35f5, 0x701a,
0x220f, 0x6c38, 0x1a56, 0x4ca3, 0xffc6, 0xb152, 0x8d61, 0x7a58,
0x9025, 0x8b3d, 0xbf0f, 0x95a3, 0xe5f4, 0xc127, 0x3bed, 0x320b,
0xb7f3, 0x6054, 0x333c, 0xd383, 0x8154, 0x5242, 0x4e0d, 0x0a94,
0x7028, 0x8689, 0x3a22, 0x0980, 0x1847, 0xb0f1, 0x9b5c, 0x4176,
0xb858, 0xd542, 0x1f6c, 0x2497, 0x6a5a, 0x9fa9, 0x8c5a, 0x7743,
0xa8a9, 0x9a02, 0x4918, 0x438c, 0xc388, 0x9e2b, 0x4cad, 0x01b6,
0xab19, 0xf777, 0x365f, 0x1eb2, 0x091e, 0x7bf8, 0x7a8e, 0x5227,
0xeab1, 0x2074, 0x4523, 0xe781, 0x01a3, 0x163d, 0x3b2e, 0x287d,
0x5e7f, 0xa063, 0xb134, 0x8fae, 0x5e8e, 0xb7b7, 0x4548, 0x1f5a,
0xfa56, 0x7a24, 0x900f, 0x42dc, 0xcc69, 0x02a0, 0x0b22, 0xdb31,
0x71fe, 0x0c7d, 0x1732, 0x1159, 0xcb09, 0xe1d2, 0x1351, 0x52e9,
0xf536, 0x5a4f, 0xc316, 0x6bf9, 0x8994, 0xb774, 0x5f3e, 0xf6d6,
0x3a61, 0xf82c, 0xcc22, 0x9d06, 0x299c, 0x09e5, 0x1eec, 0x514f,
0x8d53, 0xa650, 0x5c6e, 0xc577, 0x7958, 0x71ac, 0x8916, 0x9b4f,
0x2c09, 0x5211, 0xf6d8, 0xcaaa, 0xf7ef, 0x287f, 0x7a94, 0xab49,
0xfa2c, 0x7222, 0xe457, 0xd71a, 0x00c3, 0x1a76, 0xe98c, 0xc037,
0x8208, 0x5c2d, 0xdfda, 0xe5f5, 0x0b45, 0x15ce, 0x8a7e, 0xfcad,
0xaa2d, 0x4b5c, 0xd42e, 0xb251, 0x907e, 0x9a47, 0xc9a6, 0xd93f,
0x085e, 0x35ce, 0xa153, 0x7e7b, 0x9f0b, 0x25aa, 0x5d9f, 0xc04d,
0x8a0e, 0x2875, 0x4a1c, 0x295f, 0x1393, 0xf760, 0x9178, 0x0f5b,
0xfa7d, 0x83b4, 0x2082, 0x721d, 0x6462, 0x0368, 0x67e2, 0x8624,
0x194d, 0x22f6, 0x78fb, 0x6791, 0xb238, 0xb332, 0x7276, 0xf272,
0x47ec, 0x4504, 0xa961, 0x9fc8, 0x3fdc, 0xb413, 0x007a, 0x0806,
0x7458, 0x95c6, 0xccaa, 0x18d6, 0xe2ae, 0x1b06, 0xf3f6, 0x5050,
0xc8e8, 0xf4ac, 0xc04c, 0xf41c, 0x992f, 0xae44, 0x5f1b, 0x1113,
0x1738, 0xd9a8, 0x19ea, 0x2d33, 0x9698, 0x2fe9, 0x323f, 0xcde2,
0x6d71, 0xe37d, 0xb697, 0x2c4f, 0x4373, 0x9102, 0x075d, 0x8e25,
0x1672, 0xec28, 0x6acb, 0x86cc, 0x186e, 0x9414, 0xd674, 0xd1a5
};
/****************************************************************
Instruction tables
*****************************************************************/
/* The following code implements a parametrized description of the
* code table given above for a few reasons. It is not necessary for
* implementing the standard, to support compression with variable
* tables, so an implementation is only required to know the default
* code table to begin decompression. (If the encoder uses an
* alternate table, the table is included in compressed form inside
* the VCDIFF file.)
*
* Before adding variable-table support there were two functions which
* were hard-coded to the default table above.
* xd3_compute_default_table() would create the default table by
* filling a 256-elt array of xd3_dinst values. The corresponding
* function, xd3_choose_instruction(), would choose an instruction
* based on the hard-coded parameters of the default code table.
*
* Notes: The parametrized code table description here only generates
* tables of a certain regularity similar to the default table by
* allowing to vary the distribution of single- and
* double-instructions and change the number of near and same copy
* modes. More exotic tables are only possible by extending this
* code.
*
* For performance reasons, both the parametrized and non-parametrized
* versions of xd3_choose_instruction remain. The parametrized
* version is only needed for testing multi-table decoding support.
* If ever multi-table encoding is required, this can be optimized by
* compiling static functions for each table.
*/
/* The XD3_CHOOSE_INSTRUCTION calls xd3_choose_instruction with the
* table description when GENERIC_ENCODE_TABLES are in use. The
* IF_GENCODETBL macro enables generic-code-table specific code. */
#if GENERIC_ENCODE_TABLES
#define XD3_CHOOSE_INSTRUCTION(stream,prev,inst) xd3_choose_instruction (stream->code_table_desc, prev, inst)
#define IF_GENCODETBL(x) x
#else
#define XD3_CHOOSE_INSTRUCTION(stream,prev,inst) xd3_choose_instruction (prev, inst)
#define IF_GENCODETBL(x)
#endif
/* This structure maintains information needed by
* xd3_choose_instruction to compute the code for a double instruction
* by first indexing an array of code_table_sizes by copy mode, then
* using (offset + (muliplier * X)) */
struct _xd3_code_table_sizes {
uint8_t cpy_max;
uint8_t offset;
uint8_t mult;
};
/* This contains a complete description of a code table. */
struct _xd3_code_table_desc
{
/* Assumes a single RUN instruction */
/* Assumes that MIN_MATCH is 4 */
uint8_t add_sizes; /* Number of immediate-size single adds (default 17) */
uint8_t near_modes; /* Number of near copy modes (default 4) */
uint8_t same_modes; /* Number of same copy modes (default 3) */
uint8_t cpy_sizes; /* Number of immediate-size single copies (default 15) */
uint8_t addcopy_add_max; /* Maximum add size for an add-copy double instruction,
all modes (default 4) */
uint8_t addcopy_near_cpy_max; /* Maximum cpy size for an add-copy double instruction,
up through VCD_NEAR modes (default 6) */
uint8_t addcopy_same_cpy_max; /* Maximum cpy size for an add-copy double instruction,
VCD_SAME modes (default 4) */
uint8_t copyadd_add_max; /* Maximum add size for a copy-add double instruction,
all modes (default 1) */
uint8_t copyadd_near_cpy_max; /* Maximum cpy size for a copy-add double instruction,
up through VCD_NEAR modes (default 4) */
uint8_t copyadd_same_cpy_max; /* Maximum cpy size for a copy-add double instruction,
VCD_SAME modes (default 4) */
xd3_code_table_sizes addcopy_max_sizes[MAX_MODES];
xd3_code_table_sizes copyadd_max_sizes[MAX_MODES];
};
/* The rfc3284 code table is represented: */
static const xd3_code_table_desc __rfc3284_code_table_desc = {
17, /* add sizes */
4, /* near modes */
3, /* same modes */
15, /* copy sizes */
4, /* add-copy max add */
6, /* add-copy max cpy, near */
4, /* add-copy max cpy, same */
1, /* copy-add max add */
4, /* copy-add max cpy, near */
4, /* copy-add max cpy, same */
/* addcopy */
{ {6,163,3},{6,175,3},{6,187,3},{6,199,3},{6,211,3},{6,223,3},{4,235,1},{4,239,1},{4,243,1} },
/* copyadd */
{ {4,247,1},{4,248,1},{4,249,1},{4,250,1},{4,251,1},{4,252,1},{4,253,1},{4,254,1},{4,255,1} },
};
#if GENERIC_ENCODE_TABLES
/* An alternate code table for testing (5 near, 0 same):
*
* TYPE SIZE MODE TYPE SIZE MODE INDEX
* ---------------------------------------------------------------
* 1. Run 0 0 Noop 0 0 0
* 2. Add 0, [1,23] 0 Noop 0 0 [1,24]
* 3. Copy 0, [4,20] 0 Noop 0 0 [25,42]
* 4. Copy 0, [4,20] 1 Noop 0 0 [43,60]
* 5. Copy 0, [4,20] 2 Noop 0 0 [61,78]
* 6. Copy 0, [4,20] 3 Noop 0 0 [79,96]
* 7. Copy 0, [4,20] 4 Noop 0 0 [97,114]
* 8. Copy 0, [4,20] 5 Noop 0 0 [115,132]
* 9. Copy 0, [4,20] 6 Noop 0 0 [133,150]
* 10. Add [1,4] 0 Copy [4,6] 0 [151,162]
* 11. Add [1,4] 0 Copy [4,6] 1 [163,174]
* 12. Add [1,4] 0 Copy [4,6] 2 [175,186]
* 13. Add [1,4] 0 Copy [4,6] 3 [187,198]
* 14. Add [1,4] 0 Copy [4,6] 4 [199,210]
* 15. Add [1,4] 0 Copy [4,6] 5 [211,222]
* 16. Add [1,4] 0 Copy [4,6] 6 [223,234]
* 17. Copy 4 [0,6] Add [1,3] 0 [235,255]
* --------------------------------------------------------------- */
static const xd3_code_table_desc __alternate_code_table_desc = {
23, /* add sizes */
5, /* near modes */
0, /* same modes */
17, /* copy sizes */
4, /* add-copy max add */
6, /* add-copy max cpy, near */
0, /* add-copy max cpy, same */
3, /* copy-add max add */
4, /* copy-add max cpy, near */
0, /* copy-add max cpy, same */
/* addcopy */
{ {6,151,3},{6,163,3},{6,175,3},{6,187,3},{6,199,3},{6,211,3},{6,223,3},{0,0,0},{0,0,0} },
/* copyadd */
{ {4,235,1},{4,238,1},{4,241,1},{4,244,1},{4,247,1},{4,250,1},{4,253,1},{0,0,0},{0,0,0} },
};
#endif
/* Computes code table entries of TBL using the specified description. */
static void
xd3_build_code_table (const xd3_code_table_desc *desc, xd3_dinst *tbl)
{
usize_t size1, size2, mode;
usize_t cpy_modes = 2 + desc->near_modes + desc->same_modes;
xd3_dinst *d = tbl;
(d++)->type1 = XD3_RUN;
(d++)->type1 = XD3_ADD;
for (size1 = 1; size1 <= desc->add_sizes; size1 += 1, d += 1)
{
d->type1 = XD3_ADD;
d->size1 = size1;
}
for (mode = 0; mode < cpy_modes; mode += 1)
{
(d++)->type1 = XD3_CPY + mode;
for (size1 = MIN_MATCH; size1 < MIN_MATCH + desc->cpy_sizes; size1 += 1, d += 1)
{
d->type1 = XD3_CPY + mode;
d->size1 = size1;
}
}
for (mode = 0; mode < cpy_modes; mode += 1)
{
for (size1 = 1; size1 <= desc->addcopy_add_max; size1 += 1)
{
usize_t max = (mode < 2U + desc->near_modes) ?
desc->addcopy_near_cpy_max :
desc->addcopy_same_cpy_max;
for (size2 = MIN_MATCH; size2 <= max; size2 += 1, d += 1)
{
d->type1 = XD3_ADD;
d->size1 = size1;
d->type2 = XD3_CPY + mode;
d->size2 = size2;
}
}
}
for (mode = 0; mode < cpy_modes; mode += 1)
{
usize_t max = (mode < 2U + desc->near_modes) ?
desc->copyadd_near_cpy_max :
desc->copyadd_same_cpy_max;
for (size1 = MIN_MATCH; size1 <= max; size1 += 1)
{
for (size2 = 1; size2 <= desc->copyadd_add_max; size2 += 1, d += 1)
{
d->type1 = XD3_CPY + mode;
d->size1 = size1;
d->type2 = XD3_ADD;
d->size2 = size2;
}
}
}
XD3_ASSERT (d - tbl == 256);
}
/* This function generates the static default code table. */
static const xd3_dinst*
xd3_rfc3284_code_table (void)
{
static xd3_dinst __rfc3284_code_table[256];
if (__rfc3284_code_table[0].type1 != XD3_RUN)
{
xd3_build_code_table (& __rfc3284_code_table_desc, __rfc3284_code_table);
}
return __rfc3284_code_table;
}
#if XD3_ENCODER
#if GENERIC_ENCODE_TABLES
/* This function generates the alternate code table. */
static const xd3_dinst*
xd3_alternate_code_table (void)
{
static xd3_dinst __alternate_code_table[256];
if (__alternate_code_table[0].type1 != XD3_RUN)
{
xd3_build_code_table (& __alternate_code_table_desc, __alternate_code_table);
}
return __alternate_code_table;
}
/* This function computes the ideal second instruction INST based on
* preceding instruction PREV. If it is possible to issue a double
* instruction based on this pair it sets PREV->code2, otherwise it
* sets INST->code1. */
static void
xd3_choose_instruction (const xd3_code_table_desc *desc, xd3_rinst *prev, xd3_rinst *inst)
{
switch (inst->type)
{
case XD3_RUN:
/* The 0th instruction is RUN */
inst->code1 = 0;
break;
case XD3_ADD:
if (inst->size > desc->add_sizes)
{
/* The first instruction is non-immediate ADD */
inst->code1 = 1;
}
else
{
/* The following ADD_SIZES instructions are immediate ADDs */
inst->code1 = 1 + inst->size;
/* Now check for a possible COPY-ADD double instruction */
if (prev != NULL)
{
int prev_mode = prev->type - XD3_CPY;
/* If previous is a copy. Note: as long as the previous
* is not a RUN instruction, it should be a copy because
* it cannot be an add. This check is more clear. */
if (prev_mode >= 0 && inst->size <= desc->copyadd_add_max)
{
const xd3_code_table_sizes *sizes = & desc->copyadd_max_sizes[prev_mode];
/* This check and the inst->size-<= above are == in
the default table. */
if (prev->size <= sizes->cpy_max)
{
/* The second and third exprs are 0 in the
default table. */
prev->code2 = sizes->offset +
(sizes->mult * (prev->size - MIN_MATCH)) +
(inst->size - MIN_ADD);
}
}
}
}
break;
default:
{
int mode = inst->type - XD3_CPY;
/* The large copy instruction is offset by the run, large add,
* and immediate adds, then multipled by the number of
* immediate copies plus one (the large copy) (i.e., if there
* are 15 immediate copy instructions then there are 16 copy
* instructions per mode). */
inst->code1 = 2 + desc->add_sizes + (1 + desc->cpy_sizes) * mode;
/* Now if the copy is short enough for an immediate instruction. */
if (inst->size < MIN_MATCH + desc->cpy_sizes &&
/* TODO: there needs to be a more comprehensive test for this
* boundary condition, merge is now exercising code in which
* size < MIN_MATCH is possible and it's unclear if the above
* size < (MIN_MATCH + cpy_sizes) should be a <= from inspection
* of the default table version below. */
inst->size >= MIN_MATCH)
{
inst->code1 += inst->size + 1 - MIN_MATCH;
/* Now check for a possible ADD-COPY double instruction. */
if ( (prev != NULL) &&
(prev->type == XD3_ADD) &&
(prev->size <= desc->addcopy_add_max) )
{
const xd3_code_table_sizes *sizes = & desc->addcopy_max_sizes[mode];
if (inst->size <= sizes->cpy_max)
{
prev->code2 = sizes->offset +
(sizes->mult * (prev->size - MIN_ADD)) +
(inst->size - MIN_MATCH);
}
}
}
}
}
}
#else /* GENERIC_ENCODE_TABLES */
/* This version of xd3_choose_instruction is hard-coded for the default
table. */
static void
xd3_choose_instruction (xd3_rinst *prev, xd3_rinst *inst)
{
switch (inst->type)
{
case XD3_RUN:
inst->code1 = 0;
break;
case XD3_ADD:
inst->code1 = 1;
if (inst->size <= 17)
{
inst->code1 += inst->size;
if ( (inst->size == 1) &&
(prev != NULL) &&
(prev->size == 4) &&
(prev->type >= XD3_CPY) )
{
prev->code2 = 247 + (prev->type - XD3_CPY);
}
}
break;
default:
{
int mode = inst->type - XD3_CPY;
XD3_ASSERT (inst->type >= XD3_CPY && inst->type < 12);
inst->code1 = 19 + 16 * mode;
if (inst->size <= 18 && inst->size >= 4)
{
inst->code1 += inst->size - 3;
if ( (prev != NULL) &&
(prev->type == XD3_ADD) &&
(prev->size <= 4) )
{
if ( (inst->size <= 6) &&
(mode <= 5) )
{
prev->code2 = 163 + (mode * 12) + (3 * (prev->size - 1)) + (inst->size - 4);
XD3_ASSERT (prev->code2 <= 234);
}
else if ( (inst->size == 4) &&
(mode >= 6) )
{
prev->code2 = 235 + ((mode - 6) * 4) + (prev->size - 1);
XD3_ASSERT (prev->code2 <= 246);
}
}
}
XD3_ASSERT (inst->code1 <= 162);
}
break;
}
}
#endif /* GENERIC_ENCODE_TABLES */
/***********************************************************************
Instruction table encoder/decoder
***********************************************************************/
#if GENERIC_ENCODE_TABLES
#if GENERIC_ENCODE_TABLES_COMPUTE == 0
/* In this case, we hard-code the result of
* compute_code_table_encoding for each alternate code table,
* presuming that saves time/space. This has been 131 bytes, but
* secondary compression was turned off. */
static const uint8_t __alternate_code_table_compressed[178] =
{0xd6,0xc3,0xc4,0x00,0x00,0x01,0x8a,0x6f,0x40,0x81,0x27,0x8c,0x00,0x00,0x4a,0x4a,0x0d,0x02,0x01,0x03,
0x01,0x03,0x00,0x01,0x00,0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x07,0x08,0x09,0x0a,0x0b,0x0c,0x0d,0x0e,
0x0f,0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17,0x00,0x01,0x01,0x01,0x02,0x02,0x02,0x03,0x03,0x03,0x04,
0x04,0x04,0x04,0x00,0x04,0x05,0x06,0x01,0x02,0x03,0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x05,0x05,0x05,
0x06,0x06,0x06,0x00,0x01,0x02,0x03,0x04,0x05,0x06,0x00,0x02,0x00,0x18,0x13,0x63,0x00,0x1b,0x00,0x54,
0x00,0x15,0x23,0x6f,0x00,0x28,0x13,0x54,0x00,0x15,0x01,0x1a,0x31,0x23,0x6c,0x0d,0x23,0x48,0x00,0x15,
0x93,0x6f,0x00,0x28,0x04,0x23,0x51,0x04,0x32,0x00,0x2b,0x00,0x12,0x00,0x12,0x00,0x12,0x00,0x12,0x00,
0x12,0x00,0x12,0x53,0x57,0x9c,0x07,0x43,0x6f,0x00,0x34,0x00,0x0c,0x00,0x0c,0x00,0x0c,0x00,0x0c,0x00,
0x0c,0x00,0x0c,0x00,0x15,0x00,0x82,0x6f,0x00,0x15,0x12,0x0c,0x00,0x03,0x03,0x00,0x06,0x00,};
static int
xd3_compute_alternate_table_encoding (xd3_stream *stream, const uint8_t **data, usize_t *size)
{
(*data) = __alternate_code_table_compressed;
(*size) = sizeof (__alternate_code_table_compressed);
return 0;
}
#else
/* The alternate code table will be computed and stored here. */
static uint8_t __alternate_code_table_compressed[CODE_TABLE_VCDIFF_SIZE];
static usize_t __alternate_code_table_compressed_size;
/* This function generates a delta describing the code table for
* encoding within a VCDIFF file. This function is NOT thread safe
* because it is only intended that this function is used to generate
* statically-compiled strings. "comp_string" must be sized
* CODE_TABLE_VCDIFF_SIZE. */
int xd3_compute_code_table_encoding (xd3_stream *in_stream,
const xd3_dinst *code_table,
uint8_t *comp_string,
usize_t *comp_string_size)
{
/* Use DJW secondary compression if it is on by default. This saves
* about 20 bytes. */
uint8_t dflt_string[CODE_TABLE_STRING_SIZE];
uint8_t code_string[CODE_TABLE_STRING_SIZE];
xd3_compute_code_table_string (xd3_rfc3284_code_table (), dflt_string);
xd3_compute_code_table_string (code_table, code_string);
return xd3_encode_memory (code_string, CODE_TABLE_STRING_SIZE,
dflt_string, CODE_TABLE_STRING_SIZE,
comp_string, comp_string_size,
CODE_TABLE_VCDIFF_SIZE,
/* flags */ 0);
}
/* Compute a delta between alternate and rfc3284 tables. As soon as
* another alternate table is added, this code should become generic.
