/*
* LZ4 - Fast LZ compression algorithm
- * Copyright (C) 2011-2012, Yann Collet.
- * BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
-
+ * Copyright (C) 2011 - 2016, Yann Collet.
+ * BSD 2 - Clause License (http://www.opensource.org/licenses/bsd - license.php)
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
- *
- * * Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * * Redistributions in binary form must reproduce the above
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
- *
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
* You can contact the author at :
- * - LZ4 homepage : http://fastcompression.blogspot.com/p/lz4.html
- * - LZ4 source repository : http://code.google.com/p/lz4/
+ * - LZ4 homepage : http://www.lz4.org
+ * - LZ4 source repository : https://github.com/lz4/lz4
*
- * Changed for kernel use by:
- * Chanho Min <chanho.min@lge.com>
+ * Changed for kernel usage by:
+ * Sven Schmidt <4sschmid@informatik.uni-hamburg.de>
*/
+/*-************************************
+ * Dependencies
+ **************************************/
+#include <linux/lz4.h>
+#include "lz4defs.h"
#include <linux/module.h>
#include <linux/kernel.h>
-#include <linux/lz4.h>
#include <asm/unaligned.h>
-#include "lz4defs.h"
-/*
- * LZ4_compressCtx :
- * -----------------
- * Compress 'isize' bytes from 'source' into an output buffer 'dest' of
- * maximum size 'maxOutputSize'. * If it cannot achieve it, compression
- * will stop, and result of the function will be zero.
- * return : the number of bytes written in buffer 'dest', or 0 if the
- * compression fails
- */
-static inline int lz4_compressctx(void *ctx,
- const char *source,
- char *dest,
- int isize,
- int maxoutputsize)
+static const int LZ4_minLength = (MFLIMIT + 1);
+static const int LZ4_64Klimit = ((64 * KB) + (MFLIMIT - 1));
+
+/*-******************************
+ * Compression functions
+ ********************************/
+static FORCE_INLINE U32 LZ4_hash4(
+ U32 sequence,
+ tableType_t const tableType)
{
- HTYPE *hashtable = (HTYPE *)ctx;
- const u8 *ip = (u8 *)source;
-#if LZ4_ARCH64
- const BYTE * const base = ip;
+ if (tableType == byU16)
+ return ((sequence * 2654435761U)
+ >> ((MINMATCH * 8) - (LZ4_HASHLOG + 1)));
+ else
+ return ((sequence * 2654435761U)
+ >> ((MINMATCH * 8) - LZ4_HASHLOG));
+}
+
+static FORCE_INLINE U32 LZ4_hash5(
+ U64 sequence,
+ tableType_t const tableType)
+{
+ const U32 hashLog = (tableType == byU16)
+ ? LZ4_HASHLOG + 1
+ : LZ4_HASHLOG;
+
+#if LZ4_LITTLE_ENDIAN
+ static const U64 prime5bytes = 889523592379ULL;
+
+ return (U32)(((sequence << 24) * prime5bytes) >> (64 - hashLog));
#else
- const int base = 0;
+ static const U64 prime8bytes = 11400714785074694791ULL;
+
+ return (U32)(((sequence >> 24) * prime8bytes) >> (64 - hashLog));
#endif
- const u8 *anchor = ip;
- const u8 *const iend = ip + isize;
- const u8 *const mflimit = iend - MFLIMIT;
- #define MATCHLIMIT (iend - LASTLITERALS)
-
- u8 *op = (u8 *) dest;
- u8 *const oend = op + maxoutputsize;
- int length;
- const int skipstrength = SKIPSTRENGTH;
- u32 forwardh;
- int lastrun;
-
- /* Init */
- if (isize < MINLENGTH)
- goto _last_literals;
+}
+
+static FORCE_INLINE U32 LZ4_hashPosition(
+ const void *p,
+ tableType_t const tableType)
+{
+#if LZ4_ARCH64
+ if (tableType == byU32)
+ return LZ4_hash5(LZ4_read_ARCH(p), tableType);
+#endif
+
+ return LZ4_hash4(LZ4_read32(p), tableType);
+}
+
+static void LZ4_putPositionOnHash(
+ const BYTE *p,
+ U32 h,
+ void *tableBase,
+ tableType_t const tableType,
+ const BYTE *srcBase)
+{
+ switch (tableType) {
+ case byPtr:
+ {
+ const BYTE **hashTable = (const BYTE **)tableBase;
+
+ hashTable[h] = p;
+ return;
+ }
+ case byU32:
+ {
+ U32 *hashTable = (U32 *) tableBase;
+
+ hashTable[h] = (U32)(p - srcBase);
+ return;
+ }
+ case byU16:
+ {
