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Merge pull request #5001 from ThomasWaldmann/upgrade-lz4-master 

upgrade bundled lz4 to 1.9.2
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TW 2020-03-08 21:38:22 +01:00 committed by GitHub
parent de2bbf7c0c 6a37af5f8b
commit 108c590c02
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src/borg/algorithms/lz4/lib/lz4.c
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src/borg/algorithms/lz4/lib/lz4.h
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@ -46,24 +46,31 @@ extern "C" {
/** /**
Introduction Introduction
LZ4 is lossless compression algorithm, providing compression speed at 500 MB/s per core, LZ4 is lossless compression algorithm, providing compression speed >500 MB/s per core,
scalable with multi-cores CPU. It features an extremely fast decoder, with speed in scalable with multi-cores CPU. It features an extremely fast decoder, with speed in
multiple GB/s per core, typically reaching RAM speed limits on multi-core systems. multiple GB/s per core, typically reaching RAM speed limits on multi-core systems.
The LZ4 compression library provides in-memory compression and decompression functions. The LZ4 compression library provides in-memory compression and decompression functions.
It gives full buffer control to user.
Compression can be done in: Compression can be done in:
- a single step (described as Simple Functions) - a single step (described as Simple Functions)
- a single step, reusing a context (described in Advanced Functions) - a single step, reusing a context (described in Advanced Functions)
- unbounded multiple steps (described as Streaming compression) - unbounded multiple steps (described as Streaming compression)
lz4.h provides block compression functions. It gives full buffer control to user. lz4.h generates and decodes LZ4-compressed blocks (doc/lz4_Block_format.md).
Decompressing an lz4-compressed block also requires metadata (such as compressed size). Decompressing such a compressed block requires additional metadata.
Each application is free to encode such metadata in whichever way it wants. Exact metadata depends on exact decompression function.
For the typical case of LZ4_decompress_safe(),
metadata includes block's compressed size, and maximum bound of decompressed size.
Each application is free to encode and pass such metadata in whichever way it wants.
An additional format, called LZ4 frame specification (doc/lz4_Frame_format.md), lz4.h only handle blocks, it can not generate Frames.
take care of encoding standard metadata alongside LZ4-compressed blocks.
Frame format is required for interoperability. Blocks are different from Frames (doc/lz4_Frame_format.md).
It is delivered through a companion API, declared in lz4frame.h. Frames bundle both blocks and metadata in a specified manner.
Embedding metadata is required for compressed data to be self-contained and portable.
Frame format is delivered through a companion API, declared in lz4frame.h.
The `lz4` CLI can only manage frames.
*/ */
/*^*************************************************************** /*^***************************************************************
@ -92,8 +99,8 @@ extern "C" {
/*------ Version ------*/ /*------ Version ------*/
#define LZ4_VERSION_MAJOR 1 /* for breaking interface changes */ #define LZ4_VERSION_MAJOR 1 /* for breaking interface changes */
#define LZ4_VERSION_MINOR 8 /* for new (non-breaking) interface capabilities */ #define LZ4_VERSION_MINOR 9 /* for new (non-breaking) interface capabilities */
#define LZ4_VERSION_RELEASE 3 /* for tweaks, bug-fixes, or development */ #define LZ4_VERSION_RELEASE 2 /* for tweaks, bug-fixes, or development */
#define LZ4_VERSION_NUMBER (LZ4_VERSION_MAJOR *100*100 + LZ4_VERSION_MINOR *100 + LZ4_VERSION_RELEASE) #define LZ4_VERSION_NUMBER (LZ4_VERSION_MAJOR *100*100 + LZ4_VERSION_MINOR *100 + LZ4_VERSION_RELEASE)
@ -103,7 +110,7 @@ extern "C" {
#define LZ4_VERSION_STRING LZ4_EXPAND_AND_QUOTE(LZ4_LIB_VERSION) #define LZ4_VERSION_STRING LZ4_EXPAND_AND_QUOTE(LZ4_LIB_VERSION)
LZ4LIB_API int LZ4_versionNumber (void); /**< library version number; useful to check dll version */ LZ4LIB_API int LZ4_versionNumber (void); /**< library version number; useful to check dll version */
LZ4LIB_API const char* LZ4_versionString (void); /**< library version string; unseful to check dll version */ LZ4LIB_API const char* LZ4_versionString (void); /**< library version string; useful to check dll version */
/*-************************************ /*-************************************
@ -112,40 +119,48 @@ LZ4LIB_API const char* LZ4_versionString (void); /**< library version string;
/*! /*!
* LZ4_MEMORY_USAGE : * LZ4_MEMORY_USAGE :
* Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.) * Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.)
* Increasing memory usage improves compression ratio * Increasing memory usage improves compression ratio.
* Reduced memory usage may improve speed, thanks to cache effect * Reduced memory usage may improve speed, thanks to better cache locality.
* Default value is 14, for 16KB, which nicely fits into Intel x86 L1 cache * Default value is 14, for 16KB, which nicely fits into Intel x86 L1 cache
*/ */
#ifndef LZ4_MEMORY_USAGE #ifndef LZ4_MEMORY_USAGE
# define LZ4_MEMORY_USAGE 14 # define LZ4_MEMORY_USAGE 14
#endif #endif
/*-************************************ /*-************************************
* Simple Functions * Simple Functions
**************************************/ **************************************/
/*! LZ4_compress_default() : /*! LZ4_compress_default() :
Compresses 'srcSize' bytes from buffer 'src' * Compresses 'srcSize' bytes from buffer 'src'
into already allocated 'dst' buffer of size 'dstCapacity'. * into already allocated 'dst' buffer of size 'dstCapacity'.
Compression is guaranteed to succeed if 'dstCapacity' >= LZ4_compressBound(srcSize). * Compression is guaranteed to succeed if 'dstCapacity' >= LZ4_compressBound(srcSize).
It also runs faster, so it's a recommended setting. * It also runs faster, so it's a recommended setting.
