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Release 4.16 lib/lz4/lz4_compress.c

Directory: lib/lz4
/*
 * LZ4 - Fast LZ compression algorithm
 * 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
 * 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
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * 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://www.lz4.org
 *      - LZ4 source repository : https://github.com/lz4/lz4
 *
 *      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 <asm/unaligned.h>


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) { if (tableType == byU16) return ((sequence * 2654435761U) >> ((MINMATCH * 8) - (LZ4_HASHLOG + 1))); else return ((sequence * 2654435761U) >> ((MINMATCH * 8) - LZ4_HASHLOG)); }

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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 static const U64 prime8bytes = 11400714785074694791ULL; return (U32)(((sequence >> 24) * prime8bytes) >> (64 - hashLog)); #endif }

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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); }

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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; } } }

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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); }

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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; } }

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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); }

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/* * 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 */ LZ4_putPosition(ip, dictPtr->hashTable, tableType, base); ip++; forwardH = LZ4_hashPosition(ip, tableType); /* Main Loop */ for ( ; ; ) { const BYTE *match; BYTE *token; /* Find a match */ { 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) & (match + refDelta > lowLimit)) && (unlikely(ip[-1] == match[refDelta - 1]))) { ip--; match--; } /* Encode Literals */ { unsigned const int litLength = (unsigned int)(ip - anchor); 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; } _next_match: /* Encode Offset */ LZ4_writeLE16(op, (U16)(ip - match)); op += 2; /* Encode MatchLength */ { 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; } 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) break; /* Fill table */ LZ4_putPosition(ip - 2, dictPtr->hashTable, tableType, base); /* Test next position */ 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 */ forwardH = LZ4_hashPosition(++ip, tableType); } _last_literals: /* Encode Last Literals */ { 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); } memcpy(op, anchor, lastRun); op += lastRun; } /* End */ return (int) (((char *)op) - dest); }

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static int LZ4_compress_fast_extState( void *state, const char *source, char *dest, int inputSize, int maxOutputSize, int acceleration) { 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); } }

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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); }

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EXPORT_SYMBOL(LZ4_compress_fast);
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); }

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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 */ *srcSizePtr = 0; LZ4_putPosition(ip, ctx->hashTable, tableType, base); ip++; forwardH = LZ4_hashPosition(ip, tableType); /* Main Loop */ for ( ; ; ) { const BYTE *match; BYTE *token; /* Find a match */ { 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) && (match > lowLimit) && (unlikely(ip[-1] == match[-1]))) { ip--; match--; } /* Encode Literal length */ { unsigned int litLength = (unsigned int)(ip - anchor); 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_writeLE16(op, (U16)(ip - match)); op += 2; /* Encode MatchLength */ { size_t matchLength = LZ4_count(ip + MINMATCH, match + MINMATCH, matchlimit); if (op + ((matchLength + 240)/255) > oMaxMatch) { /* Match description too long : reduce it */ matchLength = (15 - 1) + (oMaxMatch - op) * 255; } 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); } anchor = ip; /* Test end of block */ if (ip > mflimit) break; if (op > oMaxSeq) break; /* Fill table */ LZ4_putPosition(ip - 2, ctx->hashTable, tableType, base); /* Test next position */ 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 */ forwardH = LZ4_hashPosition(++ip, tableType); } _last_literals: /* Encode Last Literals */ { 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 */ *srcSizePtr = (int) (((const char *)ip) - src); return (int) (((char *)op) - dst); }

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static int LZ4_compress_destSize_extState( LZ4_stream_t *state, const char *src, char *dst, int *srcSizePtr, int targetDstSize) { #if LZ4_ARCH64 const tableType_t tableType = byU32; #else const tableType_t tableType = byPtr; #endif 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); } }

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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); }

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EXPORT_SYMBOL(LZ4_compress_destSize); /*-****************************** * Streaming functions ********************************/
void LZ4_resetStream(LZ4_stream_t *LZ4_stream) { memset(LZ4_stream, 0, sizeof(LZ4_stream_t)); }

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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; }

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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; } }

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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; }

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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; const BYTE *smallest = (const BYTE *) source; 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; } } /* 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; } }

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EXPORT_SYMBOL(LZ4_compress_fast_continue); MODULE_LICENSE("Dual BSD/GPL"); MODULE_DESCRIPTION("LZ4 compressor");

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Directory: lib/lz4
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