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Merge pull request #503 from lz4/l120

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minor length reduction of several large lines
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Yann Collet 2018-04-19 11:50:20 -07:00 committed by GitHub
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4 changed files with 132 additions and 66 deletions
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50
doc/lz4frame_manual.html
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@ -30,9 +30,9 @@
<a name="Chapter3"></a><h2>Error management</h2><pre></pre>
<pre><b>unsigned LZ4F_isError(LZ4F_errorCode_t code); </b>/**< tells if a `LZ4F_errorCode_t` function result is an error code */<b>
<pre><b>unsigned LZ4F_isError(LZ4F_errorCode_t code); </b>/**< tells when a function result is an error code */<b>
</b></pre><BR>
<pre><b>const char* LZ4F_getErrorName(LZ4F_errorCode_t code); </b>/**< return error code string; useful for debugging */<b>
<pre><b>const char* LZ4F_getErrorName(LZ4F_errorCode_t code); </b>/**< return error code string; for debugging */<b>
</b></pre><BR>
<a name="Chapter4"></a><h2>Frame compression types</h2><pre></pre>
@ -74,13 +74,13 @@
} LZ4F_frameType_t;
</b></pre><BR>
<pre><b>typedef struct {
LZ4F_blockSizeID_t blockSizeID; </b>/* max64KB, max256KB, max1MB, max4MB ; 0 == default */<b>
LZ4F_blockMode_t blockMode; </b>/* LZ4F_blockLinked, LZ4F_blockIndependent ; 0 == default */<b>
LZ4F_contentChecksum_t contentChecksumFlag; </b>/* if enabled, frame is terminated with a 32-bits checksum of decompressed data ; 0 == disabled (default) */<b>
LZ4F_frameType_t frameType; </b>/* read-only field : LZ4F_frame or LZ4F_skippableFrame */<b>
unsigned long long contentSize; </b>/* Size of uncompressed content ; 0 == unknown */<b>
unsigned dictID; </b>/* Dictionary ID, sent by the compressor to help decoder select the correct dictionary; 0 == no dictID provided */<b>
LZ4F_blockChecksum_t blockChecksumFlag; </b>/* if enabled, each block is followed by a checksum of block's compressed data ; 0 == disabled (default) */<b>
LZ4F_blockSizeID_t blockSizeID; </b>/* max64KB, max256KB, max1MB, max4MB; 0 == default */<b>
LZ4F_blockMode_t blockMode; </b>/* LZ4F_blockLinked, LZ4F_blockIndependent; 0 == default */<b>
LZ4F_contentChecksum_t contentChecksumFlag; </b>/* 1: frame terminated with 32-bit checksum of decompressed data; 0: disabled (default) */<b>
LZ4F_frameType_t frameType; </b>/* read-only field : LZ4F_frame or LZ4F_skippableFrame */<b>
unsigned long long contentSize; </b>/* Size of uncompressed content ; 0 == unknown */<b>
unsigned dictID; </b>/* Dictionary ID, sent by compressor to help decoder select correct dictionary; 0 == no dictID provided */<b>
LZ4F_blockChecksum_t blockChecksumFlag; </b>/* 1: each block followed by a checksum of block's compressed data; 0: disabled (default) */<b>
} LZ4F_frameInfo_t;
</b><p> makes it possible to set or read frame parameters.
It's not required to set all fields, as long as the structure was initially memset() to zero.