If the function cannot compress 'src' into a more limited 'dst' budget, * If the function cannot compress 'src' into a more limited 'dst' budget,
compression stops *immediately*, and the function result is zero. * compression stops *immediately*, and the function result is zero.
Note : as a consequence, 'dst' content is not valid. * In which case, 'dst' content is undefined (invalid).
Note 2 : This function is protected against buffer overflow scenarios (never writes outside 'dst' buffer, nor read outside 'source' buffer). * srcSize : max supported value is LZ4_MAX_INPUT_SIZE.
srcSize : max supported value is LZ4_MAX_INPUT_SIZE. * dstCapacity : size of buffer 'dst' (which must be already allocated)
dstCapacity : size of buffer 'dst' (which must be already allocated) * @return : the number of bytes written into buffer 'dst' (necessarily <= dstCapacity)
return : the number of bytes written into buffer 'dst' (necessarily <= dstCapacity) * or 0 if compression fails
or 0 if compression fails */ * Note : This function is protected against buffer overflow scenarios (never writes outside 'dst' buffer, nor read outside 'source' buffer).
*/
LZ4LIB_API int LZ4_compress_default(const char* src, char* dst, int srcSize, int dstCapacity); LZ4LIB_API int LZ4_compress_default(const char* src, char* dst, int srcSize, int dstCapacity);
/*! LZ4_decompress_safe() : /*! LZ4_decompress_safe() :
compressedSize : is the exact complete size of the compressed block. * compressedSize : is the exact complete size of the compressed block.
dstCapacity : is the size of destination buffer, which must be already allocated. * dstCapacity : is the size of destination buffer (which must be already allocated), presumed an upper bound of decompressed size.
return : the number of bytes decompressed into destination buffer (necessarily <= dstCapacity) * @return : the number of bytes decompressed into destination buffer (necessarily <= dstCapacity)
If destination buffer is not large enough, decoding will stop and output an error code (negative value). * If destination buffer is not large enough, decoding will stop and output an error code (negative value).
If the source stream is detected malformed, the function will stop decoding and return a negative result. * If the source stream is detected malformed, the function will stop decoding and return a negative result.
This function is protected against malicious data packets. * Note 1 : This function is protected against malicious data packets :
*/ * it will never writes outside 'dst' buffer, nor read outside 'source' buffer,
* even if the compressed block is maliciously modified to order the decoder to do these actions.
* In such case, the decoder stops immediately, and considers the compressed block malformed.
* Note 2 : compressedSize and dstCapacity must be provided to the function, the compressed block does not contain them.
* The implementation is free to send / store / derive this information in whichever way is most beneficial.
* If there is a need for a different format which bundles together both compressed data and its metadata, consider looking at lz4frame.h instead.
*/
LZ4LIB_API int LZ4_decompress_safe (const char* src, char* dst, int compressedSize, int dstCapacity); LZ4LIB_API int LZ4_decompress_safe (const char* src, char* dst, int compressedSize, int dstCapacity);
@ -155,8 +170,7 @@ LZ4LIB_API int LZ4_decompress_safe (const char* src, char* dst, int compressedSi
#define LZ4_MAX_INPUT_SIZE 0x7E000000 /* 2 113 929 216 bytes */ #define LZ4_MAX_INPUT_SIZE 0x7E000000 /* 2 113 929 216 bytes */
#define LZ4_COMPRESSBOUND(isize) ((unsigned)(isize) > (unsigned)LZ4_MAX_INPUT_SIZE ? 0 : (isize) + ((isize)/255) + 16) #define LZ4_COMPRESSBOUND(isize) ((unsigned)(isize) > (unsigned)LZ4_MAX_INPUT_SIZE ? 0 : (isize) + ((isize)/255) + 16)
/*! /*! LZ4_compressBound() :
LZ4_compressBound() :
Provides the maximum size that LZ4 compression may output in a "worst case" scenario (input data not compressible) Provides the maximum size that LZ4 compression may output in a "worst case" scenario (input data not compressible)
This function is primarily useful for memory allocation purposes (destination buffer size). This function is primarily useful for memory allocation purposes (destination buffer size).
Macro LZ4_COMPRESSBOUND() is also provided for compilation-time evaluation (stack memory allocation for example). Macro LZ4_COMPRESSBOUND() is also provided for compilation-time evaluation (stack memory allocation for example).
@ -167,8 +181,7 @@ LZ4_compressBound() :
*/ */
LZ4LIB_API int LZ4_compressBound(int inputSize); LZ4LIB_API int LZ4_compressBound(int inputSize);
/*! /*! LZ4_compress_fast() :
LZ4_compress_fast() :
Same as LZ4_compress_default(), but allows selection of "acceleration" factor. Same as LZ4_compress_default(), but allows selection of "acceleration" factor.
The larger the acceleration value, the faster the algorithm, but also the lesser the compression. The larger the acceleration value, the faster the algorithm, but also the lesser the compression.
It's a trade-off. It can be fine tuned, with each successive value providing roughly +~3% to speed. It's a trade-off. It can be fine tuned, with each successive value providing roughly +~3% to speed.
@ -178,13 +191,12 @@ LZ4_compress_fast() :
LZ4LIB_API int LZ4_compress_fast (const char* src, char* dst, int srcSize, int dstCapacity, int acceleration); LZ4LIB_API int LZ4_compress_fast (const char* src, char* dst, int srcSize, int dstCapacity, int acceleration);
/*! /*! LZ4_compress_fast_extState() :
LZ4_compress_fast_extState() : * Same as LZ4_compress_fast(), using an externally allocated memory space for its state.
Same compression function, just using an externally allocated memory space to store compression state. * Use LZ4_sizeofState() to know how much memory must be allocated,
Use LZ4_sizeofState() to know how much memory must be allocated, * and allocate it on 8-bytes boundaries (using `malloc()` typically).
and allocate it on 8-bytes boundaries (using malloc() typically). * Then, provide this buffer as `void* state` to compression function.
