v4.19.13 snapshot.
diff --git a/lib/lz4/lz4hc_compress.c b/lib/lz4/lz4hc_compress.c
new file mode 100644
index 0000000..176f03b
--- /dev/null
+++ b/lib/lz4/lz4hc_compress.c
@@ -0,0 +1,769 @@
+/*
+ * LZ4 HC - High Compression Mode of LZ4
+ * Copyright (C) 2011-2015, 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 <linux/string.h> /* memset */
+
+/* *************************************
+ * Local Constants and types
+ ***************************************/
+
+#define OPTIMAL_ML (int)((ML_MASK - 1) + MINMATCH)
+
+#define HASH_FUNCTION(i) (((i) * 2654435761U) \
+ >> ((MINMATCH*8) - LZ4HC_HASH_LOG))
+#define DELTANEXTU16(p) chainTable[(U16)(p)] /* faster */
+
+static U32 LZ4HC_hashPtr(const void *ptr)
+{
+ return HASH_FUNCTION(LZ4_read32(ptr));
+}
+
+/**************************************
+ * HC Compression
+ **************************************/
+static void LZ4HC_init(LZ4HC_CCtx_internal *hc4, const BYTE *start)
+{
+ memset((void *)hc4->hashTable, 0, sizeof(hc4->hashTable));
+ memset(hc4->chainTable, 0xFF, sizeof(hc4->chainTable));
+ hc4->nextToUpdate = 64 * KB;
+ hc4->base = start - 64 * KB;
+ hc4->end = start;
+ hc4->dictBase = start - 64 * KB;
+ hc4->dictLimit = 64 * KB;
+ hc4->lowLimit = 64 * KB;
+}
+
+/* Update chains up to ip (excluded) */
+static FORCE_INLINE void LZ4HC_Insert(LZ4HC_CCtx_internal *hc4,
+ const BYTE *ip)
+{
+ U16 * const chainTable = hc4->chainTable;
+ U32 * const hashTable = hc4->hashTable;
+ const BYTE * const base = hc4->base;
+ U32 const target = (U32)(ip - base);
+ U32 idx = hc4->nextToUpdate;
+
+ while (idx < target) {
+ U32 const h = LZ4HC_hashPtr(base + idx);
+ size_t delta = idx - hashTable[h];
+
+ if (delta > MAX_DISTANCE)
+ delta = MAX_DISTANCE;
+
+ DELTANEXTU16(idx) = (U16)delta;
+
+ hashTable[h] = idx;
+ idx++;
+ }
+
+ hc4->nextToUpdate = target;
+}
+
+static FORCE_INLINE int LZ4HC_InsertAndFindBestMatch(
+ LZ4HC_CCtx_internal *hc4, /* Index table will be updated */
+ const BYTE *ip,
+ const BYTE * const iLimit,
+ const BYTE **matchpos,
+ const int maxNbAttempts)
+{
+ U16 * const chainTable = hc4->chainTable;
+ U32 * const HashTable = hc4->hashTable;
+ const BYTE * const base = hc4->base;
+ const BYTE * const dictBase = hc4->dictBase;
+ const U32 dictLimit = hc4->dictLimit;
+ const U32 lowLimit = (hc4->lowLimit + 64 * KB > (U32)(ip - base))
+ ? hc4->lowLimit
+ : (U32)(ip - base) - (64 * KB - 1);
+ U32 matchIndex;
+ int nbAttempts = maxNbAttempts;
+ size_t ml = 0;
+
+ /* HC4 match finder */
+ LZ4HC_Insert(hc4, ip);
+ matchIndex = HashTable[LZ4HC_hashPtr(ip)];
+
+ while ((matchIndex >= lowLimit)
+ && (nbAttempts)) {
+ nbAttempts--;
+ if (matchIndex >= dictLimit) {
+ const BYTE * const match = base + matchIndex;
+
+ if (*(match + ml) == *(ip + ml)
+ && (LZ4_read32(match) == LZ4_read32(ip))) {
+ size_t const mlt = LZ4_count(ip + MINMATCH,
+ match + MINMATCH, iLimit) + MINMATCH;
+
+ if (mlt > ml) {
+ ml = mlt;
