lib/lz4: update LZ4 decompressor module (2209fda3) · Commits · 戴 / test

lib/lz4/lz4_decompress.c

+341 −140

Original line number	Diff line number	Diff line
		@@ -43,30 +43,36 @@
		/-****************************
		* Decompression functions
		*******************************/
		/* LZ4_decompress_generic() :
		* This generic decompression function cover all use cases.
		* It shall be instantiated several times, using different sets of directives
		* Note that it is important this generic function is really inlined,

		#define DEBUGLOG(l, ...) {} /* disabled */

		#ifndef assert
		#define assert(condition) ((void)0)
		#endif

		/*
		* LZ4_decompress_generic() :
		* This generic decompression function covers all use cases.
		* It shall be instantiated several times, using different sets of directives.
		* Note that it is important for performance that this function really get inlined,
		* in order to remove useless branches during compilation optimization.
		*/
		static FORCE_INLINE int LZ4_decompress_generic(
		const char * const source,
		char * const dest,
		int inputSize,
		const char * const src,
		char * const dst,
		int srcSize,
		/*
		* If endOnInput == endOnInputSize,
		* this value is the max size of Output Buffer.
		* this value is `dstCapacity`
		*/
		int outputSize,
		/* endOnOutputSize, endOnInputSize */
		int endOnInput,
		endCondition_directive endOnInput,
		/* full, partial */
		int partialDecoding,
		/* only used if partialDecoding == partial */
		int targetOutputSize,
		earlyEnd_directive partialDecoding,
		/* noDict, withPrefix64k, usingExtDict */
		int dict,
		/* == dest when no prefix */
		dict_directive dict,
		/* always <= dst, == dst when no prefix */
		const BYTE * const lowPrefix,
		/* only if dict == usingExtDict */
		const BYTE * const dictStart,
		@@ -74,35 +80,43 @@ static FORCE_INLINE int LZ4_decompress_generic(
		const size_t dictSize
		)
		{
		/* Local Variables */
		const BYTE ip = (const BYTE ) source;
		const BYTE * const iend = ip + inputSize;
		const BYTE ip = (const BYTE ) src;
		const BYTE * const iend = ip + srcSize;

		BYTE op = (BYTE ) dest;
		BYTE op = (BYTE ) dst;
		BYTE * const oend = op + outputSize;
		BYTE *cpy;
		BYTE *oexit = op + targetOutputSize;
		const BYTE * const lowLimit = lowPrefix - dictSize;

		const BYTE * const dictEnd = (const BYTE *)dictStart + dictSize;
		static const unsigned int dec32table[] = { 0, 1, 2, 1, 4, 4, 4, 4 };
		static const int dec64table[] = { 0, 0, 0, -1, 0, 1, 2, 3 };
		static const unsigned int inc32table[8] = {0, 1, 2, 1, 0, 4, 4, 4};
		static const int dec64table[8] = {0, 0, 0, -1, -4, 1, 2, 3};

		const int safeDecode = (endOnInput == endOnInputSize);
		const int checkOffset = ((safeDecode) && (dictSize < (int)(64 * KB)));

		/* Set up the "end" pointers for the shortcut. */
		const BYTE *const shortiend = iend -
		(endOnInput ? 14 : 8) /maxLL/ - 2 /offset/;
		const BYTE *const shortoend = oend -
		(endOnInput ? 14 : 8) /maxLL/ - 18 /maxML/;

		DEBUGLOG(5, "%s (srcSize:%i, dstSize:%i)", __func__,
		srcSize, outputSize);

		/* Special cases */
		/* targetOutputSize too high => decode everything */
		if ((partialDecoding) && (oexit > oend - MFLIMIT))
		oexit = oend - MFLIMIT;
		assert(lowPrefix <= op);
		assert(src != NULL);