Then, provide this buffer as 'void* state' to compression function. */
*/
LZ4LIB_API int LZ4_sizeofState(void); LZ4LIB_API int LZ4_sizeofState(void);
LZ4LIB_API int LZ4_compress_fast_extState (void* state, const char* src, char* dst, int srcSize, int dstCapacity, int acceleration); LZ4LIB_API int LZ4_compress_fast_extState (void* state, const char* src, char* dst, int srcSize, int dstCapacity, int acceleration);
@ -204,27 +216,6 @@ LZ4LIB_API int LZ4_compress_fast_extState (void* state, const char* src, char* d
LZ4LIB_API int LZ4_compress_destSize (const char* src, char* dst, int* srcSizePtr, int targetDstSize); LZ4LIB_API int LZ4_compress_destSize (const char* src, char* dst, int* srcSizePtr, int targetDstSize);
/*! LZ4_decompress_fast() : **unsafe!**
* This function used to be a bit faster than LZ4_decompress_safe(),
* though situation has changed in recent versions,
* and now `LZ4_decompress_safe()` can be as fast and sometimes faster than `LZ4_decompress_fast()`.
* Moreover, LZ4_decompress_fast() is not protected vs malformed input, as it doesn't perform full validation of compressed data.
* As a consequence, this function is no longer recommended, and may be deprecated in future versions.
* It's only remaining specificity is that it can decompress data without knowing its compressed size.
*
* originalSize : is the uncompressed size to regenerate.
* `dst` must be already allocated, its size must be >= 'originalSize' bytes.
* @return : number of bytes read from source buffer (== compressed size).
* If the source stream is detected malformed, the function stops decoding and returns a negative result.
* note : This function requires uncompressed originalSize to be known in advance.
* The function never writes past the output buffer.
* However, since it doesn't know its 'src' size, it may read past the intended input.
* Also, because match offsets are not validated during decoding,
* reads from 'src' may underflow.
* Use this function in trusted environment **only**.
*/
LZ4LIB_API int LZ4_decompress_fast (const char* src, char* dst, int originalSize);
/*! LZ4_decompress_safe_partial() : /*! LZ4_decompress_safe_partial() :
* Decompress an LZ4 compressed block, of size 'srcSize' at position 'src', * Decompress an LZ4 compressed block, of size 'srcSize' at position 'src',
* into destination buffer 'dst' of size 'dstCapacity'. * into destination buffer 'dst' of size 'dstCapacity'.
@ -257,24 +248,43 @@ LZ4LIB_API int LZ4_decompress_safe_partial (const char* src, char* dst, int srcS
***********************************************/ ***********************************************/
typedef union LZ4_stream_u LZ4_stream_t; /* incomplete type (defined later) */ typedef union LZ4_stream_u LZ4_stream_t; /* incomplete type (defined later) */
/*! LZ4_createStream() and LZ4_freeStream() :
* LZ4_createStream() will allocate and initialize an `LZ4_stream_t` structure.
* LZ4_freeStream() releases its memory.
*/
LZ4LIB_API LZ4_stream_t* LZ4_createStream(void); LZ4LIB_API LZ4_stream_t* LZ4_createStream(void);
LZ4LIB_API int LZ4_freeStream (LZ4_stream_t* streamPtr); LZ4LIB_API int LZ4_freeStream (LZ4_stream_t* streamPtr);
/*! LZ4_resetStream() : /*! LZ4_resetStream_fast() : v1.9.0+
* An LZ4_stream_t structure can be allocated once and re-used multiple times. * Use this to prepare an LZ4_stream_t for a new chain of dependent blocks
* Use this function to start compressing a new stream. * (e.g., LZ4_compress_fast_continue()).
*
* An LZ4_stream_t must be initialized once before usage.
* This is automatically done when created by LZ4_createStream().
* However, should the LZ4_stream_t be simply declared on stack (for example),
* it's necessary to initialize it first, using LZ4_initStream().
*
* After init, start any new stream with LZ4_resetStream_fast().
* A same LZ4_stream_t can be re-used multiple times consecutively
* and compress multiple streams,
* provided that it starts each new stream with LZ4_resetStream_fast().
*
* LZ4_resetStream_fast() is much faster than LZ4_initStream(),
* but is not compatible with memory regions containing garbage data.
*
* Note: it's only useful to call LZ4_resetStream_fast()
* in the context of streaming compression.
* The *extState* functions perform their own resets.
* Invoking LZ4_resetStream_fast() before is redundant, and even counterproductive.
*/ */
LZ4LIB_API void LZ4_resetStream (LZ4_stream_t* streamPtr); LZ4LIB_API void LZ4_resetStream_fast (LZ4_stream_t* streamPtr);
/*! LZ4_loadDict() : /*! LZ4_loadDict() :
* Use this function to load a static dictionary into LZ4_stream_t. * Use this function to reference a static dictionary into LZ4_stream_t.
* Any previous data will be forgotten, only 'dictionary' will remain in memory. * The dictionary must remain available during compression.
* LZ4_loadDict() triggers a reset, so any previous data will be forgotten.
* The same dictionary will have to be loaded on decompression side for successful decoding.
* Dictionary are useful for better compression of small data (KB range).
* While LZ4 accept any input as dictionary,
* results are generally better when using Zstandard's Dictionary Builder.
* Loading a size of 0 is allowed, and is the same as reset. * Loading a size of 0 is allowed, and is the same as reset.
* @return : dictionary size, in bytes (necessarily <= 64 KB) * @return : loaded dictionary size, in bytes (necessarily <= 64 KB)
*/ */
LZ4LIB_API int LZ4_loadDict (LZ4_stream_t* streamPtr, const char* dictionary, int dictSize); LZ4LIB_API int LZ4_loadDict (LZ4_stream_t* streamPtr, const char* dictionary, int dictSize);
@ -288,10 +298,10 @@ LZ4LIB_API int LZ4_loadDict (LZ4_stream_t* streamPtr, const char* dictionary, in
* *
* Note 1 : Each invocation to LZ4_compress_fast_continue() generates a new block. * Note 1 : Each invocation to LZ4_compress_fast_continue() generates a new block.