@ -89,7 +89,7 @@
<pre><b>typedef struct {
LZ4F_frameInfo_t frameInfo;
int compressionLevel; </b>/* 0 == default (fast mode); values above LZ4HC_CLEVEL_MAX count as LZ4HC_CLEVEL_MAX; values below 0 trigger "fast acceleration", proportional to value */<b>
int compressionLevel; </b>/* 0: default (fast mode); values > LZ4HC_CLEVEL_MAX count as LZ4HC_CLEVEL_MAX; values < 0 trigger "fast acceleration" */<b>
unsigned autoFlush; </b>/* 1 == always flush, to reduce usage of internal buffers */<b>
unsigned reserved[4]; </b>/* must be zero for forward compatibility */<b>
} LZ4F_preferences_t;
@ -165,34 +165,42 @@ LZ4F_errorCode_t LZ4F_freeCompressionContext(LZ4F_cctx* cctx);
</p></pre><BR>
<pre><b>size_t LZ4F_compressUpdate(LZ4F_cctx* cctx, void* dstBuffer, size_t dstCapacity, const void* srcBuffer, size_t srcSize, const LZ4F_compressOptions_t* cOptPtr);
<pre><b>size_t LZ4F_compressUpdate(LZ4F_cctx* cctx,
void* dstBuffer, size_t dstCapacity,
const void* srcBuffer, size_t srcSize,
const LZ4F_compressOptions_t* cOptPtr);
</b><p> LZ4F_compressUpdate() can be called repetitively to compress as much data as necessary.
An important rule is that dstCapacity MUST be large enough to ensure operation success even in worst case situations.
Important rule: dstCapacity MUST be large enough to ensure operation success even in worst case situations.
This value is provided by LZ4F_compressBound().
If this condition is not respected, LZ4F_compress() will fail (result is an errorCode).
LZ4F_compressUpdate() doesn't guarantee error recovery. When an error occurs, compression context must be freed or resized.
LZ4F_compressUpdate() doesn't guarantee error recovery.
When an error occurs, compression context must be freed or resized.
`cOptPtr` is optional : NULL can be provided, in which case all options are set to default.
@return : number of bytes written into `dstBuffer` (it can be zero, meaning input data was just buffered).
or an error code if it fails (which can be tested using LZ4F_isError())
</p></pre><BR>
<pre><b>size_t LZ4F_flush(LZ4F_cctx* cctx, void* dstBuffer, size_t dstCapacity, const LZ4F_compressOptions_t* cOptPtr);
<pre><b>size_t LZ4F_flush(LZ4F_cctx* cctx,
void* dstBuffer, size_t dstCapacity,
const LZ4F_compressOptions_t* cOptPtr);
</b><p> When data must be generated and sent immediately, without waiting for a block to be completely filled,
it's possible to call LZ4_flush(). It will immediately compress any data buffered within cctx.
`dstCapacity` must be large enough to ensure the operation will be successful.
`cOptPtr` is optional : it's possible to provide NULL, all options will be set to default.
@return : number of bytes written into dstBuffer (it can be zero, which means there was no data stored within cctx)
@return : nb of bytes written into dstBuffer (can be zero, when there is no data stored within cctx)
or an error code if it fails (which can be tested using LZ4F_isError())
</p></pre><BR>
<pre><b>size_t LZ4F_compressEnd(LZ4F_cctx* cctx, void* dstBuffer, size_t dstCapacity, const LZ4F_compressOptions_t* cOptPtr);
<pre><b>size_t LZ4F_compressEnd(LZ4F_cctx* cctx,
void* dstBuffer, size_t dstCapacity,
const LZ4F_compressOptions_t* cOptPtr);
</b><p> To properly finish an LZ4 frame, invoke LZ4F_compressEnd().
It will flush whatever data remained within `cctx` (like LZ4_flush())
and properly finalize the frame, with an endMark and a checksum.
`cOptPtr` is optional : NULL can be provided, in which case all options will be set to default.
@return : number of bytes written into dstBuffer (necessarily >= 4 (endMark), or 8 if optional frame checksum is enabled)
@return : nb of bytes written into dstBuffer, necessarily >= 4 (endMark),
or an error code if it fails (which can be tested using LZ4F_isError())
A successful call to LZ4F_compressEnd() makes `cctx` available again for another compression task.