+ *matchpos = match;
+ }
+ }
+ } else {
+ const BYTE * const match = dictBase + matchIndex;
+
+ if (LZ4_read32(match) == LZ4_read32(ip)) {
+ size_t mlt;
+ const BYTE *vLimit = ip
+ + (dictLimit - matchIndex);
+
+ if (vLimit > iLimit)
+ vLimit = iLimit;
+ mlt = LZ4_count(ip + MINMATCH,
+ match + MINMATCH, vLimit) + MINMATCH;
+ if ((ip + mlt == vLimit)
+ && (vLimit < iLimit))
+ mlt += LZ4_count(ip + mlt,
+ base + dictLimit,
+ iLimit);
+ if (mlt > ml) {
+ /* virtual matchpos */
+ ml = mlt;
+ *matchpos = base + matchIndex;
+ }
+ }
+ }
+ matchIndex -= DELTANEXTU16(matchIndex);
+ }
+
+ return (int)ml;
+}
+
+static FORCE_INLINE int LZ4HC_InsertAndGetWiderMatch(
+ LZ4HC_CCtx_internal *hc4,
+ const BYTE * const ip,
+ const BYTE * const iLowLimit,
+ const BYTE * const iHighLimit,
+ int longest,
+ const BYTE **matchpos,
+ const BYTE **startpos,
+ const int maxNbAttempts)
+{
+ U16 * const chainTable = hc4->chainTable;
+ U32 * const HashTable = hc4->hashTable;
+ const BYTE * const base = hc4->base;
+ const U32 dictLimit = hc4->dictLimit;
+ const BYTE * const lowPrefixPtr = base + dictLimit;
+ const U32 lowLimit = (hc4->lowLimit + 64 * KB > (U32)(ip - base))
+ ? hc4->lowLimit
+ : (U32)(ip - base) - (64 * KB - 1);
+ const BYTE * const dictBase = hc4->dictBase;
+ U32 matchIndex;
+ int nbAttempts = maxNbAttempts;
+ int delta = (int)(ip - iLowLimit);
+
+ /* First Match */
+ LZ4HC_Insert(hc4, ip);
+ matchIndex = HashTable[LZ4HC_hashPtr(ip)];
+
+ while ((matchIndex >= lowLimit)
+ && (nbAttempts)) {
+ nbAttempts--;
+ if (matchIndex >= dictLimit) {
+ const BYTE *matchPtr = base + matchIndex;
+
+ if (*(iLowLimit + longest)
+ == *(matchPtr - delta + longest)) {
+ if (LZ4_read32(matchPtr) == LZ4_read32(ip)) {
+ int mlt = MINMATCH + LZ4_count(
+ ip + MINMATCH,
+ matchPtr + MINMATCH,
+ iHighLimit);
+ int back = 0;
+
+ while ((ip + back > iLowLimit)
+ && (matchPtr + back > lowPrefixPtr)
+ && (ip[back - 1] == matchPtr[back - 1]))
+ back--;
+
+ mlt -= back;
+
+ if (mlt > longest) {
+ longest = (int)mlt;
+ *matchpos = matchPtr + back;
+ *startpos = ip + back;
+ }
+ }
+ }
+ } else {
+ const BYTE * const matchPtr = dictBase + matchIndex;
+
+ if (LZ4_read32(matchPtr) == LZ4_read32(ip)) {
+ size_t mlt;
+ int back = 0;
+ const BYTE *vLimit = ip + (dictLimit - matchIndex);
+
+ if (vLimit > iHighLimit)
+ vLimit = iHighLimit;
+
+ mlt = LZ4_count(ip + MINMATCH,
+ matchPtr + MINMATCH, vLimit) + MINMATCH;
+
+ if ((ip + mlt == vLimit) && (vLimit < iHighLimit))
+ mlt += LZ4_count(ip + mlt, base + dictLimit,
+ iHighLimit);
+ while ((ip + back > iLowLimit)
+ && (matchIndex + back > lowLimit)
+ && (ip[back - 1] == matchPtr[back - 1]))
+ back--;
+
+ mlt -= back;
+
+ if ((int)mlt > longest) {
+ longest = (int)mlt;
+ *matchpos = base + matchIndex + back;
+ *startpos = ip + back;
+ }
+ }
+ }
+
+ matchIndex -= DELTANEXTU16(matchIndex);
+ }
+
+ return longest;
+}
+
+static FORCE_INLINE int LZ4HC_encodeSequence(