* Each block has precise boundaries. * Each block has precise boundaries.
* Each block must be decompressed separately, calling LZ4_decompress_*() with relevant metadata.
* It's not possible to append blocks together and expect a single invocation of LZ4_decompress_*() to decompress them together. * It's not possible to append blocks together and expect a single invocation of LZ4_decompress_*() to decompress them together.
* Each block must be decompressed separately, calling LZ4_decompress_*() with associated metadata.
* *
* Note 2 : The previous 64KB of source data is __assumed__ to remain present, unmodified, at same address in memory! * Note 2 : The previous 64KB of source data is __assumed__ to remain present, unmodified, at same address in memory !
* *
* Note 3 : When input is structured as a double-buffer, each buffer can have any size, including < 64 KB. * Note 3 : When input is structured as a double-buffer, each buffer can have any size, including < 64 KB.
* Make sure that buffers are separated, by at least one byte. * Make sure that buffers are separated, by at least one byte.
@ -299,7 +309,7 @@ LZ4LIB_API int LZ4_loadDict (LZ4_stream_t* streamPtr, const char* dictionary, in
* *
* Note 4 : If input buffer is a ring-buffer, it can have any size, including < 64 KB. * Note 4 : If input buffer is a ring-buffer, it can have any size, including < 64 KB.
* *
* Note 5 : After an error, the stream status is invalid, it can only be reset or freed. * Note 5 : After an error, the stream status is undefined (invalid), it can only be reset or freed.
*/ */
LZ4LIB_API int LZ4_compress_fast_continue (LZ4_stream_t* streamPtr, const char* src, char* dst, int srcSize, int dstCapacity, int acceleration); LZ4LIB_API int LZ4_compress_fast_continue (LZ4_stream_t* streamPtr, const char* src, char* dst, int srcSize, int dstCapacity, int acceleration);
@ -335,7 +345,7 @@ LZ4LIB_API int LZ4_freeStreamDecode (LZ4_streamDecode_t* LZ4_str
*/ */
LZ4LIB_API int LZ4_setStreamDecode (LZ4_streamDecode_t* LZ4_streamDecode, const char* dictionary, int dictSize); LZ4LIB_API int LZ4_setStreamDecode (LZ4_streamDecode_t* LZ4_streamDecode, const char* dictionary, int dictSize);
/*! LZ4_decoderRingBufferSize() : v1.8.2 /*! LZ4_decoderRingBufferSize() : v1.8.2+
* Note : in a ring buffer scenario (optional), * Note : in a ring buffer scenario (optional),
* blocks are presumed decompressed next to each other * blocks are presumed decompressed next to each other
* up to the moment there is not enough remaining space for next block (remainingSize < maxBlockSize), * up to the moment there is not enough remaining space for next block (remainingSize < maxBlockSize),
@ -347,7 +357,7 @@ LZ4LIB_API int LZ4_setStreamDecode (LZ4_streamDecode_t* LZ4_streamDecode, const
* or 0 if there is an error (invalid maxBlockSize). * or 0 if there is an error (invalid maxBlockSize).
*/ */
LZ4LIB_API int LZ4_decoderRingBufferSize(int maxBlockSize); LZ4LIB_API int LZ4_decoderRingBufferSize(int maxBlockSize);
#define LZ4_DECODER_RING_BUFFER_SIZE(mbs) (65536 + 14 + (mbs)) /* for static allocation; mbs presumed valid */ #define LZ4_DECODER_RING_BUFFER_SIZE(maxBlockSize) (65536 + 14 + (maxBlockSize)) /* for static allocation; maxBlockSize presumed valid */
/*! LZ4_decompress_*_continue() : /*! LZ4_decompress_*_continue() :
* These decoding functions allow decompression of consecutive blocks in "streaming" mode. * These decoding functions allow decompression of consecutive blocks in "streaming" mode.
@ -375,83 +385,72 @@ LZ4LIB_API int LZ4_decoderRingBufferSize(int maxBlockSize);
* then indicate where this data is saved using LZ4_setStreamDecode(), before decompressing next block. * then indicate where this data is saved using LZ4_setStreamDecode(), before decompressing next block.
*/ */
LZ4LIB_API int LZ4_decompress_safe_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* src, char* dst, int srcSize, int dstCapacity); LZ4LIB_API int LZ4_decompress_safe_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* src, char* dst, int srcSize, int dstCapacity);
LZ4LIB_API int LZ4_decompress_fast_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* src, char* dst, int originalSize);
/*! LZ4_decompress_*_usingDict() : /*! LZ4_decompress_*_usingDict() :
* These decoding functions work the same as * These decoding functions work the same as
* a combination of LZ4_setStreamDecode() followed by LZ4_decompress_*_continue() * a combination of LZ4_setStreamDecode() followed by LZ4_decompress_*_continue()
* They are stand-alone, and don't need an LZ4_streamDecode_t structure. * They are stand-alone, and don't need an LZ4_streamDecode_t structure.
* Dictionary is presumed stable : it must remain accessible and unmodified during next decompression. * Dictionary is presumed stable : it must remain accessible and unmodified during decompression.
* Performance tip : Decompression speed can be substantially increased
* when dst == dictStart + dictSize.
*/ */
LZ4LIB_API int LZ4_decompress_safe_usingDict (const char* src, char* dst, int srcSize, int dstCapcity, const char* dictStart, int dictSize); LZ4LIB_API int LZ4_decompress_safe_usingDict (const char* src, char* dst, int srcSize, int dstCapcity, const char* dictStart, int dictSize);
LZ4LIB_API int LZ4_decompress_fast_usingDict (const char* src, char* dst, int originalSize, const char* dictStart, int dictSize);
#endif /* LZ4_H_2983827168210 */
/*^********************************************** /*^*************************************
* !!!!!! STATIC LINKING ONLY !!!!!! * !!!!!! STATIC LINKING ONLY !!!!!!