+ U16 *hashTable = (U16 *) tableBase;
+
+ hashTable[h] = (U16)(p - srcBase);
+ return;
+ }
+ }
+}
+
+static FORCE_INLINE void LZ4_putPosition(
+ const BYTE *p,
+ void *tableBase,
+ tableType_t tableType,
+ const BYTE *srcBase)
+{
+ U32 const h = LZ4_hashPosition(p, tableType);
+
+ LZ4_putPositionOnHash(p, h, tableBase, tableType, srcBase);
+}
+
+static const BYTE *LZ4_getPositionOnHash(
+ U32 h,
+ void *tableBase,
+ tableType_t tableType,
+ const BYTE *srcBase)
+{
+ if (tableType == byPtr) {
+ const BYTE **hashTable = (const BYTE **) tableBase;
+
+ return hashTable[h];
+ }
+
+ if (tableType == byU32) {
+ const U32 * const hashTable = (U32 *) tableBase;
+
+ return hashTable[h] + srcBase;
+ }
+
+ {
+ /* default, to ensure a return */
+ const U16 * const hashTable = (U16 *) tableBase;
+
+ return hashTable[h] + srcBase;
+ }
+}
+
+static FORCE_INLINE const BYTE *LZ4_getPosition(
+ const BYTE *p,
+ void *tableBase,
+ tableType_t tableType,
+ const BYTE *srcBase)
+{
+ U32 const h = LZ4_hashPosition(p, tableType);
+
+ return LZ4_getPositionOnHash(h, tableBase, tableType, srcBase);
+}
- memset((void *)hashtable, 0, LZ4_MEM_COMPRESS);
+
+/*
+ * LZ4_compress_generic() :
+ * inlined, to ensure branches are decided at compilation time
+ */
+static FORCE_INLINE int LZ4_compress_generic(
+ LZ4_stream_t_internal * const dictPtr,
+ const char * const source,
+ char * const dest,
+ const int inputSize,
+ const int maxOutputSize,
+ const limitedOutput_directive outputLimited,
+ const tableType_t tableType,
+ const dict_directive dict,
+ const dictIssue_directive dictIssue,
+ const U32 acceleration)
+{
+ const BYTE *ip = (const BYTE *) source;
+ const BYTE *base;
+ const BYTE *lowLimit;
+ const BYTE * const lowRefLimit = ip - dictPtr->dictSize;
+ const BYTE * const dictionary = dictPtr->dictionary;
+ const BYTE * const dictEnd = dictionary + dictPtr->dictSize;
+ const size_t dictDelta = dictEnd - (const BYTE *)source;
+ const BYTE *anchor = (const BYTE *) source;
+ const BYTE * const iend = ip + inputSize;
+ const BYTE * const mflimit = iend - MFLIMIT;
+ const BYTE * const matchlimit = iend - LASTLITERALS;
+
+ BYTE *op = (BYTE *) dest;
+ BYTE * const olimit = op + maxOutputSize;
+
+ U32 forwardH;
+ size_t refDelta = 0;
+
+ /* Init conditions */
+ if ((U32)inputSize > (U32)LZ4_MAX_INPUT_SIZE) {
+ /* Unsupported inputSize, too large (or negative) */
+ return 0;
+ }
+
+ switch (dict) {
+ case noDict:
+ default:
+ base = (const BYTE *)source;
+ lowLimit = (const BYTE *)source;
+ break;
+ case withPrefix64k:
+ base = (const BYTE *)source - dictPtr->currentOffset;
+ lowLimit = (const BYTE *)source - dictPtr->dictSize;
+ break;
+ case usingExtDict:
+ base = (const BYTE *)source - dictPtr->currentOffset;
+ lowLimit = (const BYTE *)source;
+ break;
+ }
+
+ if ((tableType == byU16)
+ && (inputSize >= LZ4_64Klimit)) {
+ /* Size too large (not within 64K limit) */
+ return 0;
+ }
+
+ if (inputSize < LZ4_minLength) {
+ /* Input too small, no compression (all literals) */
+ goto _last_literals;
+ }
/* First Byte */
- hashtable[LZ4_HASH_VALUE(ip)] = ip - base;
+ LZ4_putPosition(ip, dictPtr->hashTable, tableType, base);
ip++;
- forwardh = LZ4_HASH_VALUE(ip);
+ forwardH = LZ4_hashPosition(ip, tableType);
/* Main Loop */
- for (;;) {
- int findmatchattempts = (1U << skipstrength) + 3;
- const u8 *forwardip = ip;
- const u8 *ref;
- u8 *token;
+ for ( ; ; ) {
+ const BYTE *match;
+ BYTE *token;
/* Find a match */
- do {
- u32 h = forwardh;
- int step = findmatchattempts++ >> skipstrength;
- ip = forwardip;
- forwardip = ip + step;
-
- if (unlikely(forwardip > mflimit))
- goto _last_literals;
-
- forwardh = LZ4_HASH_VALUE(forwardip);
- ref = base + hashtable[h];
- hashtable[h] = ip - base;
- } while ((ref < ip - MAX_DISTANCE) || (A32(ref) != A32(ip)));
+ {
+ const BYTE *forwardIp = ip;