+ const BYTE **ip,
+ BYTE **op,
+ const BYTE **anchor,
+ int matchLength,
+ const BYTE * const match,
+ limitedOutput_directive limitedOutputBuffer,
+ BYTE *oend)
+{
+ int length;
+ BYTE *token;
+
+ /* Encode Literal length */
+ length = (int)(*ip - *anchor);
+ token = (*op)++;
+
+ if ((limitedOutputBuffer)
+ && ((*op + (length>>8)
+ + length + (2 + 1 + LASTLITERALS)) > oend)) {
+ /* Check output limit */
+ return 1;
+ }
+ if (length >= (int)RUN_MASK) {
+ int len;
+
+ *token = (RUN_MASK<<ML_BITS);
+ len = length - RUN_MASK;
+ for (; len > 254 ; len -= 255)
+ *(*op)++ = 255;
+ *(*op)++ = (BYTE)len;
+ } else
+ *token = (BYTE)(length<<ML_BITS);
+
+ /* Copy Literals */
+ LZ4_wildCopy(*op, *anchor, (*op) + length);
+ *op += length;
+
+ /* Encode Offset */
+ LZ4_writeLE16(*op, (U16)(*ip - match));
+ *op += 2;
+
+ /* Encode MatchLength */
+ length = (int)(matchLength - MINMATCH);
+
+ if ((limitedOutputBuffer)
+ && (*op + (length>>8)
+ + (1 + LASTLITERALS) > oend)) {
+ /* Check output limit */
+ return 1;
+ }
+
+ 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;
+ }
+
+ *(*op)++ = (BYTE)length;
+ } else
+ *token += (BYTE)(length);
+
+ /* Prepare next loop */
+ *ip += matchLength;
+ *anchor = *ip;
+
+ return 0;
+}
+
+static int LZ4HC_compress_generic(
+ LZ4HC_CCtx_internal *const ctx,
+ const char * const source,
+ char * const dest,
+ int const inputSize,
+ int const maxOutputSize,
+ int compressionLevel,
+ limitedOutput_directive limit
+ )
+{
+ const BYTE *ip = (const BYTE *) source;
+ const BYTE *anchor = ip;
+ const BYTE * const iend = ip + inputSize;
+ const BYTE * const mflimit = iend - MFLIMIT;
+ const BYTE * const matchlimit = (iend - LASTLITERALS);
+
+ BYTE *op = (BYTE *) dest;
+ BYTE * const oend = op + maxOutputSize;
+
+ unsigned int maxNbAttempts;
+ int ml, ml2, ml3, ml0;
+ const BYTE *ref = NULL;
+ const BYTE *start2 = NULL;
+ const BYTE *ref2 = NULL;
+ const BYTE *start3 = NULL;
+ const BYTE *ref3 = NULL;
+ const BYTE *start0;
+ const BYTE *ref0;
+
+ /* init */
+ if (compressionLevel > LZ4HC_MAX_CLEVEL)
+ compressionLevel = LZ4HC_MAX_CLEVEL;
+ if (compressionLevel < 1)
+ compressionLevel = LZ4HC_DEFAULT_CLEVEL;
+ maxNbAttempts = 1 << (compressionLevel - 1);
+ ctx->end += inputSize;
+
+ ip++;
+
+ /* Main Loop */
+ while (ip < mflimit) {
+ ml = LZ4HC_InsertAndFindBestMatch(ctx, ip,
+ matchlimit, (&ref), maxNbAttempts);
+ if (!ml) {
+ ip++;
+ continue;
+ }
+
+ /* saved, in case we would skip too much */
+ start0 = ip;
+ ref0 = ref;
+ ml0 = ml;
+
+_Search2:
+ if (ip + ml < mflimit)
+ ml2 = LZ4HC_InsertAndGetWiderMatch(ctx,
+ ip + ml - 2, ip + 0,
+ matchlimit, ml, &ref2,
+ &start2, maxNbAttempts);
+ else
+ ml2 = ml;
+
+ if (ml2 == ml) {
+ /* No better match */
+ if (LZ4HC_encodeSequence(&ip, &op,
+ &anchor, ml, ref, limit, oend))
+ return 0;
+ continue;
+ }
+
+ if (start0 < ip) {
+ if (start2 < ip + ml0) {
+ /* empirical */
+ ip = start0;
