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-rw-r--r--LzFind.c629
1 files changed, 629 insertions, 0 deletions
diff --git a/LzFind.c b/LzFind.c
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index 0000000..c312927
--- /dev/null
+++ b/LzFind.c
@@ -0,0 +1,629 @@
+/* LzFind.c -- Match finder for LZ algorithms
+2009-04-22 : Igor Pavlov : Public domain */
+
+#define _FILE_OFFSET_BITS 64
+
+#include <errno.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "lzip.h"
+#include "LzFind.h"
+
+#define kHash2Size (1 << 10)
+#define kHash3Size (1 << 16)
+#define kHash4Size (1 << 20)
+
+#define kFix3HashSize (kHash2Size)
+#define kFix4HashSize (kHash2Size + kHash3Size)
+
+#define HASH2_CALC hashValue = cur[0] | ((uint32_t)cur[1] << 8);
+
+#define HASH3_CALC { \
+ uint32_t temp = crc32[cur[0]] ^ cur[1]; \
+ hash2Value = temp & (kHash2Size - 1); \
+ hashValue = (temp ^ ((uint32_t)cur[2] << 8)) & p->hashMask; }
+
+#define HASH4_CALC { \
+ uint32_t temp = crc32[cur[0]] ^ cur[1]; \
+ hash2Value = temp & (kHash2Size - 1); \
+ hash3Value = (temp ^ ((uint32_t)cur[2] << 8)) & (kHash3Size - 1); \
+ hashValue = (temp ^ ((uint32_t)cur[2] << 8) ^ (crc32[cur[3]] << 5)) & p->hashMask; }
+
+#define kEmptyHashValue 0
+#define kMaxValForNormalize ((uint32_t)0xFFFFFFFF)
+#define kNormalizeStepMin (1 << 10) /* it must be power of 2 */
+#define kNormalizeMask (~(kNormalizeStepMin - 1))
+
+#define kStartMaxLen 3
+
+
+static void Mf_ReadBlock(CMatchFinder *p)
+{
+ if (p->streamEndWasReached || p->result != SZ_OK)
+ return;
+ for (;;)
+ {
+ uint8_t * const dest = p->buffer + (p->streamPos - p->pos);
+ const int size = (p->bufferBase + p->blockSize - dest);
+ int rd;
+ if (size == 0)
+ return;
+ rd = readblock( p->infd, dest, size );
+ if (rd != size && errno)
+ { p->result = SZ_ERROR_READ; return; }
+ if (rd == 0)
+ {
+ p->streamEndWasReached = true;
+ return;
+ }
+ CRC32_update_buf( &p->crc, dest, rd );
+ p->streamPos += rd;
+ if (p->streamPos - p->pos > p->keepSizeAfter)
+ return;
+ }
+}
+
+
+static void Mf_CheckAndMoveAndRead(CMatchFinder *p)
+{
+ if ((uint32_t)(p->bufferBase + p->blockSize - p->buffer) <= p->keepSizeAfter)
+ {
+ memmove(p->bufferBase,
+ p->buffer - p->keepSizeBefore,
+ p->streamPos - p->pos + p->keepSizeBefore);
+ p->buffer = p->bufferBase + p->keepSizeBefore;
+ }
+ Mf_ReadBlock(p);
+}
+
+
+void Mf_Free(CMatchFinder *p)
+{
+ free(p->hash);
+ p->hash = 0;
+ free(p->bufferBase);
+ p->bufferBase = 0;
+}
+
+static CLzRef* AllocRefs(uint32_t num)
+{
+ uint32_t sizeInBytes = num * sizeof(CLzRef);
+ if (sizeInBytes / sizeof(CLzRef) != num)
+ return 0;
