1 files changed, 770 insertions, 0 deletions

diff --git a/xdelta3/testing/checksum_test.cc b/xdelta3/testing/checksum_test.cc
new file mode 100644
index 0000000..9cd3740
--- /dev/null
+++ b/xdelta3/testing/checksum_test.cc
@@ -0,0 +1,770 @@
+/* xdelta3 - delta compression tools and library -*- Mode: C++ -*-
+   Copyright 2016 Joshua MacDonald
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+#include "test.h"
+#include <assert.h>
+#include <list>
+#include <vector>
+#include <algorithm>
+
+#include "../cpp-btree/btree_map.h"
+
+extern "C" {
+uint32_t xd3_large32_cksum_old (xd3_hash_cfg *cfg, const uint8_t *base, const usize_t look);
+uint32_t xd3_large32_cksum_update_old (xd3_hash_cfg *cfg, uint32_t cksum, 
+                                       const uint8_t *base, const usize_t look);
+
+uint64_t xd3_large64_cksum_old (xd3_hash_cfg *cfg, const uint8_t *base, const usize_t look);
+uint64_t xd3_large64_cksum_update_old (xd3_hash_cfg *cfg, uint64_t cksum, 
+                                       const uint8_t *base, const usize_t look);
+}
+
+using btree::btree_map;
+using std::list;
+using std::vector;
+
+// MLCG parameters
+// a, a*
+uint32_t good_32bit_values[] = {
+  1597334677U, // ...
+  741103597U, 887987685U,
+};
+
+// a, a*
+uint64_t good_64bit_values[] = {
+  1181783497276652981ULL, 4292484099903637661ULL,
+  7664345821815920749ULL, // ...
+};
+
+void print_header() {
+  static int hdr_cnt = 0;
+  if (hdr_cnt++ % 20 == 0) {
+    printf("%-32sConf\t\tCount\tUniq\tFull\tCover\tColls"
+           "\tMB/s\tIters\t#Colls\n", "Name");
+  }
+}
+
+struct true_type { };
+struct false_type { };
+
+template <typename Word>
+usize_t bitsof();
+
+template<>
+usize_t bitsof<unsigned int>() {
+  return sizeof(unsigned int) * 8;
+}
+
+template<>
+usize_t bitsof<unsigned long>() {
+  return sizeof(unsigned long) * 8;
+}
+
+template<>
+usize_t bitsof<unsigned long long>() {
+  return sizeof(unsigned long long) * 8;
+}
+
+template <typename Word>
+struct hhash {  // shift "s" bits leaving the high bits as a hash value for
+                // this checksum, which are the most "distant" in terms of the
+                // spectral test for the rabin_karp MLCG.  For short windows,
+                // the high bits aren't enough, XOR "mask" worth of these in.
+  Word operator()(const Word t, const Word s, const Word mask) {
+    return (t >> s) ^ (t & mask);
+  }
+};
+
+template <typename Word>
+Word good_word();
+
+template<>
+uint32_t good_word<uint32_t>() {
+  return good_32bit_values[0];
+}
+
+template<>
+uint64_t good_word<uint64_t>() {
+  return good_64bit_values[0];
+}
+
+// CLASSES
+
+#define SELF Word, CksumSize, CksumSkip, Hash, Compaction
+#define MEMBER template <typename Word,         \
+                         int CksumSize,         \
+                         int CksumSkip,         \
+                         typename Hash,         \
+                         int Compaction>
+
+MEMBER
+struct cksum_params {
+  typedef Word word_type;
+  typedef Hash hash_type;
+
+  static const int cksum_size = CksumSize;
+  static const int cksum_skip = CksumSkip;
+  static const int compaction = Compaction;
+};
+
+MEMBER
+struct rabin_karp : public cksum_params<SELF> {
+  // (a^cksum_size-1 c_0) + (a^cksum_size-2 c_1) ...
