1999/1001/port/thwack.h (diff list | history)

port/thwack.h on 1999/1001
1999/1001		typedef struct Thwack Thwack; typedef struct Unthwack Unthwack; typedef struct ThwBlock ThwBlock; typedef struct UnthwBlock UnthwBlock; enum { ThwMaxBlock = 1600, /* max size of compressible block */ MinMatch = 3, /* shortest match possible */ HashLog = 10, HashSize = 1<<HashLog, HashMask = HashSize - 1, MaxLen = 8, MaxOff = 8, OffBase = 6, MinDecode = 9, /* minimum bits to decode a match or lit */ EWinBlocks = 32, /* blocks held in encoder window */ DWinBlocks = 32, /* blocks held in decoder window */ CompBlocks = 5, /* max blocks used to encode data */ MaxSeqMask = 8, /* number of bits in coding block mask */ MaxSeqStart = 256, /* max offset of initial coding block */ }; struct ThwBlock { ulong seq; /* sequence number for this data */ uchar acked; /* ok to use this block; the decoder has it */ ushort begin; /* time of first byte in hash */ uchar *edata; /* last byte of valid data */ ushort maxoff; /* time of last valid hash entry */ ushort *hash; uchar *data; }; struct Thwack { ulong nbits; /* output bit buffer */ ulong bits; uchar *dst; /* output buffer */ uchar *dmax; ulong slot; /* next block to use */ ThwBlock blocks[EWinBlocks]; ushort hash[EWinBlocks][HashSize]; uchar data[EWinBlocks][ThwMaxBlock]; }; struct UnthwBlock { ulong seq; /* sequence number for this data */ ushort maxoff; /* valid data in each block */ uchar *data; }; struct Unthwack { ulong nbits; /* input bit buffer */ ulong bits; uchar *src; /* input buffer */ uchar *smax; int slot; /* next block to use */ UnthwBlock blocks[DWinBlocks]; uchar data[DWinBlocks][ThwMaxBlock]; }; void thwackinit(Thwack*); void unthwackinit(Unthwack*); int thwack(Thwack*, uchar *dst, uchar *src, int nsrc, ulong seq); void thwackack(Thwack*, ulong seq, ulong mask); int unthwack(Unthwack*, uchar *dst, int ndst, uchar *src, int nsrc, ulong seq);