+ return (CLzRef *)malloc(sizeInBytes);
+}
+
+static void Mf_SetLimits(CMatchFinder *p)
+{
+ uint32_t limit = kMaxValForNormalize - p->pos;
+ uint32_t limit2 = p->cyclicBufferSize - p->cyclicBufferPos;
+ if (limit2 < limit)
+ limit = limit2;
+ limit2 = p->streamPos - p->pos;
+ if (limit2 <= p->keepSizeAfter)
+ {
+ if (limit2 > 0)
+ limit2 = 1;
+ }
+ else
+ limit2 -= p->keepSizeAfter;
+ if (limit2 < limit)
+ limit = limit2;
+ {
+ uint32_t lenLimit = p->streamPos - p->pos;
+ if (lenLimit > p->matchMaxLen)
+ lenLimit = p->matchMaxLen;
+ p->lenLimit = lenLimit;
+ }
+ p->posLimit = p->pos + limit;
+}
+
+
+int Mf_Init(CMatchFinder *p, const int ifd, const int mc, uint32_t historySize,
+ uint32_t keepAddBufferBefore, uint32_t matchMaxLen, uint32_t keepAddBufferAfter)
+{
+ const uint32_t sizeReserv = ( historySize >> 1 ) +
+ (keepAddBufferBefore + matchMaxLen + keepAddBufferAfter) / 2 + (1 << 19);
+
+ p->hash = 0;
+ p->cutValue = mc;
+ p->infd = ifd;
+ p->btMode = true;
+ p->numHashBytes = 4;
+ p->crc = 0xFFFFFFFFU;
+ p->keepSizeBefore = historySize + keepAddBufferBefore + 1;
+ p->keepSizeAfter = matchMaxLen + keepAddBufferAfter;
+ /* we need one additional byte, since we use MoveBlock after pos++ and before dictionary using */
+ /* keepSizeBefore + keepSizeAfter + sizeReserv must be < 4G) */
+ p->blockSize = p->keepSizeBefore + p->keepSizeAfter + sizeReserv;
+ p->buffer = p->bufferBase = (uint8_t *)malloc(p->blockSize);
+ if( p->bufferBase )
+ {
+ uint32_t newCyclicBufferSize = historySize + 1;
+ uint32_t hs;
+ p->matchMaxLen = matchMaxLen;
+ {
+ if (p->numHashBytes == 2)
+ hs = (1 << 16) - 1;
+ else
+ {
+ hs = historySize - 1;
+ hs |= (hs >> 1);
+ hs |= (hs >> 2);
+ hs |= (hs >> 4);
+ hs |= (hs >> 8);
+ hs >>= 1;
+ hs |= 0xFFFF; /* don't change it! It's required for Deflate */
+ if (hs > (1 << 24))
+ {
+ if (p->numHashBytes == 3)
+ hs = (1 << 24) - 1;
+ else
+ hs >>= 1;
+ }
+ }
+ p->hashMask = hs;
+ hs++;
+ if (p->numHashBytes > 2) hs += kHash2Size;
+ if (p->numHashBytes > 3) hs += kHash3Size;
+ if (p->numHashBytes > 4) hs += kHash4Size;
+ }
+
+ {
+ uint32_t newSize;
+ p->historySize = historySize;
+ p->hashSizeSum = hs;
+ p->cyclicBufferSize = newCyclicBufferSize;
+ p->numSons = (p->btMode ? newCyclicBufferSize * 2 : newCyclicBufferSize);
+ newSize = p->hashSizeSum + p->numSons;
+ p->hash = AllocRefs(newSize);
+ if (p->hash != 0)
+ {
+ uint32_t i;
+ p->son = p->hash + p->hashSizeSum;
+ for (i = 0; i < p->hashSizeSum; i++)
+ p->hash[i] = kEmptyHashValue;
+ p->cyclicBufferPos = 0;
+ p->pos = p->streamPos = p->cyclicBufferSize;
+ p->result = SZ_OK;
+ p->streamEndWasReached = false;