+  rabin_karp()
+    : powers(make_powers()),
+      product(powers[0] * good_word<Word>()),
+      incr_state(0) { }
+
+  static Word* make_powers() {
+    Word *p = new Word[CksumSize];
+    p[CksumSize - 1] = 1;
+    for (int i = CksumSize - 2; i >= 0; i--) {
+      p[i] = p[i + 1] * good_word<Word>();
+    }
+    return p;
+  }
+
+  ~rabin_karp() {
+    delete [] powers;
+  }
+
+  Word step(const uint8_t *ptr) {
+    Word h = 0;
+    for (int i = 0; i < CksumSize; i++) {
+      h += (ptr[i]) * powers[i];
+    }
+    return h;
+  }
+
+  Word state0(const uint8_t *ptr) {
+    incr_state = step(ptr);
+    return incr_state;
+  }
+
+  Word incr(const uint8_t *ptr) {
+    incr_state = good_word<Word>() * incr_state -
+      product * (ptr[-1]) + (ptr[CksumSize - 1]);
+    return incr_state;
+  }
+
+  const Word *const powers;
+  const Word  product;
+  Word        incr_state;
+};
+
+MEMBER
+struct with_stream : public cksum_params<SELF> {
+  xd3_stream stream;
+
+  with_stream()
+  {
+    xd3_config cfg;
+    memset (&stream, 0, sizeof (stream));
+    xd3_init_config (&cfg, 0);
+    cfg.smatch_cfg = XD3_SMATCH_SOFT;
+    cfg.smatcher_soft.large_look = CksumSize;
+    cfg.smatcher_soft.large_step = CksumSkip;
+    cfg.smatcher_soft.small_look = 4;
+    cfg.smatcher_soft.small_chain = 4;
+    cfg.smatcher_soft.small_lchain = 4;
+    cfg.smatcher_soft.max_lazy = 4;
+    cfg.smatcher_soft.long_enough = 4;
+    CHECK_EQ(0, xd3_config_stream (&stream, &cfg));
+
+    CHECK_EQ(0, xd3_size_hashtable (&stream,
+                                    1<<10 /* ignored */,
+                                    stream.smatcher.large_look,
+                                    & stream.large_hash));
+  }
+  ~with_stream() 
+  {
+    xd3_free_stream (&stream);
+  }
+};
+
+MEMBER
+struct large_cksum : public with_stream<SELF> {
+  Word step(const uint8_t *ptr) {
+    return xd3_large_cksum (&this->stream.large_hash, ptr, CksumSize);
+  }
+
+  Word state0(const uint8_t *ptr) {
+    incr_state = step(ptr);
+    return incr_state;
+  }
+
+  Word incr(const uint8_t *ptr) {
+    incr_state = xd3_large_cksum_update (&this->stream.large_hash, 
+                                         incr_state, ptr - 1, CksumSize);
+    return incr_state;
+  }
+
+  Word incr_state;
+};
+
+#if SIZEOF_USIZE_T == 4
+#define xd3_large_cksum_old         xd3_large32_cksum_old
+#define xd3_large_cksum_update_old  xd3_large32_cksum_update_old
+#elif SIZEOF_USIZE_T == 8
+#define xd3_large_cksum_old         xd3_large64_cksum_old
+#define xd3_large_cksum_update_old  xd3_large64_cksum_update_old
+#endif
+
+MEMBER
+struct large_cksum_old : public with_stream<SELF> {
+  Word step(const uint8_t *ptr) {
+    return xd3_large_cksum_old (&this->stream.large_hash, ptr, CksumSize);
+  }
+
+  Word state0(const uint8_t *ptr) {
+    incr_state = step(ptr);
+    return incr_state;
+  }
+
+  Word incr(const uint8_t *ptr) {
+    incr_state = xd3_large_cksum_update_old (&this->stream.large_hash, 
+                                             incr_state, ptr - 1, CksumSize);
+    return incr_state;
+  }
+
+  Word incr_state;
+};
+
+// TESTS
+
+template <typename Word>
+struct file_stats {
+  typedef const uint8_t* ptr_type;
+  typedef Word word_type;
+  typedef btree::btree_multimap<word_type, ptr_type> table_type;
+  typedef typename table_type::iterator table_iterator;
+
+  usize_t cksum_size;
+  usize_t cksum_skip;
+  usize_t unique;
+  usize_t unique_values;
+  usize_t count;
+  table_type table;
+
+  file_stats(usize_t size, usize_t skip)
+    : cksum_size(size),
+      cksum_skip(skip),
+      unique(0),
+      unique_values(0),
+      count(0) {
+  }
+
+  void reset() {
+    unique = 0;
+    unique_values = 0;
+    count = 0;
+    table.clear();
+  }
+
+  void update(word_type word, ptr_type ptr) {