+ unsigned int step = 1;
+ unsigned int searchMatchNb = acceleration << LZ4_SKIPTRIGGER;
+
+ do {
+ U32 const h = forwardH;
+
+ ip = forwardIp;
+ forwardIp += step;
+ step = (searchMatchNb++ >> LZ4_SKIPTRIGGER);
+
+ if (unlikely(forwardIp > mflimit))
+ goto _last_literals;
+
+ match = LZ4_getPositionOnHash(h,
+ dictPtr->hashTable,
+ tableType, base);
+
+ if (dict == usingExtDict) {
+ if (match < (const BYTE *)source) {
+ refDelta = dictDelta;
+ lowLimit = dictionary;
+ } else {
+ refDelta = 0;
+ lowLimit = (const BYTE *)source;
+ } }
+
+ forwardH = LZ4_hashPosition(forwardIp,
+ tableType);
+
+ LZ4_putPositionOnHash(ip, h, dictPtr->hashTable,
+ tableType, base);
+ } while (((dictIssue == dictSmall)
+ ? (match < lowRefLimit)
+ : 0)
+ || ((tableType == byU16)
+ ? 0
+ : (match + MAX_DISTANCE < ip))
+ || (LZ4_read32(match + refDelta)
+ != LZ4_read32(ip)));
+ }
/* Catch up */
- while ((ip > anchor) && (ref > (u8 *)source) &&
- unlikely(ip[-1] == ref[-1])) {
+ while (((ip > anchor) & (match + refDelta > lowLimit))
+ && (unlikely(ip[-1] == match[refDelta - 1]))) {
ip--;
- ref--;
+ match--;
}
- /* Encode Literal length */
- length = (int)(ip - anchor);
- token = op++;
- /* check output limit */
- if (unlikely(op + length + (2 + 1 + LASTLITERALS) +
- (length >> 8) > oend))
- return 0;
+ /* Encode Literals */
+ {
+ unsigned const int litLength = (unsigned int)(ip - anchor);
- if (length >= (int)RUN_MASK) {
- int len;
- *token = (RUN_MASK << ML_BITS);
- len = length - RUN_MASK;
- for (; len > 254 ; len -= 255)
- *op++ = 255;
- *op++ = (u8)len;
- } else
- *token = (length << ML_BITS);
+ token = op++;
+
+ if ((outputLimited) &&
+ /* Check output buffer overflow */
+ (unlikely(op + litLength +
+ (2 + 1 + LASTLITERALS) +
+ (litLength / 255) > olimit)))
+ return 0;
+
+ if (litLength >= RUN_MASK) {
+ int len = (int)litLength - RUN_MASK;
+
+ *token = (RUN_MASK << ML_BITS);
+
+ for (; len >= 255; len -= 255)
+ *op++ = 255;
+ *op++ = (BYTE)len;
+ } else
+ *token = (BYTE)(litLength << ML_BITS);
+
+ /* Copy Literals */
+ LZ4_wildCopy(op, anchor, op + litLength);
+ op += litLength;
+ }
- /* Copy Literals */
- LZ4_BLINDCOPY(anchor, op, length);
_next_match:
/* Encode Offset */
- LZ4_WRITE_LITTLEENDIAN_16(op, (u16)(ip - ref));
+ LZ4_writeLE16(op, (U16)(ip - match));
+ op += 2;
- /* Start Counting */
- ip += MINMATCH;
- /* MinMatch verified */
- ref += MINMATCH;
- anchor = ip;
- while (likely(ip < MATCHLIMIT - (STEPSIZE - 1))) {
- #if LZ4_ARCH64
- u64 diff = A64(ref) ^ A64(ip);
- #else
- u32 diff = A32(ref) ^ A32(ip);
- #endif
- if (!diff) {
- ip += STEPSIZE;
- ref += STEPSIZE;
- continue;
- }
- ip += LZ4_NBCOMMONBYTES(diff);
- goto _endcount;
- }
- #if LZ4_ARCH64
- if ((ip < (MATCHLIMIT - 3)) && (A32(ref) == A32(ip))) {
- ip += 4;
- ref += 4;
- }
- #endif
- if ((ip < (MATCHLIMIT - 1)) && (A16(ref) == A16(ip))) {
- ip += 2;
- ref += 2;
- }
- if ((ip < MATCHLIMIT) && (*ref == *ip))
- ip++;
-_endcount:
/* Encode MatchLength */
- length = (int)(ip - anchor);
- /* Check output limit */
- if (unlikely(op + (1 + LASTLITERALS) + (length >> 8) > oend))
- return 0;
- if (length >= (int)ML_MASK) {
- *token += ML_MASK;
- length -= ML_MASK;
- for (; length > 509 ; length -= 510) {
- *op++ = 255;
- *op++ = 255;
- }
- if (length > 254) {
- length -= 255;
- *op++ = 255;
+ {
+ unsigned int matchCode;
+
+ if ((dict == usingExtDict)
+ && (lowLimit == dictionary)) {
+ const BYTE *limit;
+
+ match += refDelta;
+ limit = ip + (dictEnd - match);
+
+ if (limit > matchlimit)
+ limit = matchlimit;
+
+ matchCode = LZ4_count(ip + MINMATCH,
+ match + MINMATCH, limit);
+
+ ip += MINMATCH + matchCode;
+
+ if (ip == limit) {
+ unsigned const int more = LZ4_count(ip,
+ (const BYTE *)source,
+ matchlimit);
+
+ matchCode += more;
+ ip += more;
+ }
+ } else {
+ matchCode = LZ4_count(ip + MINMATCH,