@ -201,7 +209,7 @@ LZ4F_errorCode_t LZ4F_freeCompressionContext(LZ4F_cctx* cctx);
<a name="Chapter9"></a><h2>Decompression functions</h2><pre></pre>
<pre><b>typedef struct {
unsigned stableDst; </b>/* pledge that at least 64KB+64Bytes of previously decompressed data remain unmodifed where it was decoded. This optimization skips storage operations in tmp buffers */<b>
unsigned stableDst; </b>/* pledges that last 64KB decompressed data will remain available unmodified. This optimization skips storage operations in tmp buffers. */<b>
unsigned reserved[3]; </b>/* must be set to zero for forward compatibility */<b>
} LZ4F_decompressOptions_t;
</b></pre><BR>
@ -212,7 +220,7 @@ LZ4F_errorCode_t LZ4F_freeDecompressionContext(LZ4F_dctx* dctx);
The function provides a pointer to an allocated and initialized LZ4F_dctx object.
The result is an errorCode, which can be tested using LZ4F_isError().
dctx memory can be released using LZ4F_freeDecompressionContext();
The result of LZ4F_freeDecompressionContext() is indicative of the current state of decompressionContext when being released.
Result of LZ4F_freeDecompressionContext() indicates current state of decompressionContext when being released.
That is, it should be == 0 if decompression has been completed fully and correctly.
</p></pre><BR>
@ -252,8 +260,8 @@ LZ4F_errorCode_t LZ4F_freeDecompressionContext(LZ4F_dctx* dctx);
The function will read up to *srcSizePtr bytes from srcBuffer,
and decompress data into dstBuffer, of capacity *dstSizePtr.
The number of bytes consumed from srcBuffer will be written into *srcSizePtr (necessarily <= original value).
The number of bytes decompressed into dstBuffer will be written into *dstSizePtr (necessarily <= original value).
The nb of bytes consumed from srcBuffer will be written into *srcSizePtr (necessarily <= original value).
The nb of bytes decompressed into dstBuffer will be written into *dstSizePtr (necessarily <= original value).
The function does not necessarily read all input bytes, so always check value in *srcSizePtr.
Unconsumed source data must be presented again in subsequent invocations.

4
lib/Makefile
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@ -116,6 +116,10 @@ clean:
#-----------------------------------------------------------------------------
ifneq (,$(filter $(shell uname),Linux Darwin GNU/kFreeBSD GNU OpenBSD FreeBSD NetBSD DragonFly SunOS))
.PHONY: listL120
listL120: # extract lines >= 120 characters in *.{c,h}, by Takayuki Matsuoka (note : $$, for Makefile compatibility)
find . -type f -name '*.c' -o -name '*.h' | while read -r filename; do awk 'length > 120 {print FILENAME "(" FNR "): " $$0}' $$filename; done
DESTDIR ?=
# directory variables : GNU conventions prefer lowercase
# see https://www.gnu.org/prep/standards/html_node/Makefile-Conventions.html

94
lib/lz4.c
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@ -69,7 +69,9 @@
* Prefer these methods in priority order (0 > 1 > 2)
*/
#ifndef LZ4_FORCE_MEMORY_ACCESS /* can be defined externally */
# if defined(__GNUC__) && ( defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) || defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6Z__) || defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6T2__) )
# if defined(__GNUC__) && \
( defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) || defined(__ARM_ARCH_6K__) \