+ ref = ref0;
+ ml = ml0;
+ }
+ }
+
+ /* Here, start0 == ip */
+ if ((start2 - ip) < 3) {
+ /* First Match too small : removed */
+ ml = ml2;
+ ip = start2;
+ ref = ref2;
+ goto _Search2;
+ }
+
+_Search3:
+ /*
+ * Currently we have :
+ * ml2 > ml1, and
+ * ip1 + 3 <= ip2 (usually < ip1 + ml1)
+ */
+ if ((start2 - ip) < OPTIMAL_ML) {
+ int correction;
+ int new_ml = ml;
+
+ if (new_ml > OPTIMAL_ML)
+ new_ml = OPTIMAL_ML;
+ if (ip + new_ml > start2 + ml2 - MINMATCH)
+ new_ml = (int)(start2 - ip) + ml2 - MINMATCH;
+
+ correction = new_ml - (int)(start2 - ip);
+
+ if (correction > 0) {
+ start2 += correction;
+ ref2 += correction;
+ ml2 -= correction;
+ }
+ }
+ /*
+ * Now, we have start2 = ip + new_ml,
+ * with new_ml = min(ml, OPTIMAL_ML = 18)
+ */
+
+ if (start2 + ml2 < mflimit)
+ ml3 = LZ4HC_InsertAndGetWiderMatch(ctx,
+ start2 + ml2 - 3, start2,
+ matchlimit, ml2, &ref3, &start3,
+ maxNbAttempts);
+ else
+ ml3 = ml2;
+
+ if (ml3 == ml2) {
+ /* No better match : 2 sequences to encode */
+ /* ip & ref are known; Now for ml */
+ if (start2 < ip + ml)
+ ml = (int)(start2 - ip);
+ /* Now, encode 2 sequences */
+ if (LZ4HC_encodeSequence(&ip, &op, &anchor,
+ ml, ref, limit, oend))
+ return 0;
+ ip = start2;
+ if (LZ4HC_encodeSequence(&ip, &op, &anchor,
+ ml2, ref2, limit, oend))
+ return 0;
+ continue;
+ }
+
+ if (start3 < ip + ml + 3) {
+ /* Not enough space for match 2 : remove it */
+ if (start3 >= (ip + ml)) {
+ /* can write Seq1 immediately
+ * ==> Seq2 is removed,
+ * so Seq3 becomes Seq1
+ */
+ if (start2 < ip + ml) {
+ int correction = (int)(ip + ml - start2);
+
+ start2 += correction;
+ ref2 += correction;
+ ml2 -= correction;
+ if (ml2 < MINMATCH) {
+ start2 = start3;
+ ref2 = ref3;
+ ml2 = ml3;
+ }
+ }
+
+ if (LZ4HC_encodeSequence(&ip, &op, &anchor,
+ ml, ref, limit, oend))
+ return 0;
+ ip = start3;
+ ref = ref3;
+ ml = ml3;
+
+ start0 = start2;
+ ref0 = ref2;
+ ml0 = ml2;
+ goto _Search2;
+ }
+
+ start2 = start3;
+ ref2 = ref3;
+ ml2 = ml3;
+ goto _Search3;
+ }
+
+ /*
+ * OK, now we have 3 ascending matches;
+ * let's write at least the first one
+ * ip & ref are known; Now for ml
+ */
+ if (start2 < ip + ml) {
+ if ((start2 - ip) < (int)ML_MASK) {
+ int correction;
+
+ if (ml > OPTIMAL_ML)
+ ml = OPTIMAL_ML;
+ if (ip + ml > start2 + ml2 - MINMATCH)
+ ml = (int)(start2 - ip) + ml2 - MINMATCH;
+ correction = ml - (int)(start2 - ip);
+ if (correction > 0) {
+ start2 += correction;
+ ref2 += correction;
+ ml2 -= correction;
+ }
+ } else
+ ml = (int)(start2 - ip);
+ }
+ if (LZ4HC_encodeSequence(&ip, &op, &anchor, ml,
+ ref, limit, oend))
+ return 0;
+
+ ip = start2;
+ ref = ref2;
+ ml = ml2;
+
+ start2 = start3;
+ ref2 = ref3;
+ ml2 = ml3;
+
+ goto _Search3;
+ }
+
+ /* Encode Last Literals */
+ {
+ int lastRun = (int)(iend - anchor);
+
+ if ((limit)
+ && (((char *)op - dest) + lastRun + 1
+ + ((lastRun + 255 - RUN_MASK)/255)
+ > (U32)maxOutputSize)) {