+    table_iterator t_i = table.find(word);
+
+    count++;
+    if (t_i != table.end()) {
+      int collisions = 0;
+      for (table_iterator p_i = t_i;
+           p_i != table.end() && p_i->first == word;
+           ++p_i) {
+        if (memcmp(p_i->second, ptr, cksum_size) == 0) {
+          return;
+        }
+        collisions++;
+      }
+      if (collisions >= 1000) {
+        fprintf(stderr, "Something is not right, lots of collisions=%d\n", 
+                collisions);
+        abort();
+      }
+    } else {
+      unique_values++;
+    }
+    unique++;
+    table.insert(std::make_pair(word, ptr));
+    return;
+  }
+
+  void freeze() {
+    table.clear();
+  }
+};
+
+struct test_result_base;
+
+static vector<test_result_base*> all_tests;
+
+struct test_result_base {
+  virtual ~test_result_base() {
+  }
+  virtual void reset() = 0;
+  virtual void print() = 0;
+  virtual void get(const uint8_t* buf, const size_t buf_size, 
+                   usize_t iters) = 0;
+  virtual void stat() = 0;
+  virtual usize_t count() = 0;
+  virtual usize_t dups() = 0;
+  virtual double uniqueness() = 0;
+  virtual double fullness() = 0;
+  virtual double collisions() = 0;
+  virtual double coverage() = 0;
+  virtual double compression() = 0;
+  virtual double time() = 0;
+  virtual double total_time() = 0;
+  virtual usize_t total_count() = 0;
+  virtual usize_t total_dups() = 0;
+};
+
+template <typename Checksum>
+struct test_result : public test_result_base {
+  Checksum cksum;
+  const char *test_name;
+  file_stats<typename Checksum::word_type> fstats;
+  usize_t test_size;
+  usize_t n_steps;
+  usize_t n_incrs;
+  typename Checksum::word_type s_bits;
+  typename Checksum::word_type s_mask;
+  usize_t t_entries;
+  usize_t h_bits;
+  usize_t h_buckets_full;
+  char *hash_table;
+  long accum_millis;
+  usize_t accum_iters;
+
+  // These are not reset
+  double accum_time;
+  usize_t accum_count;
+  usize_t accum_dups;
+  usize_t accum_colls;
+  size_t accum_size;
+
+  test_result(const char *name)
+    : test_name(name),
+      fstats(Checksum::cksum_size, Checksum::cksum_skip),
+      hash_table(NULL),
+      accum_millis(0),
+      accum_iters(0),
+      accum_time(0.0),
+      accum_count(0),
+      accum_dups(0),
+      accum_colls(0),
+      accum_size(0) {
+    all_tests.push_back(this);
+  }
+
+  ~test_result() {
+    reset();
+  }
+
+  void reset() {
+    // size of file
+    test_size = 0;
+
+    // count
+    n_steps = 0;
+    n_incrs = 0;
+
+    // four values used by new_table()/summarize_table()
+    s_bits = 0;
+    s_mask = 0;
+    t_entries = 0;
+    h_bits = 0;
+    h_buckets_full = 0;
+
+    accum_millis = 0;
+    accum_iters = 0;
+
+    fstats.reset();
+
+    // temporary
+    if (hash_table) {
+      delete(hash_table);
+      hash_table = NULL;
+    }
+  }
+
+  usize_t count() {
+    if (Checksum::cksum_skip == 1) {
+      return n_incrs;
+    } else {
+      return n_steps;
+    }
+  }
+
+  usize_t dups() {
+    return fstats.count - fstats.unique;
+  }
+
+  /* Fraction of distinct strings of length cksum_size which are not
+   * represented in the hash table. */
+  double collisions() {
+    return (fstats.unique - fstats.unique_values) / (double) fstats.unique;
+  }
+  usize_t colls() {
+    return (fstats.unique - fstats.unique_values);
+  }
+
+  double uniqueness() {
+    return 1.0 - (double) dups() / count();
+  }
+
+  double fullness() {
+    return (double) h_buckets_full / (1 << h_bits);
+  }
+
+  double coverage() {
+    return (double) h_buckets_full / uniqueness() / count();
+  }
+
+  double compression() {
+    return 1.0 - coverage();
+  }
+
+  double time() {
+    return (double) accum_millis / accum_iters;
+  }
+
+  double total_time() {
+    return accum_time;
+  }
+
+  usize_t total_count() {
+    return accum_count;