|| defined(__ARM_ARCH_6Z__) || defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6T2__) )
# define LZ4_FORCE_MEMORY_ACCESS 2
# elif (defined(__INTEL_COMPILER) && !defined(_WIN32)) || defined(__GNUC__)
# define LZ4_FORCE_MEMORY_ACCESS 1
@ -80,7 +82,7 @@
* LZ4_FORCE_SW_BITCOUNT
* Define this parameter if your target system or compiler does not support hardware bit count
*/
#if defined(_MSC_VER) && defined(_WIN32_WCE) /* Visual Studio for Windows CE does not support Hardware bit count */
#if defined(_MSC_VER) && defined(_WIN32_WCE) /* Visual Studio for WinCE doesn't support Hardware bit count */
# define LZ4_FORCE_SW_BITCOUNT
#endif
@ -322,7 +324,7 @@ static const int LZ4_minLength = (MFLIMIT+1);
# endif
#endif
#define LZ4_STATIC_ASSERT(c) { enum { LZ4_static_assert = 1/(int)(!!(c)) }; } /* use only *after* variable declarations */
#define LZ4_STATIC_ASSERT(c) { enum { LZ4_static_assert = 1/(int)(!!(c)) }; } /* use after variable declarations */
#if defined(LZ4_DEBUG) && (LZ4_DEBUG>=2)
# include <stdio.h>
@ -533,7 +535,9 @@ static void LZ4_putIndexOnHash(U32 idx, U32 h, void* tableBase, tableType_t cons
}
}
static void LZ4_putPositionOnHash(const BYTE* p, U32 h, void* tableBase, tableType_t const tableType, const BYTE* srcBase)
static void LZ4_putPositionOnHash(const BYTE* p, U32 h,
void* tableBase, tableType_t const tableType,
const BYTE* srcBase)
{
switch (tableType)
{
@ -559,8 +563,16 @@ LZ4_FORCE_INLINE void LZ4_putPosition(const BYTE* p, void* tableBase, tableType_
static U32 LZ4_getIndexOnHash(U32 h, const void* tableBase, tableType_t tableType)
{
LZ4_STATIC_ASSERT(LZ4_MEMORY_USAGE > 2);
if (tableType == byU32) { const U32* const hashTable = (const U32*) tableBase; assert(h < (1U << (LZ4_MEMORY_USAGE-2))); return hashTable[h]; }
if (tableType == byU16) { const U16* const hashTable = (const U16*) tableBase; assert(h < (1U << (LZ4_MEMORY_USAGE-1))); return hashTable[h]; }
if (tableType == byU32) {
const U32* const hashTable = (const U32*) tableBase;
assert(h < (1U << (LZ4_MEMORY_USAGE-2)));
return hashTable[h];
}
if (tableType == byU16) {
const U16* const hashTable = (const U16*) tableBase;
assert(h < (1U << (LZ4_MEMORY_USAGE-1)));
return hashTable[h];
}
assert(0); return 0; /* forbidden case */
}
@ -571,7 +583,9 @@ static const BYTE* LZ4_getPositionOnHash(U32 h, const void* tableBase, tableType
{ const U16* const hashTable = (const U16*) tableBase; return hashTable[h] + srcBase; } /* default, to ensure a return */
}
LZ4_FORCE_INLINE const BYTE* LZ4_getPosition(const BYTE* p, const void* tableBase, tableType_t tableType, const BYTE* srcBase)
LZ4_FORCE_INLINE const BYTE* LZ4_getPosition(const BYTE* p,
const void* tableBase, tableType_t tableType,
const BYTE* srcBase)
{
U32 const h = LZ4_hashPosition(p, tableType);
return LZ4_getPositionOnHash(h, tableBase, tableType, srcBase);
@ -654,7 +668,7 @@ LZ4_FORCE_INLINE int LZ4_compress_generic(
/* the dictCtx currentOffset is indexed on the start of the dictionary,
* while a dictionary in the current context precedes the currentOffset */
const BYTE* dictBase = dictDirective == usingDictCtx ?