+ match + MINMATCH, matchlimit);
+ ip += MINMATCH + matchCode;
}
- *op++ = (u8)length;
- } else
- *token += length;
+
+ if (outputLimited &&
+ /* Check output buffer overflow */
+ (unlikely(op +
+ (1 + LASTLITERALS) +
+ (matchCode >> 8) > olimit)))
+ return 0;
+
+ if (matchCode >= ML_MASK) {
+ *token += ML_MASK;
+ matchCode -= ML_MASK;
+ LZ4_write32(op, 0xFFFFFFFF);
+
+ while (matchCode >= 4 * 255) {
+ op += 4;
+ LZ4_write32(op, 0xFFFFFFFF);
+ matchCode -= 4 * 255;
+ }
+
+ op += matchCode / 255;
+ *op++ = (BYTE)(matchCode % 255);
+ } else
+ *token += (BYTE)(matchCode);
+ }
+
+ anchor = ip;
/* Test end of chunk */
- if (ip > mflimit) {
- anchor = ip;
+ if (ip > mflimit)
break;
- }
/* Fill table */
- hashtable[LZ4_HASH_VALUE(ip-2)] = ip - 2 - base;
+ LZ4_putPosition(ip - 2, dictPtr->hashTable, tableType, base);
/* Test next position */
- ref = base + hashtable[LZ4_HASH_VALUE(ip)];
- hashtable[LZ4_HASH_VALUE(ip)] = ip - base;
- if ((ref > ip - (MAX_DISTANCE + 1)) && (A32(ref) == A32(ip))) {
+ match = LZ4_getPosition(ip, dictPtr->hashTable,
+ tableType, base);
+
+ if (dict == usingExtDict) {
+ if (match < (const BYTE *)source) {
+ refDelta = dictDelta;
+ lowLimit = dictionary;
+ } else {
+ refDelta = 0;
+ lowLimit = (const BYTE *)source;
+ }
+ }
+
+ LZ4_putPosition(ip, dictPtr->hashTable, tableType, base);
+
+ if (((dictIssue == dictSmall) ? (match >= lowRefLimit) : 1)
+ && (match + MAX_DISTANCE >= ip)
+ && (LZ4_read32(match + refDelta) == LZ4_read32(ip))) {
token = op++;
*token = 0;
goto _next_match;
}
/* Prepare next loop */
- anchor = ip++;
- forwardh = LZ4_HASH_VALUE(ip);
+ forwardH = LZ4_hashPosition(++ip, tableType);
}
_last_literals:
/* Encode Last Literals */
- lastrun = (int)(iend - anchor);
- if (((char *)op - dest) + lastrun + 1
- + ((lastrun + 255 - RUN_MASK) / 255) > (u32)maxoutputsize)
- return 0;
+ {
+ size_t const lastRun = (size_t)(iend - anchor);
+
+ if ((outputLimited) &&
+ /* Check output buffer overflow */
+ ((op - (BYTE *)dest) + lastRun + 1 +
+ ((lastRun + 255 - RUN_MASK) / 255) > (U32)maxOutputSize))
+ return 0;
+
+ if (lastRun >= RUN_MASK) {
+ size_t accumulator = lastRun - RUN_MASK;
+ *op++ = RUN_MASK << ML_BITS;
+ for (; accumulator >= 255; accumulator -= 255)
+ *op++ = 255;
+ *op++ = (BYTE) accumulator;
+ } else {
+ *op++ = (BYTE)(lastRun << ML_BITS);
+ }
- if (lastrun >= (int)RUN_MASK) {
- *op++ = (RUN_MASK << ML_BITS);
- lastrun -= RUN_MASK;
- for (; lastrun > 254 ; lastrun -= 255)
- *op++ = 255;
- *op++ = (u8)lastrun;
- } else
- *op++ = (lastrun << ML_BITS);
- memcpy(op, anchor, iend - anchor);
- op += iend - anchor;
+ memcpy(op, anchor, lastRun);
+
+ op += lastRun;
+ }
/* End */
- return (int)(((char *)op) - dest);
+ return (int) (((char *)op) - dest);
}
-static inline int lz4_compress64kctx(void *ctx,
- const char *source,
- char *dest,
- int isize,
- int maxoutputsize)
+static int LZ4_compress_fast_extState(
+ void *state,
+ const char *source,
+ char *dest,
+ int inputSize,
+ int maxOutputSize,
+ int acceleration)
{
- u16 *hashtable = (u16 *)ctx;
- const u8 *ip = (u8 *) source;
- const u8 *anchor = ip;
- const u8 *const base = ip;
- const u8 *const iend = ip + isize;
- const u8 *const mflimit = iend - MFLIMIT;
- #define MATCHLIMIT (iend - LASTLITERALS)
-
- u8 *op = (u8 *) dest;
- u8 *const oend = op + maxoutputsize;
- int len, length;
- const int skipstrength = SKIPSTRENGTH;
- u32 forwardh;
- int lastrun;
-
- /* Init */
- if (isize < MINLENGTH)
- goto _last_literals;
+ LZ4_stream_t_internal *ctx = &((LZ4_stream_t *)state)->internal_donotuse;
+#if LZ4_ARCH64
+ const tableType_t tableType = byU32;
+#else
+ const tableType_t tableType = byPtr;
+#endif
+
+ LZ4_resetStream((LZ4_stream_t *)state);
+
+ if (acceleration < 1)
+ acceleration = LZ4_ACCELERATION_DEFAULT;
+
+ if (maxOutputSize >= LZ4_COMPRESSBOUND(inputSize)) {