***********************************************/ ***************************************/
/*-************************************ /*-****************************************************************************
* Unstable declarations * Experimental section
************************************** *
* Declarations in this section should be considered unstable. * Symbols declared in this section must be considered unstable. Their
* Use at your own peril, etc., etc. * signatures or semantics may change, or they may be removed altogether in the
* They may be removed in the future. * future. They are therefore only safe to depend on when the caller is
* Their signatures may change. * statically linked against the library.
**************************************/ *
* To protect against unsafe usage, not only are the declarations guarded,
* the definitions are hidden by default
* when building LZ4 as a shared/dynamic library.
*
* In order to access these declarations,
* define LZ4_STATIC_LINKING_ONLY in your application
* before including LZ4's headers.
*
* In order to make their implementations accessible dynamically, you must
* define LZ4_PUBLISH_STATIC_FUNCTIONS when building the LZ4 library.
******************************************************************************/
#ifdef LZ4_STATIC_LINKING_ONLY #ifdef LZ4_STATIC_LINKING_ONLY
/*! LZ4_resetStream_fast() : #ifndef LZ4_STATIC_3504398509
* Use this, like LZ4_resetStream(), to prepare a context for a new chain of #define LZ4_STATIC_3504398509
* calls to a streaming API (e.g., LZ4_compress_fast_continue()).
* #ifdef LZ4_PUBLISH_STATIC_FUNCTIONS
* Note: #define LZ4LIB_STATIC_API LZ4LIB_API
* Using this in advance of a non- streaming-compression function is redundant, #else
* and potentially bad for performance, since they all perform their own custom #define LZ4LIB_STATIC_API
* reset internally. #endif
*
* Differences from LZ4_resetStream():
* When an LZ4_stream_t is known to be in a internally coherent state,
* it can often be prepared for a new compression with almost no work, only
* sometimes falling back to the full, expensive reset that is always required
* when the stream is in an indeterminate state (i.e., the reset performed by
* LZ4_resetStream()).
*
* LZ4_streams are guaranteed to be in a valid state when:
* - returned from LZ4_createStream()
* - reset by LZ4_resetStream()
* - memset(stream, 0, sizeof(LZ4_stream_t)), though this is discouraged
* - the stream was in a valid state and was reset by LZ4_resetStream_fast()
* - the stream was in a valid state and was then used in any compression call
* that returned success
* - the stream was in an indeterminate state and was used in a compression
* call that fully reset the state (e.g., LZ4_compress_fast_extState()) and
* that returned success
*
* When a stream isn't known to be in a valid state, it is not safe to pass to
* any fastReset or streaming function. It must first be cleansed by the full
* LZ4_resetStream().
*/
LZ4LIB_API void LZ4_resetStream_fast (LZ4_stream_t* streamPtr);
/*! LZ4_compress_fast_extState_fastReset() : /*! LZ4_compress_fast_extState_fastReset() :
* A variant of LZ4_compress_fast_extState(). * A variant of LZ4_compress_fast_extState().
* *
* Using this variant avoids an expensive initialization step. It is only safe * Using this variant avoids an expensive initialization step.
* to call if the state buffer is known to be correctly initialized already * It is only safe to call if the state buffer is known to be correctly initialized already
* (see above comment on LZ4_resetStream_fast() for a definition of "correctly * (see above comment on LZ4_resetStream_fast() for a definition of "correctly initialized").
* initialized"). From a high level, the difference is that this function * From a high level, the difference is that
* initializes the provided state with a call to something like * this function initializes the provided state with a call to something like LZ4_resetStream_fast()
* LZ4_resetStream_fast() while LZ4_compress_fast_extState() starts with a * while LZ4_compress_fast_extState() starts with a call to LZ4_resetStream().
* call to LZ4_resetStream().
*/ */
LZ4LIB_API int LZ4_compress_fast_extState_fastReset (void* state, const char* src, char* dst, int srcSize, int dstCapacity, int acceleration); LZ4LIB_STATIC_API int LZ4_compress_fast_extState_fastReset (void* state, const char* src, char* dst, int srcSize, int dstCapacity, int acceleration);
/*! LZ4_attach_dictionary() : /*! LZ4_attach_dictionary() :
* This is an experimental API that allows for the efficient use of a * This is an experimental API that allows
* static dictionary many times. * efficient use of a static dictionary many times.
* *
* Rather than re-loading the dictionary buffer into a working context before * Rather than re-loading the dictionary buffer into a working context before
* each compression, or copying a pre-loaded dictionary's LZ4_stream_t into a * each compression, or copying a pre-loaded dictionary's LZ4_stream_t into a
@ -462,8 +461,8 @@ LZ4LIB_API int LZ4_compress_fast_extState_fastReset (void* state, const char* sr
* Currently, only streams which have been prepared by LZ4_loadDict() should * Currently, only streams which have been prepared by LZ4_loadDict() should
* be expected to work. * be expected to work.
* *
* Alternatively, the provided dictionary stream pointer may be NULL, in which * Alternatively, the provided dictionaryStream may be NULL,
* case any existing dictionary stream is unset. * in which case any existing dictionary stream is unset.
* *
* If a dictionary is provided, it replaces any pre-existing stream history. * If a dictionary is provided, it replaces any pre-existing stream history.
* The dictionary contents are the only history that can be referenced and * The dictionary contents are the only history that can be referenced and
@ -475,17 +474,85 @@ LZ4LIB_API int LZ4_compress_fast_extState_fastReset (void* state, const char* sr
* stream (and source buffer) must remain in-place / accessible / unchanged * stream (and source buffer) must remain in-place / accessible / unchanged
* through the completion of the first compression call on the stream. * through the completion of the first compression call on the stream.
