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- typedef struct Thwack Thwack;
- typedef struct Unthwack Unthwack;
- typedef struct ThwBlock ThwBlock;
- typedef struct UnthwBlock UnthwBlock;
- enum
- {
- ThwStats = 8,
- ThwMaxBlock = 1600, /* max size of compressible block */
- HashLog = 12,
- HashSize = 1<<HashLog,
- HashMask = HashSize - 1,
- MinMatch = 3, /* shortest match possible */
- MaxOff = 8,
- OffBase = 6,
- MinDecode = 8, /* minimum bits to decode a match or lit; >= 8 */
- EWinBlocks = 22, /* blocks held in encoder window */
- DWinBlocks = 32, /* blocks held in decoder window */
- CompBlocks = 10, /* 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
- {
- int 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
- {
- 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, ulong stats[ThwStats]);
- void thwackack(Thwack*, ulong seq, ulong mask);
- int unthwack(Unthwack*, uchar *dst, int ndst, uchar *src, int nsrc, ulong seq);
- ulong unthwackstate(Unthwack *ut, uchar *mask);
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