* For now there is only one alternate table for testing. */
static int
xd3_compute_alternate_table_encoding (xd3_stream *stream, const uint8_t **data, usize_t *size)
{
int ret;
if (__alternate_code_table_compressed[0] == 0)
{
if ((ret = xd3_compute_code_table_encoding (stream, xd3_alternate_code_table (),
__alternate_code_table_compressed,
& __alternate_code_table_compressed_size)))
{
return ret;
}
/* During development of a new code table, enable this variable to print
* the new static contents and determine its size. At run time the
* table will be filled in appropriately, but at least it should have
* the proper size beforehand. */
#if GENERIC_ENCODE_TABLES_COMPUTE_PRINT
{
int i;
DP(RINT, "\nstatic const usize_t __alternate_code_table_compressed_size = %u;\n",
__alternate_code_table_compressed_size);
DP(RINT, "static const uint8_t __alternate_code_table_compressed[%u] =\n{",
__alternate_code_table_compressed_size);
for (i = 0; i < __alternate_code_table_compressed_size; i += 1)
{
DP(RINT, "0x%02x,", __alternate_code_table_compressed[i]);
if ((i % 20) == 19) { DP(RINT, "\n"); }
}
DP(RINT, "};\n");
}
#endif
}
(*data) = __alternate_code_table_compressed;
(*size) = __alternate_code_table_compressed_size;
return 0;
}
#endif /* GENERIC_ENCODE_TABLES_COMPUTE != 0 */
#endif /* GENERIC_ENCODE_TABLES */
#endif /* XD3_ENCODER */
/* This function generates the 1536-byte string specified in sections 5.4 and
* 7 of rfc3284, which is used to represent a code table within a VCDIFF
* file. */
void xd3_compute_code_table_string (const xd3_dinst *code_table, uint8_t *str)
{
int i, s;
XD3_ASSERT (CODE_TABLE_STRING_SIZE == 6 * 256);
for (s = 0; s < 6; s += 1)
{
for (i = 0; i < 256; i += 1)
{
switch (s)
{
case 0: *str++ = (code_table[i].type1 >= XD3_CPY ? XD3_CPY : code_table[i].type1); break;
case 1: *str++ = (code_table[i].type2 >= XD3_CPY ? XD3_CPY : code_table[i].type2); break;
case 2: *str++ = (code_table[i].size1); break;
case 3: *str++ = (code_table[i].size2); break;
case 4: *str++ = (code_table[i].type1 >= XD3_CPY ? code_table[i].type1 - XD3_CPY : 0); break;
case 5: *str++ = (code_table[i].type2 >= XD3_CPY ? code_table[i].type2 - XD3_CPY : 0); break;
}
}
}
}
/* This function translates the code table string into the internal representation. The
* stream's near and same-modes should already be set. */
static int
xd3_apply_table_string (xd3_stream *stream, const uint8_t *code_string)
{
int i, s;
int modes = TOTAL_MODES (stream);
xd3_dinst *code_table;
if ((code_table = stream->code_table_alloc =
(xd3_dinst*) xd3_alloc (stream,
(usize_t) sizeof (xd3_dinst),
256)) == NULL)
{
return ENOMEM;
}
for (s = 0; s < 6; s += 1)
{
for (i = 0; i < 256; i += 1)
{
switch (s)
{
case 0:
if (*code_string > XD3_CPY)
{
stream->msg = "invalid code-table opcode";
return XD3_INTERNAL;
}
code_table[i].type1 = *code_string++;
break;
case 1:
if (*code_string > XD3_CPY)
{
stream->msg = "invalid code-table opcode";
return XD3_INTERNAL;
}
code_table[i].type2 = *code_string++;
break;
case 2:
if (*code_string != 0 && code_table[i].type1 == XD3_NOOP)
{
stream->msg = "invalid code-table size";
return XD3_INTERNAL;
}
code_table[i].size1 = *code_string++;
break;
case 3:
if (*code_string != 0 && code_table[i].type2 == XD3_NOOP)
{
stream->msg = "invalid code-table size";
return XD3_INTERNAL;
}
code_table[i].size2 = *code_string++;
break;
case 4:
if (*code_string >= modes)
{
stream->msg = "invalid code-table mode";
return XD3_INTERNAL;
}
if (*code_string != 0 && code_table[i].type1 != XD3_CPY)
{
stream->msg = "invalid code-table mode";
return XD3_INTERNAL;
}
code_table[i].type1 += *code_string++;
break;
case 5:
if (*code_string >= modes)
{
stream->msg = "invalid code-table mode";
return XD3_INTERNAL;
}
if (*code_string != 0 && code_table[i].type2 != XD3_CPY)
{
stream->msg = "invalid code-table mode";
return XD3_INTERNAL;
}
code_table[i].type2 += *code_string++;
break;
}
}
}
stream->code_table = code_table;
return 0;
}
/* This function applies a code table delta and returns an actual code table. */
static int
xd3_apply_table_encoding (xd3_stream *in_stream, const uint8_t *data, usize_t size)
{
uint8_t dflt_string[CODE_TABLE_STRING_SIZE];
uint8_t code_string[CODE_TABLE_STRING_SIZE];
usize_t code_size;
int ret;
xd3_compute_code_table_string (xd3_rfc3284_code_table (), dflt_string);
if ((ret = xd3_decode_memory (data, size,
dflt_string, CODE_TABLE_STRING_SIZE,
code_string, &code_size,
CODE_TABLE_STRING_SIZE,
0))) { return ret; }
if (code_size != sizeof (code_string))
{
in_stream->msg = "corrupt code-table encoding";
return XD3_INTERNAL;
}
return xd3_apply_table_string (in_stream, code_string);
}
/***********************************************************************/
static inline void
xd3_swap_uint8p (uint8_t** p1, uint8_t** p2)
{
uint8_t *t = (*p1);
(*p1) = (*p2);
(*p2) = t;
}
static inline void
xd3_swap_usize_t (usize_t* p1, usize_t* p2)
{
usize_t t = (*p1);
(*p1) = (*p2);
(*p2) = t;
}
/* It's not constant time, but it computes the log. */
static int
xd3_check_pow2 (xoff_t value, usize_t *logof)
{
xoff_t x = 1;
usize_t nolog;
if (logof == NULL) {
logof = &nolog;
}
*logof = 0;
for (; x != 0; x <<= 1, *logof += 1)
{
if (x == value)
{
return 0;
}
}
return XD3_INTERNAL;
}
static usize_t
xd3_pow2_roundup (usize_t x)
{
usize_t i = 1;
while (x > i) {
i <<= 1U;
}
return i;
}
static xoff_t
xd3_xoff_roundup (xoff_t x)
{
xoff_t i = 1;
while (x > i) {
i <<= 1U;
}
return i;
}
static usize_t
xd3_round_blksize (usize_t sz, usize_t blksz)
{
usize_t mod = sz & (blksz-1);
XD3_ASSERT (xd3_check_pow2 (blksz, NULL) == 0);
return mod ? (sz + (blksz - mod)) : sz;
}
/***********************************************************************
Adler32 stream function: code copied from Zlib, defined in RFC1950
***********************************************************************/
#define A32_BASE 65521L /* Largest prime smaller than 2^16 */
#define A32_NMAX 5552 /* NMAX is the largest n such that 255n(n+1)/2 + (n+1)(BASE-1) <= 2^32-1 */
#define A32_DO1(buf,i) {s1 += buf[i]; s2 += s1;}
#define A32_DO2(buf,i) A32_DO1(buf,i); A32_DO1(buf,i+1);
#define A32_DO4(buf,i) A32_DO2(buf,i); A32_DO2(buf,i+2);
#define A32_DO8(buf,i) A32_DO4(buf,i); A32_DO4(buf,i+4);
#define A32_DO16(buf) A32_DO8(buf,0); A32_DO8(buf,8);
static unsigned long adler32 (unsigned long adler, const uint8_t *buf,
usize_t len)
{
unsigned long s1 = adler & 0xffff;
unsigned long s2 = (adler >> 16) & 0xffff;
int k;
while (len > 0)
{
k = (len < A32_NMAX) ? len : A32_NMAX;
len -= k;
while (k >= 16)
{
A32_DO16(buf);
buf += 16;
k -= 16;
}
if (k != 0)
{
do
{
s1 += *buf++;
s2 += s1;
}
while (--k);
}
s1 %= A32_BASE;
s2 %= A32_BASE;
}
return (s2 << 16) | s1;
}
/***********************************************************************
Run-length function
***********************************************************************/
#if XD3_ENCODER
static usize_t
xd3_comprun (const uint8_t *seg, usize_t slook, uint8_t *run_cp)
{
usize_t i;
usize_t run_l = 0;
uint8_t run_c = 0;
for (i = 0; i < slook; i += 1)
{
NEXTRUN(seg[i]);
}
(*run_cp) = run_c;
return run_l;
}
#endif
/***********************************************************************
Basic encoder/decoder functions
***********************************************************************/
static inline int
xd3_decode_byte (xd3_stream *stream, usize_t *val)
{
if (stream->avail_in == 0)
{
stream->msg = "further input required";
return XD3_INPUT;
}
(*val) = stream->next_in[0];
DECODE_INPUT (1);
return 0;
}
static inline int
xd3_decode_bytes (xd3_stream *stream, uint8_t *buf, usize_t *pos, usize_t size)
{
usize_t want;
usize_t take;
/* Note: The case where (*pos == size) happens when a zero-length
* appheader or code table is transmitted, but there is nothing in
* the standard against that. */
while (*pos < size)
{
if (stream->avail_in == 0)
{
stream->msg = "further input required";
return XD3_INPUT;
}
want = size - *pos;
take = min (want, stream->avail_in);
memcpy (buf + *pos, stream->next_in, (size_t) take);
DECODE_INPUT (take);
(*pos) += take;
}
return 0;
}
#if XD3_ENCODER
static inline int
xd3_emit_byte (xd3_stream *stream,
xd3_output **outputp,
uint8_t code)
{
xd3_output *output = (*outputp);
if (output->next == output->avail)
{
xd3_output *aoutput;
if ((aoutput = xd3_alloc_output (stream, output)) == NULL)
{
return ENOMEM;
}
output = (*outputp) = aoutput;
}
output->base[output->next++] = code;
return 0;
}
static inline int
xd3_emit_bytes (xd3_stream *stream,
xd3_output **outputp,
const uint8_t *base,
usize_t size)
{
xd3_output *output = (*outputp);
do
{
usize_t take;
if (output->next == output->avail)
{
xd3_output *aoutput;
if ((aoutput = xd3_alloc_output (stream, output)) == NULL)
{
return ENOMEM;
}
output = (*outputp) = aoutput;
}
take = min (output->avail - output->next, size);
memcpy (output->base + output->next, base, (size_t) take);
output->next += take;
size -= take;
base += take;
}
while (size > 0);
return 0;
}
#endif /* XD3_ENCODER */
/*********************************************************************
Integer encoder/decoder functions
**********************************************************************/
#define DECODE_INTEGER_TYPE(PART,OFLOW) \
while (stream->avail_in != 0) \
{ \
usize_t next = stream->next_in[0]; \
\
DECODE_INPUT(1); \
\
if (PART & OFLOW) \
{ \
stream->msg = "overflow in decode_integer"; \
return XD3_INVALID_INPUT; \
} \
\
PART = (PART << 7) | (next & 127); \
\
if ((next & 128) == 0) \
{ \
(*val) = PART; \
PART = 0; \
return 0; \
} \
} \
\
stream->msg = "further input required"; \
return XD3_INPUT
#define READ_INTEGER_TYPE(TYPE, OFLOW) \
TYPE val = 0; \
const uint8_t *inp = (*inpp); \
usize_t next; \
\
do \
{ \
if (inp == max) \
{ \
stream->msg = "end-of-input in read_integer"; \
return XD3_INVALID_INPUT; \
} \
\
if (val & OFLOW) \
{ \
stream->msg = "overflow in read_intger"; \
return XD3_INVALID_INPUT; \
} \
\
next = (*inp++); \
val = (val << 7) | (next & 127); \
} \
while (next & 128); \
\
(*valp) = val; \
(*inpp) = inp; \
\
return 0
#define EMIT_INTEGER_TYPE() \
/* max 64-bit value in base-7 encoding is 9.1 bytes */ \
uint8_t buf[10]; \
usize_t bufi = 10; \
\
/* This loop performs division and turns on all MSBs. */ \
do \
{ \
buf[--bufi] = (num & 127) | 128; \
num >>= 7U; \
} \
while (num != 0); \
\
/* Turn off MSB of the last byte. */ \
buf[9] &= 127; \
\
return xd3_emit_bytes (stream, output, buf + bufi, 10 - bufi)
#define IF_SIZEOF32(x) if (num < (1U << (7 * (x)))) return (x);
#define IF_SIZEOF64(x) if (num < (1ULL << (7 * (x)))) return (x);
#if USE_UINT32
static inline uint32_t
xd3_sizeof_uint32_t (uint32_t num)
{
IF_SIZEOF32(1);
IF_SIZEOF32(2);
IF_SIZEOF32(3);
IF_SIZEOF32(4);
return 5;
}
static inline int
xd3_decode_uint32_t (xd3_stream *stream, uint32_t *val)
{ DECODE_INTEGER_TYPE (stream->dec_32part, UINT32_OFLOW_MASK); }
static inline int
xd3_read_uint32_t (xd3_stream *stream, const uint8_t **inpp,
const uint8_t *max, uint32_t *valp)
{ READ_INTEGER_TYPE (uint32_t, UINT32_OFLOW_MASK); }
#if XD3_ENCODER
static inline int
xd3_emit_uint32_t (xd3_stream *stream, xd3_output **output, uint32_t num)
{ EMIT_INTEGER_TYPE (); }
#endif
#endif
#if USE_UINT64
static inline int
xd3_decode_uint64_t (xd3_stream *stream, uint64_t *val)
{ DECODE_INTEGER_TYPE (stream->dec_64part, UINT64_OFLOW_MASK); }
#if XD3_ENCODER
static inline int
xd3_emit_uint64_t (xd3_stream *stream, xd3_output **output, uint64_t num)
{ EMIT_INTEGER_TYPE (); }
#endif
/* These are tested but not used */
#if REGRESSION_TEST
static int
xd3_read_uint64_t (xd3_stream *stream, const uint8_t **inpp,
const uint8_t *max, uint64_t *valp)
{ READ_INTEGER_TYPE (uint64_t, UINT64_OFLOW_MASK); }
static uint32_t
xd3_sizeof_uint64_t (uint64_t num)
{
IF_SIZEOF64(1);
IF_SIZEOF64(2);
IF_SIZEOF64(3);
IF_SIZEOF64(4);
IF_SIZEOF64(5);
IF_SIZEOF64(6);
IF_SIZEOF64(7);
IF_SIZEOF64(8);
IF_SIZEOF64(9);
return 10;
}
#endif
#endif
/***********************************************************************
Address cache stuff
***********************************************************************/
static int
xd3_alloc_cache (xd3_stream *stream)
{
if (stream->acache.near_array != NULL)
{
xd3_free (stream, stream->acache.near_array);
}
if (stream->acache.same_array != NULL)
{
xd3_free (stream, stream->acache.same_array);
}
if (((stream->acache.s_near > 0) &&
(stream->acache.near_array = (usize_t*)
xd3_alloc (stream, stream->acache.s_near,