+ Mf_ReadBlock(p);
+ Mf_SetLimits(p);
+ return 1;
+ }
+ }
+ }
+ Mf_Free(p);
+ return 0;
+}
+
+static void Mf_Normalize3(uint32_t subValue, CLzRef *items, uint32_t numItems)
+{
+ uint32_t i;
+ for (i = 0; i < numItems; i++)
+ {
+ uint32_t value = items[i];
+ if (value <= subValue)
+ value = kEmptyHashValue;
+ else
+ value -= subValue;
+ items[i] = value;
+ }
+}
+
+static void Mf_Normalize(CMatchFinder *p)
+{
+ uint32_t subValue = (p->pos - p->historySize - 1) & kNormalizeMask;
+ Mf_Normalize3(subValue, p->hash, p->hashSizeSum + p->numSons);
+ p->posLimit -= subValue;
+ p->pos -= subValue;
+ p->streamPos -= subValue;
+}
+
+static void Mf_CheckLimits(CMatchFinder *p)
+{
+ if (p->pos == kMaxValForNormalize)
+ Mf_Normalize(p);
+ if (!p->streamEndWasReached && p->keepSizeAfter == p->streamPos - p->pos)
+ Mf_CheckAndMoveAndRead(p);
+ if (p->cyclicBufferPos == p->cyclicBufferSize)
+ p->cyclicBufferPos = 0;
+ Mf_SetLimits(p);
+}
+
+static uint32_t * Hc_GetMatchesSpec(uint32_t lenLimit, uint32_t curMatch, uint32_t pos, const uint8_t *cur, CLzRef *son,
+ uint32_t _cyclicBufferPos, uint32_t _cyclicBufferSize, uint32_t cutValue,
+ uint32_t *distances, uint32_t maxLen)
+{
+ son[_cyclicBufferPos] = curMatch;
+ for (;;)
+ {
+ uint32_t delta = pos - curMatch;
+ if (cutValue-- == 0 || delta >= _cyclicBufferSize)
+ return distances;
+ {
+ const uint8_t *pb = cur - delta;
+ curMatch = son[_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)];
+ if (pb[maxLen] == cur[maxLen] && *pb == *cur)
+ {
+ uint32_t len = 0;
+ while (++len != lenLimit)
+ if (pb[len] != cur[len])
+ break;
+ if (maxLen < len)
+ {
+ *distances++ = maxLen = len;
+ *distances++ = delta - 1;
+ if (len == lenLimit)
+ return distances;
+ }
+ }
+ }
+ }
+}
+
+
+static uint32_t * GetMatchesSpec1( uint32_t lenLimit, uint32_t curMatch,
+ uint32_t pos, const uint8_t *cur, CLzRef *son,
+ uint32_t _cyclicBufferPos, uint32_t _cyclicBufferSize, uint32_t cutValue,
+ uint32_t *distances, uint32_t maxLen )
+{
+ CLzRef *ptr0 = son + (_cyclicBufferPos << 1) + 1;
+ CLzRef *ptr1 = son + (_cyclicBufferPos << 1);
+ uint32_t len0 = 0, len1 = 0;
+ for (;;)
+ {
+ uint32_t delta = pos - curMatch;
+ if (cutValue-- == 0 || delta >= _cyclicBufferSize)
+ {
+ *ptr0 = *ptr1 = kEmptyHashValue;
+ return distances;
+ }
+ {
+ CLzRef *pair = son + ((_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)) << 1);
+ const uint8_t *pb = cur - delta;
+ uint32_t len = (len0 < len1 ? len0 : len1);
+ if (pb[len] == cur[len])
+ {
+ if (++len != lenLimit && pb[len] == cur[len])
+ while (++len != lenLimit)
+ if (pb[len] != cur[len])
