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authorBernhard Schmidt <berni@debian.org>2020-10-20 19:17:00 +0200
committerBernhard Schmidt <berni@debian.org>2020-10-20 19:17:00 +0200
commit80285c31e83a8e233016e227a393543d508194eb (patch)
treea76135587c708bf9e9bf424af2149b119efe6320 /src/compat/compat-lz4.h
parent5246174f27866c0e9e22844d998f3c97cac54050 (diff)
New upstream version 2.5~rc3upstream/2.5_rc3
Diffstat (limited to 'src/compat/compat-lz4.h')
-rw-r--r--src/compat/compat-lz4.h737
1 files changed, 519 insertions, 218 deletions
diff --git a/src/compat/compat-lz4.h b/src/compat/compat-lz4.h
index 0aae19c..32108e2 100644
--- a/src/compat/compat-lz4.h
+++ b/src/compat/compat-lz4.h
@@ -1,7 +1,7 @@
/*
* LZ4 - Fast LZ compression algorithm
* Header File
- * Copyright (C) 2011-2016, Yann Collet.
+ * Copyright (C) 2011-present, Yann Collet.
BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
@@ -32,13 +32,13 @@
- LZ4 homepage : http://www.lz4.org
- LZ4 source repository : https://github.com/lz4/lz4
*/
-#ifndef LZ4_H_2983827168210
-#define LZ4_H_2983827168210
-
#if defined (__cplusplus)
extern "C" {
#endif
+#ifndef LZ4_H_2983827168210
+#define LZ4_H_2983827168210
+
/* --- Dependency --- */
#include <stddef.h> /* size_t */
@@ -46,24 +46,31 @@ extern "C" {
/**
Introduction
- LZ4 is lossless compression algorithm, providing compression speed at 400 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
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.
+ It gives full buffer control to user.
Compression can be done in:
- a single step (described as Simple Functions)
- a single step, reusing a context (described in Advanced Functions)
- unbounded multiple steps (described as Streaming compression)
- lz4.h provides block compression functions. It gives full buffer control to user.
- Decompressing an lz4-compressed block also requires metadata (such as compressed size).
- Each application is free to encode such metadata in whichever way it wants.
+ lz4.h generates and decodes LZ4-compressed blocks (doc/lz4_Block_format.md).
+ Decompressing such a compressed block requires additional metadata.
+ 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.
+
+ lz4.h only handle blocks, it can not generate Frames.
- An additional format, called LZ4 frame specification (doc/lz4_Frame_format.md),
- take care of encoding standard metadata alongside LZ4-compressed blocks.
- If your application requires interoperability, it's recommended to use it.
- A library is provided to take care of it, see lz4frame.h.
+ Blocks are different from Frames (doc/lz4_Frame_format.md).
+ 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.
*/
/*^***************************************************************
@@ -72,20 +79,28 @@ extern "C" {
/*
* LZ4_DLL_EXPORT :
* Enable exporting of functions when building a Windows DLL
+* LZ4LIB_VISIBILITY :
+* Control library symbols visibility.
*/
+#ifndef LZ4LIB_VISIBILITY
+# if defined(__GNUC__) && (__GNUC__ >= 4)
+# define LZ4LIB_VISIBILITY __attribute__ ((visibility ("default")))
+# else
+# define LZ4LIB_VISIBILITY
+# endif
+#endif
#if defined(LZ4_DLL_EXPORT) && (LZ4_DLL_EXPORT==1)
-# define LZ4LIB_API __declspec(dllexport)
+# define LZ4LIB_API __declspec(dllexport) LZ4LIB_VISIBILITY
#elif defined(LZ4_DLL_IMPORT) && (LZ4_DLL_IMPORT==1)
-# define LZ4LIB_API __declspec(dllimport) /* It isn't required but allows to generate better code, saving a function pointer load from the IAT and an indirect jump.*/
+# define LZ4LIB_API __declspec(dllimport) LZ4LIB_VISIBILITY /* It isn't required but allows to generate better code, saving a function pointer load from the IAT and an indirect jump.*/
#else
-# define LZ4LIB_API
+# define LZ4LIB_API LZ4LIB_VISIBILITY
#endif
-
-/*========== Version =========== */
+/*------ Version ------*/
#define LZ4_VERSION_MAJOR 1 /* for breaking interface changes */
-#define LZ4_VERSION_MINOR 7 /* for new (non-breaking) interface capabilities */
-#define LZ4_VERSION_RELEASE 5 /* for tweaks, bug-fixes, or development */
+#define LZ4_VERSION_MINOR 9 /* for new (non-breaking) interface capabilities */
+#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)
@@ -94,8 +109,8 @@ extern "C" {
#define LZ4_EXPAND_AND_QUOTE(str) LZ4_QUOTE(str)
#define LZ4_VERSION_STRING LZ4_EXPAND_AND_QUOTE(LZ4_LIB_VERSION)
-LZ4LIB_API int LZ4_versionNumber (void);
-LZ4LIB_API const char* LZ4_versionString (void);
+LZ4LIB_API int LZ4_versionNumber (void); /**< library version number; useful to check dll version */
+LZ4LIB_API const char* LZ4_versionString (void); /**< library version string; useful to check dll version */
/*-************************************
@@ -104,41 +119,49 @@ LZ4LIB_API const char* LZ4_versionString (void);
/*!