(usize_t) sizeof (usize_t)))
== NULL) ||
((stream->acache.s_same > 0) &&
(stream->acache.same_array = (usize_t*)
xd3_alloc (stream, stream->acache.s_same * 256,
(usize_t) sizeof (usize_t)))
== NULL))
{
return ENOMEM;
}
return 0;
}
void
xd3_init_cache (xd3_addr_cache* acache)
{
if (acache->s_near > 0)
{
memset (acache->near_array, 0, acache->s_near * sizeof (usize_t));
acache->next_slot = 0;
}
if (acache->s_same > 0)
{
memset (acache->same_array, 0, acache->s_same * 256 * sizeof (usize_t));
}
}
static void
xd3_update_cache (xd3_addr_cache* acache, usize_t addr)
{
if (acache->s_near > 0)
{
acache->near_array[acache->next_slot] = addr;
acache->next_slot = (acache->next_slot + 1) % acache->s_near;
}
if (acache->s_same > 0)
{
acache->same_array[addr % (acache->s_same*256)] = addr;
}
}
#if XD3_ENCODER
/* OPT: this gets called a lot, can it be optimized? */
static int
xd3_encode_address (xd3_stream *stream,
usize_t addr,
usize_t here,
uint8_t* mode)
{
usize_t d, bestd;
usize_t i, bestm, ret;
xd3_addr_cache* acache = & stream->acache;
#define SMALLEST_INT(x) do { if (((x) & ~127U) == 0) { goto good; } } while (0)
/* Attempt to find the address mode that yields the smallest integer value
* for "d", the encoded address value, thereby minimizing the encoded size
* of the address. */
bestd = addr;
bestm = VCD_SELF;
XD3_ASSERT (addr < here);
SMALLEST_INT (bestd);
if ((d = here-addr) < bestd)
{
bestd = d;
bestm = VCD_HERE;
SMALLEST_INT (bestd);
}
for (i = 0; i < acache->s_near; i += 1)
{
/* Note: If we used signed computation here, we'd could compte d
* and then check (d >= 0 && d < bestd). */
if (addr >= acache->near_array[i])
{
d = addr - acache->near_array[i];
if (d < bestd)
{
bestd = d;
bestm = i+2; /* 2 counts the VCD_SELF, VCD_HERE modes */
SMALLEST_INT (bestd);
}
}
}
if (acache->s_same > 0 &&
acache->same_array[d = addr%(acache->s_same*256)] == addr)
{
bestd = d%256;
/* 2 + s_near offsets past the VCD_NEAR modes */
bestm = acache->s_near + 2 + d/256;
if ((ret = xd3_emit_byte (stream, & ADDR_TAIL (stream), bestd)))
{
return ret;
}
}
else
{
good:
if ((ret = xd3_emit_size (stream, & ADDR_TAIL (stream), bestd)))
{
return ret;
}
}
xd3_update_cache (acache, addr);
(*mode) += bestm;
return 0;
}
#endif
static int
xd3_decode_address (xd3_stream *stream, usize_t here,
usize_t mode, const uint8_t **inpp,
const uint8_t *max, uint32_t *valp)
{
int ret;
usize_t same_start = 2 + stream->acache.s_near;
if (mode < same_start)
{
if ((ret = xd3_read_size (stream, inpp, max, valp))) { return ret; }
switch (mode)
{
case VCD_SELF:
break;
case VCD_HERE:
(*valp) = here - (*valp);
break;
default:
(*valp) += stream->acache.near_array[mode - 2];
break;
}
}
else
{
if (*inpp == max)
{
stream->msg = "address underflow";
return XD3_INVALID_INPUT;
}
mode -= same_start;
(*valp) = stream->acache.same_array[mode*256 + (**inpp)];
(*inpp) += 1;
}
xd3_update_cache (& stream->acache, *valp);
return 0;
}
/***********************************************************************
Alloc/free
***********************************************************************/
static void*
__xd3_alloc_func (void* opaque, size_t items, usize_t size)
{
return malloc (items * (size_t) size);
}
static void
__xd3_free_func (void* opaque, void* address)
{
free (address);
}
static void*
xd3_alloc (xd3_stream *stream,
usize_t elts,
usize_t size)
{
void *a = stream->alloc (stream->opaque, elts, size);
if (a != NULL)
{
IF_DEBUG (stream->alloc_cnt += 1);
IF_DEBUG2 (DP(RINT "[stream %p malloc] size %u ptr %p\n",
stream, elts * size, a));
}
else
{
stream->msg = "out of memory";
}
return a;
}
static void
xd3_free (xd3_stream *stream,
void *ptr)
{
if (ptr != NULL)
{
IF_DEBUG (stream->free_cnt += 1);
XD3_ASSERT (stream->free_cnt <= stream->alloc_cnt);
IF_DEBUG2 (DP(RINT "[stream %p free] %p\n",
stream, ptr));
stream->free (stream->opaque, ptr);
}
}
#if XD3_ENCODER
static void*
xd3_alloc0 (xd3_stream *stream,
usize_t elts,
usize_t size)
{
void *a = xd3_alloc (stream, elts, size);
if (a != NULL)
{
memset (a, 0, (size_t) (elts * size));
}
return a;
}
static xd3_output*
xd3_alloc_output (xd3_stream *stream,
xd3_output *old_output)
{
xd3_output *output;
uint8_t *base;
if (stream->enc_free != NULL)
{
output = stream->enc_free;
stream->enc_free = output->next_page;
}
else
{
if ((output = (xd3_output*) xd3_alloc (stream, 1,
(usize_t) sizeof (xd3_output)))
== NULL)
{
return NULL;
}
if ((base = (uint8_t*) xd3_alloc (stream, XD3_ALLOCSIZE,
sizeof (uint8_t))) == NULL)
{
xd3_free (stream, output);
return NULL;
}
output->base = base;
output->avail = XD3_ALLOCSIZE;
}
output->next = 0;
if (old_output)
{
old_output->next_page = output;
}
output->next_page = NULL;
return output;
}
static usize_t
xd3_sizeof_output (xd3_output *output)
{
usize_t s = 0;
for (; output; output = output->next_page)
{
s += output->next;
}
return s;
}
static void
xd3_freelist_output (xd3_stream *stream,
xd3_output *output)
{
xd3_output *tmp;
while (output)
{
tmp = output;
output = output->next_page;
tmp->next = 0;
tmp->next_page = stream->enc_free;
stream->enc_free = tmp;
}
}
static void
xd3_free_output (xd3_stream *stream,
xd3_output *output)
{
xd3_output *next;
again:
if (output == NULL)
{
return;
}
next = output->next_page;
xd3_free (stream, output->base);
xd3_free (stream, output);
output = next;
goto again;
}
#endif /* XD3_ENCODER */
void
xd3_free_stream (xd3_stream *stream)
{
xd3_iopt_buflist *blist = stream->iopt_alloc;
while (blist != NULL)
{
xd3_iopt_buflist *tmp = blist;
blist = blist->next;
xd3_free (stream, tmp->buffer);
xd3_free (stream, tmp);
}
xd3_free (stream, stream->large_table);
xd3_free (stream, stream->small_table);
xd3_free (stream, stream->small_prev);
#if XD3_ENCODER
{
int i;
for (i = 0; i < ENC_SECTS; i += 1)
{
xd3_free_output (stream, stream->enc_heads[i]);
}
xd3_free_output (stream, stream->enc_free);
}
#endif
xd3_free (stream, stream->acache.near_array);
xd3_free (stream, stream->acache.same_array);
xd3_free (stream, stream->inst_sect.copied1);
xd3_free (stream, stream->addr_sect.copied1);
xd3_free (stream, stream->data_sect.copied1);
xd3_free (stream, stream->dec_buffer);
xd3_free (stream, (uint8_t*) stream->dec_lastwin);
xd3_free (stream, stream->buf_in);
xd3_free (stream, stream->dec_appheader);
xd3_free (stream, stream->dec_codetbl);
xd3_free (stream, stream->code_table_alloc);
#if SECONDARY_ANY
xd3_free (stream, stream->inst_sect.copied2);
xd3_free (stream, stream->addr_sect.copied2);
xd3_free (stream, stream->data_sect.copied2);
if (stream->sec_type != NULL)
{
stream->sec_type->destroy (stream, stream->sec_stream_d);
stream->sec_type->destroy (stream, stream->sec_stream_i);
stream->sec_type->destroy (stream, stream->sec_stream_a);
}
#endif
xd3_free (stream, stream->whole_target.adds);
xd3_free (stream, stream->whole_target.inst);
xd3_free (stream, stream->whole_target.wininfo);
XD3_ASSERT (stream->alloc_cnt == stream->free_cnt);
memset (stream, 0, sizeof (xd3_stream));
}
#if (XD3_DEBUG > 1 || VCDIFF_TOOLS)
static const char*
xd3_rtype_to_string (xd3_rtype type, int print_mode)
{
switch (type)
{
case XD3_NOOP:
return "NOOP ";
case XD3_RUN:
return "RUN ";
case XD3_ADD:
return "ADD ";
default: break;
}
if (! print_mode)
{
return "CPY ";
}
switch (type)
{
case XD3_CPY + 0: return "CPY_0";
case XD3_CPY + 1: return "CPY_1";
case XD3_CPY + 2: return "CPY_2";
case XD3_CPY + 3: return "CPY_3";
case XD3_CPY + 4: return "CPY_4";
case XD3_CPY + 5: return "CPY_5";
case XD3_CPY + 6: return "CPY_6";
case XD3_CPY + 7: return "CPY_7";
case XD3_CPY + 8: return "CPY_8";
case XD3_CPY + 9: return "CPY_9";
default: return "CPY>9";
}
}
#endif
/****************************************************************
Stream configuration
******************************************************************/
int
xd3_config_stream(xd3_stream *stream,
xd3_config *config)
{
int ret;
xd3_config defcfg;
xd3_smatcher *smatcher = &stream->smatcher;
if (config == NULL)
{
config = & defcfg;
memset (config, 0, sizeof (*config));
}
/* Initial setup: no error checks yet */
memset (stream, 0, sizeof (*stream));
stream->winsize = config->winsize ? config->winsize : XD3_DEFAULT_WINSIZE;
stream->sprevsz = config->sprevsz ? config->sprevsz : XD3_DEFAULT_SPREVSZ;
if (config->iopt_size == 0)
{
stream->iopt_size = XD3_ALLOCSIZE / sizeof(xd3_rinst);
stream->iopt_unlimited = 1;
}
else
{
stream->iopt_size = config->iopt_size;
}
stream->getblk = config->getblk;
stream->alloc = config->alloc ? config->alloc : __xd3_alloc_func;
stream->free = config->freef ? config->freef : __xd3_free_func;
stream->opaque = config->opaque;
stream->flags = config->flags;
/* Secondary setup. */
stream->sec_data = config->sec_data;
stream->sec_inst = config->sec_inst;
stream->sec_addr = config->sec_addr;
stream->sec_data.data_type = DATA_SECTION;
stream->sec_inst.data_type = INST_SECTION;
stream->sec_addr.data_type = ADDR_SECTION;
/* Check static sizes. */
if (sizeof (usize_t) != SIZEOF_USIZE_T ||
sizeof (xoff_t) != SIZEOF_XOFF_T ||
(ret = xd3_check_pow2(XD3_ALLOCSIZE, NULL)))
{
stream->msg = "incorrect compilation: wrong integer sizes";
return XD3_INTERNAL;
}
/* Check/set secondary compressor. */
switch (stream->flags & XD3_SEC_TYPE)
{
case 0:
if (stream->flags & XD3_SEC_NOALL)
{
stream->msg = "XD3_SEC flags require a secondary compressor type";
return XD3_INTERNAL;
}
break;
case XD3_SEC_FGK:
FGK_CASE (stream);
case XD3_SEC_DJW:
DJW_CASE (stream);
case XD3_SEC_LZMA:
LZMA_CASE (stream);
default:
stream->msg = "too many secondary compressor types set";
return XD3_INTERNAL;
}
/* Check/set encoder code table. */
switch (stream->flags & XD3_ALT_CODE_TABLE) {
case 0:
stream->code_table_desc = & __rfc3284_code_table_desc;
stream->code_table_func = xd3_rfc3284_code_table;
break;
#if GENERIC_ENCODE_TABLES
case XD3_ALT_CODE_TABLE:
stream->code_table_desc = & __alternate_code_table_desc;
stream->code_table_func = xd3_alternate_code_table;
stream->comp_table_func = xd3_compute_alternate_table_encoding;
break;
#endif
default:
stream->msg = "alternate code table support was not compiled";
return XD3_INTERNAL;
}
/* Check sprevsz */
if (smatcher->small_chain == 1 &&
smatcher->small_lchain == 1)
{
stream->sprevsz = 0;
}
else
{
if ((ret = xd3_check_pow2 (stream->sprevsz, NULL)))
{
stream->msg = "sprevsz is required to be a power of two";
return XD3_INTERNAL;
}
stream->sprevmask = stream->sprevsz - 1;
}
/* Default scanner settings. */
#if XD3_ENCODER
switch (config->smatch_cfg)
{
IF_BUILD_SOFT(case XD3_SMATCH_SOFT:
{
*smatcher = config->smatcher_soft;
smatcher->string_match = __smatcher_soft.string_match;
smatcher->name = __smatcher_soft.name;
if (smatcher->large_look < MIN_MATCH ||
smatcher->large_step < 1 ||
smatcher->small_look < MIN_MATCH)
{
stream->msg = "invalid soft string-match config";
return XD3_INVALID;
}
break;
})
IF_BUILD_DEFAULT(case XD3_SMATCH_DEFAULT:
*smatcher = __smatcher_default;
break;)
IF_BUILD_SLOW(case XD3_SMATCH_SLOW:
*smatcher = __smatcher_slow;
break;)
IF_BUILD_FASTEST(case XD3_SMATCH_FASTEST:
*smatcher = __smatcher_fastest;
break;)
IF_BUILD_FASTER(case XD3_SMATCH_FASTER:
*smatcher = __smatcher_faster;
break;)
IF_BUILD_FAST(case XD3_SMATCH_FAST:
*smatcher = __smatcher_fast;
break;)
default:
stream->msg = "invalid string match config type";
return XD3_INTERNAL;
}
if (config->smatch_cfg == XD3_SMATCH_DEFAULT &&
(stream->flags & XD3_COMPLEVEL_MASK) != 0)
{
int level = (stream->flags & XD3_COMPLEVEL_MASK) >> XD3_COMPLEVEL_SHIFT;
switch (level)
{
case 1:
IF_BUILD_FASTEST(*smatcher = __smatcher_fastest;
break;)
case 2:
IF_BUILD_FASTER(*smatcher = __smatcher_faster;
break;)
case 3: case 4: case 5:
IF_BUILD_FAST(*smatcher = __smatcher_fast;
break;)
case 6:
IF_BUILD_DEFAULT(*smatcher = __smatcher_default;
break;)
default:
IF_BUILD_SLOW(*smatcher = __smatcher_slow;
break;)
IF_BUILD_DEFAULT(*smatcher = __smatcher_default;
break;)
IF_BUILD_FAST(*smatcher = __smatcher_fast;
break;)
IF_BUILD_FASTER(*smatcher = __smatcher_faster;
break;)
IF_BUILD_FASTEST(*smatcher = __smatcher_fastest;
break;)
}
}
#endif
return 0;
}
/***********************************************************
Getblk interface
***********************************************************/
inline
xoff_t xd3_source_eof(const xd3_source *src)
{
xoff_t r = (src->blksize * src->max_blkno) + (xoff_t)src->onlastblk;
return r;
}
inline
usize_t xd3_bytes_on_srcblk (xd3_source *src, xoff_t blkno)
{
usize_t r = (blkno == src->max_blkno ?