+ if (inputSize < LZ4_64Klimit)
+ return LZ4_compress_generic(ctx, source,
+ dest, inputSize, 0,
+ noLimit, byU16, noDict,
+ noDictIssue, acceleration);
+ else
+ return LZ4_compress_generic(ctx, source,
+ dest, inputSize, 0,
+ noLimit, tableType, noDict,
+ noDictIssue, acceleration);
+ } else {
+ if (inputSize < LZ4_64Klimit)
+ return LZ4_compress_generic(ctx, source,
+ dest, inputSize,
+ maxOutputSize, limitedOutput, byU16, noDict,
+ noDictIssue, acceleration);
+ else
+ return LZ4_compress_generic(ctx, source,
+ dest, inputSize,
+ maxOutputSize, limitedOutput, tableType, noDict,
+ noDictIssue, acceleration);
+ }
+}
+
+int LZ4_compress_fast(const char *source, char *dest, int inputSize,
+ int maxOutputSize, int acceleration, void *wrkmem)
+{
+ return LZ4_compress_fast_extState(wrkmem, source, dest, inputSize,
+ maxOutputSize, acceleration);
+}
+EXPORT_SYMBOL(LZ4_compress_fast);
- memset((void *)hashtable, 0, LZ4_MEM_COMPRESS);
+int LZ4_compress_default(const char *source, char *dest, int inputSize,
+ int maxOutputSize, void *wrkmem)
+{
+ return LZ4_compress_fast(source, dest, inputSize,
+ maxOutputSize, LZ4_ACCELERATION_DEFAULT, wrkmem);
+}
+EXPORT_SYMBOL(LZ4_compress_default);
+
+/*-******************************
+ * *_destSize() variant
+ ********************************/
+static int LZ4_compress_destSize_generic(
+ LZ4_stream_t_internal * const ctx,
+ const char * const src,
+ char * const dst,
+ int * const srcSizePtr,
+ const int targetDstSize,
+ const tableType_t tableType)
+{
+ const BYTE *ip = (const BYTE *) src;
+ const BYTE *base = (const BYTE *) src;
+ const BYTE *lowLimit = (const BYTE *) src;
+ const BYTE *anchor = ip;
+ const BYTE * const iend = ip + *srcSizePtr;
+ const BYTE * const mflimit = iend - MFLIMIT;
+ const BYTE * const matchlimit = iend - LASTLITERALS;
+
+ BYTE *op = (BYTE *) dst;
+ BYTE * const oend = op + targetDstSize;
+ BYTE * const oMaxLit = op + targetDstSize - 2 /* offset */
+ - 8 /* because 8 + MINMATCH == MFLIMIT */ - 1 /* token */;
+ BYTE * const oMaxMatch = op + targetDstSize
+ - (LASTLITERALS + 1 /* token */);
+ BYTE * const oMaxSeq = oMaxLit - 1 /* token */;
+
+ U32 forwardH;
+
+ /* Init conditions */
+ /* Impossible to store anything */
+ if (targetDstSize < 1)
+ return 0;
+ /* Unsupported input size, too large (or negative) */
+ if ((U32)*srcSizePtr > (U32)LZ4_MAX_INPUT_SIZE)
+ return 0;
+ /* Size too large (not within 64K limit) */
+ if ((tableType == byU16) && (*srcSizePtr >= LZ4_64Klimit))
+ return 0;
+ /* Input too small, no compression (all literals) */
+ if (*srcSizePtr < LZ4_minLength)
+ goto _last_literals;
/* First Byte */
- ip++;
- forwardh = LZ4_HASH64K_VALUE(ip);
+ *srcSizePtr = 0;
+ LZ4_putPosition(ip, ctx->hashTable, tableType, base);
+ ip++; forwardH = LZ4_hashPosition(ip, tableType);
/* Main Loop */
- for (;;) {
- int findmatchattempts = (1U << skipstrength) + 3;
- const u8 *forwardip = ip;
- const u8 *ref;
- u8 *token;
+ for ( ; ; ) {
+ const BYTE *match;
+ BYTE *token;
/* Find a match */
- do {
- u32 h = forwardh;
- int step = findmatchattempts++ >> skipstrength;
- ip = forwardip;
- forwardip = ip + step;
-
- if (forwardip > mflimit)
- goto _last_literals;
-
- forwardh = LZ4_HASH64K_VALUE(forwardip);
- ref = base + hashtable[h];
- hashtable[h] = (u16)(ip - base);
- } while (A32(ref) != A32(ip));
+ {
+ const BYTE *forwardIp = ip;
+ unsigned int step = 1;
+ unsigned int searchMatchNb = 1 << LZ4_SKIPTRIGGER;
+
+ do {
+ U32 h = forwardH;
+
+ ip = forwardIp;
+ forwardIp += step;
+ step = (searchMatchNb++ >> LZ4_SKIPTRIGGER);
+
+ if (unlikely(forwardIp > mflimit))
+ goto _last_literals;
+
+ match = LZ4_getPositionOnHash(h, ctx->hashTable,
+ tableType, base);
+ forwardH = LZ4_hashPosition(forwardIp,
+ tableType);
+ LZ4_putPositionOnHash(ip, h,
+ ctx->hashTable, tableType,
+ base);
+