* LZ4_MEMORY_USAGE :
* Memory usage formula : N->2^N Bytes (examples : 10 -> 1KB; 12 -> 4KB ; 16 -> 64KB; 20 -> 1MB; etc.)
- * Increasing memory usage improves compression ratio
- * Reduced memory usage can improve speed, due to cache effect
+ * Increasing memory usage improves compression ratio.
+ * 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
*/
-#define LZ4_MEMORY_USAGE 14
+#ifndef LZ4_MEMORY_USAGE
+# define LZ4_MEMORY_USAGE 14
+#endif
/*-************************************
* Simple Functions
**************************************/
/*! LZ4_compress_default() :
- Compresses 'sourceSize' bytes from buffer 'source'
- into already allocated 'dest' buffer of size 'maxDestSize'.
- Compression is guaranteed to succeed if 'maxDestSize' >= LZ4_compressBound(sourceSize).
- It also runs faster, so it's a recommended setting.
- If the function cannot compress 'source' into a more limited 'dest' budget,
- compression stops *immediately*, and the function result is zero.
- As a consequence, 'dest' content is not valid.
- This function never writes outside 'dest' buffer, nor read outside 'source' buffer.
- sourceSize : Max supported value is LZ4_MAX_INPUT_VALUE
- maxDestSize : full or partial size of buffer 'dest' (which must be already allocated)
- return : the number of bytes written into buffer 'dest' (necessarily <= maxOutputSize)
- or 0 if compression fails */
-LZ4LIB_API int LZ4_compress_default(const char* source, char* dest, int sourceSize, int maxDestSize);
+ * Compresses 'srcSize' bytes from buffer 'src'
+ * into already allocated 'dst' buffer of size 'dstCapacity'.
+ * Compression is guaranteed to succeed if 'dstCapacity' >= LZ4_compressBound(srcSize).
+ * It also runs faster, so it's a recommended setting.
+ * If the function cannot compress 'src' into a more limited 'dst' budget,
+ * compression stops *immediately*, and the function result is zero.
+ * In which case, 'dst' content is undefined (invalid).
+ * srcSize : max supported value is LZ4_MAX_INPUT_SIZE.
+ * dstCapacity : size of buffer 'dst' (which must be already allocated)
+ * @return : the number of bytes written into buffer 'dst' (necessarily <= dstCapacity)
+ * 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);
/*! LZ4_decompress_safe() :
- compressedSize : is the precise full size of the compressed block.
- maxDecompressedSize : is the size of destination buffer, which must be already allocated.
- return : the number of bytes decompressed into destination buffer (necessarily <= maxDecompressedSize)
- If destination buffer is not large enough, decoding will stop and output an error code (<0).
- If the source stream is detected malformed, the function will stop decoding and return a negative result.
- This function is protected against buffer overflow exploits, including malicious data packets.
- It never writes outside output buffer, nor reads outside input buffer.
-*/
-LZ4LIB_API int LZ4_decompress_safe (const char* source, char* dest, int compressedSize, int maxDecompressedSize);
+ * compressedSize : is the exact complete size of the compressed block.
+ * 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)
+ * 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.
+ * 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);
/*-************************************
@@ -147,184 +170,389 @@ LZ4LIB_API int LZ4_decompress_safe (const char* source, char* dest, int compress
#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)
-/*!
-LZ4_compressBound() :
+/*! LZ4_compressBound() :
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).
Macro LZ4_COMPRESSBOUND() is also provided for compilation-time evaluation (stack memory allocation for example).