		/* Empty output buffer */
		if ((endOnInput) && (unlikely(outputSize == 0)))
		return ((inputSize == 1) && (*ip == 0)) ? 0 : -1;
		return ((srcSize == 1) && (*ip == 0)) ? 0 : -1;

		if ((!endOnInput) && (unlikely(outputSize == 0)))
		return (*ip == 0 ? 1 : -1);

		if ((endOnInput) && unlikely(srcSize == 0))
		return -1;

		/* Main Loop : decode sequences */
		while (1) {
		size_t length;
		@@ -111,12 +125,74 @@ static FORCE_INLINE int LZ4_decompress_generic(

		/* get literal length */
		unsigned int const token = *ip++;

		length = token>>ML_BITS;

		/* ip < iend before the increment */
		assert(!endOnInput \|\| ip <= iend);

		/*
		* A two-stage shortcut for the most common case:
		* 1) If the literal length is 0..14, and there is enough
		* space, enter the shortcut and copy 16 bytes on behalf
		* of the literals (in the fast mode, only 8 bytes can be
		* safely copied this way).
		* 2) Further if the match length is 4..18, copy 18 bytes
		* in a similar manner; but we ensure that there's enough
		* space in the output for those 18 bytes earlier, upon
		* entering the shortcut (in other words, there is a
		* combined check for both stages).
		*/
		if ((endOnInput ? length != RUN_MASK : length <= 8)
		/*
		* strictly "less than" on input, to re-enter
		* the loop with at least one byte
		*/
		&& likely((endOnInput ? ip < shortiend : 1) &
		(op <= shortoend))) {
		/* Copy the literals */
		memcpy(op, ip, endOnInput ? 16 : 8);
		op += length; ip += length;

		/*
		* The second stage:
		* prepare for match copying, decode full info.
		* If it doesn't work out, the info won't be wasted.
		*/
		length = token & ML_MASK; /* match length */
		offset = LZ4_readLE16(ip);
		ip += 2;
		match = op - offset;
		assert(match <= op); /* check overflow */

		/* Do not deal with overlapping matches. */
		if ((length != ML_MASK) &&
		(offset >= 8) &&
		(dict == withPrefix64k \|\| match >= lowPrefix)) {
		/* Copy the match. */
		memcpy(op + 0, match + 0, 8);
		memcpy(op + 8, match + 8, 8);
		memcpy(op + 16, match + 16, 2);
		op += length + MINMATCH;
		/* Both stages worked, load the next token. */
		continue;
		}

		/*
		* The second stage didn't work out, but the info
		* is ready. Propel it right to the point of match
		* copying.
		*/
		goto _copy_match;
		}

		/* decode literal length */
		if (length == RUN_MASK) {
		unsigned int s;

		if (unlikely(endOnInput ? ip >= iend - RUN_MASK : 0)) {
		/* overflow detection */
		goto _output_error;
		}
		do {
		s = *ip++;
		length += s;
		@@ -125,14 +201,14 @@ static FORCE_INLINE int LZ4_decompress_generic(
		: 1) & (s == 255));

		if ((safeDecode)
		&& unlikely(
		(size_t)(op + length) < (size_t)(op))) {
		&& unlikely((uptrval)(op) +
		length < (uptrval)(op))) {
		/* overflow detection */
		goto _output_error;
		}
		if ((safeDecode)
		&& unlikely(
		(size_t)(ip + length) < (size_t)(ip))) {
		&& unlikely((uptrval)(ip) +
		length < (uptrval)(ip))) {
		/* overflow detection */
		goto _output_error;
		}
		@@ -140,16 +216,19 @@ static FORCE_INLINE int LZ4_decompress_generic(

		/* copy literals */
		cpy = op + length;
		if (((endOnInput) && ((cpy > (partialDecoding ? oexit : oend - MFLIMIT))
		LZ4_STATIC_ASSERT(MFLIMIT >= WILDCOPYLENGTH);

		if (((endOnInput) && ((cpy > oend - MFLIMIT)
		\|\| (ip + length > iend - (2 + 1 + LASTLITERALS))))
		\|\| ((!endOnInput) && (cpy > oend - WILDCOPYLENGTH))) {
		if (partialDecoding) {
		if (cpy > oend) {
		/*
		* Error :
		* write attempt beyond end of output buffer
		* Partial decoding :
		* stop in the middle of literal segment
		*/
		goto _output_error;
		cpy = oend;
		length = oend - op;
		}
		if ((endOnInput)
		&& (ip + length > iend)) {
		@@ -184,29 +263,43 @@ static FORCE_INLINE int LZ4_decompress_generic(
		memcpy(op, ip, length);
		ip += length;
		op += length;