+ break;
+ if (maxLen < len)
+ {
+ *distances++ = maxLen = len;
+ *distances++ = delta - 1;
+ if (len == lenLimit)
+ {
+ *ptr1 = pair[0];
+ *ptr0 = pair[1];
+ return distances;
+ }
+ }
+ }
+ if (pb[len] < cur[len])
+ {
+ *ptr1 = curMatch;
+ ptr1 = pair + 1;
+ curMatch = *ptr1;
+ len1 = len;
+ }
+ else
+ {
+ *ptr0 = curMatch;
+ ptr0 = pair;
+ curMatch = *ptr0;
+ len0 = len;
+ }
+ }
+ }
+}
+
+static void SkipMatchesSpec(uint32_t lenLimit, uint32_t curMatch, uint32_t pos, const uint8_t *cur, CLzRef *son,
+ uint32_t _cyclicBufferPos, uint32_t _cyclicBufferSize, uint32_t cutValue)
+{
+ CLzRef *ptr0 = son + (_cyclicBufferPos << 1) + 1;
+ CLzRef *ptr1 = son + (_cyclicBufferPos << 1);
+ uint32_t len0 = 0, len1 = 0;
+ for (;;)
+ {
+ uint32_t delta = pos - curMatch;
+ if (cutValue-- == 0 || delta >= _cyclicBufferSize)
+ {
+ *ptr0 = *ptr1 = kEmptyHashValue;
+ return;
+ }
+ {
+ CLzRef *pair = son + ((_cyclicBufferPos - delta + ((delta > _cyclicBufferPos) ? _cyclicBufferSize : 0)) << 1);
+ const uint8_t *pb = cur - delta;
+ uint32_t len = (len0 < len1 ? len0 : len1);
+ if (pb[len] == cur[len])
+ {
+ while (++len != lenLimit)
+ if (pb[len] != cur[len])
+ break;
+ {
+ if (len == lenLimit)
+ {
+ *ptr1 = pair[0];
+ *ptr0 = pair[1];
+ return;
+ }
+ }
+ }
+ if (pb[len] < cur[len])
+ {
+ *ptr1 = curMatch;
+ ptr1 = pair + 1;
+ curMatch = *ptr1;
+ len1 = len;
+ }
+ else
+ {
+ *ptr0 = curMatch;
+ ptr0 = pair;
+ curMatch = *ptr0;
+ len0 = len;
+ }
+ }
+ }
+}
+
+#define MOVE_POS \
+ ++p->cyclicBufferPos; \
+ p->buffer++; \
+ if (++p->pos == p->posLimit) Mf_CheckLimits(p);
+
+#define MOVE_POS_RET MOVE_POS return offset;
+
+static void Mf_MovePos(CMatchFinder *p) { MOVE_POS; }
+
+#define GET_MATCHES_HEADER2(minLen, ret_op) \
+ uint32_t lenLimit; uint32_t hashValue; const uint8_t *cur; uint32_t curMatch; \
+ lenLimit = p->lenLimit; { if (lenLimit < minLen) { Mf_MovePos(p); ret_op; }} \
+ cur = p->buffer;
+
+#define GET_MATCHES_HEADER(minLen) GET_MATCHES_HEADER2(minLen, return 0)
+#define SKIP_HEADER(minLen) GET_MATCHES_HEADER2(minLen, continue)
+
+#define MF_PARAMS(p) p->pos, p->buffer, p->son, p->cyclicBufferPos, p->cyclicBufferSize, p->cutValue
+
+#define GET_MATCHES_FOOTER(offset, maxLen) \
+ offset = (uint32_t)(GetMatchesSpec1(lenLimit, curMatch, MF_PARAMS(p), \
+ distances + offset, maxLen) - distances); MOVE_POS_RET;
+
+#define SKIP_FOOTER \
+ SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p)); MOVE_POS;
+
+static uint32_t Bt2_MatchFinder_GetMatches(CMatchFinder *p, uint32_t *distances)
+{
+ uint32_t offset;
+ GET_MATCHES_HEADER(2)
+ HASH2_CALC;
+ curMatch = p->hash[hashValue];