- Note that LZ4_compress_default() compress faster when dest buffer size is >= LZ4_compressBound(srcSize)
+ Note that LZ4_compress_default() compresses faster when dstCapacity is >= LZ4_compressBound(srcSize)
inputSize : max supported value is LZ4_MAX_INPUT_SIZE
return : maximum output size in a "worst case" scenario
- or 0, if input size is too large ( > LZ4_MAX_INPUT_SIZE)
+ or 0, if input size is incorrect (too large or negative)
*/
LZ4LIB_API int LZ4_compressBound(int inputSize);
-/*!
-LZ4_compress_fast() :
- Same as LZ4_compress_default(), but allows to select an "acceleration" factor.
+/*! LZ4_compress_fast() :
+ 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.
It's a trade-off. It can be fine tuned, with each successive value providing roughly +~3% to speed.
An acceleration value of "1" is the same as regular LZ4_compress_default()
- Values <= 0 will be replaced by ACCELERATION_DEFAULT (see lz4.c), which is 1.
+ Values <= 0 will be replaced by ACCELERATION_DEFAULT (currently == 1, see lz4.c).
*/
-LZ4LIB_API int LZ4_compress_fast (const char* source, char* dest, int sourceSize, int maxDestSize, int acceleration);
+LZ4LIB_API int LZ4_compress_fast (const char* src, char* dst, int srcSize, int dstCapacity, int acceleration);
-/*!
-LZ4_compress_fast_extState() :
- 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,
- and allocate it on 8-bytes boundaries (using malloc() typically).
- Then, provide it as 'void* state' to compression function.
-*/
+/*! LZ4_compress_fast_extState() :
+ * Same as LZ4_compress_fast(), using an externally allocated memory space for its state.
+ * Use LZ4_sizeofState() to know how much memory must be allocated,
+ * and allocate it on 8-bytes boundaries (using `malloc()` typically).
+ * Then, provide this buffer as `void* state` to compression function.
+ */
LZ4LIB_API int LZ4_sizeofState(void);
-LZ4LIB_API int LZ4_compress_fast_extState (void* state, const char* source, char* dest, int inputSize, int maxDestSize, int acceleration);
-
-
-/*!
-LZ4_compress_destSize() :
- Reverse the logic, by compressing as much data as possible from 'source' buffer
- into already allocated buffer 'dest' of size 'targetDestSize'.
- This function either compresses the entire 'source' content into 'dest' if it's large enough,
- or fill 'dest' buffer completely with as much data as possible from 'source'.
- *sourceSizePtr : will be modified to indicate how many bytes where read from 'source' to fill 'dest'.
- New value is necessarily <= old value.
- return : Nb bytes written into 'dest' (necessarily <= targetDestSize)
- or 0 if compression fails
-*/
-LZ4LIB_API int LZ4_compress_destSize (const char* source, char* dest, int* sourceSizePtr, int targetDestSize);
-
-
-/*!
-LZ4_decompress_fast() :
- originalSize : is the original and therefore uncompressed size
- return : the number of bytes read from the source buffer (in other words, the compressed size)
- If the source stream is detected malformed, the function will stop decoding and return a negative result.
- Destination buffer must be already allocated. Its size must be a minimum of 'originalSize' bytes.
- note : This function fully respect memory boundaries for properly formed compressed data.
- It is a bit faster than LZ4_decompress_safe().
- However, it does not provide any protection against intentionally modified data stream (malicious input).
- Use this function in trusted environment only (data to decode comes from a trusted source).
-*/
-LZ4LIB_API int LZ4_decompress_fast (const char* source, char* dest, int originalSize);
-
-/*!
-LZ4_decompress_safe_partial() :
- This function decompress a compressed block of size 'compressedSize' at position 'source'
- into destination buffer 'dest' of size 'maxDecompressedSize'.
- The function tries to stop decompressing operation as soon as 'targetOutputSize' has been reached,
- reducing decompression time.
- return : the number of bytes decoded in the destination buffer (necessarily <= maxDecompressedSize)
- Note : this number can be < 'targetOutputSize' should the compressed block to decode be smaller.
- Always control how many bytes were decoded.
- If the source stream is detected malformed, the function will stop decoding and return a negative result.
- This function never writes outside of output buffer, and never reads outside of input buffer. It is therefore protected against malicious data packets
+LZ4LIB_API int LZ4_compress_fast_extState (void* state, const char* src, char* dst, int srcSize, int dstCapacity, int acceleration);
+
+
+/*! LZ4_compress_destSize() :
+ * Reverse the logic : compresses as much data as possible from 'src' buffer
+ * into already allocated buffer 'dst', of size >= 'targetDestSize'.