src->onlastblk :
src->blksize);
return r;
}
/* This function interfaces with the client getblk function, checks
* its results, updates frontier_blkno, max_blkno, onlastblk, eof_known. */
static int
xd3_getblk (xd3_stream *stream, xoff_t blkno)
{
int ret;
xd3_source *source = stream->src;
if (source->curblk == NULL || blkno != source->curblkno)
{
source->getblkno = blkno;
if (stream->getblk == NULL)
{
stream->msg = "getblk source input";
return XD3_GETSRCBLK;
}
ret = stream->getblk (stream, source, blkno);
if (ret != 0)
{
IF_DEBUG1 (DP(RINT "[getblk] app error blkno %"Q"u: %s\n",
blkno, xd3_strerror (ret)));
return ret;
}
}
if (blkno >= source->frontier_blkno)
{
if (blkno > source->max_blkno)
{
source->max_blkno = blkno;
source->onlastblk = source->onblk;
}
if (source->onblk == source->blksize)
{
source->frontier_blkno = blkno + 1;
IF_DEBUG2 (DP(RINT "[getblk] full source blkno %"Q"u: "
"source length unknown %"Q"u\n",
blkno,
xd3_source_eof (source)));
}
else
{
if (!source->eof_known)
{
IF_DEBUG2 (DP(RINT "[getblk] eof block has %d bytes; "
"source length known %"Q"u\n",
xd3_bytes_on_srcblk (source, blkno),
xd3_source_eof (source)));
source->eof_known = 1;
}
source->frontier_blkno = blkno;
}
}
XD3_ASSERT (source->curblk != NULL);
IF_DEBUG2 (DP(RINT "[getblk] read source block %"Q"u onblk %u blksize %u\n",
blkno, source->onblk, source->blksize));
if (blkno == source->max_blkno)
{
/* In case the application sets the source as 1 block w/ a
preset buffer. */
source->onlastblk = source->onblk;
if (source->onblk == source->blksize)
{
source->frontier_blkno = blkno + 1;
}
}
return 0;
}
/***********************************************************
Stream open/close
***************************************************************/
int
xd3_set_source (xd3_stream *stream,
xd3_source *src)
{
usize_t shiftby;
stream->src = src;
src->srclen = 0;
src->srcbase = 0;
/* Enforce power-of-two blocksize so that source-block number
* calculations are cheap. */
if (xd3_check_pow2 (src->blksize, &shiftby) != 0)
{
src->blksize = xd3_pow2_roundup(src->blksize);
xd3_check_pow2 (src->blksize, &shiftby);
IF_DEBUG1 (DP(RINT "raising src_blksz to %u\n", src->blksize));
}
src->shiftby = shiftby;
src->maskby = (1 << shiftby) - 1;
if (xd3_check_pow2 (src->max_winsize, NULL) != 0)
{
src->max_winsize = xd3_xoff_roundup(src->max_winsize);
IF_DEBUG1 (DP(RINT "raising src_maxsize to %"Q"u\n", src->blksize));
}
src->max_winsize = max(src->max_winsize, XD3_ALLOCSIZE);
return 0;
}
int
xd3_set_source_and_size (xd3_stream *stream,
xd3_source *user_source,
xoff_t source_size) {
int ret = xd3_set_source (stream, user_source);
if (ret == 0)
{
stream->src->eof_known = 1;
IF_DEBUG2 (DP(RINT "[set source] size known %"Q"u\n",
source_size));
xd3_blksize_div(source_size,
stream->src,
&stream->src->max_blkno,
&stream->src->onlastblk);
}
return ret;
}
void
xd3_abort_stream (xd3_stream *stream)
{
stream->dec_state = DEC_ABORTED;
stream->enc_state = ENC_ABORTED;
}
int
xd3_close_stream (xd3_stream *stream)
{
if (stream->enc_state != 0 && stream->enc_state != ENC_ABORTED)
{
if (stream->buf_leftover != NULL)
{
stream->msg = "encoding is incomplete";
return XD3_INTERNAL;
}
if (stream->enc_state == ENC_POSTWIN)
{
#if XD3_ENCODER
xd3_encode_reset (stream);
#endif
stream->current_window += 1;
stream->enc_state = ENC_INPUT;
}
/* If encoding, should be ready for more input but not actually
have any. */
if (stream->enc_state != ENC_INPUT || stream->avail_in != 0)
{
stream->msg = "encoding is incomplete";
return XD3_INTERNAL;
}
}
else
{
switch (stream->dec_state)
{
case DEC_VCHEAD:
case DEC_WININD:
/* TODO: Address the zero-byte ambiguity. Does the encoder
* emit a window or not? If so, then catch an error here.
* If not, need another routine to say
* decode_at_least_one_if_empty. */
case DEC_ABORTED:
break;
default:
/* If decoding, should be ready for the next window. */
stream->msg = "EOF in decode";
return XD3_INTERNAL;
}
}
return 0;
}
/**************************************************************
Application header
****************************************************************/
int
xd3_get_appheader (xd3_stream *stream,
uint8_t **data,
usize_t *size)
{
if (stream->dec_state < DEC_WININD)
{
stream->msg = "application header not available";
return XD3_INTERNAL;
}
(*data) = stream->dec_appheader;
(*size) = stream->dec_appheadsz;
return 0;
}
/**********************************************************
Decoder stuff
*************************************************/
#include "xdelta3-decode.h"
/****************************************************************
Encoder stuff
*****************************************************************/
#if XD3_ENCODER
void
xd3_set_appheader (xd3_stream *stream,
const uint8_t *data,
usize_t size)
{
stream->enc_appheader = data;
stream->enc_appheadsz = size;
}
#if XD3_DEBUG
static int
xd3_iopt_check (xd3_stream *stream)
{
usize_t ul = xd3_rlist_length (& stream->iopt_used);
usize_t fl = xd3_rlist_length (& stream->iopt_free);
return (ul + fl + (stream->iout ? 1 : 0)) == stream->iopt_size;
}
#endif
static xd3_rinst*
xd3_iopt_free (xd3_stream *stream, xd3_rinst *i)
{
xd3_rinst *n = xd3_rlist_remove (i);
xd3_rlist_push_back (& stream->iopt_free, i);
return n;
}
static void
xd3_iopt_free_nonadd (xd3_stream *stream, xd3_rinst *i)
{
if (i->type != XD3_ADD)
{
xd3_rlist_push_back (& stream->iopt_free, i);
}
}
/* When an instruction is ready to flush from the iopt buffer, this
* function is called to produce an encoding. It writes the
* instruction plus size, address, and data to the various encoding
* sections. */
static int
xd3_iopt_finish_encoding (xd3_stream *stream, xd3_rinst *inst)
{
int ret;
/* Check for input overflow. */
XD3_ASSERT (inst->pos + inst->size <= stream->avail_in);
switch (inst->type)
{
case XD3_CPY:
{
/* the address may have an offset if there is a source window. */
usize_t addr;
xd3_source *src = stream->src;
if (src != NULL)
{
/* If there is a source copy, the source must have its
* source window decided before we can encode. This can
* be bad -- we have to make this decision even if no
* source matches have been found. */
if (stream->srcwin_decided == 0)
{
if ((ret = xd3_srcwin_setup (stream))) { return ret; }
}
else
{
stream->srcwin_decided_early = (!stream->src->eof_known ||
(stream->srcwin_cksum_pos <
xd3_source_eof (stream->src)));
}
/* xtra field indicates the copy is from the source */
if (inst->xtra)
{
XD3_ASSERT (inst->addr >= src->srcbase);
XD3_ASSERT (inst->addr + inst->size <=
src->srcbase + src->srclen);
addr = (usize_t)(inst->addr - src->srcbase);
stream->n_scpy += 1;
stream->l_scpy += (xoff_t) inst->size;
}
else
{
/* with source window: target copy address is offset
* by taroff. */
addr = stream->taroff + (usize_t) inst->addr;
stream->n_tcpy += 1;
stream->l_tcpy += (xoff_t) inst->size;
}
}
else
{
addr = (usize_t) inst->addr;
stream->n_tcpy += 1;
stream->l_tcpy += inst->size;
}
/* Note: used to assert inst->size >= MIN_MATCH, but not true
* for merge operations & identical match heuristics. */
/* the "here" position is always offset by taroff */
if ((ret = xd3_encode_address (stream, addr, inst->pos + stream->taroff,
& inst->type)))
{
return ret;
}
IF_DEBUG2 ({
static int cnt;
DP(RINT "[iopt copy:%d] pos %"Q"u-%"Q"u addr %"Q"u-%"Q"u size %u\n",
cnt++,
stream->total_in + inst->pos,
stream->total_in + inst->pos + inst->size,
inst->addr, inst->addr + inst->size, inst->size);
});
break;
}
case XD3_RUN:
{
XD3_ASSERT (inst->size >= MIN_MATCH);
if ((ret = xd3_emit_byte (stream, & DATA_TAIL (stream), inst->xtra))) { return ret; }
stream->n_run += 1;
stream->l_run += inst->size;
IF_DEBUG2 ({
static int cnt;
DP(RINT "[iopt run:%d] pos %"Q"u size %u\n", cnt++, stream->total_in + inst->pos, inst->size);
});
break;
}
case XD3_ADD:
{
if ((ret = xd3_emit_bytes (stream, & DATA_TAIL (stream),
stream->next_in + inst->pos, inst->size))) { return ret; }
stream->n_add += 1;
stream->l_add += inst->size;
IF_DEBUG2 ({
static int cnt;
DP(RINT "[iopt add:%d] pos %"Q"u size %u\n", cnt++, stream->total_in + inst->pos, inst->size);
});
break;
}
}
/* This is the only place stream->unencoded_offset is incremented. */
XD3_ASSERT (stream->unencoded_offset == inst->pos);
stream->unencoded_offset += inst->size;
inst->code2 = 0;
XD3_CHOOSE_INSTRUCTION (stream, stream->iout, inst);
if (stream->iout != NULL)
{
if (stream->iout->code2 != 0)
{
if ((ret = xd3_emit_double (stream, stream->iout, inst, stream->iout->code2))) { return ret; }
xd3_iopt_free_nonadd (stream, stream->iout);
xd3_iopt_free_nonadd (stream, inst);
stream->iout = NULL;
return 0;
}
else
{
if ((ret = xd3_emit_single (stream, stream->iout, stream->iout->code1))) { return ret; }
xd3_iopt_free_nonadd (stream, stream->iout);
}
}
stream->iout = inst;
return 0;
}
/* This possibly encodes an add instruction, iadd, which must remain
* on the stack until the following call to
* xd3_iopt_finish_encoding. */
static int
xd3_iopt_add (xd3_stream *stream, usize_t pos, xd3_rinst *iadd)
{
int ret;
usize_t off = stream->unencoded_offset;
if (pos > off)
{
iadd->type = XD3_ADD;
iadd->pos = off;
iadd->size = pos - off;
if ((ret = xd3_iopt_finish_encoding (stream, iadd))) { return ret; }
}
return 0;
}
/* This function calls xd3_iopt_finish_encoding to finish encoding an
* instruction, and it may also produce an add instruction for an
* unmatched region. */
static int
xd3_iopt_add_encoding (xd3_stream *stream, xd3_rinst *inst)
{
int ret;
xd3_rinst iadd;
if ((ret = xd3_iopt_add (stream, inst->pos, & iadd))) { return ret; }
if ((ret = xd3_iopt_finish_encoding (stream, inst))) { return ret; }
return 0;
}
/* Generates a final add instruction to encode the remaining input. */
static int
xd3_iopt_add_finalize (xd3_stream *stream)
{
int ret;
xd3_rinst iadd;
if ((ret = xd3_iopt_add (stream, stream->avail_in, & iadd))) { return ret; }
if (stream->iout)
{
if ((ret = xd3_emit_single (stream, stream->iout, stream->iout->code1))) { return ret; }
xd3_iopt_free_nonadd (stream, stream->iout);
stream->iout = NULL;
}
return 0;
}
/* Compact the instruction buffer by choosing the best non-overlapping
* instructions when lazy string-matching. There are no ADDs in the
* iopt buffer because those are synthesized in xd3_iopt_add_encoding
* and during xd3_iopt_add_finalize. */
static int
xd3_iopt_flush_instructions (xd3_stream *stream, int force)
{
xd3_rinst *r1 = xd3_rlist_front (& stream->iopt_used);
xd3_rinst *r2;
xd3_rinst *r3;
usize_t r1end;
usize_t r2end;
usize_t r2off;
usize_t r2moff;
usize_t gap;
usize_t flushed;
int ret;
XD3_ASSERT (xd3_iopt_check (stream));
/* Note: once tried to skip this step if it's possible to assert
* there are no overlapping instructions. Doesn't work because
* xd3_opt_erase leaves overlapping instructions. */
while (! xd3_rlist_end (& stream->iopt_used, r1) &&
! xd3_rlist_end (& stream->iopt_used, r2 = xd3_rlist_next (r1)))
{
r1end = r1->pos + r1->size;
/* If the instructions do not overlap, continue. */
if (r1end <= r2->pos)
{
r1 = r2;
continue;
}
r2end = r2->pos + r2->size;
/* The min_match adjustments prevent this. */
XD3_ASSERT (r2end > (r1end + LEAST_MATCH_INCR));
/* If r3 is available... */
if (! xd3_rlist_end (& stream->iopt_used, r3 = xd3_rlist_next (r2)))
{
/* If r3 starts before r1 finishes or just about, r2 is irrelevant */
if (r3->pos <= r1end + 1)
{
xd3_iopt_free (stream, r2);
continue;
}
}
else if (! force)
{
/* Unless force, end the loop when r3 is not available. */
break;
}
r2off = r2->pos - r1->pos;
r2moff = r2end - r1end;
gap = r2end - r1->pos;
/* If the two matches overlap almost entirely, choose the better match
* and discard the other. The else branch can still create inefficient
* copies, e.g., a 4-byte copy that takes 4 bytes to encode, which
* xd3_smatch() wouldn't allow by its crude efficiency check. However,
* in this case there are adjacent copies which mean the add would cost
* one extra byte. Allow the inefficiency here. */
if (gap < 2*MIN_MATCH || r2moff <= 2 || r2off <= 2)
{
/* Only one match should be used, choose the longer one. */
if (r1->size < r2->size)
{
xd3_iopt_free (stream, r1);
r1 = r2;
}
else
{
/* We are guaranteed that r1 does not overlap now, so advance past r2 */
r1 = xd3_iopt_free (stream, r2);
}
continue;
}
else
{
/* Shorten one of the instructions -- could be optimized
* based on the address cache. */
usize_t average;
usize_t newsize;
usize_t adjust1;
XD3_ASSERT (r1end > r2->pos && r2end > r1->pos);
/* Try to balance the length of both instructions, but avoid
* making both longer than MAX_MATCH_SPLIT . */
average = gap / 2;
newsize = min (MAX_MATCH_SPLIT, gap - average);
/* Should be possible to simplify this code. */
if (newsize > r1->size)
{
/* shorten r2 */
adjust1 = r1end - r2->pos;
}
else if (newsize > r2->size)
{
/* shorten r1 */
adjust1 = r1end - r2->pos;
XD3_ASSERT (r1->size > adjust1);
r1->size -= adjust1;
/* don't shorten r2 */
adjust1 = 0;
}
else
{
/* shorten r1 */
adjust1 = r1->size - newsize;
if (r2->pos > r1end - adjust1)
{
adjust1 -= r2->pos - (r1end - adjust1);
}
XD3_ASSERT (r1->size > adjust1);
r1->size -= adjust1;
/* shorten r2 */
XD3_ASSERT (r1->pos + r1->size >= r2->pos);
adjust1 = r1->pos + r1->size - r2->pos;
}
/* Fallthrough above if-else, shorten r2 */
XD3_ASSERT (r2->size > adjust1);
r2->size -= adjust1;
r2->pos += adjust1;
r2->addr += adjust1;
XD3_ASSERT (r1->size >= MIN_MATCH);
XD3_ASSERT (r2->size >= MIN_MATCH);
r1 = r2;
}
}
XD3_ASSERT (xd3_iopt_check (stream));
/* If forcing, pick instructions until the list is empty, otherwise
* this empties 50% of the queue. */
for (flushed = 0; ! xd3_rlist_empty (& stream->iopt_used); )
{
xd3_rinst *renc = xd3_rlist_pop_front (& stream->iopt_used);
if ((ret = xd3_iopt_add_encoding (stream, renc)))
{
return ret;
}
if (! force)
{
if (++flushed > stream->iopt_size / 2)
{
break;
}
/* If there are only two instructions remaining, break,
* because they were not optimized. This means there were
* more than 50% eliminated by the loop above. */
r1 = xd3_rlist_front (& stream->iopt_used);
if (xd3_rlist_end(& stream->iopt_used, r1) ||
xd3_rlist_end(& stream->iopt_used, r2 = xd3_rlist_next (r1)) ||
xd3_rlist_end(& stream->iopt_used, r3 = xd3_rlist_next (r2)))
{
break;
}
}
}
XD3_ASSERT (xd3_iopt_check (stream));
XD3_ASSERT (!force || xd3_rlist_length (& stream->iopt_used) == 0);
return 0;
}
static int
xd3_iopt_get_slot (xd3_stream *stream, xd3_rinst** iptr)
{
xd3_rinst *i;
int ret;
if (xd3_rlist_empty (& stream->iopt_free))
{
if (stream->iopt_unlimited)
{
usize_t elts = XD3_ALLOCSIZE / sizeof(xd3_rinst);
if ((ret = xd3_alloc_iopt (stream, elts)))
{
return ret;
}
stream->iopt_size += elts;
}
else
{
if ((ret = xd3_iopt_flush_instructions (stream, 0))) { return ret; }
XD3_ASSERT (! xd3_rlist_empty (& stream->iopt_free));
}
}
i = xd3_rlist_pop_back (& stream->iopt_free);
xd3_rlist_push_back (& stream->iopt_used, i);
(*iptr) = i;
++stream->i_slots_used;
return 0;
}