+ /* Check output limit */
+ return 0;
+ }
+ if (lastRun >= (int)RUN_MASK) {
+ *op++ = (RUN_MASK<<ML_BITS);
+ lastRun -= RUN_MASK;
+ for (; lastRun > 254 ; lastRun -= 255)
+ *op++ = 255;
+ *op++ = (BYTE) lastRun;
+ } else
+ *op++ = (BYTE)(lastRun<<ML_BITS);
+ memcpy(op, anchor, iend - anchor);
+ op += iend - anchor;
+ }
+
+ /* End */
+ return (int) (((char *)op) - dest);
+}
+
+static int LZ4_compress_HC_extStateHC(
+ void *state,
+ const char *src,
+ char *dst,
+ int srcSize,
+ int maxDstSize,
+ int compressionLevel)
+{
+ LZ4HC_CCtx_internal *ctx = &((LZ4_streamHC_t *)state)->internal_donotuse;
+
+ if (((size_t)(state)&(sizeof(void *) - 1)) != 0) {
+ /* Error : state is not aligned
+ * for pointers (32 or 64 bits)
+ */
+ return 0;
+ }
+
+ LZ4HC_init(ctx, (const BYTE *)src);
+
+ if (maxDstSize < LZ4_compressBound(srcSize))
+ return LZ4HC_compress_generic(ctx, src, dst,
+ srcSize, maxDstSize, compressionLevel, limitedOutput);
+ else
+ return LZ4HC_compress_generic(ctx, src, dst,
+ srcSize, maxDstSize, compressionLevel, noLimit);
+}
+
+int LZ4_compress_HC(const char *src, char *dst, int srcSize,
+ int maxDstSize, int compressionLevel, void *wrkmem)
+{
+ return LZ4_compress_HC_extStateHC(wrkmem, src, dst,
+ srcSize, maxDstSize, compressionLevel);
+}
+EXPORT_SYMBOL(LZ4_compress_HC);
+
+/**************************************
+ * Streaming Functions
+ **************************************/
+void LZ4_resetStreamHC(LZ4_streamHC_t *LZ4_streamHCPtr, int compressionLevel)
+{
+ LZ4_streamHCPtr->internal_donotuse.base = NULL;
+ LZ4_streamHCPtr->internal_donotuse.compressionLevel = (unsigned int)compressionLevel;
+}
+
+int LZ4_loadDictHC(LZ4_streamHC_t *LZ4_streamHCPtr,
+ const char *dictionary,
+ int dictSize)
+{
+ LZ4HC_CCtx_internal *ctxPtr = &LZ4_streamHCPtr->internal_donotuse;
+
+ if (dictSize > 64 * KB) {
+ dictionary += dictSize - 64 * KB;
+ dictSize = 64 * KB;
+ }
+ LZ4HC_init(ctxPtr, (const BYTE *)dictionary);
+ if (dictSize >= 4)
+ LZ4HC_Insert(ctxPtr, (const BYTE *)dictionary + (dictSize - 3));
+ ctxPtr->end = (const BYTE *)dictionary + dictSize;
+ return dictSize;
+}
+EXPORT_SYMBOL(LZ4_loadDictHC);
+
+/* compression */
+
+static void LZ4HC_setExternalDict(
+ LZ4HC_CCtx_internal *ctxPtr,
+ const BYTE *newBlock)
+{
+ if (ctxPtr->end >= ctxPtr->base + 4) {
+ /* Referencing remaining dictionary content */
+ LZ4HC_Insert(ctxPtr, ctxPtr->end - 3);
+ }
+
+ /*
+ * Only one memory segment for extDict,
+ * so any previous extDict is lost at this stage
+ */
+ ctxPtr->lowLimit = ctxPtr->dictLimit;
+ ctxPtr->dictLimit = (U32)(ctxPtr->end - ctxPtr->base);
+ ctxPtr->dictBase = ctxPtr->base;
+ ctxPtr->base = newBlock - ctxPtr->dictLimit;
+ ctxPtr->end = newBlock;
+ /* match referencing will resume from there */
+ ctxPtr->nextToUpdate = ctxPtr->dictLimit;
+}
+EXPORT_SYMBOL(LZ4HC_setExternalDict);
+
+static int LZ4_compressHC_continue_generic(