dictionary + dictSize - dictCtx->currentOffset : /* is it possible that dictCtx->currentOffset != dictCtx->dictSize ? Yes if the dictionary context is not reset */
dictionary + dictSize - dictCtx->currentOffset :
dictionary + dictSize - startIndex;
BYTE* op = (BYTE*) dest;
@ -671,7 +685,7 @@ LZ4_FORCE_INLINE int LZ4_compress_generic(
lowLimit = (const BYTE*)source - (dictDirective == withPrefix64k ? dictSize : 0);
if ((tableType == byU16) && (inputSize>=LZ4_64Klimit)) return 0; /* Size too large (not within 64K limit) */
if ((tableType == byU16) && (inputSize>=LZ4_64Klimit)) return 0; /* Size too large (not within 64K limit) */
/* Update context state */
if (dictDirective == usingDictCtx) {
@ -685,7 +699,7 @@ LZ4_FORCE_INLINE int LZ4_compress_generic(
cctx->currentOffset += (U32)inputSize;
cctx->tableType = tableType;
if (inputSize<LZ4_minLength) goto _last_literals; /* Input too small, no compression (all literals) */
if (inputSize<LZ4_minLength) goto _last_literals; /* Input too small, no compression (all literals) */
/* First Byte */
LZ4_putPosition(ip, cctx->hashTable, tableType, base);
@ -794,7 +808,8 @@ LZ4_FORCE_INLINE int LZ4_compress_generic(
/* Copy Literals */
LZ4_wildCopy(op, anchor, op+litLength);
op+=litLength;
DEBUGLOG(6, "seq.start:%i, literals=%u, match.start:%i", (int)(anchor-(const BYTE*)source), litLength, (int)(ip-(const BYTE*)source));
DEBUGLOG(6, "seq.start:%i, literals=%u, match.start:%i",
(int)(anchor-(const BYTE*)source), litLength, (int)(ip-(const BYTE*)source));
}
_next_match:
@ -909,7 +924,8 @@ _next_match:
token=op++;
*token=0;
if (maybe_extMem) offset = current - matchIndex;
DEBUGLOG(6, "seq.start:%i, literals=%u, match.start:%i", (int)(anchor-(const BYTE*)source), 0, (int)(ip-(const BYTE*)source));
DEBUGLOG(6, "seq.start:%i, literals=%u, match.start:%i",
(int)(anchor-(const BYTE*)source), 0, (int)(ip-(const BYTE*)source));
goto _next_match;
}
}
@ -1653,19 +1669,25 @@ _output_error:
LZ4_FORCE_O2_GCC_PPC64LE
int LZ4_decompress_safe(const char* source, char* dest, int compressedSize, int maxDecompressedSize)
{
return LZ4_decompress_generic(source, dest, compressedSize, maxDecompressedSize, endOnInputSize, full, 0, noDict, (BYTE*)dest, NULL, 0);
return LZ4_decompress_generic(source, dest, compressedSize, maxDecompressedSize,
endOnInputSize, full, 0, noDict,
(BYTE*)dest, NULL, 0);
}
LZ4_FORCE_O2_GCC_PPC64LE
int LZ4_decompress_safe_partial(const char* source, char* dest, int compressedSize, int targetOutputSize, int maxDecompressedSize)
{
return LZ4_decompress_generic(source, dest, compressedSize, maxDecompressedSize, endOnInputSize, partial, targetOutputSize, noDict, (BYTE*)dest, NULL, 0);
return LZ4_decompress_generic(source, dest, compressedSize, maxDecompressedSize,
endOnInputSize, partial, targetOutputSize,
noDict, (BYTE*)dest, NULL, 0);
}
LZ4_FORCE_O2_GCC_PPC64LE
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);
return LZ4_decompress_generic(source, dest, 0, originalSize,
endOnOutputSize, full, 0, withPrefix64k,
(BYTE*)(dest - 64 KB), NULL, 64 KB);
}
@ -1807,21 +1829,45 @@ int LZ4_decompress_safe_forceExtDict(const char* source, char* dest, int compres
* Obsolete Functions
***************************************************/
/* obsolete compression functions */
int LZ4_compress_limitedOutput(const char* source, char* dest, int inputSize, int maxOutputSize) { return LZ4_compress_default(source, dest, inputSize, maxOutputSize); }
int LZ4_compress(const char* source, char* dest, int inputSize) { return LZ4_compress_default(source, dest, inputSize, LZ4_compressBound(inputSize)); }