/* A copy is about to be emitted that extends backwards to POS,
* therefore it may completely cover some existing instructions in the
* buffer. If an instruction is completely covered by this new match,
* erase it. If the new instruction is covered by the previous one,
* return 1 to skip it. */
static void
xd3_iopt_erase (xd3_stream *stream, usize_t pos, usize_t size)
{
while (! xd3_rlist_empty (& stream->iopt_used))
{
xd3_rinst *r = xd3_rlist_back (& stream->iopt_used);
/* Verify that greedy is working. The previous instruction
* should end before the new one begins. */
XD3_ASSERT ((stream->flags & XD3_BEGREEDY) == 0 || (r->pos + r->size <= pos));
/* Verify that min_match is working. The previous instruction
* should end before the new one ends. */
XD3_ASSERT ((stream->flags & XD3_BEGREEDY) != 0 || (r->pos + r->size < pos + size));
/* See if the last instruction starts before the new
* instruction. If so, there is nothing to erase. */
if (r->pos < pos)
{
return;
}
/* Otherwise, the new instruction covers the old one, delete it
and repeat. */
xd3_rlist_remove (r);
xd3_rlist_push_back (& stream->iopt_free, r);
--stream->i_slots_used;
}
}
/* This function tells the last matched input position. */
static usize_t
xd3_iopt_last_matched (xd3_stream *stream)
{
xd3_rinst *r;
if (xd3_rlist_empty (& stream->iopt_used))
{
return 0;
}
r = xd3_rlist_back (& stream->iopt_used);
return r->pos + r->size;
}
/*********************************************************
Emit routines
***********************************************************/
static int
xd3_emit_single (xd3_stream *stream, xd3_rinst *single, usize_t code)
{
int has_size = stream->code_table[code].size1 == 0;
int ret;
IF_DEBUG2 (DP(RINT "[emit1] %u %s (%u) code %u\n",
single->pos,
xd3_rtype_to_string ((xd3_rtype) single->type, 0),
single->size,
code));
if ((ret = xd3_emit_byte (stream, & INST_TAIL (stream), code)))
{
return ret;
}
if (has_size)
{
if ((ret = xd3_emit_size (stream, & INST_TAIL (stream), single->size)))
{
return ret;
}
}
return 0;
}
static int
xd3_emit_double (xd3_stream *stream, xd3_rinst *first,
xd3_rinst *second, usize_t code)
{
int ret;
/* All double instructions use fixed sizes, so all we need to do is
* output the instruction code, no sizes. */
XD3_ASSERT (stream->code_table[code].size1 != 0 &&
stream->code_table[code].size2 != 0);
if ((ret = xd3_emit_byte (stream, & INST_TAIL (stream), code)))
{
return ret;
}
IF_DEBUG2 (DP(RINT "[emit2]: %u %s (%u) %s (%u) code %u\n",
first->pos,
xd3_rtype_to_string ((xd3_rtype) first->type, 0),
first->size,
xd3_rtype_to_string ((xd3_rtype) second->type, 0),
second->size,
code));
return 0;
}
/* This enters a potential run instruction into the iopt buffer. The
* position argument is relative to the target window. */
static int
xd3_emit_run (xd3_stream *stream, usize_t pos, usize_t size, uint8_t *run_c)
{
xd3_rinst* ri;
int ret;
if ((ret = xd3_iopt_get_slot (stream, & ri))) { return ret; }
ri->type = XD3_RUN;
ri->xtra = *run_c;
ri->pos = pos;
ri->size = size;
return 0;
}
/* This enters a potential copy instruction into the iopt buffer. The
* position argument is relative to the target window.. */
int
xd3_found_match (xd3_stream *stream, usize_t pos,
usize_t size, xoff_t addr, int is_source)
{
xd3_rinst* ri;
int ret;
if ((ret = xd3_iopt_get_slot (stream, & ri))) { return ret; }
ri->type = XD3_CPY;
ri->xtra = is_source;
ri->pos = pos;
ri->size = size;
ri->addr = addr;
return 0;
}
static int
xd3_emit_hdr (xd3_stream *stream)
{
int ret;
int use_secondary = stream->sec_type != NULL;
int use_adler32 = stream->flags & (XD3_ADLER32 | XD3_ADLER32_RECODE);
int vcd_source = xd3_encoder_used_source (stream);
usize_t win_ind = 0;
usize_t del_ind = 0;
usize_t enc_len;
usize_t tgt_len;
usize_t data_len;
usize_t inst_len;
usize_t addr_len;
if (stream->current_window == 0)
{
usize_t hdr_ind = 0;
int use_appheader = stream->enc_appheader != NULL;
int use_gencodetbl = GENERIC_ENCODE_TABLES &&
(stream->code_table_desc != & __rfc3284_code_table_desc);
if (use_secondary) { hdr_ind |= VCD_SECONDARY; }
if (use_gencodetbl) { hdr_ind |= VCD_CODETABLE; }
if (use_appheader) { hdr_ind |= VCD_APPHEADER; }
if ((ret = xd3_emit_byte (stream, & HDR_TAIL (stream),
VCDIFF_MAGIC1)) != 0 ||
(ret = xd3_emit_byte (stream, & HDR_TAIL (stream),
VCDIFF_MAGIC2)) != 0 ||
(ret = xd3_emit_byte (stream, & HDR_TAIL (stream),
VCDIFF_MAGIC3)) != 0 ||
(ret = xd3_emit_byte (stream, & HDR_TAIL (stream),
VCDIFF_VERSION)) != 0 ||
(ret = xd3_emit_byte (stream, & HDR_TAIL (stream), hdr_ind)) != 0)
{
return ret;
}
/* Secondary compressor ID */
#if SECONDARY_ANY
if (use_secondary &&
(ret = xd3_emit_byte (stream, & HDR_TAIL (stream),
stream->sec_type->id)))
{
return ret;
}
#endif
/* Compressed code table */
if (use_gencodetbl)
{
usize_t code_table_size;
const uint8_t *code_table_data;
if ((ret = stream->comp_table_func (stream, & code_table_data,
& code_table_size)))
{
return ret;
}
if ((ret = xd3_emit_size (stream, & HDR_TAIL (stream),
code_table_size + 2)) ||
(ret = xd3_emit_byte (stream, & HDR_TAIL (stream),
stream->code_table_desc->near_modes)) ||
(ret = xd3_emit_byte (stream, & HDR_TAIL (stream),
stream->code_table_desc->same_modes)) ||
(ret = xd3_emit_bytes (stream, & HDR_TAIL (stream),
code_table_data, code_table_size)))
{
return ret;
}
}
/* Application header */
if (use_appheader)
{
if ((ret = xd3_emit_size (stream, & HDR_TAIL (stream),
stream->enc_appheadsz)) ||
(ret = xd3_emit_bytes (stream, & HDR_TAIL (stream),
stream->enc_appheader,
stream->enc_appheadsz)))
{
return ret;
}
}
}
/* try to compress this window */
#if SECONDARY_ANY
if (use_secondary)
{
int data_sec = 0;
int inst_sec = 0;
int addr_sec = 0;
# define ENCODE_SECONDARY_SECTION(UPPER,LOWER) \
((stream->flags & XD3_SEC_NO ## UPPER) == 0 && \
(ret = xd3_encode_secondary (stream, \
& UPPER ## _HEAD (stream), \
& UPPER ## _TAIL (stream), \
& xd3_sec_ ## LOWER (stream), \
& stream->sec_ ## LOWER, \
& LOWER ## _sec)))
if (ENCODE_SECONDARY_SECTION (DATA, data) ||
ENCODE_SECONDARY_SECTION (INST, inst) ||
ENCODE_SECONDARY_SECTION (ADDR, addr))
{
return ret;
}
del_ind |= (data_sec ? VCD_DATACOMP : 0);
del_ind |= (inst_sec ? VCD_INSTCOMP : 0);
del_ind |= (addr_sec ? VCD_ADDRCOMP : 0);
}
#endif
/* if (vcd_target) { win_ind |= VCD_TARGET; } */
if (vcd_source) { win_ind |= VCD_SOURCE; }
if (use_adler32) { win_ind |= VCD_ADLER32; }
/* window indicator */
if ((ret = xd3_emit_byte (stream, & HDR_TAIL (stream), win_ind)))
{
return ret;
}
/* source window */
if (vcd_source)
{
/* or (vcd_target) { ... } */
if ((ret = xd3_emit_size (stream, & HDR_TAIL (stream),
stream->src->srclen)) ||
(ret = xd3_emit_offset (stream, & HDR_TAIL (stream),
stream->src->srcbase))) { return ret; }
}
tgt_len = stream->avail_in;
data_len = xd3_sizeof_output (DATA_HEAD (stream));
inst_len = xd3_sizeof_output (INST_HEAD (stream));
addr_len = xd3_sizeof_output (ADDR_HEAD (stream));
/* The enc_len field is a redundency for future extensions.*/
enc_len = (1 + (xd3_sizeof_size (tgt_len) +
xd3_sizeof_size (data_len) +
xd3_sizeof_size (inst_len) +
xd3_sizeof_size (addr_len)) +
data_len +
inst_len +
addr_len +
(use_adler32 ? 4 : 0));
if ((ret = xd3_emit_size (stream, & HDR_TAIL (stream), enc_len)) ||
(ret = xd3_emit_size (stream, & HDR_TAIL (stream), tgt_len)) ||
(ret = xd3_emit_byte (stream, & HDR_TAIL (stream), del_ind)) ||
(ret = xd3_emit_size (stream, & HDR_TAIL (stream), data_len)) ||
(ret = xd3_emit_size (stream, & HDR_TAIL (stream), inst_len)) ||
(ret = xd3_emit_size (stream, & HDR_TAIL (stream), addr_len)))
{
return ret;
}
if (use_adler32)
{
uint8_t send[4];
uint32_t a32;
if (stream->flags & XD3_ADLER32)
{
a32 = adler32 (1L, stream->next_in, stream->avail_in);
}
else
{
a32 = stream->recode_adler32;
}
/* Four bytes. */
send[0] = (uint8_t) (a32 >> 24);
send[1] = (uint8_t) (a32 >> 16);
send[2] = (uint8_t) (a32 >> 8);
send[3] = (uint8_t) (a32 & 0x000000FFU);
if ((ret = xd3_emit_bytes (stream, & HDR_TAIL (stream), send, 4)))
{
return ret;
}
}
return 0;
}
/****************************************************************
Encode routines
****************************************************************/
static int
xd3_encode_buffer_leftover (xd3_stream *stream)
{
usize_t take;
usize_t room;
/* Allocate the buffer. */
if (stream->buf_in == NULL &&
(stream->buf_in = (uint8_t*) xd3_alloc (stream, stream->winsize, 1)) == NULL)
{
return ENOMEM;
}
IF_DEBUG2 (DP(RINT "[leftover] flush?=%s\n", (stream->flags & XD3_FLUSH) ? "yes" : "no"));
/* Take leftover input first. */
if (stream->buf_leftover != NULL)
{
XD3_ASSERT (stream->buf_avail == 0);
XD3_ASSERT (stream->buf_leftavail < stream->winsize);
IF_DEBUG2 (DP(RINT "[leftover] previous %u avail %u\n", stream->buf_leftavail, stream->avail_in));
memcpy (stream->buf_in, stream->buf_leftover, stream->buf_leftavail);
stream->buf_leftover = NULL;
stream->buf_avail = stream->buf_leftavail;
}
/* Copy into the buffer. */
room = stream->winsize - stream->buf_avail;
take = min (room, stream->avail_in);
memcpy (stream->buf_in + stream->buf_avail, stream->next_in, take);
stream->buf_avail += take;
if (take < stream->avail_in)
{
/* Buffer is full */
stream->buf_leftover = stream->next_in + take;
stream->buf_leftavail = stream->avail_in - take;
}
else if ((stream->buf_avail < stream->winsize) && !(stream->flags & XD3_FLUSH))
{
/* Buffer has space */
IF_DEBUG2 (DP(RINT "[leftover] emptied %u\n", take));
return XD3_INPUT;
}
/* Use the buffer: */
IF_DEBUG2 (DP(RINT "[leftover] take %u remaining %u\n", take, stream->buf_leftavail));
stream->next_in = stream->buf_in;
stream->avail_in = stream->buf_avail;
stream->buf_avail = 0;
return 0;
}
/* Allocates one block of xd3_rlist elements */
static int
xd3_alloc_iopt (xd3_stream *stream, usize_t elts)
{
usize_t i;
xd3_iopt_buflist* last =
(xd3_iopt_buflist*) xd3_alloc (stream, sizeof (xd3_iopt_buflist), 1);
if (last == NULL ||
(last->buffer = (xd3_rinst*) xd3_alloc (stream, sizeof (xd3_rinst), elts)) == NULL)
{
return ENOMEM;
}
last->next = stream->iopt_alloc;
stream->iopt_alloc = last;
for (i = 0; i < elts; i += 1)
{
xd3_rlist_push_back (& stream->iopt_free, & last->buffer[i]);
}
return 0;
}
/* This function allocates all memory initially used by the encoder. */
static int
xd3_encode_init (xd3_stream *stream, int full_init)
{
int i;
if (full_init)
{
int large_comp = (stream->src != NULL);
int small_comp = ! (stream->flags & XD3_NOCOMPRESS);
/* Memory allocations for checksum tables are delayed until
* xd3_string_match_init in the first call to string_match--that way
* identical or short inputs require no table allocation. */
if (large_comp)
{
usize_t hash_values = (stream->src->max_winsize /
stream->smatcher.large_step);
xd3_size_hashtable (stream,
hash_values,
& stream->large_hash);
}
if (small_comp)
{
/* TODO: This is under devel: used to have min(sprevsz) here, which sort
* of makes sense, but observed fast performance w/ larger tables, which
* also sort of makes sense. @@@ */
usize_t hash_values = stream->winsize;
xd3_size_hashtable (stream,
hash_values,
& stream->small_hash);
}
}
/* data buffers */
for (i = 0; i < ENC_SECTS; i += 1)
{
if ((stream->enc_heads[i] =
stream->enc_tails[i] =
xd3_alloc_output (stream, NULL)) == NULL)
{
return ENOMEM;
}
}
/* iopt buffer */
xd3_rlist_init (& stream->iopt_used);
xd3_rlist_init (& stream->iopt_free);
if (xd3_alloc_iopt (stream, stream->iopt_size) != 0) { goto fail; }
XD3_ASSERT (xd3_rlist_length (& stream->iopt_free) == stream->iopt_size);
XD3_ASSERT (xd3_rlist_length (& stream->iopt_used) == 0);
/* address cache, code table */
stream->acache.s_near = stream->code_table_desc->near_modes;
stream->acache.s_same = stream->code_table_desc->same_modes;
stream->code_table = stream->code_table_func ();
return xd3_alloc_cache (stream);
fail:
return ENOMEM;
}
int
xd3_encode_init_full (xd3_stream *stream)
{
return xd3_encode_init (stream, 1);
}
int
xd3_encode_init_partial (xd3_stream *stream)
{
return xd3_encode_init (stream, 0);
}
/* Called after the ENC_POSTOUT state, this puts the output buffers
* back into separate lists and re-initializes some variables. (The
* output lists were spliced together during the ENC_FLUSH state.) */
static void
xd3_encode_reset (xd3_stream *stream)
{
int i;
xd3_output *olist;
stream->avail_in = 0;
stream->small_reset = 1;
stream->i_slots_used = 0;
if (stream->src != NULL)
{
stream->src->srcbase = 0;
stream->src->srclen = 0;
stream->srcwin_decided = 0;
stream->srcwin_decided_early = 0;
stream->match_minaddr = 0;
stream->match_maxaddr = 0;
stream->taroff = 0;
}
/* Reset output chains. */
olist = stream->enc_heads[0];
for (i = 0; i < ENC_SECTS; i += 1)
{
XD3_ASSERT (olist != NULL);
stream->enc_heads[i] = olist;
stream->enc_tails[i] = olist;
olist = olist->next_page;
stream->enc_heads[i]->next = 0;
stream->enc_heads[i]->next_page = NULL;
stream->enc_tails[i]->next_page = NULL;
stream->enc_tails[i] = stream->enc_heads[i];
}
xd3_freelist_output (stream, olist);
}
/* The main encoding routine. */
int
xd3_encode_input (xd3_stream *stream)
{
int ret, i;
if (stream->dec_state != 0)
{
stream->msg = "encoder/decoder transition";
return XD3_INTERNAL;
}
switch (stream->enc_state)
{
case ENC_INIT:
/* Only reached on first time through: memory setup. */
if ((ret = xd3_encode_init_full (stream))) { return ret; }
stream->enc_state = ENC_INPUT;
case ENC_INPUT:
/* If there is no input yet, just return. This checks for
* next_in == NULL, not avail_in == 0 since zero bytes is a
* valid input. There is an assertion in xd3_avail_input() that
* next_in != NULL for this reason. By returning right away we
* avoid creating an input buffer before the caller has supplied
* its first data. It is possible for xd3_avail_input to be
* called both before and after the first call to
* xd3_encode_input(). */
if (stream->next_in == NULL)
{
return XD3_INPUT;
}
enc_flush:
/* See if we should buffer the input: either if there is already
* a leftover buffer, or if the input is short of winsize
* without flush. The label at this point is reached by a goto
* below, when there is leftover input after postout. */
if ((stream->buf_leftover != NULL) ||
(stream->buf_avail != 0) ||
(stream->avail_in < stream->winsize && ! (stream->flags & XD3_FLUSH)))
{
if ((ret = xd3_encode_buffer_leftover (stream))) { return ret; }
}
/* Initalize the address cache before each window. */
xd3_init_cache (& stream->acache);
stream->input_position = 0;
stream->min_match = MIN_MATCH;
stream->unencoded_offset = 0;
stream->enc_state = ENC_SEARCH;
IF_DEBUG2 (DP(RINT "[WINSTART:%"Q"u] input bytes %u offset %"Q"u\n",
stream->current_window, stream->avail_in,
stream->total_in));
return XD3_WINSTART;
case ENC_SEARCH:
IF_DEBUG2 (DP(RINT "[SEARCH] match_state %d avail_in %u %s\n",
stream->match_state, stream->avail_in,
stream->src ? "source" : "no source"));
/* Reentrant matching. */
if (stream->src != NULL)
{
switch (stream->match_state)
{
case MATCH_TARGET:
/* Try matching forward at the start of the target.