+ } while (((tableType == byU16)
+ ? 0
+ : (match + MAX_DISTANCE < ip))
+ || (LZ4_read32(match) != LZ4_read32(ip)));
+ }
/* Catch up */
- while ((ip > anchor) && (ref > (u8 *)source)
- && (ip[-1] == ref[-1])) {
+ while ((ip > anchor)
+ && (match > lowLimit)
+ && (unlikely(ip[-1] == match[-1]))) {
ip--;
- ref--;
+ match--;
}
/* Encode Literal length */
- length = (int)(ip - anchor);
- token = op++;
- /* Check output limit */
- if (unlikely(op + length + (2 + 1 + LASTLITERALS)
- + (length >> 8) > oend))
- return 0;
- if (length >= (int)RUN_MASK) {
- *token = (RUN_MASK << ML_BITS);
- len = length - RUN_MASK;
- for (; len > 254 ; len -= 255)
- *op++ = 255;
- *op++ = (u8)len;
- } else
- *token = (length << ML_BITS);
+ {
+ unsigned int litLength = (unsigned int)(ip - anchor);
- /* Copy Literals */
- LZ4_BLINDCOPY(anchor, op, length);
+ token = op++;
+ if (op + ((litLength + 240) / 255)
+ + litLength > oMaxLit) {
+ /* Not enough space for a last match */
+ op--;
+ goto _last_literals;
+ }
+ if (litLength >= RUN_MASK) {
+ unsigned int len = litLength - RUN_MASK;
+ *token = (RUN_MASK<<ML_BITS);
+ for (; len >= 255; len -= 255)
+ *op++ = 255;
+ *op++ = (BYTE)len;
+ } else
+ *token = (BYTE)(litLength << ML_BITS);
+
+ /* Copy Literals */
+ LZ4_wildCopy(op, anchor, op + litLength);
+ op += litLength;
+ }
_next_match:
/* Encode Offset */
- LZ4_WRITE_LITTLEENDIAN_16(op, (u16)(ip - ref));
+ LZ4_writeLE16(op, (U16)(ip - match)); op += 2;
- /* Start Counting */
- ip += MINMATCH;
- /* MinMatch verified */
- ref += MINMATCH;
- anchor = ip;
+ /* Encode MatchLength */
+ {
+ size_t matchLength = LZ4_count(ip + MINMATCH,
+ match + MINMATCH, matchlimit);
- while (ip < MATCHLIMIT - (STEPSIZE - 1)) {
- #if LZ4_ARCH64
- u64 diff = A64(ref) ^ A64(ip);
- #else
- u32 diff = A32(ref) ^ A32(ip);
- #endif
-
- if (!diff) {
- ip += STEPSIZE;
- ref += STEPSIZE;
- continue;
+ if (op + ((matchLength + 240)/255) > oMaxMatch) {
+ /* Match description too long : reduce it */
+ matchLength = (15 - 1) + (oMaxMatch - op) * 255;
}
- ip += LZ4_NBCOMMONBYTES(diff);
- goto _endcount;
- }
- #if LZ4_ARCH64
- if ((ip < (MATCHLIMIT - 3)) && (A32(ref) == A32(ip))) {
- ip += 4;
- ref += 4;
+ ip += MINMATCH + matchLength;
+
+ if (matchLength >= ML_MASK) {
+ *token += ML_MASK;
+ matchLength -= ML_MASK;
+ while (matchLength >= 255) {
+ matchLength -= 255;
+ *op++ = 255;
+ }
+ *op++ = (BYTE)matchLength;
+ } else
+ *token += (BYTE)(matchLength);
}
- #endif
- if ((ip < (MATCHLIMIT - 1)) && (A16(ref) == A16(ip))) {
- ip += 2;
- ref += 2;
- }
- if ((ip < MATCHLIMIT) && (*ref == *ip))
- ip++;
-_endcount:
- /* Encode MatchLength */
- len = (int)(ip - anchor);
- /* Check output limit */
- if (unlikely(op + (1 + LASTLITERALS) + (len >> 8) > oend))
- return 0;
- if (len >= (int)ML_MASK) {
- *token += ML_MASK;
- len -= ML_MASK;
- for (; len > 509 ; len -= 510) {
- *op++ = 255;
- *op++ = 255;
- }
- if (len > 254) {
- len -= 255;
- *op++ = 255;
- }
- *op++ = (u8)len;
- } else
- *token += len;
+ anchor = ip;
- /* Test end of chunk */
- if (ip > mflimit) {
- anchor = ip;
+ /* Test end of block */
+ if (ip > mflimit)
+ break;
+ if (op > oMaxSeq)
break;
- }
/* Fill table */
- hashtable[LZ4_HASH64K_VALUE(ip-2)] = (u16)(ip - 2 - base);
+ LZ4_putPosition(ip - 2, ctx->hashTable, tableType, base);
/* Test next position */
- ref = base + hashtable[LZ4_HASH64K_VALUE(ip)];
- hashtable[LZ4_HASH64K_VALUE(ip)] = (u16)(ip - base);
- if (A32(ref) == A32(ip)) {
- token = op++;
- *token = 0;
+ match = LZ4_getPosition(ip, ctx->hashTable, tableType, base);
+ LZ4_putPosition(ip, ctx->hashTable, tableType, base);
+
+ if ((match + MAX_DISTANCE >= ip)
+ && (LZ4_read32(match) == LZ4_read32(ip))) {
+ token = op++; *token = 0;
goto _next_match;
}
/* Prepare next loop */
- anchor = ip++;
- forwardh = LZ4_HASH64K_VALUE(ip);