int LZ4_compress_limitedOutput_withState (void* state, const char* src, char* dst, int srcSize, int dstSize) { return LZ4_compress_fast_extState(state, src, dst, srcSize, dstSize, 1); }
int LZ4_compress_withState (void* state, const char* src, char* dst, int srcSize) { return LZ4_compress_fast_extState(state, src, dst, srcSize, LZ4_compressBound(srcSize), 1); }
int LZ4_compress_limitedOutput_continue (LZ4_stream_t* LZ4_stream, const char* src, char* dst, int srcSize, int maxDstSize) { return LZ4_compress_fast_continue(LZ4_stream, src, dst, srcSize, maxDstSize, 1); }
int LZ4_compress_continue (LZ4_stream_t* LZ4_stream, const char* source, char* dest, int inputSize) { return LZ4_compress_fast_continue(LZ4_stream, source, dest, inputSize, LZ4_compressBound(inputSize), 1); }
int LZ4_compress_limitedOutput(const char* source, char* dest, int inputSize, int maxOutputSize)
{
return LZ4_compress_default(source, dest, inputSize, maxOutputSize);
}
int LZ4_compress(const char* source, char* dest, int inputSize)
{
return LZ4_compress_default(source, dest, inputSize, LZ4_compressBound(inputSize));
}
int LZ4_compress_limitedOutput_withState (void* state, const char* src, char* dst, int srcSize, int dstSize)
{
return LZ4_compress_fast_extState(state, src, dst, srcSize, dstSize, 1);
}
int LZ4_compress_withState (void* state, const char* src, char* dst, int srcSize)
{
return LZ4_compress_fast_extState(state, src, dst, srcSize, LZ4_compressBound(srcSize), 1);
}
int LZ4_compress_limitedOutput_continue (LZ4_stream_t* LZ4_stream, const char* src, char* dst, int srcSize, int dstCapacity)
{
return LZ4_compress_fast_continue(LZ4_stream, src, dst, srcSize, dstCapacity, 1);
}
int LZ4_compress_continue (LZ4_stream_t* LZ4_stream, const char* source, char* dest, int inputSize)
{
return LZ4_compress_fast_continue(LZ4_stream, source, dest, inputSize, LZ4_compressBound(inputSize), 1);
}
/*
These function names are deprecated and should no longer be used.
These decompression functions are deprecated and should no longer be used.
They are only provided here for compatibility with older user programs.
- LZ4_uncompress is totally equivalent to LZ4_decompress_fast
- LZ4_uncompress_unknownOutputSize is totally equivalent to LZ4_decompress_safe
*/
int LZ4_uncompress (const char* source, char* dest, int outputSize) { return LZ4_decompress_fast(source, dest, outputSize); }
int LZ4_uncompress_unknownOutputSize (const char* source, char* dest, int isize, int maxOutputSize) { return LZ4_decompress_safe(source, dest, isize, maxOutputSize); }
int LZ4_uncompress (const char* source, char* dest, int outputSize)
{
return LZ4_decompress_fast(source, dest, outputSize);
}
int LZ4_uncompress_unknownOutputSize (const char* source, char* dest, int isize, int maxOutputSize)
{
return LZ4_decompress_safe(source, dest, isize, maxOutputSize);
}
/* Obsolete Streaming functions */

50
lib/lz4frame.h
View File

@ -93,8 +93,8 @@ extern "C" {
**************************************/
typedef size_t LZ4F_errorCode_t;
LZ4FLIB_API unsigned LZ4F_isError(LZ4F_errorCode_t code); /**< tells if a `LZ4F_errorCode_t` function result is an error code */
LZ4FLIB_API const char* LZ4F_getErrorName(LZ4F_errorCode_t code); /**< return error code string; useful for debugging */
LZ4FLIB_API unsigned LZ4F_isError(LZ4F_errorCode_t code); /**< tells when a function result is an error code */
LZ4FLIB_API const char* LZ4F_getErrorName(LZ4F_errorCode_t code); /**< return error code string; for debugging */
/*-************************************
@ -162,13 +162,13 @@ typedef LZ4F_contentChecksum_t contentChecksum_t;
* It's not required to set all fields, as long as the structure was initially memset() to zero.