+  }
+
+  usize_t total_dups() {
+    return accum_dups;
+  }
+
+  usize_t total_colls() {
+    return accum_dups;
+  }
+
+  void stat() {
+    accum_time += time();
+    accum_count += count();
+    accum_dups += dups();
+    accum_colls += colls();
+    accum_size += test_size;
+  }
+
+  void print() {
+    if (fstats.count != count()) {
+      fprintf(stderr, "internal error: %" W "d != %" W "d\n", fstats.count, count());
+      abort();
+    }
+    print_header();
+    printf("%-32s%d/%d 2^%" W "u\t%" W "u\t%0.4f\t%.4f\t%.4f\t%.1e\t%.2f\t"
+           "%" W "u\t%" W "u\n",
+           test_name,
+           Checksum::cksum_size,
+           Checksum::cksum_skip,
+           h_bits,
+           count(),
+           uniqueness(),
+           fullness(),
+           coverage(),
+           collisions(),
+           0.001 * accum_iters * test_size / accum_millis,
+           accum_iters,
+           colls());
+  }
+
+  usize_t size_log2 (usize_t slots) {
+    usize_t bits = bitsof<typename Checksum::word_type>() - 1;
+    usize_t i;
+
+    for (i = 3; i <= bits; i += 1) {
+      if (slots <= (1U << i)) {
+        return i - Checksum::compaction;
+      }
+    }
+
+    return bits;
+  }
+
+  void new_table(usize_t entries) {
+    t_entries = entries;
+    h_bits = size_log2(entries);
+
+    usize_t n = 1 << h_bits;
+
+    s_bits = bitsof<typename Checksum::word_type>() - h_bits;
+    s_mask = n - 1U;
+
+    hash_table = new char[n / 8];
+    memset(hash_table, 0, n / 8);
+  }
+
+  int get_table_bit(usize_t i) {
+    return hash_table[i/8] & (1 << i%8);
+  }
+
+  int set_table_bit(usize_t i) {
+    return hash_table[i/8] |= (1 << i%8);
+  }
+
+  void summarize_table() {
+    usize_t n = 1 << h_bits;
+    usize_t f = 0;
+    for (usize_t i = 0; i < n; i++) {
+      if (get_table_bit(i)) {
+        f++;
+      }
+    }
+    h_buckets_full = f;
+  }
+
+  void get(const uint8_t* buf, const size_t buf_size, usize_t test_iters) {
+    typename Checksum::hash_type hash;
+    const uint8_t *ptr;
+    const uint8_t *end;
+    usize_t periods;
+    int64_t last_offset;
+    int64_t stop;
+
+    test_size = buf_size;
+    last_offset = buf_size - Checksum::cksum_size;
+
+    if (last_offset < 0) {
+      periods = 0;
+      n_steps = 0;
+      n_incrs = 0;
+      stop = -Checksum::cksum_size;
+    } else {
+      periods = last_offset / Checksum::cksum_skip;
+      n_steps = periods + 1;
+      n_incrs = last_offset + 1;
+      stop = last_offset - (periods + 1) * Checksum::cksum_skip;
+    }
+
+    // Compute file stats once.
+    if (fstats.unique_values == 0) {
+      if (Checksum::cksum_skip == 1) {
+        for (size_t i = 0; i <= buf_size - Checksum::cksum_size; i++) {
+          fstats.update(hash(cksum.step(buf + i), s_bits, s_mask), buf + i);
+        }
+      } else {
+        ptr = buf + last_offset;
+        end = buf + stop;
+
+        for (; ptr != end; ptr -= Checksum::cksum_skip) {
+          fstats.update(hash(cksum.step(ptr), s_bits, s_mask), ptr);
+        }
+      }
+      fstats.freeze();
+    }
+
+    long start_test = get_millisecs_now();
+
+    if (Checksum::cksum_skip != 1) {
+      new_table(n_steps);
+
+      for (usize_t i = 0; i < test_iters; i++) {
+        ptr = buf + last_offset;
+        end = buf + stop;
+
+        for (; ptr != end; ptr -= Checksum::cksum_skip) {
+          set_table_bit(hash(cksum.step(ptr), s_bits, s_mask));
+        }
+      }
+
+      summarize_table();
+    }
+
+    stop = buf_size - Checksum::cksum_size + 1;
+    if (stop < 0) {
+      stop = 0;
+    }
+
+    if (Checksum::cksum_skip == 1) {
+      new_table(n_incrs);
+
+      for (usize_t i = 0; i < test_iters; i++) {
+        ptr = buf;
+        end = buf + stop;
+
+        if (ptr != end) {
+          set_table_bit(hash(cksum.state0(ptr++), s_bits, s_mask));