+ forwardH = LZ4_hashPosition(++ip, tableType);
}
_last_literals:
/* Encode Last Literals */
- lastrun = (int)(iend - anchor);
- if (op + lastrun + 1 + (lastrun - RUN_MASK + 255) / 255 > oend)
- return 0;
- if (lastrun >= (int)RUN_MASK) {
- *op++ = (RUN_MASK << ML_BITS);
- lastrun -= RUN_MASK;
- for (; lastrun > 254 ; lastrun -= 255)
- *op++ = 255;
- *op++ = (u8)lastrun;
- } else
- *op++ = (lastrun << ML_BITS);
- memcpy(op, anchor, iend - anchor);
- op += iend - anchor;
+ {
+ size_t lastRunSize = (size_t)(iend - anchor);
+
+ if (op + 1 /* token */
+ + ((lastRunSize + 240) / 255) /* litLength */
+ + lastRunSize /* literals */ > oend) {
+ /* adapt lastRunSize to fill 'dst' */
+ lastRunSize = (oend - op) - 1;
+ lastRunSize -= (lastRunSize + 240) / 255;
+ }
+ ip = anchor + lastRunSize;
+
+ if (lastRunSize >= RUN_MASK) {
+ size_t accumulator = lastRunSize - RUN_MASK;
+
+ *op++ = RUN_MASK << ML_BITS;
+ for (; accumulator >= 255; accumulator -= 255)
+ *op++ = 255;
+ *op++ = (BYTE) accumulator;
+ } else {
+ *op++ = (BYTE)(lastRunSize<<ML_BITS);
+ }
+ memcpy(op, anchor, lastRunSize);
+ op += lastRunSize;
+ }
+
/* End */
- return (int)(((char *)op) - dest);
+ *srcSizePtr = (int) (((const char *)ip) - src);
+ return (int) (((char *)op) - dst);
}
-int lz4_compress(const unsigned char *src, size_t src_len,
- unsigned char *dst, size_t *dst_len, void *wrkmem)
+static int LZ4_compress_destSize_extState(
+ LZ4_stream_t *state,
+ const char *src,
+ char *dst,
+ int *srcSizePtr,
+ int targetDstSize)
{
- int ret = -1;
- int out_len = 0;
+#if LZ4_ARCH64
+ const tableType_t tableType = byU32;
+#else
+ const tableType_t tableType = byPtr;
+#endif
- if (src_len < LZ4_64KLIMIT)
- out_len = lz4_compress64kctx(wrkmem, src, dst, src_len,
- lz4_compressbound(src_len));
- else
- out_len = lz4_compressctx(wrkmem, src, dst, src_len,
- lz4_compressbound(src_len));
+ LZ4_resetStream(state);
+
+ if (targetDstSize >= LZ4_COMPRESSBOUND(*srcSizePtr)) {
+ /* compression success is guaranteed */
+ return LZ4_compress_fast_extState(
+ state, src, dst, *srcSizePtr,
+ targetDstSize, 1);
+ } else {
+ if (*srcSizePtr < LZ4_64Klimit)
+ return LZ4_compress_destSize_generic(
+ &state->internal_donotuse,
+ src, dst, srcSizePtr,
+ targetDstSize, byU16);
+ else
+ return LZ4_compress_destSize_generic(
+ &state->internal_donotuse,
+ src, dst, srcSizePtr,
+ targetDstSize, tableType);
+ }
+}
+
+
+int LZ4_compress_destSize(
+ const char *src,
+ char *dst,
+ int *srcSizePtr,
+ int targetDstSize,
+ void *wrkmem)
+{
+ return LZ4_compress_destSize_extState(wrkmem, src, dst, srcSizePtr,
+ targetDstSize);
+}
+EXPORT_SYMBOL(LZ4_compress_destSize);
+
+/*-******************************
+ * Streaming functions
+ ********************************/
+void LZ4_resetStream(LZ4_stream_t *LZ4_stream)
+{
+ memset(LZ4_stream, 0, sizeof(LZ4_stream_t));
+}
+
+int LZ4_loadDict(LZ4_stream_t *LZ4_dict,
+ const char *dictionary, int dictSize)
+{
+ LZ4_stream_t_internal *dict = &LZ4_dict->internal_donotuse;
+ const BYTE *p = (const BYTE *)dictionary;
+ const BYTE * const dictEnd = p + dictSize;
+ const BYTE *base;
+
+ if ((dict->initCheck)
+ || (dict->currentOffset > 1 * GB)) {
+ /* Uninitialized structure, or reuse overflow */
+ LZ4_resetStream(LZ4_dict);
+ }
+
+ if (dictSize < (int)HASH_UNIT) {
+ dict->dictionary = NULL;
+ dict->dictSize = 0;
+ return 0;
+ }
+
+ if ((dictEnd - p) > 64 * KB)
+ p = dictEnd - 64 * KB;
+ dict->currentOffset += 64 * KB;
+ base = p - dict->currentOffset;
+ dict->dictionary = p;
+ dict->dictSize = (U32)(dictEnd - p);
+ dict->currentOffset += dict->dictSize;
+
+ while (p <= dictEnd - HASH_UNIT) {
+ LZ4_putPosition(p, dict->hashTable, byU32, base);
+ p += 3;
+ }
+
+ return dict->dictSize;
+}
+EXPORT_SYMBOL(LZ4_loadDict);
+
+static void LZ4_renormDictT(LZ4_stream_t_internal *LZ4_dict,
+ const BYTE *src)
+{