*/ */
LZ4LIB_API void LZ4_attach_dictionary(LZ4_stream_t *working_stream, const LZ4_stream_t *dictionary_stream); LZ4LIB_STATIC_API void LZ4_attach_dictionary(LZ4_stream_t* workingStream, const LZ4_stream_t* dictionaryStream);
/*! In-place compression and decompression
*
* It's possible to have input and output sharing the same buffer,
* for highly contrained memory environments.
* In both cases, it requires input to lay at the end of the buffer,
* and decompression to start at beginning of the buffer.
* Buffer size must feature some margin, hence be larger than final size.
*
* |<------------------------buffer--------------------------------->|
* |<-----------compressed data--------->|
* |<-----------decompressed size------------------>|
* |<----margin---->|
*
* This technique is more useful for decompression,
* since decompressed size is typically larger,
* and margin is short.
*
* In-place decompression will work inside any buffer
* which size is >= LZ4_DECOMPRESS_INPLACE_BUFFER_SIZE(decompressedSize).
* This presumes that decompressedSize > compressedSize.
* Otherwise, it means compression actually expanded data,
* and it would be more efficient to store such data with a flag indicating it's not compressed.
* This can happen when data is not compressible (already compressed, or encrypted).
*
* For in-place compression, margin is larger, as it must be able to cope with both
* history preservation, requiring input data to remain unmodified up to LZ4_DISTANCE_MAX,
* and data expansion, which can happen when input is not compressible.
* As a consequence, buffer size requirements are much higher,
* and memory savings offered by in-place compression are more limited.
*
* There are ways to limit this cost for compression :
* - Reduce history size, by modifying LZ4_DISTANCE_MAX.
* Note that it is a compile-time constant, so all compressions will apply this limit.
* Lower values will reduce compression ratio, except when input_size < LZ4_DISTANCE_MAX,
* so it's a reasonable trick when inputs are known to be small.
* - Require the compressor to deliver a "maximum compressed size".
* This is the `dstCapacity` parameter in `LZ4_compress*()`.
* When this size is < LZ4_COMPRESSBOUND(inputSize), then compression can fail,
* in which case, the return code will be 0 (zero).
* The caller must be ready for these cases to happen,
* and typically design a backup scheme to send data uncompressed.
* The combination of both techniques can significantly reduce
* the amount of margin required for in-place compression.
*
* In-place compression can work in any buffer
* which size is >= (maxCompressedSize)
* with maxCompressedSize == LZ4_COMPRESSBOUND(srcSize) for guaranteed compression success.
* LZ4_COMPRESS_INPLACE_BUFFER_SIZE() depends on both maxCompressedSize and LZ4_DISTANCE_MAX,
* so it's possible to reduce memory requirements by playing with them.
*/
#define LZ4_DECOMPRESS_INPLACE_MARGIN(compressedSize) (((compressedSize) >> 8) + 32)
#define LZ4_DECOMPRESS_INPLACE_BUFFER_SIZE(decompressedSize) ((decompressedSize) + LZ4_DECOMPRESS_INPLACE_MARGIN(decompressedSize)) /**< note: presumes that compressedSize < decompressedSize. note2: margin is overestimated a bit, since it could use compressedSize instead */
#ifndef LZ4_DISTANCE_MAX /* history window size; can be user-defined at compile time */
# define LZ4_DISTANCE_MAX 65535 /* set to maximum value by default */
#endif #endif
/*-************************************ #define LZ4_COMPRESS_INPLACE_MARGIN (LZ4_DISTANCE_MAX + 32) /* LZ4_DISTANCE_MAX can be safely replaced by srcSize when it's smaller */
* Private definitions #define LZ4_COMPRESS_INPLACE_BUFFER_SIZE(maxCompressedSize) ((maxCompressedSize) + LZ4_COMPRESS_INPLACE_MARGIN) /**< maxCompressedSize is generally LZ4_COMPRESSBOUND(inputSize), but can be set to any lower value, with the risk that compression can fail (return code 0(zero)) */
**************************************
* Do not use these definitions. #endif /* LZ4_STATIC_3504398509 */
* They are exposed to allow static allocation of `LZ4_stream_t` and `LZ4_streamDecode_t`. #endif /* LZ4_STATIC_LINKING_ONLY */
* Using these definitions will expose code to API and/or ABI break in future versions of the library.
**************************************/
#ifndef LZ4_H_98237428734687
#define LZ4_H_98237428734687
/*-************************************************************
* PRIVATE DEFINITIONS
**************************************************************
* Do not use these definitions directly.
* They are only exposed to allow static allocation of `LZ4_stream_t` and `LZ4_streamDecode_t`.
* Accessing members will expose code to API and/or ABI break in future versions of the library.
**************************************************************/
#define LZ4_HASHLOG (LZ4_MEMORY_USAGE-2) #define LZ4_HASHLOG (LZ4_MEMORY_USAGE-2)
#define LZ4_HASHTABLESIZE (1 << LZ4_MEMORY_USAGE) #define LZ4_HASHTABLESIZE (1 << LZ4_MEMORY_USAGE)
#define LZ4_HASH_SIZE_U32 (1 << LZ4_HASHLOG) /* required as macro for static allocation */ #define LZ4_HASH_SIZE_U32 (1 << LZ4_HASHLOG) /* required as macro for static allocation */
@ -497,7 +564,7 @@ typedef struct LZ4_stream_t_internal LZ4_stream_t_internal;
struct LZ4_stream_t_internal { struct LZ4_stream_t_internal {
uint32_t hashTable[LZ4_HASH_SIZE_U32]; uint32_t hashTable[LZ4_HASH_SIZE_U32];
uint32_t currentOffset; uint32_t currentOffset;
uint16_t initCheck; uint16_t dirty;
uint16_t tableType; uint16_t tableType;
const uint8_t* dictionary; const uint8_t* dictionary;
const LZ4_stream_t_internal* dictCtx; const LZ4_stream_t_internal* dictCtx;
@ -517,7 +584,7 @@ typedef struct LZ4_stream_t_internal LZ4_stream_t_internal;
struct LZ4_stream_t_internal { struct LZ4_stream_t_internal {
unsigned int hashTable[LZ4_HASH_SIZE_U32]; unsigned int hashTable[LZ4_HASH_SIZE_U32];
unsigned int currentOffset; unsigned int currentOffset;
unsigned short initCheck; unsigned short dirty;
unsigned short tableType; unsigned short tableType;
const unsigned char* dictionary; const unsigned char* dictionary;
const LZ4_stream_t_internal* dictCtx; const LZ4_stream_t_internal* dictCtx;
@ -526,38 +593,54 @@ struct LZ4_stream_t_internal {
typedef struct { typedef struct {
const unsigned char* externalDict; const unsigned char* externalDict;
size_t extDictSize;
const unsigned char* prefixEnd; const unsigned char* prefixEnd;
size_t extDictSize;
size_t prefixSize; size_t prefixSize;
} LZ4_streamDecode_t_internal; } LZ4_streamDecode_t_internal;
#endif #endif
/*! /*! LZ4_stream_t :
* LZ4_stream_t :
* information structure to track an LZ4 stream. * information structure to track an LZ4 stream.