* This is entered the first time through, to check for
* a perfect match, and whenever there is a source match
* that extends to the end of the previous window. The
* match_srcpos field is initially zero and later set
* during xd3_source_extend_match. */
if (stream->avail_in > 0)
{
/* This call can't fail because the source window is
* unrestricted. */
ret = xd3_source_match_setup (stream, stream->match_srcpos);
XD3_ASSERT (ret == 0);
stream->match_state = MATCH_FORWARD;
}
else
{
stream->match_state = MATCH_SEARCHING;
stream->match_fwd = 0;
}
XD3_ASSERT (stream->match_fwd == 0);
case MATCH_FORWARD:
case MATCH_BACKWARD:
if (stream->avail_in != 0)
{
if ((ret = xd3_source_extend_match (stream)) != 0)
{
return ret;
}
/* The search has to make forward progress here
* or else it can get stuck in a match-backward
* (getsrcblk) then match-forward (getsrcblk),
* find insufficient match length, then repeat
* exactly the same search.
*/
stream->input_position += stream->match_fwd;
}
case MATCH_SEARCHING:
/* Continue string matching. (It's possible that the
* initial match continued through the entire input, in
* which case we're still in MATCH_FORWARD and should
* remain so for the next input window.) */
break;
}
}
/* String matching... */
if (stream->avail_in != 0 &&
(ret = stream->smatcher.string_match (stream)))
{
return ret;
}
stream->enc_state = ENC_INSTR;
case ENC_INSTR:
/* Note: Jump here to encode VCDIFF deltas w/o using this
* string-matching code. Merging code code enters here. */
/* Flush the instrution buffer, then possibly add one more
* instruction, then emit the header. */
if ((ret = xd3_iopt_flush_instructions (stream, 1)) ||
(ret = xd3_iopt_add_finalize (stream)))
{
return ret;
}
stream->enc_state = ENC_FLUSH;
case ENC_FLUSH:
/* Note: main_recode_func() bypasses string-matching by setting
* ENC_FLUSH. */
if ((ret = xd3_emit_hdr (stream)))
{
return ret;
}
/* Begin output. */
stream->enc_current = HDR_HEAD (stream);
/* Chain all the outputs together. After doing this, it looks
* as if there is only one section. The other enc_heads are set
* to NULL to avoid freeing them more than once. */
for (i = 1; i < ENC_SECTS; i += 1)
{
stream->enc_tails[i-1]->next_page = stream->enc_heads[i];
stream->enc_heads[i] = NULL;
}
enc_output:
stream->enc_state = ENC_POSTOUT;
stream->next_out = stream->enc_current->base;
stream->avail_out = stream->enc_current->next;
stream->total_out += (xoff_t) stream->avail_out;
/* If there is any output in this buffer, return it, otherwise
* fall through to handle the next buffer or finish the window
* after all buffers have been output. */
if (stream->avail_out > 0)
{
/* This is the only place xd3_encode returns XD3_OUTPUT */
return XD3_OUTPUT;
}
case ENC_POSTOUT:
if (stream->avail_out != 0)
{
stream->msg = "missed call to consume output";
return XD3_INTERNAL;
}
/* Continue outputting one buffer at a time, until the next is NULL. */
if ((stream->enc_current = stream->enc_current->next_page) != NULL)
{
goto enc_output;
}
stream->total_in += (xoff_t) stream->avail_in;
stream->enc_state = ENC_POSTWIN;
IF_DEBUG2 (DP(RINT "[WINFINISH:%"Q"u] in=%"Q"u\n",
stream->current_window,
stream->total_in));
return XD3_WINFINISH;
case ENC_POSTWIN:
xd3_encode_reset (stream);
stream->current_window += 1;
stream->enc_state = ENC_INPUT;
/* If there is leftover input to flush, repeat. */
if (stream->buf_leftover != NULL)
{
goto enc_flush;
}
/* Ready for more input. */
return XD3_INPUT;
default:
stream->msg = "invalid state";
return XD3_INTERNAL;
}
}
#endif /* XD3_ENCODER */
/*****************************************************************
Client convenience functions
******************************************************************/
static int
xd3_process_stream (int is_encode,
xd3_stream *stream,
int (*func) (xd3_stream *),
int close_stream,
const uint8_t *input,
usize_t input_size,
uint8_t *output,
usize_t *output_size,
usize_t output_size_max)
{
usize_t ipos = 0;
usize_t n = min(stream->winsize, input_size);
(*output_size) = 0;
stream->flags |= XD3_FLUSH;
xd3_avail_input (stream, input + ipos, n);
ipos += n;
for (;;)
{
int ret;
switch((ret = func (stream)))
{
case XD3_OUTPUT: { /* memcpy below */ break; }
case XD3_INPUT: {
n = min(stream->winsize, input_size - ipos);
if (n == 0) {
goto done;
}
xd3_avail_input (stream, input + ipos, n);
ipos += n;
continue;
}
case XD3_GOTHEADER: { /* ignore */ continue; }
case XD3_WINSTART: { /* ignore */ continue; }
case XD3_WINFINISH: { /* ignore */ continue; }
case XD3_GETSRCBLK:
{
stream->msg = "stream requires source input";
return XD3_INTERNAL;
}
case 0:
{
/* xd3_encode_input/xd3_decode_input never return 0 */
stream->msg = "invalid return: 0";
return XD3_INTERNAL;
}
default:
return ret;
}
if (*output_size + stream->avail_out > output_size_max)
{
stream->msg = "insufficient output space";
return ENOSPC;
}
memcpy (output + *output_size, stream->next_out, stream->avail_out);
*output_size += stream->avail_out;
xd3_consume_output (stream);
}
done:
return (close_stream == 0) ? 0 : xd3_close_stream (stream);
}
static int
xd3_process_memory (int is_encode,
int (*func) (xd3_stream *),
int close_stream,
const uint8_t *input,
usize_t input_size,
const uint8_t *source,
usize_t source_size,
uint8_t *output,
usize_t *output_size,
usize_t output_size_max,
int flags) {
xd3_stream stream;
xd3_config config;
xd3_source src;
int ret;
memset (& stream, 0, sizeof (stream));
memset (& config, 0, sizeof (config));
if (input == NULL || output == NULL) {
stream.msg = "invalid input/output buffer";
ret = XD3_INTERNAL;
goto exit;
}
config.flags = flags;
if (is_encode)
{
config.winsize = min(input_size, (usize_t) XD3_DEFAULT_WINSIZE);
config.iopt_size = min(input_size / 32, XD3_DEFAULT_IOPT_SIZE);
config.iopt_size = max(config.iopt_size, 128U);
config.sprevsz = xd3_pow2_roundup (config.winsize);
}
if ((ret = xd3_config_stream (&stream, &config)) != 0)
{
goto exit;
}
if (source != NULL)
{
memset (& src, 0, sizeof (src));
src.blksize = source_size;
src.onblk = source_size;
src.curblk = source;
src.curblkno = 0;
src.max_winsize = source_size;
if ((ret = xd3_set_source_and_size (&stream, &src, source_size)) != 0)
{
goto exit;
}
}
if ((ret = xd3_process_stream (is_encode,
& stream,
func, 1,
input, input_size,
output,
output_size,
output_size_max)) != 0)
{
goto exit;
}
exit:
if (ret != 0)
{
IF_DEBUG2 (DP(RINT "process_memory: %d: %s\n", ret, stream.msg));
}
xd3_free_stream(&stream);
return ret;
}
int
xd3_decode_stream (xd3_stream *stream,
const uint8_t *input,
usize_t input_size,
uint8_t *output,
usize_t *output_size,
usize_t output_size_max)
{
return xd3_process_stream (0, stream, & xd3_decode_input, 1,
input, input_size,
output, output_size, output_size_max);
}
int
xd3_decode_memory (const uint8_t *input,
usize_t input_size,
const uint8_t *source,
usize_t source_size,
uint8_t *output,
usize_t *output_size,
usize_t output_size_max,
int flags) {
return xd3_process_memory (0, & xd3_decode_input, 1,
input, input_size,
source, source_size,
output, output_size, output_size_max,
flags);
}
#if XD3_ENCODER
int
xd3_encode_stream (xd3_stream *stream,
const uint8_t *input,
usize_t input_size,
uint8_t *output,
usize_t *output_size,
usize_t output_size_max)
{
return xd3_process_stream (1, stream, & xd3_encode_input, 1,
input, input_size,
output, output_size, output_size_max);
}
int
xd3_encode_memory (const uint8_t *input,
usize_t input_size,
const uint8_t *source,
usize_t source_size,
uint8_t *output,
usize_t *output_size,
usize_t output_size_max,
int flags) {
return xd3_process_memory (1, & xd3_encode_input, 1,
input, input_size,
source, source_size,
output, output_size, output_size_max,
flags);
}
#endif
/*************************************************************
String matching helpers
*************************************************************/
#if XD3_ENCODER
/* Do the initial xd3_string_match() checksum table setup.
* Allocations are delayed until first use to avoid allocation
* sometimes (e.g., perfect matches, zero-length inputs). */
static int
xd3_string_match_init (xd3_stream *stream)
{
const int DO_SMALL = ! (stream->flags & XD3_NOCOMPRESS);
const int DO_LARGE = (stream->src != NULL);
if (DO_LARGE && stream->large_table == NULL)
{
if ((stream->large_table =
(usize_t*) xd3_alloc0 (stream, stream->large_hash.size, sizeof (usize_t))) == NULL)
{
return ENOMEM;
}
}
if (DO_SMALL)
{
/* Subsequent calls can return immediately after checking reset. */
if (stream->small_table != NULL)
{
/* The target hash table is reinitialized once per window. */
/* TODO: This would not have to be reinitialized if absolute
* offsets were being stored. */
if (stream->small_reset)
{
stream->small_reset = 0;
memset (stream->small_table, 0,
sizeof (usize_t) * stream->small_hash.size);
}
return 0;
}
if ((stream->small_table =
(usize_t*) xd3_alloc0 (stream,
stream->small_hash.size,
sizeof (usize_t))) == NULL)
{
return ENOMEM;
}
/* If there is a previous table needed. */
if (stream->smatcher.small_lchain > 1 ||
stream->smatcher.small_chain > 1)
{
if ((stream->small_prev =
(xd3_slist*) xd3_alloc (stream,
stream->sprevsz,
sizeof (xd3_slist))) == NULL)
{
return ENOMEM;
}
}
}
return 0;
}
#if XD3_USE_LARGEFILE64
/* This function handles the 32/64bit ambiguity -- file positions are 64bit
* but the hash table for source-offsets is 32bit. */
static xoff_t
xd3_source_cksum_offset(xd3_stream *stream, usize_t low)
{
xoff_t scp = stream->srcwin_cksum_pos;
xoff_t s0 = scp >> 32;
usize_t sr = (usize_t) scp;
if (s0 == 0) {
return low;
}
/* This should not be >= because srcwin_cksum_pos is the next
* position to index. */
if (low > sr) {
return (--s0 << 32) | low;
}
return (s0 << 32) | low;
}
#else
static xoff_t
xd3_source_cksum_offset(xd3_stream *stream, usize_t low)
{
return (xoff_t) low;
}
#endif
/* This function sets up the stream->src fields srcbase, srclen. The
* call is delayed until these values are needed to encode a copy
* address. At this point the decision has to be made. */
static int
xd3_srcwin_setup (xd3_stream *stream)
{
xd3_source *src = stream->src;
xoff_t length, x;
/* Check the undecided state. */
XD3_ASSERT (src->srclen == 0 && src->srcbase == 0);
/* Avoid repeating this call. */
stream->srcwin_decided = 1;
/* If the stream is flushing, then the iopt buffer was able to
* contain the complete encoding. If no copies were issued no
* source window is actually needed. This prevents the VCDIFF
* header from including source base/len. xd3_emit_hdr checks for
* srclen == 0. */
if (stream->enc_state == ENC_INSTR && stream->match_maxaddr == 0)
{
goto done;
}
/* Check for overflow, srclen is usize_t - this can't happen unless
* XD3_DEFAULT_SRCBACK and related parameters are extreme - should
* use smaller windows. */
length = stream->match_maxaddr - stream->match_minaddr;
x = (xoff_t) USIZE_T_MAX;
if (length > x)
{
stream->msg = "source window length overflow (not 64bit)";
return XD3_INTERNAL;
}
/* If ENC_INSTR, then we know the exact source window to use because
* no more copies can be issued. */
if (stream->enc_state == ENC_INSTR)
{
src->srcbase = stream->match_minaddr;
src->srclen = (usize_t) length;
XD3_ASSERT (src->srclen);
goto done;
}
/* Otherwise, we have to make a guess. More copies may still be
* issued, but we have to decide the source window base and length
* now. */
src->srcbase = stream->match_minaddr;
src->srclen = max ((usize_t) length,
stream->avail_in + (stream->avail_in >> 2));
/* OPT: If we know the source size, it might be possible to reduce
* srclen. */
XD3_ASSERT (src->srclen);
done:
/* Set the taroff. This convenience variable is used even when
stream->src == NULL. */
stream->taroff = src->srclen;
return 0;
}
/* Sets the bounding region for a newly discovered source match, prior
* to calling xd3_source_extend_match(). This sets the match_maxfwd,
* match_maxback variables. Note: srcpos is an absolute position
* (xoff_t) but the match_maxfwd, match_maxback variables are usize_t.