		/* Necessarily EOF, due to parsing restrictions */
		if (!partialDecoding \|\| (cpy == oend))
		break;
		}

		} else {
		/* may overwrite up to WILDCOPYLENGTH beyond cpy */
		LZ4_wildCopy(op, ip, cpy);
		ip += length;
		op = cpy;
		}

		/* get offset */
		offset = LZ4_readLE16(ip);
		ip += 2;
		match = op - offset;

		if ((checkOffset) && (unlikely(match < lowLimit))) {
		/* get matchlength */
		length = token & ML_MASK;

		_copy_match:
		if ((checkOffset) && (unlikely(match + dictSize < lowPrefix))) {
		/* Error : offset outside buffers */
		goto _output_error;
		}

		/* costs ~1%; silence an msan warning when offset == 0 */
		/*
		* note : when partialDecoding, there is no guarantee that
		* at least 4 bytes remain available in output buffer
		*/
		if (!partialDecoding) {
		assert(oend > op);
		assert(oend - op >= 4);

		LZ4_write32(op, (U32)offset);
		}

		/* get matchlength */
		length = token & ML_MASK;
		if (length == ML_MASK) {
		unsigned int s;

		@@ -221,7 +314,7 @@ static FORCE_INLINE int LZ4_decompress_generic(

		if ((safeDecode)
		&& unlikely(
		(size_t)(op + length) < (size_t)op)) {
		(uptrval)(op) + length < (uptrval)op)) {
		/* overflow detection */
		goto _output_error;
		}
		@@ -229,24 +322,26 @@ static FORCE_INLINE int LZ4_decompress_generic(

		length += MINMATCH;

		/* check external dictionary */
		/* match starting within external dictionary */
		if ((dict == usingExtDict) && (match < lowPrefix)) {
		if (unlikely(op + length > oend - LASTLITERALS)) {
		/* doesn't respect parsing restriction */
		if (!partialDecoding)
		goto _output_error;
		length = min(length, (size_t)(oend - op));
		}

		if (length <= (size_t)(lowPrefix - match)) {
		/*
		* match can be copied as a single segment
		* from external dictionary
		* match fits entirely within external
		* dictionary : just copy
		*/
		memmove(op, dictEnd - (lowPrefix - match),
		length);
		op += length;
		} else {
		/*
		* match encompass external
		* match stretches into both external
		* dictionary and current block
		*/
		size_t const copySize = (size_t)(lowPrefix - match);
		@@ -254,7 +349,6 @@ static FORCE_INLINE int LZ4_decompress_generic(

		memcpy(op, dictEnd - copySize, copySize);
		op += copySize;

		if (restSize > (size_t)(op - lowPrefix)) {
		/* overlap copy */
		BYTE * const endOfMatch = op + restSize;
		@@ -267,23 +361,44 @@ static FORCE_INLINE int LZ4_decompress_generic(
		op += restSize;
		}
		}

		continue;
		}

		/* copy match within block */
		cpy = op + length;

		if (unlikely(offset < 8)) {
		const int dec64 = dec64table[offset];
		/*
		* partialDecoding :
		* may not respect endBlock parsing restrictions
		*/
		assert(op <= oend);
		if (partialDecoding &&
		(cpy > oend - MATCH_SAFEGUARD_DISTANCE)) {
		size_t const mlen = min(length, (size_t)(oend - op));
		const BYTE * const matchEnd = match + mlen;
		BYTE * const copyEnd = op + mlen;

