1999/1111/port/thwack.c (diff list | history)

1999/1022/sys/src/9/port/thwack.c:1,5 – 1999/1111/sys/src/9/port/thwack.c:1,5 (short | long | prev | next)
1999/1001		#include "u.h"
1999/1022		#include "../port/lib.h"
1999/1111		#include "lib.h"
1999/1001		#include "mem.h" #include "dat.h" #include "fns.h"
1999/1022/sys/src/9/port/thwack.c:6,15 – 1999/1111/sys/src/9/port/thwack.c:6,28
1999/1001		#include "thwack.h"
1999/1111		/* * don't include compressed blocks */ #define NOUNCOMP
1999/1001		typedef struct Huff Huff;
1999/1022		enum {
1999/1111		MaxFastLen = 9, BigLenCode = 0x1f4, /* minimum code for large lenth encoding */ BigLenBits = 9, BigLenBase = 4 /* starting items to encode for big lens */ }; enum {
1999/1022		StatBytes, StatOutBytes, StatLits,
1999/1022/sys/src/9/port/thwack.c:32,46 – 1999/1111/sys/src/9/port/thwack.c:45,59
1999/1001
1999/1007		static Huff lentab[MaxFastLen] =
1999/1001		{ {1, 0x0}, /* 0 */ {2, 0x2}, /* 10 */ {4, 0xc}, /* 1100 */ {4, 0xd}, /* 1101 */
1999/1111		{3, 0x6}, /* 110 */
1999/1007		{5, 0x1c}, /* 11100 */ {6, 0x3a}, /* 111010 */ {6, 0x3b}, /* 111011 */ {7, 0x78}, /* 1111000 */ {7, 0x79}, /* 1111001 */
1999/1111		{5, 0x1d}, /* 11101 */ {6, 0x3c}, /* 111100 */ {7, 0x7a}, /* 1111010 */ {7, 0x7b}, /* 1111011 */ {8, 0xf8}, /* 11111000 */ {8, 0xf9}, /* 11111001 */
1999/1001		}; void
1999/1022/sys/src/9/port/thwack.c:215,220 – 1999/1111/sys/src/9/port/thwack.c:228,239
1999/1022		*twdst++ = seq - cseq; *twdst++ = cmask;
1999/1001
1999/1111		#ifndef NOUNCOMP tw->slot++; if(tw->slot >= EWinBlocks) tw->slot = 0; #endif
1999/1022		cont = (s[0] << 16) | (s[1] << 8) | s[2];
1999/1001		esrc = s + n;
1999/1022/sys/src/9/port/thwack.c:261,266 – 1999/1111/sys/src/9/port/thwack.c:280,286
1999/1022		lits++; blocks->maxoff++;
1999/1001
1999/1111		#ifdef NOUNCOMP
1999/1022		/* * speed hack * check for compression progress, bail if none achieved
1999/1022/sys/src/9/port/thwack.c:270,275 – 1999/1111/sys/src/9/port/thwack.c:290,296
1999/1022		return -1; half = esrc; }
1999/1111		#endif
1999/1001
1999/1022		if(s + MinMatch <= esrc){ blocks->hash[(h ^ blocks->seq) & HashMask] = now;
1999/1022/sys/src/9/port/thwack.c:284,301 – 1999/1111/sys/src/9/port/thwack.c:305,313
1999/1022		blocks->maxoff += len; matches++;
1999/1001
1999/1022		toff--; for(bits = OffBase; toff >= (1 << bits); bits++) ; if(bits >= MaxOff+OffBase) panic("thwack offset"); twbits = (twbits << 4) | 0x8 | (bits - OffBase); if(bits != OffBase) bits--; twbits = (twbits << bits) | toff & ((1 << bits) - 1); twnbits += bits + 4; offbits += bits + 4;
1999/1111		/* * length of match */
1999/1022		len -= MinMatch; if(len < MaxFastLen){ bits = lentab[len].bits;
1999/1022/sys/src/9/port/thwack.c:303,313 – 1999/1111/sys/src/9/port/thwack.c:315,320
1999/1022		twnbits += bits; lenbits += bits; }else{ for(; twnbits >= 8; twnbits -= 8){ if(twdst >= twdmax) return -1; *twdst++ = twbits >> (twnbits - 8); } code = BigLenCode; bits = BigLenBits; use = BigLenBase;
1999/1022/sys/src/9/port/thwack.c:315,330 – 1999/1111/sys/src/9/port/thwack.c:322,361
1999/1022		while(len >= use){ len -= use; code = (code + use) << 1; use <<= bits & 1;
1999/1111		use <<= (bits & 1) ^ 1;
1999/1022		bits++; } if(bits > MaxLenDecode + BigLenBits) panic("length too big"); twbits = (twbits << bits) | (code + len); twnbits += bits; lenbits += bits;
1999/1111		for(; twnbits >= 8; twnbits -= 8){ if(twdst >= twdmax) return -1; *twdst++ = twbits >> (twnbits - 8); }
1999/1022		}
1999/1111		/* * offset in history */ toff--; for(bits = OffBase; toff >= (1 << bits); bits++) ; if(bits < MaxOff+OffBase-1){ twbits = (twbits << 3) | (bits - OffBase); if(bits != OffBase) bits--; twnbits += bits + 3; offbits += bits + 3; }else{ twbits = (twbits << 4) | 0xe | (bits - (MaxOff+OffBase-1)); bits--; twnbits += bits + 4; offbits += bits + 4; } twbits = (twbits << bits) | toff & ((1 << bits) - 1);
1999/1001		for(; s != ss; s++){ if(s + MinMatch <= esrc){ h = hashit(cont);
1999/1022/sys/src/9/port/thwack.c:353,361 – 1999/1111/sys/src/9/port/thwack.c:384,394
1999/1022		*twdst++ = twbits >> (twnbits - 8); }
1999/1111		#ifdef NOUNCOMP
1999/1001		tw->slot++; if(tw->slot >= EWinBlocks) tw->slot = 0;
1999/1111		#endif
1999/1001
1999/1022		stats[StatOutBytes] += twdst - dst;
1999/1001