+        }
+
+        for (; ptr != end; ptr++) {
+          typename Checksum::word_type w = cksum.incr(ptr);
+          CHECK_EQ(w, cksum.step(ptr));
+          set_table_bit(hash(w, s_bits, s_mask));
+        }
+      }
+
+      summarize_table();
+    }
+
+    accum_iters += test_iters;
+    accum_millis += get_millisecs_now() - start_test;
+  }
+};
+
+static int read_whole_file(const char *name,
+                           uint8_t **buf_ptr,
+                           size_t *buf_len) {
+  main_file file;
+  int ret;
+  xoff_t len;
+  size_t nread;
+  main_file_init(&file);
+  file.filename = name;
+  ret = main_file_open(&file, name, XO_READ);
+  if (ret != 0) {
+    fprintf(stderr, "open failed\n");
+    goto exit;
+  }
+  ret = main_file_stat(&file, &len);
+  if (ret != 0) {
+    fprintf(stderr, "stat failed\n");
+    goto exit;
+  }
+  
+  (*buf_len) = (size_t)len;
+  (*buf_ptr) = (uint8_t*) main_malloc(*buf_len);
+  ret = main_file_read(&file, *buf_ptr, *buf_len, &nread,
+                       "read failed");
+  if (ret == 0 && *buf_len == nread) {
+    ret = 0;
+  } else {
+    fprintf(stderr, "invalid read\n");
+    ret = XD3_INTERNAL;
+  }
+ exit:
+  main_file_cleanup(&file);
+  return ret;
+}
+
+int main(int argc, char** argv) {
+  int i;
+  uint8_t *buf = NULL;
+  size_t buf_len = 0;
+  int ret;
+
+  if (argc <= 1) {
+    fprintf(stderr, "usage: %s file ...\n", argv[0]);
+    return 1;
+  }
+
+// TODO: The xdelta3-hash.h code is identical now; add sameness test.
+// using rabin_karp<> template.
+#define TEST(T,Z,S,C)                                   \
+  test_result<large_cksum<T,Z,S,hhash<T>,C>>            \
+    _xck_ ## T ## _ ## Z ## _ ## S ## _ ## C            \
+    ("xck_" #T "_" #Z "_" #S "_" #C);                   \
+  test_result<large_cksum_old<T,Z,S,hhash<T>,C>>        \
+    _old_ ## T ## _ ## Z ## _ ## S ## _ ## C            \
+    ("old_" #T "_" #Z "_" #S "_" #C)
+
+#define TESTS(SIZE, SKIP)        \
+  TEST(usize_t, SIZE, SKIP, 1);  \
+  TEST(usize_t, SIZE, SKIP, 2)
+   
+  TESTS(5, 1);
+  TESTS(6, 1);
+  TESTS(7, 1);
+  TESTS(8, 1);
+  TESTS(9, 1);
+  TESTS(10, 1);
+  TESTS(11, 1);
+  TESTS(12, 1);
+  TESTS(13, 1);
+  TESTS(14, 1);
+  TESTS(15, 1);
+  TESTS(16, 1);
+  TESTS(17, 1);
+  TESTS(18, 1);
+  TESTS(19, 1);
+  TESTS(20, 1);
+  TESTS(21, 1);
+  TESTS(22, 1);
+  TESTS(23, 1);
+  TESTS(24, 1);
+  TESTS(25, 1);
+  TESTS(26, 1);
+  TESTS(27, 1);
+  TESTS(28, 1);
+  TESTS(29, 1);
+  TESTS(30, 1);
+  TESTS(31, 1);
+  TESTS(32, 1);
+  TESTS(33, 1);
+  TESTS(34, 1);
+  TESTS(35, 1);
+  TESTS(36, 1);
+  TESTS(37, 1);
+  TESTS(38, 1);
+  TESTS(39, 1);
+
+
+  for (i = 1; i < argc; i++) {
+    if ((ret = read_whole_file(argv[i],
+                               & buf,
+                               & buf_len))) {
+      return 1;
+    }
+
+    fprintf(stderr, "file %s is %zu bytes\n",
+            argv[i], buf_len);
+
+    double min_time = -1.0;
+    double min_compression = 0.0;
+
+    for (vector<test_result_base*>::iterator iter = all_tests.begin();
+         iter != all_tests.end(); ++iter) {
+      test_result_base *test = *iter;
+      test->reset();
+
+      usize_t iters = 1;
+      long start_test = get_millisecs_now();
+
+      do {
+        test->get(buf, buf_len, iters);
+        iters *= 3;
+        iters /= 2;
+      } while (get_millisecs_now() - start_test < 2000);
+
+      test->stat();
+
+      if (min_time < 0.0) {
+        min_compression = test->compression();
+        min_time = test->time();
+      }
+
+      if (min_time > test->time()) {
+        min_time = test->time();
+      }
+
+      if (min_compression > test->compression()) {
+        min_compression = test->compression();
+      }
+
+      test->print();
+    }
+
+    main_free(buf);
+    buf = NULL;
+  }
+
+  return 0;      
+}