		if (matchEnd > op) {
		/* overlap copy */
		while (op < copyEnd)
		op++ = match++;
		} else {
		memcpy(op, match, mlen);
		}
		op = copyEnd;
		if (op == oend)
		break;
		continue;
		}

		if (unlikely(offset < 8)) {
		op[0] = match[0];
		op[1] = match[1];
		op[2] = match[2];
		op[3] = match[3];
		match += dec32table[offset];
		match += inc32table[offset];
		memcpy(op + 4, match, 4);
		match -= dec64;
		match -= dec64table[offset];
		} else {
		LZ4_copy8(op, match);
		match += 8;
		@@ -291,7 +406,7 @@ static FORCE_INLINE int LZ4_decompress_generic(

		op += 8;

		if (unlikely(cpy > oend - 12)) {
		if (unlikely(cpy > oend - MATCH_SAFEGUARD_DISTANCE)) {
		BYTE * const oCopyLimit = oend - (WILDCOPYLENGTH - 1);

		if (cpy > oend - LASTLITERALS) {
		@@ -307,60 +422,139 @@ static FORCE_INLINE int LZ4_decompress_generic(
		match += oCopyLimit - op;
		op = oCopyLimit;
		}

		while (op < cpy)
		op++ = match++;
		} else {
		LZ4_copy8(op, match);

		if (length > 16)
		LZ4_wildCopy(op + 8, match + 8, cpy);
		}

		op = cpy; /* correction */
		op = cpy; /* wildcopy correction */
		}

		/* end of decoding */
		if (endOnInput) {
		/* Nb of output bytes decoded */
		return (int) (((char *)op) - dest);
		return (int) (((char *)op) - dst);
		} else {
		/* Nb of input bytes read */
		return (int) (((const char *)ip) - source);
		return (int) (((const char *)ip) - src);
		}

		/* Overflow error detected */
		_output_error:
		return -1;
		return (int) (-(((const char *)ip) - src)) - 1;
		}

		int LZ4_decompress_safe(const char source, char dest,
		int compressedSize, int maxDecompressedSize)
		{
		return LZ4_decompress_generic(source, dest, compressedSize,
		maxDecompressedSize, endOnInputSize, full, 0,
		return LZ4_decompress_generic(source, dest,
		compressedSize, maxDecompressedSize,
		endOnInputSize, decode_full_block,
		noDict, (BYTE *)dest, NULL, 0);
		}

		int LZ4_decompress_safe_partial(const char source, char dest,
		int compressedSize, int targetOutputSize, int maxDecompressedSize)
		int LZ4_decompress_safe_partial(const char src, char dst,
		int compressedSize, int targetOutputSize, int dstCapacity)
		{
		return LZ4_decompress_generic(source, dest, compressedSize,
		maxDecompressedSize, endOnInputSize, partial,
		targetOutputSize, noDict, (BYTE *)dest, NULL, 0);
		dstCapacity = min(targetOutputSize, dstCapacity);
		return LZ4_decompress_generic(src, dst, compressedSize, dstCapacity,
		endOnInputSize, partial_decode,
		noDict, (BYTE *)dst, NULL, 0);
		}

		int LZ4_decompress_fast(const char source, char dest, int originalSize)
		{
		return LZ4_decompress_generic(source, dest, 0, originalSize,
		endOnOutputSize, full, 0, withPrefix64k,
		(BYTE )(dest - 64 KB), NULL, 64 * KB);
		endOnOutputSize, decode_full_block,
		withPrefix64k,
		(BYTE )dest - 64 KB, NULL, 0);
		}

