Data.Torrent.Piece

Pieces are used to validate torrent content.

Piece attributes

type PieceIx = Int

Zero-based index of piece in torrent content.

type PieceCount = Int

Number of pieces in torrent or a part of torrent.

type PieceSize = Int

Size of piece in bytes. Should be a power of 2.

NOTE: Have max and min size constrained to wide used semi-standard values. This bounds should be used to make decision about piece size for new torrents.

minPieceSize :: Int

Piece size should not be less than this value.

maxPieceSize :: Int

To prevent transfer degradation piece size should not exceed this value.

defaultPieceSize :: Int64 -> Int

Find the optimal piece size for a given torrent size.

Piece data

data Piece a

Piece payload should be strict or lazy bytestring.

Constructors

Piece

Fields

pieceIndex :: !PieceIx

Zero-based piece index in torrent.

pieceData :: !a

Payload.

Instances

Typeable1 Piece

Eq a => Eq (Piece a)

Read a => Read (Piece a)

Show a => Show (Piece a)

ToJSON a0 => ToJSON (Piece a0)

FromJSON a0 => FromJSON (Piece a0)

NFData (Piece a)

Pretty (Piece a)

Payload bytes are omitted.

pieceSize :: Piece BL.ByteString -> PieceSize

Get size of piece in bytes.

isPiece :: PieceSize -> Block BL.ByteString -> Bool

Test if a block can be safely turned into a piece.

Piece control

newtype HashArray

A flat array of SHA1 sums of each piece.

Constructors

HashArray

Fields

unHashArray :: BS.ByteString

Instances

Eq HashArray

Read HashArray

Show HashArray

ToJSON HashArray

Represented as base64 encoded JSON string.

FromJSON HashArray

BEncode HashArray

data PieceInfo

Part of torrent file used for torrent content validation.

Constructors

PieceInfo

Fields

piPieceLength :: !PieceSize

Number of bytes in each piece.

piPieceHashes :: !HashArray

Concatenation of all 20-byte SHA1 hash values.

Instances

Eq PieceInfo

Read PieceInfo

Show PieceInfo

Typeable PieceInfo

ToJSON PieceInfo

FromJSON PieceInfo

NFData PieceInfo

Pretty PieceInfo

Hashes are omitted.

BEncode PieceInfo

pieceCount :: PieceInfo -> PieceCount

Find count of pieces in the torrent. If torrent size is not a multiple of piece size then the count is rounded up.

Lens

pieceLength :: Lens' PieceInfo PieceSize

Number of bytes in each piece.

pieceHashes :: Lens' PieceInfo HashArray

Concatenation of all 20-byte SHA1 hash values.

Validation

pieceHash :: PieceInfo -> PieceIx -> BS.ByteString

Extract validation hash by specified piece index.

checkPieceLazy :: PieceInfo -> Piece BL.ByteString -> Bool

Validate piece with metainfo hash.

Internal

getPieceInfo :: Get PieceInfo

putPieceInfo :: PieceInfo -> BDict -> BDict