+ p->hash[hashValue] = p->pos;
+ offset = 0;
+ GET_MATCHES_FOOTER(offset, 1)
+}
+
+static uint32_t Bt3_MatchFinder_GetMatches(CMatchFinder *p, uint32_t *distances)
+{
+ uint32_t hash2Value, delta2, maxLen, offset;
+ GET_MATCHES_HEADER(3)
+
+ HASH3_CALC;
+
+ delta2 = p->pos - p->hash[hash2Value];
+ curMatch = p->hash[kFix3HashSize + hashValue];
+
+ p->hash[hash2Value] =
+ p->hash[kFix3HashSize + hashValue] = p->pos;
+
+
+ maxLen = 2;
+ offset = 0;
+ if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur)
+ {
+ for (; maxLen != lenLimit; maxLen++)
+ if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen])
+ break;
+ distances[0] = maxLen;
+ distances[1] = delta2 - 1;
+ offset = 2;
+ if (maxLen == lenLimit)
+ {
+ SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p));
+ MOVE_POS_RET;
+ }
+ }
+ GET_MATCHES_FOOTER(offset, maxLen)
+}
+
+static uint32_t Bt4_MatchFinder_GetMatches(CMatchFinder *p, uint32_t *distances)
+{
+ uint32_t hash2Value, hash3Value, delta2, delta3, maxLen, offset;
+ GET_MATCHES_HEADER(4)
+
+ HASH4_CALC;
+
+ delta2 = p->pos - p->hash[ hash2Value];
+ delta3 = p->pos - p->hash[kFix3HashSize + hash3Value];
+ curMatch = p->hash[kFix4HashSize + hashValue];
+
+ p->hash[ hash2Value] =
+ p->hash[kFix3HashSize + hash3Value] =
+ p->hash[kFix4HashSize + hashValue] = p->pos;
+
+ maxLen = 1;
+ offset = 0;
+ if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur)
+ {
+ distances[0] = maxLen = 2;
+ distances[1] = delta2 - 1;
+ offset = 2;
+ }
+ if (delta2 != delta3 && delta3 < p->cyclicBufferSize && *(cur - delta3) == *cur)
+ {
+ maxLen = 3;
+ distances[offset + 1] = delta3 - 1;
+ offset += 2;
+ delta2 = delta3;
+ }
+ if (offset != 0)
+ {
+ for (; maxLen != lenLimit; maxLen++)
+ if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen])
+ break;
+ distances[offset - 2] = maxLen;
+ if (maxLen == lenLimit)
+ {
+ SkipMatchesSpec(lenLimit, curMatch, MF_PARAMS(p));
+ MOVE_POS_RET;
+ }
+ }
+ if (maxLen < 3)
+ maxLen = 3;
+ GET_MATCHES_FOOTER(offset, maxLen)
+}
+
+static uint32_t Hc4_MatchFinder_GetMatches(CMatchFinder *p, uint32_t *distances)
+{
+ uint32_t hash2Value, hash3Value, delta2, delta3, maxLen, offset;
+ GET_MATCHES_HEADER(4)
+
+ HASH4_CALC;
+
+ delta2 = p->pos - p->hash[ hash2Value];
+ delta3 = p->pos - p->hash[kFix3HashSize + hash3Value];
+ curMatch = p->hash[kFix4HashSize + hashValue];
+
+ p->hash[ hash2Value] =
+ p->hash[kFix3HashSize + hash3Value] =
+ p->hash[kFix4HashSize + hashValue] = p->pos;
+
+ maxLen = 1;
+ offset = 0;
+ if (delta2 < p->cyclicBufferSize && *(cur - delta2) == *cur)
+ {
+ distances[0] = maxLen = 2;