		/* ===== Instantiate a few more decoding cases, used more than once. ===== */

		int LZ4_decompress_safe_withPrefix64k(const char source, char dest,
		int compressedSize, int maxOutputSize)
		{
		return LZ4_decompress_generic(source, dest,
		compressedSize, maxOutputSize,
		endOnInputSize, decode_full_block,
		withPrefix64k,
		(BYTE )dest - 64 KB, NULL, 0);
		}

		static int LZ4_decompress_safe_withSmallPrefix(const char source, char dest,
		int compressedSize,
		int maxOutputSize,
		size_t prefixSize)
		{
		return LZ4_decompress_generic(source, dest,
		compressedSize, maxOutputSize,
		endOnInputSize, decode_full_block,
		noDict,
		(BYTE *)dest - prefixSize, NULL, 0);
		}

		int LZ4_decompress_safe_forceExtDict(const char source, char dest,
		int compressedSize, int maxOutputSize,
		const void *dictStart, size_t dictSize)
		{
		return LZ4_decompress_generic(source, dest,
		compressedSize, maxOutputSize,
		endOnInputSize, decode_full_block,
		usingExtDict, (BYTE *)dest,
		(const BYTE *)dictStart, dictSize);
		}

		static int LZ4_decompress_fast_extDict(const char source, char dest,
		int originalSize,
		const void *dictStart, size_t dictSize)
		{
		return LZ4_decompress_generic(source, dest,
		0, originalSize,
		endOnOutputSize, decode_full_block,
		usingExtDict, (BYTE *)dest,
		(const BYTE *)dictStart, dictSize);
		}

		/*
		* The "double dictionary" mode, for use with e.g. ring buffers: the first part
		* of the dictionary is passed as prefix, and the second via dictStart + dictSize.
		* These routines are used only once, in LZ4_decompress_*_continue().
		*/
		static FORCE_INLINE
		int LZ4_decompress_safe_doubleDict(const char source, char dest,
		int compressedSize, int maxOutputSize,
		size_t prefixSize,
		const void *dictStart, size_t dictSize)
		{
		return LZ4_decompress_generic(source, dest,
		compressedSize, maxOutputSize,
		endOnInputSize, decode_full_block,
		usingExtDict, (BYTE *)dest - prefixSize,
		(const BYTE *)dictStart, dictSize);
		}

		static FORCE_INLINE
		int LZ4_decompress_fast_doubleDict(const char source, char dest,
		int originalSize, size_t prefixSize,
		const void *dictStart, size_t dictSize)
		{
		return LZ4_decompress_generic(source, dest,
		0, originalSize,
		endOnOutputSize, decode_full_block,
		usingExtDict, (BYTE *)dest - prefixSize,
		(const BYTE *)dictStart, dictSize);
		}

		/* ===== streaming decompression functions ===== */

		int LZ4_setStreamDecode(LZ4_streamDecode_t *LZ4_streamDecode,
		const char *dictionary, int dictSize)
		{
		LZ4_streamDecode_t_internal lz4sd = (LZ4_streamDecode_t_internal ) LZ4_streamDecode;
		LZ4_streamDecode_t_internal *lz4sd =
		&LZ4_streamDecode->internal_donotuse;

		lz4sd->prefixSize = (size_t) dictSize;
		lz4sd->prefixEnd = (const BYTE *) dictionary + dictSize;
		@@ -382,30 +576,46 @@ int LZ4_setStreamDecode(LZ4_streamDecode_t *LZ4_streamDecode,
		int LZ4_decompress_safe_continue(LZ4_streamDecode_t *LZ4_streamDecode,
		const char source, char dest, int compressedSize, int maxOutputSize)
		{
		LZ4_streamDecode_t_internal *lz4sd = &LZ4_streamDecode->internal_donotuse;
		LZ4_streamDecode_t_internal *lz4sd =
		&LZ4_streamDecode->internal_donotuse;
		int result;

		if (lz4sd->prefixEnd == (BYTE *)dest) {
		result = LZ4_decompress_generic(source, dest,
		compressedSize,
		maxOutputSize,
		endOnInputSize, full, 0,
		usingExtDict, lz4sd->prefixEnd - lz4sd->prefixSize,
		lz4sd->externalDict,
		lz4sd->extDictSize);