* For all fields, 0 sets it to default value */
typedef struct {
LZ4F_blockSizeID_t blockSizeID; /* max64KB, max256KB, max1MB, max4MB ; 0 == default */
LZ4F_blockMode_t blockMode; /* LZ4F_blockLinked, LZ4F_blockIndependent ; 0 == default */
LZ4F_contentChecksum_t contentChecksumFlag; /* if enabled, frame is terminated with a 32-bits checksum of decompressed data ; 0 == disabled (default) */
LZ4F_frameType_t frameType; /* read-only field : LZ4F_frame or LZ4F_skippableFrame */
unsigned long long contentSize; /* Size of uncompressed content ; 0 == unknown */
unsigned dictID; /* Dictionary ID, sent by the compressor to help decoder select the correct dictionary; 0 == no dictID provided */
LZ4F_blockChecksum_t blockChecksumFlag; /* if enabled, each block is followed by a checksum of block's compressed data ; 0 == disabled (default) */
LZ4F_blockSizeID_t blockSizeID; /* max64KB, max256KB, max1MB, max4MB; 0 == default */
LZ4F_blockMode_t blockMode; /* LZ4F_blockLinked, LZ4F_blockIndependent; 0 == default */
LZ4F_contentChecksum_t contentChecksumFlag; /* 1: frame terminated with 32-bit checksum of decompressed data; 0: disabled (default) */
LZ4F_frameType_t frameType; /* read-only field : LZ4F_frame or LZ4F_skippableFrame */
unsigned long long contentSize; /* Size of uncompressed content ; 0 == unknown */
unsigned dictID; /* Dictionary ID, sent by compressor to help decoder select correct dictionary; 0 == no dictID provided */
LZ4F_blockChecksum_t blockChecksumFlag; /* 1: each block followed by a checksum of block's compressed data; 0: disabled (default) */
} LZ4F_frameInfo_t;
/*! LZ4F_preferences_t :
@ -177,7 +177,7 @@ typedef struct {
* All reserved fields must be set to zero. */
typedef struct {
LZ4F_frameInfo_t frameInfo;
int compressionLevel; /* 0 == default (fast mode); values above LZ4HC_CLEVEL_MAX count as LZ4HC_CLEVEL_MAX; values below 0 trigger "fast acceleration", proportional to value */
int compressionLevel; /* 0: default (fast mode); values > LZ4HC_CLEVEL_MAX count as LZ4HC_CLEVEL_MAX; values < 0 trigger "fast acceleration" */
unsigned autoFlush; /* 1 == always flush, to reduce usage of internal buffers */
unsigned reserved[4]; /* must be zero for forward compatibility */
} LZ4F_preferences_t;
@ -264,36 +264,44 @@ LZ4FLIB_API size_t LZ4F_compressBound(size_t srcSize, const LZ4F_preferences_t*
/*! LZ4F_compressUpdate() :
* LZ4F_compressUpdate() can be called repetitively to compress as much data as necessary.
* An important rule is that dstCapacity MUST be large enough to ensure operation success even in worst case situations.
* Important rule: dstCapacity MUST be large enough to ensure operation success even in worst case situations.
* This value is provided by LZ4F_compressBound().
* If this condition is not respected, LZ4F_compress() will fail (result is an errorCode).
* LZ4F_compressUpdate() doesn't guarantee error recovery. When an error occurs, compression context must be freed or resized.
* LZ4F_compressUpdate() doesn't guarantee error recovery.
* When an error occurs, compression context must be freed or resized.
* `cOptPtr` is optional : NULL can be provided, in which case all options are set to default.
* @return : number of bytes written into `dstBuffer` (it can be zero, meaning input data was just buffered).
* or an error code if it fails (which can be tested using LZ4F_isError())
*/
LZ4FLIB_API size_t LZ4F_compressUpdate(LZ4F_cctx* cctx, void* dstBuffer, size_t dstCapacity, const void* srcBuffer, size_t srcSize, const LZ4F_compressOptions_t* cOptPtr);
LZ4FLIB_API size_t LZ4F_compressUpdate(LZ4F_cctx* cctx,
void* dstBuffer, size_t dstCapacity,
const void* srcBuffer, size_t srcSize,
const LZ4F_compressOptions_t* cOptPtr);
/*! LZ4F_flush() :
* When data must be generated and sent immediately, without waiting for a block to be completely filled,
* it's possible to call LZ4_flush(). It will immediately compress any data buffered within cctx.
* `dstCapacity` must be large enough to ensure the operation will be successful.