* init this structure before first use. * LZ4_stream_t can also be created using LZ4_createStream(), which is recommended.
* note : only use in association with static linking ! * The structure definition can be convenient for static allocation
* this definition is not API/ABI safe, * (on stack, or as part of larger structure).
* it may change in a future version ! * Init this structure with LZ4_initStream() before first use.
* note : only use this definition in association with static linking !
* this definition is not API/ABI safe, and may change in a future version.
*/ */
#define LZ4_STREAMSIZE_U64 ((1 << (LZ4_MEMORY_USAGE-3)) + 4) #define LZ4_STREAMSIZE_U64 ((1 << (LZ4_MEMORY_USAGE-3)) + 4 + ((sizeof(void*)==16) ? 4 : 0) /*AS-400*/ )
#define LZ4_STREAMSIZE (LZ4_STREAMSIZE_U64 * sizeof(unsigned long long)) #define LZ4_STREAMSIZE (LZ4_STREAMSIZE_U64 * sizeof(unsigned long long))
union LZ4_stream_u { union LZ4_stream_u {
unsigned long long table[LZ4_STREAMSIZE_U64]; unsigned long long table[LZ4_STREAMSIZE_U64];
LZ4_stream_t_internal internal_donotuse; LZ4_stream_t_internal internal_donotuse;
} ; /* previously typedef'd to LZ4_stream_t */ } ; /* previously typedef'd to LZ4_stream_t */
/*! LZ4_initStream() : v1.9.0+
* An LZ4_stream_t structure must be initialized at least once.
* This is automatically done when invoking LZ4_createStream(),
* but it's not when the structure is simply declared on stack (for example).
*
* Use LZ4_initStream() to properly initialize a newly declared LZ4_stream_t.
* It can also initialize any arbitrary buffer of sufficient size,
* and will @return a pointer of proper type upon initialization.
*
* Note : initialization fails if size and alignment conditions are not respected.
* In which case, the function will @return NULL.
* Note2: An LZ4_stream_t structure guarantees correct alignment and size.
* Note3: Before v1.9.0, use LZ4_resetStream() instead
*/
LZ4LIB_API LZ4_stream_t* LZ4_initStream (void* buffer, size_t size);
/*!
* LZ4_streamDecode_t : /*! LZ4_streamDecode_t :
* information structure to track an LZ4 stream during decompression. * information structure to track an LZ4 stream during decompression.
* init this structure using LZ4_setStreamDecode (or memset()) before first use * init this structure using LZ4_setStreamDecode() before first use.
* note : only use in association with static linking ! * note : only use in association with static linking !
* this definition is not API/ABI safe, * this definition is not API/ABI safe,
* and may change in a future version ! * and may change in a future version !
*/ */
#define LZ4_STREAMDECODESIZE_U64 4 #define LZ4_STREAMDECODESIZE_U64 (4 + ((sizeof(void*)==16) ? 2 : 0) /*AS-400*/ )
#define LZ4_STREAMDECODESIZE (LZ4_STREAMDECODESIZE_U64 * sizeof(unsigned long long)) #define LZ4_STREAMDECODESIZE (LZ4_STREAMDECODESIZE_U64 * sizeof(unsigned long long))
union LZ4_streamDecode_u { union LZ4_streamDecode_u {
unsigned long long table[LZ4_STREAMDECODESIZE_U64]; unsigned long long table[LZ4_STREAMDECODESIZE_U64];
@ -565,16 +648,22 @@ union LZ4_streamDecode_u {
} ; /* previously typedef'd to LZ4_streamDecode_t */ } ; /* previously typedef'd to LZ4_streamDecode_t */
/*-************************************ /*-************************************
* Obsolete Functions * Obsolete Functions
**************************************/ **************************************/
/*! Deprecation warnings /*! Deprecation warnings
Should deprecation warnings be a problem, *
it is generally possible to disable them, * Deprecated functions make the compiler generate a warning when invoked.
typically with -Wno-deprecated-declarations for gcc * This is meant to invite users to update their source code.
or _CRT_SECURE_NO_WARNINGS in Visual. * Should deprecation warnings be a problem, it is generally possible to disable them,
Otherwise, it's also possible to define LZ4_DISABLE_DEPRECATE_WARNINGS */ * typically with -Wno-deprecated-declarations for gcc
* or _CRT_SECURE_NO_WARNINGS in Visual.
*
* Another method is to define LZ4_DISABLE_DEPRECATE_WARNINGS
* before including the header file.