		if (lz4sd->prefixSize == 0) {
		/* The first call, no dictionary yet. */
		assert(lz4sd->extDictSize == 0);
		result = LZ4_decompress_safe(source, dest,
		compressedSize, maxOutputSize);
		if (result <= 0)
		return result;
		lz4sd->prefixSize = result;
		lz4sd->prefixEnd = (BYTE *)dest + result;
		} else if (lz4sd->prefixEnd == (BYTE *)dest) {
		/* They're rolling the current segment. */
		if (lz4sd->prefixSize >= 64 * KB - 1)
		result = LZ4_decompress_safe_withPrefix64k(source, dest,
		compressedSize, maxOutputSize);
		else if (lz4sd->extDictSize == 0)
		result = LZ4_decompress_safe_withSmallPrefix(source,
		dest, compressedSize, maxOutputSize,
		lz4sd->prefixSize);
		else
		result = LZ4_decompress_safe_doubleDict(source, dest,
		compressedSize, maxOutputSize,
		lz4sd->prefixSize,
		lz4sd->externalDict, lz4sd->extDictSize);
		if (result <= 0)
		return result;

		lz4sd->prefixSize += result;
		lz4sd->prefixEnd += result;
		} else {
		/*
		* The buffer wraps around, or they're
		* switching to another buffer.
		*/
		lz4sd->extDictSize = lz4sd->prefixSize;
		lz4sd->externalDict = lz4sd->prefixEnd - lz4sd->extDictSize;
		result = LZ4_decompress_generic(source, dest,
		result = LZ4_decompress_safe_forceExtDict(source, dest,
		compressedSize, maxOutputSize,
		endOnInputSize, full, 0,
		usingExtDict, (BYTE *)dest,
		lz4sd->externalDict, lz4sd->extDictSize);
		if (result <= 0)
		return result;
		@@ -422,75 +632,66 @@ int LZ4_decompress_fast_continue(LZ4_streamDecode_t *LZ4_streamDecode,
		LZ4_streamDecode_t_internal *lz4sd = &LZ4_streamDecode->internal_donotuse;
		int result;

		if (lz4sd->prefixEnd == (BYTE *)dest) {
		result = LZ4_decompress_generic(source, dest, 0, originalSize,
		endOnOutputSize, full, 0,
		usingExtDict,
		lz4sd->prefixEnd - lz4sd->prefixSize,
		if (lz4sd->prefixSize == 0) {
		assert(lz4sd->extDictSize == 0);
		result = LZ4_decompress_fast(source, dest, originalSize);
		if (result <= 0)
		return result;
		lz4sd->prefixSize = originalSize;
		lz4sd->prefixEnd = (BYTE *)dest + originalSize;
		} else if (lz4sd->prefixEnd == (BYTE *)dest) {
		if (lz4sd->prefixSize >= 64 * KB - 1 \|\|
		lz4sd->extDictSize == 0)
		result = LZ4_decompress_fast(source, dest,
		originalSize);
		else
		result = LZ4_decompress_fast_doubleDict(source, dest,
		originalSize, lz4sd->prefixSize,
		lz4sd->externalDict, lz4sd->extDictSize);

		if (result <= 0)
		return result;

		lz4sd->prefixSize += originalSize;
		lz4sd->prefixEnd += originalSize;
		} else {
		lz4sd->extDictSize = lz4sd->prefixSize;
		lz4sd->externalDict = lz4sd->prefixEnd - lz4sd->extDictSize;
		result = LZ4_decompress_generic(source, dest, 0, originalSize,
		endOnOutputSize, full, 0,
		usingExtDict, (BYTE *)dest,
		lz4sd->externalDict, lz4sd->extDictSize);
		result = LZ4_decompress_fast_extDict(source, dest,
		originalSize, lz4sd->externalDict, lz4sd->extDictSize);
		if (result <= 0)
		return result;
		lz4sd->prefixSize = originalSize;
		lz4sd->prefixEnd = (BYTE *)dest + originalSize;
		}

