blob: e37f3afbbc6a34a6a4ed814838298c09e7297fa3 (
plain)
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
|
-- |
-- Copyright : (c) Sam T. 2013
-- License : MIT
-- Maintainer : pxqr.sta@gmail.com
-- Stability : experimental
-- Portability : portable
--
-- This module provides peer capabilities detection.
--
-- > See http://www.bittorrent.org/beps/bep_0004.html
--
module Network.BitTorrent.Extension
( Capabilities, ppCaps, defaultCaps, enabledCaps
, Extension, ppExtension, encodeExts, decodeExts
) where
import Data.Bits
import Data.List
import Data.Word
type Capabilities = Word64
ppCaps :: Capabilities -> String
ppCaps = intercalate ", " . map ppExtension . decodeExts
defaultCaps :: Capabilities
defaultCaps = 0
enabledCaps :: Capabilities -- ^ of the client.
-> Capabilities -- ^ of the peer.
-> Capabilities -- ^ should be considered as enabled.
enabledCaps = (.&.)
data Extension = ExtDHT -- ^ BEP 5
| ExtFast -- ^ BEP 6
deriving (Show, Eq, Ord, Enum, Bounded)
ppExtension :: Extension -> String
ppExtension ExtDHT = "DHT"
ppExtension ExtFast = "Fast Extension"
extensionMask :: Extension -> Word64
extensionMask ExtDHT = 0x01
extensionMask ExtFast = 0x04
encodeExts :: [Extension] -> Capabilities
encodeExts = foldr (.&.) 0 . map extensionMask
decodeExts :: Capabilities -> [Extension]
decodeExts rb = filter (testMask rb . extensionMask) [minBound..maxBound]
where
testMask bits x = bits .&. x > 0
|