*/
#ifdef LZ4_DISABLE_DEPRECATE_WARNINGS #ifdef LZ4_DISABLE_DEPRECATE_WARNINGS
# define LZ4_DEPRECATED(message) /* disable deprecation warnings */ # define LZ4_DEPRECATED(message) /* disable deprecation warnings */
#else #else
@ -594,8 +683,8 @@ union LZ4_streamDecode_u {
#endif /* LZ4_DISABLE_DEPRECATE_WARNINGS */ #endif /* LZ4_DISABLE_DEPRECATE_WARNINGS */
/* Obsolete compression functions */ /* Obsolete compression functions */
LZ4_DEPRECATED("use LZ4_compress_default() instead") LZ4LIB_API int LZ4_compress (const char* source, char* dest, int sourceSize); LZ4_DEPRECATED("use LZ4_compress_default() instead") LZ4LIB_API int LZ4_compress (const char* src, char* dest, int srcSize);
LZ4_DEPRECATED("use LZ4_compress_default() instead") LZ4LIB_API int LZ4_compress_limitedOutput (const char* source, char* dest, int sourceSize, int maxOutputSize); LZ4_DEPRECATED("use LZ4_compress_default() instead") LZ4LIB_API int LZ4_compress_limitedOutput (const char* src, char* dest, int srcSize, int maxOutputSize);
LZ4_DEPRECATED("use LZ4_compress_fast_extState() instead") LZ4LIB_API int LZ4_compress_withState (void* state, const char* source, char* dest, int inputSize); LZ4_DEPRECATED("use LZ4_compress_fast_extState() instead") LZ4LIB_API int LZ4_compress_withState (void* state, const char* source, char* dest, int inputSize);
LZ4_DEPRECATED("use LZ4_compress_fast_extState() instead") LZ4LIB_API int LZ4_compress_limitedOutput_withState (void* state, const char* source, char* dest, int inputSize, int maxOutputSize); LZ4_DEPRECATED("use LZ4_compress_fast_extState() instead") LZ4LIB_API int LZ4_compress_limitedOutput_withState (void* state, const char* source, char* dest, int inputSize, int maxOutputSize);
LZ4_DEPRECATED("use LZ4_compress_fast_continue() instead") LZ4LIB_API int LZ4_compress_continue (LZ4_stream_t* LZ4_streamPtr, const char* source, char* dest, int inputSize); LZ4_DEPRECATED("use LZ4_compress_fast_continue() instead") LZ4LIB_API int LZ4_compress_continue (LZ4_stream_t* LZ4_streamPtr, const char* source, char* dest, int inputSize);
@ -623,7 +712,51 @@ LZ4_DEPRECATED("Use LZ4_saveDict() instead") LZ4LIB_API char* LZ4_slideInput
LZ4_DEPRECATED("use LZ4_decompress_safe_usingDict() instead") LZ4LIB_API int LZ4_decompress_safe_withPrefix64k (const char* src, char* dst, int compressedSize, int maxDstSize); LZ4_DEPRECATED("use LZ4_decompress_safe_usingDict() instead") LZ4LIB_API int LZ4_decompress_safe_withPrefix64k (const char* src, char* dst, int compressedSize, int maxDstSize);
LZ4_DEPRECATED("use LZ4_decompress_fast_usingDict() instead") LZ4LIB_API int LZ4_decompress_fast_withPrefix64k (const char* src, char* dst, int originalSize); LZ4_DEPRECATED("use LZ4_decompress_fast_usingDict() instead") LZ4LIB_API int LZ4_decompress_fast_withPrefix64k (const char* src, char* dst, int originalSize);
#endif /* LZ4_H_2983827168210 */ /*! LZ4_decompress_fast() : **unsafe!**
* These functions used to be faster than LZ4_decompress_safe(),
* but it has changed, and they are now slower than LZ4_decompress_safe().
* This is because LZ4_decompress_fast() doesn't know the input size,
* and therefore must progress more cautiously in the input buffer to not read beyond the end of block.
* On top of that `LZ4_decompress_fast()` is not protected vs malformed or malicious inputs, making it a security liability.
* As a consequence, LZ4_decompress_fast() is strongly discouraged, and deprecated.
*
* The last remaining LZ4_decompress_fast() specificity is that
* it can decompress a block without knowing its compressed size.
* Such functionality could be achieved in a more secure manner,
* by also providing the maximum size of input buffer,
* but it would require new prototypes, and adaptation of the implementation to this new use case.
*
* Parameters:
* originalSize : is the uncompressed size to regenerate.
* `dst` must be already allocated, its size must be >= 'originalSize' bytes.
* @return : number of bytes read from source buffer (== compressed size).
* The function expects to finish at block's end exactly.
* If the source stream is detected malformed, the function stops decoding and returns a negative result.
* note : LZ4_decompress_fast*() requires originalSize. Thanks to this information, it never writes past the output buffer.
* However, since it doesn't know its 'src' size, it may read an unknown amount of input, past input buffer bounds.
* Also, since match offsets are not validated, match reads from 'src' may underflow too.
* These issues never happen if input (compressed) data is correct.
* But they may happen if input data is invalid (error or intentional tampering).
* As a consequence, use these functions in trusted environments with trusted data **only**.
*/
LZ4_DEPRECATED("This function is deprecated and unsafe. Consider using LZ4_decompress_safe() instead")
LZ4LIB_API int LZ4_decompress_fast (const char* src, char* dst, int originalSize);
LZ4_DEPRECATED("This function is deprecated and unsafe. Consider using LZ4_decompress_safe_continue() instead")
LZ4LIB_API int LZ4_decompress_fast_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* src, char* dst, int originalSize);
LZ4_DEPRECATED("This function is deprecated and unsafe. Consider using LZ4_decompress_safe_usingDict() instead")
LZ4LIB_API int LZ4_decompress_fast_usingDict (const char* src, char* dst, int originalSize, const char* dictStart, int dictSize);
/*! LZ4_resetStream() :
* An LZ4_stream_t structure must be initialized at least once.
* This is done with LZ4_initStream(), or LZ4_resetStream().
* Consider switching to LZ4_initStream(),
* invoking LZ4_resetStream() will trigger deprecation warnings in the future.
*/
LZ4LIB_API void LZ4_resetStream (LZ4_stream_t* streamPtr);
#endif /* LZ4_H_98237428734687 */
#if defined (__cplusplus) #if defined (__cplusplus)