* Returns 0 if the setup succeeds, or 1 if the source position lies
* outside an already-decided srcbase/srclen window. */
static int
xd3_source_match_setup (xd3_stream *stream, xoff_t srcpos)
{
xd3_source *src = stream->src;
usize_t greedy_or_not;
xoff_t frontier_pos;
stream->match_maxback = 0;
stream->match_maxfwd = 0;
stream->match_back = 0;
stream->match_fwd = 0;
/* This avoids a non-blocking endless loop caused by scanning
* backwards across a block boundary, only to find not enough
* matching bytes to beat the current min_match due to a better lazy
* target match: the re-entry to xd3_string_match() repeats the same
* long match because the input position hasn't changed. TODO: if
* ever duplicates are added to the source hash table, this logic
* won't suffice to avoid loops. See testing/regtest.cc's
* TestNonBlockingProgress test! */
if (srcpos != 0 && srcpos == stream->match_last_srcpos)
{
IF_DEBUG2(DP(RINT "[match_setup] looping failure\n"));
goto bad;
}
/* Implement src->max_winsize, which prevents the encoder from seeking
* back further than the LRU cache maintaining FIFO discipline, (to
* avoid seeking). Note the +1 here ensures that "frontier_pos" is
* the address of the next byte in the stream, and ensures that the
* maximum offset is less than the source window size (in
* blocks). */
frontier_pos =
(stream->src->frontier_blkno + 1) * stream->src->blksize;
IF_DEBUG1(DP(RINT "[match_setup] frontier_pos %"Q"u, srcpos %"Q"u, "
"src->max_winsize %u\n",
frontier_pos, srcpos, stream->src->max_winsize));
if (srcpos < frontier_pos &&
frontier_pos - srcpos > stream->src->max_winsize) {
IF_DEBUG1(DP(RINT "[match_setup] rejected due to src->max_winsize "
"distance eof=%"Q"u srcpos=%"Q"u maxsz=%u\n",
xd3_source_eof (stream->src),
srcpos, stream->src->max_winsize));
goto bad;
}
/* Going backwards, the 1.5-pass algorithm allows some
* already-matched input may be covered by a longer source match.
* The greedy algorithm does not allow this. */
if (stream->flags & XD3_BEGREEDY)
{
/* The greedy algorithm allows backward matching to the last
matched position. */
greedy_or_not = xd3_iopt_last_matched (stream);
}
else
{
/* The 1.5-pass algorithm allows backward matching to go back as
* far as the unencoded offset, which is updated as instructions
* pass out of the iopt buffer. If this (default) is chosen, it
* means xd3_iopt_erase may be called to eliminate instructions
* when a covering source match is found. */
greedy_or_not = stream->unencoded_offset;
}
/* Backward target match limit. */
XD3_ASSERT (stream->input_position >= greedy_or_not);
stream->match_maxback = stream->input_position - greedy_or_not;
/* Forward target match limit. */
XD3_ASSERT (stream->avail_in > stream->input_position);
stream->match_maxfwd = stream->avail_in - stream->input_position;
/* Now we take the source position into account. It depends whether
* the srclen/srcbase have been decided yet. */
if (stream->srcwin_decided == 0)
{
/* Unrestricted case: the match can cover the entire source,
* 0--src->size. We compare the usize_t
* match_maxfwd/match_maxback against the xoff_t
* src->size/srcpos values and take the min. */
if (srcpos < (xoff_t) stream->match_maxback)
{
stream->match_maxback = (usize_t) srcpos;
}
if (stream->src->eof_known)
{
xoff_t srcavail = xd3_source_eof (stream->src) - srcpos;
if (srcavail < (xoff_t) stream->match_maxfwd)
{
stream->match_maxfwd = (usize_t) srcavail;
}
}
IF_DEBUG1(DP(RINT
"[match_setup] srcpos %"Q"u (tgtpos %"Q"u) "
"unrestricted maxback %u maxfwd %u\n",
srcpos,
stream->total_in + stream->input_position,
stream->match_maxback,
stream->match_maxfwd));
goto good;
}
/* Decided some source window. */
XD3_ASSERT (src->srclen > 0);
/* Restricted case: fail if the srcpos lies outside the source window */
if ((srcpos < src->srcbase) ||
(srcpos > (src->srcbase + (xoff_t) src->srclen)))
{
IF_DEBUG1(DP(RINT "[match_setup] restricted source window failure\n"));
goto bad;
}
else
{
usize_t srcavail;
srcavail = (usize_t) (srcpos - src->srcbase);
if (srcavail < stream->match_maxback)
{
stream->match_maxback = srcavail;
}
srcavail = (usize_t) (src->srcbase + (xoff_t) src->srclen - srcpos);
if (srcavail < stream->match_maxfwd)
{
stream->match_maxfwd = srcavail;
}
IF_DEBUG1(DP(RINT
"[match_setup] srcpos %"Q"u (tgtpos %"Q"u) "
"restricted maxback %u maxfwd %u\n",
srcpos,
stream->total_in + stream->input_position,
stream->match_maxback,
stream->match_maxfwd));
goto good;
}
good:
stream->match_state = MATCH_BACKWARD;
stream->match_srcpos = srcpos;
stream->match_last_srcpos = srcpos;
return 0;
bad:
stream->match_state = MATCH_SEARCHING;
return 1;
}
static inline int
xd3_forward_match(const uint8_t *s1c, const uint8_t *s2c, int n)
{
int i = 0;
#if UNALIGNED_OK
int nint = n / sizeof(int);
if (nint >> 3)
{
int j = 0;
const int *s1 = (const int*)s1c;
const int *s2 = (const int*)s2c;
int nint_8 = nint - 8;
while (i <= nint_8 &&
s1[i++] == s2[j++] &&
s1[i++] == s2[j++] &&
s1[i++] == s2[j++] &&
s1[i++] == s2[j++] &&
s1[i++] == s2[j++] &&
s1[i++] == s2[j++] &&
s1[i++] == s2[j++] &&
s1[i++] == s2[j++]) { }
i = (i - 1) * sizeof(int);
}
#endif
while (i < n && s1c[i] == s2c[i])
{
i++;
}
return i;
}
/* This function expands the source match backward and forward. It is
* reentrant, since xd3_getblk may return XD3_GETSRCBLK, so most
* variables are kept in xd3_stream. There are two callers of this
* function, the string_matching routine when a checksum match is
* discovered, and xd3_encode_input whenever a continuing (or initial)
* match is suspected. The two callers do different things with the
* input_position, thus this function leaves that variable untouched.
* If a match is taken the resulting stream->match_fwd is left
* non-zero. */
static int
xd3_source_extend_match (xd3_stream *stream)
{
int ret;
xd3_source *src = stream->src;
xoff_t matchoff; /* matchoff is the current right/left-boundary of
the source match being tested. */
usize_t streamoff; /* streamoff is the current right/left-boundary
of the input match being tested. */
xoff_t tryblk; /* tryblk, tryoff are the block, offset position
of matchoff */
usize_t tryoff;
usize_t tryrem; /* tryrem is the number of matchable bytes */
usize_t matched;
IF_DEBUG2(DP(RINT "[extend match] srcpos %"Q"u\n",
stream->match_srcpos));
XD3_ASSERT (src != NULL);
/* Does it make sense to compute backward match AFTER forward match? */
if (stream->match_state == MATCH_BACKWARD)
{
/* Note: this code is practically duplicated below, substituting
* match_fwd/match_back and direction. TODO: Consolidate? */
matchoff = stream->match_srcpos - stream->match_back;
streamoff = stream->input_position - stream->match_back;
xd3_blksize_div (matchoff, src, &tryblk, &tryoff);
/* this loops backward over source blocks */
while (stream->match_back < stream->match_maxback)
{
/* see if we're backing across a source block boundary */
if (tryoff == 0)
{
tryoff = src->blksize;
tryblk -= 1;
}
if ((ret = xd3_getblk (stream, tryblk)))
{
/* if search went too far back, continue forward. */
if (ret == XD3_TOOFARBACK)
{
break;
}
/* could be a XD3_GETSRCBLK failure. */
return ret;
}
tryrem = min (tryoff, stream->match_maxback - stream->match_back);
IF_DEBUG2(DP(RINT "[maxback] maxback %u trysrc %"Q"u/%u tgt %u tryrem %u\n",
stream->match_maxback, tryblk, tryoff, streamoff, tryrem));
/* TODO: This code can be optimized similar to xd3_match_forward() */
for (; tryrem != 0; tryrem -= 1, stream->match_back += 1)
{
if (src->curblk[tryoff-1] != stream->next_in[streamoff-1])
{
goto doneback;
}
tryoff -= 1;
streamoff -= 1;
}
}
doneback:
stream->match_state = MATCH_FORWARD;
}
XD3_ASSERT (stream->match_state == MATCH_FORWARD);
matchoff = stream->match_srcpos + stream->match_fwd;
streamoff = stream->input_position + stream->match_fwd;
xd3_blksize_div (matchoff, src, & tryblk, & tryoff);
/* Note: practically the same code as backwards case above: same comments */
while (stream->match_fwd < stream->match_maxfwd)
{
if (tryoff == src->blksize)
{
tryoff = 0;
tryblk += 1;
}
if ((ret = xd3_getblk (stream, tryblk)))
{
/* if search went too far back, continue forward. */
if (ret == XD3_TOOFARBACK)
{
break;
}
/* could be a XD3_GETSRCBLK failure. */
return ret;
}
tryrem = min(stream->match_maxfwd - stream->match_fwd,
src->onblk - tryoff);
if (tryrem == 0)
{
/* Generally, this means we have a power-of-two size source
* and we just found the end-of-file, in this case it's an
* empty block. */
XD3_ASSERT (src->onblk < src->blksize);
break;
}
matched = xd3_forward_match(src->curblk + tryoff,
stream->next_in + streamoff,
tryrem);
tryoff += matched;
streamoff += matched;
stream->match_fwd += matched;
if (tryrem != matched)
{
break;
}
}
stream->match_state = MATCH_SEARCHING;
/* If the match ends short of the last instruction end, we probably
* don't want it. There is the possibility that a copy ends short
* of the last copy but also goes further back, in which case we
* might want it. This code does not implement such: if so we would
* need more complicated xd3_iopt_erase logic. */
if (stream->match_fwd < stream->min_match)
{
stream->match_fwd = 0;
}
else
{
usize_t total = stream->match_fwd + stream->match_back;
/* Correct the variables to remove match_back from the equation. */
usize_t target_position = stream->input_position - stream->match_back;
usize_t match_length = stream->match_back + stream->match_fwd;
xoff_t match_position = stream->match_srcpos - stream->match_back;
xoff_t match_end = stream->match_srcpos + stream->match_fwd;
/* At this point we may have to erase any iopt-buffer
* instructions that are fully covered by a backward-extending
* copy. */
if (stream->match_back > 0)
{
xd3_iopt_erase (stream, target_position, total);
}
stream->match_back = 0;
/* Update ranges. The first source match occurs with both
values set to 0. */
if (stream->match_maxaddr == 0 ||
match_position < stream->match_minaddr)
{
stream->match_minaddr = match_position;
}
if (match_end > stream->match_maxaddr)
{
/* Note: per-window */
stream->match_maxaddr = match_end;
}
if (match_end > stream->maxsrcaddr)
{
/* Note: across windows */
stream->maxsrcaddr = match_end;
}
IF_DEBUG1 ({
static int x = 0;
DP(RINT "[source match:%d] <inp %"Q"u %"Q"u> <src %"Q"u %"Q"u> (%s) [ %u bytes ]\n",
x++,
stream->total_in + target_position,
stream->total_in + target_position + match_length,
match_position,
match_position + match_length,
(stream->total_in + target_position == match_position) ? "same" : "diff",
match_length);
});
if ((ret = xd3_found_match (stream,
/* decoder position */ target_position,
/* length */ match_length,
/* address */ match_position,
/* is_source */ 1)))
{
return ret;
}
/* If the match ends with the available input: */
if (target_position + match_length == stream->avail_in)
{
/* Setup continuing match for the next window. */
stream->match_state = MATCH_TARGET;
stream->match_srcpos = match_end;
}
}
return 0;
}
/* Update the small hash. Values in the small_table are offset by
* HASH_CKOFFSET (1) to distinguish empty buckets from real offsets. */
static void
xd3_scksum_insert (xd3_stream *stream,
usize_t inx,
usize_t scksum,
usize_t pos)
{
/* If we are maintaining previous duplicates. */
if (stream->small_prev)
{
usize_t last_pos = stream->small_table[inx];
xd3_slist *pos_list = & stream->small_prev[pos & stream->sprevmask];
/* Note last_pos is offset by HASH_CKOFFSET. */
pos_list->last_pos = last_pos;
}
/* Enter the new position into the hash bucket. */
stream->small_table[inx] = pos + HASH_CKOFFSET;
}
#if XD3_DEBUG
static int
xd3_check_smatch (const uint8_t *ref0, const uint8_t *inp0,
const uint8_t *inp_max, usize_t cmp_len)
{
usize_t i;
for (i = 0; i < cmp_len; i += 1)
{
XD3_ASSERT (ref0[i] == inp0[i]);
}
if (inp0 + cmp_len < inp_max)
{
XD3_ASSERT (inp0[i] != ref0[i]);
}
return 1;
}
#endif /* XD3_DEBUG */
/* When the hash table indicates a possible small string match, it
* calls this routine to find the best match. The first matching
* position is taken from the small_table, HASH_CKOFFSET is subtracted
* to get the actual position. After checking that match, if previous
* linked lists are in use (because stream->smatcher.small_chain > 1),
* previous matches are tested searching for the longest match. If
* (stream->min_match > MIN_MATCH) then a lazy match is in effect.
*/
static usize_t
xd3_smatch (xd3_stream *stream,
usize_t base,
usize_t scksum,
usize_t *match_offset)
{
usize_t cmp_len;
usize_t match_length = 0;
usize_t chain = (stream->min_match == MIN_MATCH ?
stream->smatcher.small_chain :
stream->smatcher.small_lchain);
const uint8_t *inp_max = stream->next_in + stream->avail_in;
const uint8_t *inp;
const uint8_t *ref;
SMALL_HASH_DEBUG1 (stream, stream->next_in + stream->input_position);
XD3_ASSERT (stream->min_match + stream->input_position <= stream->avail_in);
base -= HASH_CKOFFSET;
again:
IF_DEBUG2 (DP(RINT "smatch at base=%u inp=%u cksum=%u\n", base,
stream->input_position, scksum));
/* For small matches, we can always go to the end-of-input because
* the matching position must be less than the input position. */
XD3_ASSERT (base < stream->input_position);
ref = stream->next_in + base;
inp = stream->next_in + stream->input_position;
SMALL_HASH_DEBUG2 (stream, ref);
/* Expand potential match forward. */
while (inp < inp_max && *inp == *ref)
{
++inp;
++ref;
}
cmp_len = (usize_t)(inp - (stream->next_in + stream->input_position));
/* Verify correctness */
XD3_ASSERT (xd3_check_smatch (stream->next_in + base,
stream->next_in + stream->input_position,
inp_max, cmp_len));
/* Update longest match */
if (cmp_len > match_length)
{
( match_length) = cmp_len;
(*match_offset) = base;
/* Stop if we match the entire input or have a long_enough match. */
if (inp == inp_max || cmp_len >= stream->smatcher.long_enough)
{
goto done;
}
}
/* If we have not reached the chain limit, see if there is another
previous position. */
while (--chain != 0)
{
/* Calculate the previous offset. */
usize_t prev_pos = stream->small_prev[base & stream->sprevmask].last_pos;
usize_t diff_pos;
if (prev_pos == 0)
{
break;
}
prev_pos -= HASH_CKOFFSET;
if (prev_pos > base)
{
break;
}
base = prev_pos;
XD3_ASSERT (stream->input_position > base);
diff_pos = stream->input_position - base;
/* Stop searching if we go beyond sprevsz, since those entries
* are for unrelated checksum entries. */
if (diff_pos & ~stream->sprevmask)
{
break;
}
goto again;
}
done:
/* Crude efficiency test: if the match is very short and very far back, it's
* unlikely to help, but the exact calculation requires knowing the state of
* the address cache and adjacent instructions, which we can't do here.