+ if ((LZ4_dict->currentOffset > 0x80000000) ||
+ ((uptrval)LZ4_dict->currentOffset > (uptrval)src)) {
+ /* address space overflow */
+ /* rescale hash table */
+ U32 const delta = LZ4_dict->currentOffset - 64 * KB;
+ const BYTE *dictEnd = LZ4_dict->dictionary + LZ4_dict->dictSize;
+ int i;
+
+ for (i = 0; i < LZ4_HASH_SIZE_U32; i++) {
+ if (LZ4_dict->hashTable[i] < delta)
+ LZ4_dict->hashTable[i] = 0;
+ else
+ LZ4_dict->hashTable[i] -= delta;
+ }
+ LZ4_dict->currentOffset = 64 * KB;
+ if (LZ4_dict->dictSize > 64 * KB)
+ LZ4_dict->dictSize = 64 * KB;
+ LZ4_dict->dictionary = dictEnd - LZ4_dict->dictSize;
+ }
+}
+
+int LZ4_saveDict(LZ4_stream_t *LZ4_dict, char *safeBuffer, int dictSize)
+{
+ LZ4_stream_t_internal * const dict = &LZ4_dict->internal_donotuse;
+ const BYTE * const previousDictEnd = dict->dictionary + dict->dictSize;
+
+ if ((U32)dictSize > 64 * KB) {
+ /* useless to define a dictionary > 64 * KB */
+ dictSize = 64 * KB;
+ }
+ if ((U32)dictSize > dict->dictSize)
+ dictSize = dict->dictSize;
+
+ memmove(safeBuffer, previousDictEnd - dictSize, dictSize);
+
+ dict->dictionary = (const BYTE *)safeBuffer;
+ dict->dictSize = (U32)dictSize;
+
+ return dictSize;
+}
+EXPORT_SYMBOL(LZ4_saveDict);
+
+int LZ4_compress_fast_continue(LZ4_stream_t *LZ4_stream, const char *source,
+ char *dest, int inputSize, int maxOutputSize, int acceleration)
+{
+ LZ4_stream_t_internal *streamPtr = &LZ4_stream->internal_donotuse;
+ const BYTE * const dictEnd = streamPtr->dictionary
+ + streamPtr->dictSize;
- if (out_len < 0)
- goto exit;
+ const BYTE *smallest = (const BYTE *) source;
- *dst_len = out_len;
+ if (streamPtr->initCheck) {
+ /* Uninitialized structure detected */
+ return 0;
+ }
+
+ if ((streamPtr->dictSize > 0) && (smallest > dictEnd))
+ smallest = dictEnd;
+
+ LZ4_renormDictT(streamPtr, smallest);
+
+ if (acceleration < 1)
+ acceleration = LZ4_ACCELERATION_DEFAULT;
+
+ /* Check overlapping input/dictionary space */
+ {
+ const BYTE *sourceEnd = (const BYTE *) source + inputSize;
+
+ if ((sourceEnd > streamPtr->dictionary)
+ && (sourceEnd < dictEnd)) {
+ streamPtr->dictSize = (U32)(dictEnd - sourceEnd);
+ if (streamPtr->dictSize > 64 * KB)
+ streamPtr->dictSize = 64 * KB;
+ if (streamPtr->dictSize < 4)
+ streamPtr->dictSize = 0;
+ streamPtr->dictionary = dictEnd - streamPtr->dictSize;
+ }
+ }
- return 0;
-exit:
- return ret;
+ /* prefix mode : source data follows dictionary */
+ if (dictEnd == (const BYTE *)source) {
+ int result;
+
+ if ((streamPtr->dictSize < 64 * KB) &&
+ (streamPtr->dictSize < streamPtr->currentOffset)) {
+ result = LZ4_compress_generic(
+ streamPtr, source, dest, inputSize,
+ maxOutputSize, limitedOutput, byU32,
+ withPrefix64k, dictSmall, acceleration);
+ } else {
+ result = LZ4_compress_generic(
+ streamPtr, source, dest, inputSize,
+ maxOutputSize, limitedOutput, byU32,
+ withPrefix64k, noDictIssue, acceleration);
+ }
+ streamPtr->dictSize += (U32)inputSize;
+ streamPtr->currentOffset += (U32)inputSize;
+ return result;
+ }
+
+ /* external dictionary mode */
+ {
+ int result;
+
+ if ((streamPtr->dictSize < 64 * KB) &&
+ (streamPtr->dictSize < streamPtr->currentOffset)) {
+ result = LZ4_compress_generic(
+ streamPtr, source, dest, inputSize,
+ maxOutputSize, limitedOutput, byU32,
+ usingExtDict, dictSmall, acceleration);
+ } else {
+ result = LZ4_compress_generic(
+ streamPtr, source, dest, inputSize,
+ maxOutputSize, limitedOutput, byU32,
+ usingExtDict, noDictIssue, acceleration);
+ }
+ streamPtr->dictionary = (const BYTE *)source;
+ streamPtr->dictSize = (U32)inputSize;
+ streamPtr->currentOffset += (U32)inputSize;
+ return result;
+ }
}
-EXPORT_SYMBOL(lz4_compress);
+EXPORT_SYMBOL(LZ4_compress_fast_continue);
MODULE_LICENSE("Dual BSD/GPL");
MODULE_DESCRIPTION("LZ4 compressor");
projects / karo-tx-linux.git / blobdiff