+ distances[1] = delta2 - 1;
+ offset = 2;
+ }
+ if (delta2 != delta3 && delta3 < p->cyclicBufferSize && *(cur - delta3) == *cur)
+ {
+ maxLen = 3;
+ distances[offset + 1] = delta3 - 1;
+ offset += 2;
+ delta2 = delta3;
+ }
+ if (offset != 0)
+ {
+ for (; maxLen != lenLimit; maxLen++)
+ if (cur[(ptrdiff_t)maxLen - delta2] != cur[maxLen])
+ break;
+ distances[offset - 2] = maxLen;
+ if (maxLen == lenLimit)
+ {
+ p->son[p->cyclicBufferPos] = curMatch;
+ MOVE_POS_RET;
+ }
+ }
+ if (maxLen < 3)
+ maxLen = 3;
+ offset = (uint32_t)(Hc_GetMatchesSpec(lenLimit, curMatch, MF_PARAMS(p),
+ distances + offset, maxLen) - (distances));
+ MOVE_POS_RET
+}
+
+
+static void Bt2_MatchFinder_Skip(CMatchFinder *p, uint32_t num)
+{
+ do
+ {
+ SKIP_HEADER(2)
+ HASH2_CALC;
+ curMatch = p->hash[hashValue];
+ p->hash[hashValue] = p->pos;
+ SKIP_FOOTER
+ }
+ while (--num != 0);
+}
+
+
+static void Bt3_MatchFinder_Skip(CMatchFinder *p, uint32_t num)
+{
+ do
+ {
+ uint32_t hash2Value;
+ SKIP_HEADER(3)
+ HASH3_CALC;
+ curMatch = p->hash[kFix3HashSize + hashValue];
+ p->hash[hash2Value] =
+ p->hash[kFix3HashSize + hashValue] = p->pos;
+ SKIP_FOOTER
+ }
+ while (--num != 0);
+}
+
+static void Bt4_MatchFinder_Skip(CMatchFinder *p, uint32_t num)
+{
+ do
+ {
+ uint32_t hash2Value, hash3Value;
+ SKIP_HEADER(4)
+ HASH4_CALC;
+ curMatch = p->hash[kFix4HashSize + hashValue];
+ p->hash[ hash2Value] =
+ p->hash[kFix3HashSize + hash3Value] = p->pos;
+ p->hash[kFix4HashSize + hashValue] = p->pos;
+ SKIP_FOOTER
+ }
+ while (--num != 0);
+}
+
+static void Hc4_MatchFinder_Skip(CMatchFinder *p, uint32_t num)
+{
+ do
+ {
+ uint32_t hash2Value, hash3Value;
+ SKIP_HEADER(4)
+ HASH4_CALC;
+ curMatch = p->hash[kFix4HashSize + hashValue];
+ p->hash[ hash2Value] =
+ p->hash[kFix3HashSize + hash3Value] =
+ p->hash[kFix4HashSize + hashValue] = p->pos;
+ p->son[p->cyclicBufferPos] = curMatch;
+ MOVE_POS
+ }
+ while (--num != 0);
+}
+
+
+void Mf_CreateVTable(CMatchFinder *p, IMatchFinder *vTable)
+{
+ if (!p->btMode)
+ {
+ vTable->GetMatches = (Mf_GetMatches_Func)Hc4_MatchFinder_GetMatches;
+ vTable->Skip = (Mf_Skip_Func)Hc4_MatchFinder_Skip;
+ }
+ else if (p->numHashBytes == 2)
+ {
+ vTable->GetMatches = (Mf_GetMatches_Func)Bt2_MatchFinder_GetMatches;
+ vTable->Skip = (Mf_Skip_Func)Bt2_MatchFinder_Skip;
+ }
+ else if (p->numHashBytes == 3)
+ {
+ vTable->GetMatches = (Mf_GetMatches_Func)Bt3_MatchFinder_GetMatches;
+ vTable->Skip = (Mf_Skip_Func)Bt3_MatchFinder_Skip;
+ }
+ else
+ {
+ vTable->GetMatches = (Mf_GetMatches_Func)Bt4_MatchFinder_GetMatches;
+ vTable->Skip = (Mf_Skip_Func)Bt4_MatchFinder_Skip;
+ }
+}