+ * This function either compresses the entire 'src' content into 'dst' if it's large enough,
+ * or fill 'dst' buffer completely with as much data as possible from 'src'.
+ * note: acceleration parameter is fixed to "default".
+ *
+ * *srcSizePtr : will be modified to indicate how many bytes where read from 'src' to fill 'dst'.
+ * New value is necessarily <= input value.
+ * @return : Nb bytes written into 'dst' (necessarily <= targetDestSize)
+ * or 0 if compression fails.
*/
-LZ4LIB_API int LZ4_decompress_safe_partial (const char* source, char* dest, int compressedSize, int targetOutputSize, int maxDecompressedSize);
+LZ4LIB_API int LZ4_compress_destSize (const char* src, char* dst, int* srcSizePtr, int targetDstSize);
+
+
+/*! LZ4_decompress_safe_partial() :
+ * Decompress an LZ4 compressed block, of size 'srcSize' at position 'src',
+ * into destination buffer 'dst' of size 'dstCapacity'.
+ * Up to 'targetOutputSize' bytes will be decoded.
+ * The function stops decoding on reaching this objective,
+ * which can boost performance when only the beginning of a block is required.
+ *
+ * @return : the number of bytes decoded in `dst` (necessarily <= dstCapacity)
+ * If source stream is detected malformed, function returns a negative result.
+ *
+ * Note : @return can be < targetOutputSize, if compressed block contains less data.
+ *
+ * Note 2 : this function features 2 parameters, targetOutputSize and dstCapacity,
+ * and expects targetOutputSize <= dstCapacity.
+ * It effectively stops decoding on reaching targetOutputSize,
+ * so dstCapacity is kind of redundant.
+ * This is because in a previous version of this function,
+ * decoding operation would not "break" a sequence in the middle.
+ * As a consequence, there was no guarantee that decoding would stop at exactly targetOutputSize,
+ * it could write more bytes, though only up to dstCapacity.
+ * Some "margin" used to be required for this operation to work properly.
+ * This is no longer necessary.
+ * The function nonetheless keeps its signature, in an effort to not break API.
+ */
+LZ4LIB_API int LZ4_decompress_safe_partial (const char* src, char* dst, int srcSize, int targetOutputSize, int dstCapacity);
/*-*********************************************
* Streaming Compression Functions
***********************************************/
-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 int LZ4_freeStream (LZ4_stream_t* streamPtr);
-/*! LZ4_resetStream() :
- * An LZ4_stream_t structure can be allocated once and re-used multiple times.
- * Use this function to init an allocated `LZ4_stream_t` structure and start a new compression.
+/*! LZ4_resetStream_fast() : v1.9.0+
+ * Use this to prepare an LZ4_stream_t for a new chain of dependent blocks
+ * (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() :
- * Use this function to load a static dictionary into LZ4_stream.
- * Any previous data will be forgotten, only 'dictionary' will remain in memory.
- * Loading a size of 0 is allowed.
- * Return : dictionary size, in bytes (necessarily <= 64 KB)
+ * Use this function to reference a static dictionary into LZ4_stream_t.
+ * 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.
+ * @return : loaded dictionary size, in bytes (necessarily <= 64 KB)
*/
LZ4LIB_API int LZ4_loadDict (LZ4_stream_t* streamPtr, const char* dictionary, int dictSize);
/*! LZ4_compress_fast_continue() :
- * Compress buffer content 'src', using data from previously compressed blocks as dictionary to improve compression ratio.
- * Important : Previous data blocks are assumed to still be present and unmodified !
- * 'dst' buffer must be already allocated.
- * If maxDstSize >= LZ4_compressBound(srcSize), compression is guaranteed to succeed, and runs faster.
- * If not, and if compressed data cannot fit into 'dst' buffer size, compression stops, and function returns a zero.
+ * Compress 'src' content using data from previously compressed blocks, for better compression ratio.
+ * 'dst' buffer must be already allocated.
+ * If dstCapacity >= LZ4_compressBound(srcSize), compression is guaranteed to succeed, and runs faster.
+ *
+ * @return : size of compressed block
+ * or 0 if there is an error (typically, cannot fit into 'dst').
+ *
+ * Note 1 : Each invocation to LZ4_compress_fast_continue() generates a new block.
+ * 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.
+ *
+ * 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.
+ * Make sure that buffers are separated, by at least one byte.
+ * This construction ensures that each block only depends on previous block.