+ LZ4_streamHC_t *LZ4_streamHCPtr,
+ const char *source,
+ char *dest,
+ int inputSize,
+ int maxOutputSize,
+ limitedOutput_directive limit)
+{
+ LZ4HC_CCtx_internal *ctxPtr = &LZ4_streamHCPtr->internal_donotuse;
+
+ /* auto - init if forgotten */
+ if (ctxPtr->base == NULL)
+ LZ4HC_init(ctxPtr, (const BYTE *) source);
+
+ /* Check overflow */
+ if ((size_t)(ctxPtr->end - ctxPtr->base) > 2 * GB) {
+ size_t dictSize = (size_t)(ctxPtr->end - ctxPtr->base)
+ - ctxPtr->dictLimit;
+ if (dictSize > 64 * KB)
+ dictSize = 64 * KB;
+ LZ4_loadDictHC(LZ4_streamHCPtr,
+ (const char *)(ctxPtr->end) - dictSize, (int)dictSize);
+ }
+
+ /* Check if blocks follow each other */
+ if ((const BYTE *)source != ctxPtr->end)
+ LZ4HC_setExternalDict(ctxPtr, (const BYTE *)source);
+
+ /* Check overlapping input/dictionary space */
+ {
+ const BYTE *sourceEnd = (const BYTE *) source + inputSize;
+ const BYTE * const dictBegin = ctxPtr->dictBase + ctxPtr->lowLimit;
+ const BYTE * const dictEnd = ctxPtr->dictBase + ctxPtr->dictLimit;
+
+ if ((sourceEnd > dictBegin)
+ && ((const BYTE *)source < dictEnd)) {
+ if (sourceEnd > dictEnd)
+ sourceEnd = dictEnd;
+ ctxPtr->lowLimit = (U32)(sourceEnd - ctxPtr->dictBase);
+
+ if (ctxPtr->dictLimit - ctxPtr->lowLimit < 4)
+ ctxPtr->lowLimit = ctxPtr->dictLimit;
+ }
+ }
+
+ return LZ4HC_compress_generic(ctxPtr, source, dest,
+ inputSize, maxOutputSize, ctxPtr->compressionLevel, limit);
+}
+
+int LZ4_compress_HC_continue(
+ LZ4_streamHC_t *LZ4_streamHCPtr,
+ const char *source,
+ char *dest,
+ int inputSize,
+ int maxOutputSize)
+{
+ if (maxOutputSize < LZ4_compressBound(inputSize))
+ return LZ4_compressHC_continue_generic(LZ4_streamHCPtr,
+ source, dest, inputSize, maxOutputSize, limitedOutput);
+ else
+ return LZ4_compressHC_continue_generic(LZ4_streamHCPtr,
+ source, dest, inputSize, maxOutputSize, noLimit);
+}
+EXPORT_SYMBOL(LZ4_compress_HC_continue);
+
+/* dictionary saving */
+
+int LZ4_saveDictHC(
+ LZ4_streamHC_t *LZ4_streamHCPtr,
+ char *safeBuffer,
+ int dictSize)
+{
+ LZ4HC_CCtx_internal *const streamPtr = &LZ4_streamHCPtr->internal_donotuse;
+ int const prefixSize = (int)(streamPtr->end
+ - (streamPtr->base + streamPtr->dictLimit));
+
+ if (dictSize > 64 * KB)
+ dictSize = 64 * KB;
+ if (dictSize < 4)
+ dictSize = 0;
+ if (dictSize > prefixSize)
+ dictSize = prefixSize;
+
+ memmove(safeBuffer, streamPtr->end - dictSize, dictSize);
+
+ {
+ U32 const endIndex = (U32)(streamPtr->end - streamPtr->base);
+
+ streamPtr->end = (const BYTE *)safeBuffer + dictSize;
+ streamPtr->base = streamPtr->end - endIndex;
+ streamPtr->dictLimit = endIndex - dictSize;
+ streamPtr->lowLimit = endIndex - dictSize;
+
+ if (streamPtr->nextToUpdate < streamPtr->dictLimit)
+ streamPtr->nextToUpdate = streamPtr->dictLimit;
+ }
+ return dictSize;
+}
+EXPORT_SYMBOL(LZ4_saveDictHC);
+
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_DESCRIPTION("LZ4 HC compressor");