		return result;
		}

		/*
		* Advanced decoding functions :
		* *_usingDict() :
		* These decoding functions work the same as "_continue" ones,
		* the dictionary must be explicitly provided within parameters
		*/
		static FORCE_INLINE int LZ4_decompress_usingDict_generic(const char *source,
		char *dest, int compressedSize, int maxOutputSize, int safe,
		int LZ4_decompress_safe_usingDict(const char source, char dest,
		int compressedSize, int maxOutputSize,
		const char *dictStart, int dictSize)
		{
		if (dictSize == 0)
		return LZ4_decompress_generic(source, dest,
		compressedSize, maxOutputSize, safe, full, 0,
		noDict, (BYTE *)dest, NULL, 0);
		return LZ4_decompress_safe(source, dest,
		compressedSize, maxOutputSize);
		if (dictStart+dictSize == dest) {
		if (dictSize >= (int)(64 * KB - 1))
		return LZ4_decompress_generic(source, dest,
		compressedSize, maxOutputSize, safe, full, 0,
		withPrefix64k, (BYTE )dest - 64 KB, NULL, 0);
		return LZ4_decompress_generic(source, dest, compressedSize,
		maxOutputSize, safe, full, 0, noDict,
		(BYTE *)dest - dictSize, NULL, 0);
		if (dictSize >= 64 * KB - 1)
		return LZ4_decompress_safe_withPrefix64k(source, dest,
		compressedSize, maxOutputSize);
		return LZ4_decompress_safe_withSmallPrefix(source, dest,
		compressedSize, maxOutputSize, dictSize);
		}
		return LZ4_decompress_generic(source, dest, compressedSize,
		maxOutputSize, safe, full, 0, usingExtDict,
		(BYTE )dest, (const BYTE )dictStart, dictSize);
		return LZ4_decompress_safe_forceExtDict(source, dest,
		compressedSize, maxOutputSize, dictStart, dictSize);
		}

		int LZ4_decompress_safe_usingDict(const char source, char dest,
		int compressedSize, int maxOutputSize,
		int LZ4_decompress_fast_usingDict(const char source, char dest,
		int originalSize,
		const char *dictStart, int dictSize)
		{
		return LZ4_decompress_usingDict_generic(source, dest,
		compressedSize, maxOutputSize, 1, dictStart, dictSize);
		}
		if (dictSize == 0 \|\| dictStart + dictSize == dest)
		return LZ4_decompress_fast(source, dest, originalSize);

		int LZ4_decompress_fast_usingDict(const char source, char dest,
		int originalSize, const char *dictStart, int dictSize)
		{
		return LZ4_decompress_usingDict_generic(source, dest, 0,
		originalSize, 0, dictStart, dictSize);
		return LZ4_decompress_fast_extDict(source, dest, originalSize,
		dictStart, dictSize);
		}

		#ifndef STATIC

lib/lz4/lz4defs.h

+8 −1

Original line number	Diff line number	Diff line
		@@ -75,6 +75,11 @@ typedef uintptr_t uptrval;
		#define WILDCOPYLENGTH 8
		#define LASTLITERALS 5
		#define MFLIMIT (WILDCOPYLENGTH + MINMATCH)
		/*
		* ensure it's possible to write 2 x wildcopyLength
		* without overflowing output buffer
		*/
		#define MATCH_SAFEGUARD_DISTANCE ((2 * WILDCOPYLENGTH) - MINMATCH)

		/* Increase this value ==> compression run slower on incompressible data */
		#define LZ4_SKIPTRIGGER 6
		@@ -222,6 +227,8 @@ typedef enum { noDict = 0, withPrefix64k, usingExtDict } dict_directive;
		typedef enum { noDictIssue = 0, dictSmall } dictIssue_directive;

		typedef enum { endOnOutputSize = 0, endOnInputSize = 1 } endCondition_directive;
		typedef enum { full = 0, partial = 1 } earlyEnd_directive;
		typedef enum { decode_full_block = 0, partial_decode = 1 } earlyEnd_directive;

		#define LZ4_STATIC_ASSERT(c) BUILD_BUG_ON(!(c))

		#endif

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