* Rather than encode a probably inefficient copy here and check it later
* (which complicates the code a lot), do this:
*/
if (match_length == 4 && stream->input_position - (*match_offset) >= 1<<14)
{
/* It probably takes >2 bytes to encode an address >= 2^14 from here */
return 0;
}
if (match_length == 5 && stream->input_position - (*match_offset) >= 1<<21)
{
/* It probably takes >3 bytes to encode an address >= 2^21 from here */
return 0;
}
/* It's unlikely that a window is large enough for the (match_length == 6 &&
* address >= 2^28) check */
return match_length;
}
#if XD3_DEBUG
static void
xd3_verify_small_state (xd3_stream *stream,
const uint8_t *inp,
uint32_t x_cksum)
{
uint32_t state;
uint32_t cksum = xd3_scksum (&state, inp, stream->smatcher.small_look);
XD3_ASSERT (cksum == x_cksum);
}
static void
xd3_verify_large_state (xd3_stream *stream,
const uint8_t *inp,
uint32_t x_cksum)
{
uint32_t cksum = xd3_lcksum (inp, stream->smatcher.large_look);
XD3_ASSERT (cksum == x_cksum);
}
static void
xd3_verify_run_state (xd3_stream *stream,
const uint8_t *inp,
usize_t x_run_l,
uint8_t *x_run_c)
{
usize_t slook = stream->smatcher.small_look;
uint8_t run_c;
usize_t run_l = xd3_comprun (inp, slook, &run_c);
XD3_ASSERT (run_l == 0 || run_c == *x_run_c);
XD3_ASSERT (x_run_l > slook || run_l == x_run_l);
}
#endif /* XD3_DEBUG */
/* This function computes more source checksums to advance the window.
* Called at every entrance to the string-match loop and each time
* stream->input_position reaches the value returned as
* *next_move_point. NB: this is one of the most expensive functions
* in this code and also the most critical for good compression.
* TODO: optimize the inner loop
*/
static int
xd3_srcwin_move_point (xd3_stream *stream, usize_t *next_move_point)
{
xoff_t logical_input_cksum_pos;
xoff_t source_size;
if (stream->src->eof_known)
{
source_size = xd3_source_eof (stream->src);
XD3_ASSERT(stream->srcwin_cksum_pos <= source_size);
if (stream->srcwin_cksum_pos == source_size)
{
*next_move_point = USIZE_T_MAX;
return 0;
}
}
/* Begin by advancing at twice the input rate, up to half the
* maximum window size. */
logical_input_cksum_pos = min((stream->total_in + stream->input_position) * 2,
(stream->total_in + stream->input_position) +
(stream->src->max_winsize / 2));
/* If srcwin_cksum_pos is already greater, wait until the difference
* is met. */
if (stream->srcwin_cksum_pos > logical_input_cksum_pos)
{
*next_move_point = stream->input_position +
(usize_t)(stream->srcwin_cksum_pos - logical_input_cksum_pos);
return 0;
}
/* A long match may have extended past srcwin_cksum_pos. Don't
* start checksumming already-matched source data. */
if (stream->maxsrcaddr > stream->srcwin_cksum_pos)
{
stream->srcwin_cksum_pos = stream->maxsrcaddr;
}
if (logical_input_cksum_pos < stream->srcwin_cksum_pos)
{
logical_input_cksum_pos = stream->srcwin_cksum_pos;
}
/* Advance at least one source block. With the command-line
* defaults this means:
*
* if (src->size <= src->max_winsize), index the entire source at once
* using the position of the first non-match. This is good for
* small inputs, especially when the content may have moved anywhere
* in the file (e.g., tar files).
*
* if (src->size > src->max_winsize), index at least one block (which
* the command-line sets to 1/32 of src->max_winsize) ahead of the
* logical position. This is good for different reasons: when a
* long match spanning several source blocks is encountered, this
* avoids computing checksums for those blocks. If the data can
* move anywhere, this is bad.
*/
logical_input_cksum_pos += stream->src->blksize;
while (stream->srcwin_cksum_pos < logical_input_cksum_pos &&
(!stream->src->eof_known ||
stream->srcwin_cksum_pos < xd3_source_eof (stream->src)))
{
xoff_t blkno;
xoff_t blkbaseoffset;
usize_t blkrem;
ssize_t oldpos; /* Using ssize_t because of a */
ssize_t blkpos; /* do { blkpos-- }
while (blkpos >= oldpos); */
int ret;
xd3_blksize_div (stream->srcwin_cksum_pos,
stream->src, &blkno, &blkrem);
oldpos = blkrem;
if ((ret = xd3_getblk (stream, blkno)))
{
/* TOOFARBACK should never occur here, since we read forward. */
if (ret == XD3_TOOFARBACK)
{
ret = XD3_INTERNAL;
}
IF_DEBUG1 (DP(RINT
"[srcwin_move_point] async getblk return for %"Q"u\n",
blkno));
return ret;
}
IF_DEBUG1 (DP(RINT
"[srcwin_move_point] T=%"Q"u{%"Q"u} S=%"Q"u EOF=%"Q"u %s\n",
stream->total_in + stream->input_position,
logical_input_cksum_pos,
stream->srcwin_cksum_pos,
xd3_source_eof (stream->src),
stream->src->eof_known ? "known" : "unknown"));
blkpos = xd3_bytes_on_srcblk (stream->src, blkno);
if (blkpos < (ssize_t) stream->smatcher.large_look)
{
stream->srcwin_cksum_pos = (blkno + 1) * stream->src->blksize;
IF_DEBUG1 (DP(RINT "[srcwin_move_point] continue (end-of-block)\n"));
continue;
}
/* This inserts checksums for the entire block, in reverse,
* starting from the end of the block. This logic does not test
* stream->srcwin_cksum_pos because it always advances it to the
* start of the next block.
*
* oldpos is the srcwin_cksum_pos within this block. blkpos is
* the number of bytes available. Each iteration inspects
* large_look bytes then steps back large_step bytes. The
* if-stmt above ensures at least one large_look of data. */
blkpos -= stream->smatcher.large_look;
blkbaseoffset = stream->src->blksize * blkno;
do
{
uint32_t cksum = xd3_lcksum (stream->src->curblk + blkpos,
stream->smatcher.large_look);
usize_t hval = xd3_checksum_hash (& stream->large_hash, cksum);
stream->large_table[hval] =
(usize_t) (blkbaseoffset +
(xoff_t)(blkpos + HASH_CKOFFSET));
IF_DEBUG (stream->large_ckcnt += 1);
blkpos -= stream->smatcher.large_step;
}
while (blkpos >= oldpos);
stream->srcwin_cksum_pos = (blkno + 1) * stream->src->blksize;
}
IF_DEBUG1 (DP(RINT
"[srcwin_move_point] exited loop T=%"Q"u{%"Q"u} "
"S=%"Q"u EOF=%"Q"u %s\n",
stream->total_in + stream->input_position,
logical_input_cksum_pos,
stream->srcwin_cksum_pos,
xd3_source_eof (stream->src),
stream->src->eof_known ? "known" : "unknown"));
if (stream->src->eof_known)
{
source_size = xd3_source_eof (stream->src);
if (stream->srcwin_cksum_pos >= source_size)
{
/* This invariant is needed for xd3_source_cksum_offset() */
stream->srcwin_cksum_pos = source_size;
*next_move_point = USIZE_T_MAX;
IF_DEBUG1 (DP(RINT
"[srcwin_move_point] finished with source input\n"));
return 0;
}
}
/* How long until this function should be called again. */
XD3_ASSERT(stream->srcwin_cksum_pos >= logical_input_cksum_pos);
*next_move_point = stream->input_position + 1 +
(usize_t)(stream->srcwin_cksum_pos - logical_input_cksum_pos);
return 0;
}
#endif /* XD3_ENCODER */
/********************************************************************
TEMPLATE pass
*********************************************************************/
#endif /* __XDELTA3_C_INLINE_PASS__ */
#ifdef __XDELTA3_C_TEMPLATE_PASS__
#if XD3_ENCODER
/********************************************************************
Templates
*******************************************************************/
/* Template macros */
#define XD3_TEMPLATE(x) XD3_TEMPLATE2(x,TEMPLATE)
#define XD3_TEMPLATE2(x,n) XD3_TEMPLATE3(x,n)
#define XD3_TEMPLATE3(x,n) x ## n
#define XD3_STRINGIFY(x) XD3_STRINGIFY2(x)
#define XD3_STRINGIFY2(x) #x
static int XD3_TEMPLATE(xd3_string_match_) (xd3_stream *stream);
static const xd3_smatcher XD3_TEMPLATE(__smatcher_) =
{
XD3_STRINGIFY(TEMPLATE),
XD3_TEMPLATE(xd3_string_match_),
#if SOFTCFG == 1
0, 0, 0, 0, 0, 0, 0
#else
LLOOK, LSTEP, SLOOK, SCHAIN, SLCHAIN, MAXLAZY, LONGENOUGH
#endif
};
static int
XD3_TEMPLATE(xd3_string_match_) (xd3_stream *stream)
{
const int DO_SMALL = ! (stream->flags & XD3_NOCOMPRESS);
const int DO_LARGE = (stream->src != NULL);
const int DO_RUN = (1);
const uint8_t *inp;
uint32_t scksum = 0;
uint32_t scksum_state = 0;
uint32_t lcksum = 0;
usize_t sinx;
usize_t linx;
uint8_t run_c;
usize_t run_l;
int ret;
usize_t match_length;
usize_t match_offset = 0;
usize_t next_move_point;
/* If there will be no compression due to settings or short input,
* skip it entirely. */
if (! (DO_SMALL || DO_LARGE || DO_RUN) ||
stream->input_position + SLOOK > stream->avail_in) { goto loopnomore; }
if ((ret = xd3_string_match_init (stream))) { return ret; }
/* The restartloop label is reached when the incremental loop state
* needs to be reset. */
restartloop:
/* If there is not enough input remaining for any kind of match,
skip it. */
if (stream->input_position + SLOOK > stream->avail_in) { goto loopnomore; }
/* Now reset the incremental loop state: */
/* The min_match variable is updated to avoid matching the same lazy
* match over and over again. For example, if you find a (small)
* match of length 9 at one position, you will likely find a match
* of length 8 at the next position. */
if (xd3_iopt_last_matched (stream) > stream->input_position)
{
stream->min_match = max(MIN_MATCH,
1 + xd3_iopt_last_matched(stream) -
stream->input_position);
}
else
{
stream->min_match = MIN_MATCH;
}
/* The current input byte. */
inp = stream->next_in + stream->input_position;
/* Small match state. */
if (DO_SMALL)
{
scksum = xd3_scksum (&scksum_state, inp, SLOOK);
}
/* Run state. */
if (DO_RUN)
{
run_l = xd3_comprun (inp, SLOOK, & run_c);
}
/* Large match state. We continue the loop even after not enough
* bytes for LLOOK remain, so always check stream->input_position in
* DO_LARGE code. */
if (DO_LARGE && (stream->input_position + LLOOK <= stream->avail_in))
{
/* Source window: next_move_point is the point that
* stream->input_position must reach before computing more
* source checksum. */
if ((ret = xd3_srcwin_move_point (stream, & next_move_point)))
{
return ret;
}
lcksum = xd3_lcksum (inp, LLOOK);
}
/* TRYLAZYLEN: True if a certain length match should be followed by
* lazy search. This checks that LEN is shorter than MAXLAZY and
* that there is enough leftover data to consider lazy matching.
* "Enough" is set to 2 since the next match will start at the next
* offset, it must match two extra characters. */
#define TRYLAZYLEN(LEN,POS,MAX) ((MAXLAZY) > 0 && (LEN) < (MAXLAZY) \
&& (POS) + (LEN) <= (MAX) - 2)
/* HANDLELAZY: This statement is called each time an instruciton is
* emitted (three cases). If the instruction is large enough, the
* loop is restarted, otherwise lazy matching may ensue. */
#define HANDLELAZY(mlen) \
if (TRYLAZYLEN ((mlen), (stream->input_position), (stream->avail_in))) \
{ stream->min_match = (mlen) + LEAST_MATCH_INCR; goto updateone; } \
else \
{ stream->input_position += (mlen); goto restartloop; }
/* Now loop over one input byte at a time until a match is found... */
for (;; inp += 1, stream->input_position += 1)
{
/* Now we try three kinds of string match in order of expense:
* run, large match, small match. */
/* Expand the start of a RUN. The test for (run_l == SLOOK)
* avoids repeating this check when we pass through a run area
* performing lazy matching. The run is only expanded once when
* the min_match is first reached. If lazy matching is
* performed, the run_l variable will remain inconsistent until
* the first non-running input character is reached, at which
* time the run_l may then again grow to SLOOK. */
if (DO_RUN && run_l == SLOOK)
{
usize_t max_len = stream->avail_in - stream->input_position;
IF_DEBUG (xd3_verify_run_state (stream, inp, run_l, &run_c));
while (run_l < max_len && inp[run_l] == run_c) { run_l += 1; }
/* Output a RUN instruction. */
if (run_l >= stream->min_match && run_l >= MIN_RUN)
{
if ((ret = xd3_emit_run (stream, stream->input_position,
run_l, &run_c))) { return ret; }
HANDLELAZY (run_l);
}
}
/* If there is enough input remaining. */
if (DO_LARGE && (stream->input_position + LLOOK <= stream->avail_in))
{
if ((stream->input_position >= next_move_point) &&
(ret = xd3_srcwin_move_point (stream, & next_move_point)))
{
return ret;
}
linx = xd3_checksum_hash (& stream->large_hash, lcksum);
IF_DEBUG (xd3_verify_large_state (stream, inp, lcksum));
if (stream->large_table[linx] != 0)
{
/* the match_setup will fail if the source window has
* been decided and the match lies outside it.
* OPT: Consider forcing a window at this point to
* permit a new source window. */
xoff_t adj_offset =
xd3_source_cksum_offset(stream,
stream->large_table[linx] -
HASH_CKOFFSET);
if (xd3_source_match_setup (stream, adj_offset) == 0)
{
if ((ret = xd3_source_extend_match (stream)))
{
return ret;
}
/* Update stream position. match_fwd is zero if no
* match. */
if (stream->match_fwd > 0)
{
HANDLELAZY (stream->match_fwd);
}
}
}
}
/* Small matches. */
if (DO_SMALL)
{
sinx = xd3_checksum_hash (& stream->small_hash, scksum);
/* Verify incremental state in debugging mode. */
IF_DEBUG (xd3_verify_small_state (stream, inp, scksum));
/* Search for the longest match */
if (stream->small_table[sinx] != 0)
{
match_length = xd3_smatch (stream,
stream->small_table[sinx],
scksum,
& match_offset);
}
else
{
match_length = 0;
}
/* Insert a hash for this string. */
xd3_scksum_insert (stream, sinx, scksum, stream->input_position);
/* Maybe output a COPY instruction */
if (match_length >= stream->min_match)
{
IF_DEBUG2 ({
static int x = 0;
DP(RINT "[target match:%d] <inp %u %u> <cpy %u %u> "
"(-%d) [ %u bytes ]\n",
x++,
stream->input_position,
stream->input_position + match_length,
match_offset,
match_offset + match_length,
stream->input_position - match_offset,
match_length);
});
if ((ret = xd3_found_match (stream,
/* decoder position */
stream->input_position,
/* length */ match_length,
/* address */ (xoff_t) match_offset,
/* is_source */ 0)))
{
return ret;
}
/* Copy instruction. */
HANDLELAZY (match_length);
}
}
/* The logic above prevents excess work during lazy matching by
* increasing min_match to avoid smaller matches. Each time we
* advance stream->input_position by one, the minimum match
* shortens as well. */
if (stream->min_match > MIN_MATCH)
{
stream->min_match -= 1;
}
updateone:
/* See if there are no more incremental cksums to compute. */
if (stream->input_position + SLOOK == stream->avail_in)
{
goto loopnomore;
}
/* Compute next RUN, CKSUM */
if (DO_RUN)
{
NEXTRUN (inp[SLOOK]);
}
if (DO_SMALL)
{
scksum = xd3_small_cksum_update (&scksum_state, inp, SLOOK);
}
if (DO_LARGE && (stream->input_position + LLOOK < stream->avail_in))
{
lcksum = xd3_large_cksum_update (lcksum, inp, LLOOK);
}
}
loopnomore:
return 0;
}
#endif /* XD3_ENCODER */
#endif /* __XDELTA3_C_TEMPLATE_PASS__ */
|