* `cOptPtr` is optional : it's possible to provide NULL, all options will be set to default.
* @return : number of bytes written into dstBuffer (it can be zero, which means there was no data stored within cctx)
* @return : nb of bytes written into dstBuffer (can be zero, when there is no data stored within cctx)
* or an error code if it fails (which can be tested using LZ4F_isError())
*/
LZ4FLIB_API size_t LZ4F_flush(LZ4F_cctx* cctx, void* dstBuffer, size_t dstCapacity, const LZ4F_compressOptions_t* cOptPtr);
LZ4FLIB_API size_t LZ4F_flush(LZ4F_cctx* cctx,
void* dstBuffer, size_t dstCapacity,
const LZ4F_compressOptions_t* cOptPtr);
/*! LZ4F_compressEnd() :
* To properly finish an LZ4 frame, invoke LZ4F_compressEnd().
* It will flush whatever data remained within `cctx` (like LZ4_flush())
* and properly finalize the frame, with an endMark and a checksum.
* `cOptPtr` is optional : NULL can be provided, in which case all options will be set to default.
* @return : number of bytes written into dstBuffer (necessarily >= 4 (endMark), or 8 if optional frame checksum is enabled)
* @return : nb of bytes written into dstBuffer, necessarily >= 4 (endMark),
* or an error code if it fails (which can be tested using LZ4F_isError())
* A successful call to LZ4F_compressEnd() makes `cctx` available again for another compression task.
*/
LZ4FLIB_API size_t LZ4F_compressEnd(LZ4F_cctx* cctx, void* dstBuffer, size_t dstCapacity, const LZ4F_compressOptions_t* cOptPtr);
LZ4FLIB_API size_t LZ4F_compressEnd(LZ4F_cctx* cctx,
void* dstBuffer, size_t dstCapacity,
const LZ4F_compressOptions_t* cOptPtr);
/*-*********************************
@ -303,7 +311,7 @@ typedef struct LZ4F_dctx_s LZ4F_dctx; /* incomplete type */
typedef LZ4F_dctx* LZ4F_decompressionContext_t; /* compatibility with previous API versions */
typedef struct {
unsigned stableDst; /* pledge that at least 64KB+64Bytes of previously decompressed data remain unmodifed where it was decoded. This optimization skips storage operations in tmp buffers */
unsigned stableDst; /* pledges that last 64KB decompressed data will remain available unmodified. This optimization skips storage operations in tmp buffers. */
unsigned reserved[3]; /* must be set to zero for forward compatibility */
} LZ4F_decompressOptions_t;
@ -316,7 +324,7 @@ typedef struct {
* The function provides a pointer to an allocated and initialized LZ4F_dctx object.
* The result is an errorCode, which can be tested using LZ4F_isError().
* dctx memory can be released using LZ4F_freeDecompressionContext();
* The result of LZ4F_freeDecompressionContext() is indicative of the current state of decompressionContext when being released.
* Result of LZ4F_freeDecompressionContext() indicates current state of decompressionContext when being released.
* That is, it should be == 0 if decompression has been completed fully and correctly.
*/
LZ4FLIB_API LZ4F_errorCode_t LZ4F_createDecompressionContext(LZ4F_dctx** dctxPtr, unsigned version);
@ -357,8 +365,8 @@ LZ4FLIB_API size_t LZ4F_getFrameInfo(LZ4F_dctx* dctx,
* The function will read up to *srcSizePtr bytes from srcBuffer,
* and decompress data into dstBuffer, of capacity *dstSizePtr.
*
* The number of bytes consumed from srcBuffer will be written into *srcSizePtr (necessarily <= original value).
* The number of bytes decompressed into dstBuffer will be written into *dstSizePtr (necessarily <= original value).
* The nb of bytes consumed from srcBuffer will be written into *srcSizePtr (necessarily <= original value).
* The nb of bytes decompressed into dstBuffer will be written into *dstSizePtr (necessarily <= original value).
*
* The function does not necessarily read all input bytes, so always check value in *srcSizePtr.
* Unconsumed source data must be presented again in subsequent invocations.