+ *
+ * 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 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 maxDstSize, int acceleration);
+LZ4LIB_API int LZ4_compress_fast_continue (LZ4_stream_t* streamPtr, const char* src, char* dst, int srcSize, int dstCapacity, int acceleration);
/*! LZ4_saveDict() :
- * If previously compressed data block is not guaranteed to remain available at its memory location,
+ * If last 64KB data cannot be guaranteed to remain available at its current memory location,
* save it into a safer place (char* safeBuffer).
- * Note : you don't need to call LZ4_loadDict() afterwards,
- * dictionary is immediately usable, you can therefore call LZ4_compress_fast_continue().
- * Return : saved dictionary size in bytes (necessarily <= dictSize), or 0 if error.
+ * This is schematically equivalent to a memcpy() followed by LZ4_loadDict(),
+ * but is much faster, because LZ4_saveDict() doesn't need to rebuild tables.
+ * @return : saved dictionary size in bytes (necessarily <= maxDictSize), or 0 if error.
*/
-LZ4LIB_API int LZ4_saveDict (LZ4_stream_t* streamPtr, char* safeBuffer, int dictSize);
+LZ4LIB_API int LZ4_saveDict (LZ4_stream_t* streamPtr, char* safeBuffer, int maxDictSize);
/*-**********************************************
* Streaming Decompression Functions
* Bufferless synchronous API
************************************************/
-typedef union LZ4_streamDecode_u LZ4_streamDecode_t; /* incomplete type (defined later) */
+typedef union LZ4_streamDecode_u LZ4_streamDecode_t; /* tracking context */
-/* creation / destruction of streaming decompression tracking structure */
+/*! LZ4_createStreamDecode() and LZ4_freeStreamDecode() :
+ * creation / destruction of streaming decompression tracking context.
+ * A tracking context can be re-used multiple times.
+ */
LZ4LIB_API LZ4_streamDecode_t* LZ4_createStreamDecode(void);
LZ4LIB_API int LZ4_freeStreamDecode (LZ4_streamDecode_t* LZ4_stream);
/*! LZ4_setStreamDecode() :
- * Use this function to instruct where to find the dictionary.
- * Setting a size of 0 is allowed (same effect as reset).
- * @return : 1 if OK, 0 if error
+ * An LZ4_streamDecode_t context can be allocated once and re-used multiple times.
+ * Use this function to start decompression of a new stream of blocks.
+ * A dictionary can optionally be set. Use NULL or size 0 for a reset order.
+ * Dictionary is presumed stable : it must remain accessible and unmodified during next decompression.
+ * @return : 1 if OK, 0 if error
*/
LZ4LIB_API int LZ4_setStreamDecode (LZ4_streamDecode_t* LZ4_streamDecode, const char* dictionary, int dictSize);
-/*!
-LZ4_decompress_*_continue() :
- These decoding functions allow decompression of multiple blocks in "streaming" mode.
- Previously decoded blocks *must* remain available at the memory position where they were decoded (up to 64 KB)
- In the case of a ring buffers, decoding buffer must be either :
- - Exactly same size as encoding buffer, with same update rule (block boundaries at same positions)
- In which case, the decoding & encoding ring buffer can have any size, including very small ones ( < 64 KB).
- - Larger than encoding buffer, by a minimum of maxBlockSize more bytes.
- maxBlockSize is implementation dependent. It's the maximum size you intend to compress into a single block.
- In which case, encoding and decoding buffers do not need to be synchronized,
- and encoding ring buffer can have any size, including small ones ( < 64 KB).
- - _At least_ 64 KB + 8 bytes + maxBlockSize.
- In which case, encoding and decoding buffers do not need to be synchronized,
- and encoding ring buffer can have any size, including larger than decoding buffer.
- Whenever these conditions are not possible, save the last 64KB of decoded data into a safe buffer,
- and indicate where it is saved using LZ4_setStreamDecode()
+/*! LZ4_decoderRingBufferSize() : v1.8.2+
+ * Note : in a ring buffer scenario (optional),
+ * blocks are presumed decompressed next to each other
+ * up to the moment there is not enough remaining space for next block (remainingSize < maxBlockSize),
+ * at which stage it resumes from beginning of ring buffer.
+ * When setting such a ring buffer for streaming decompression,
+ * provides the minimum size of this ring buffer
+ * to be compatible with any source respecting maxBlockSize condition.
+ * @return : minimum ring buffer size,
+ * or 0 if there is an error (invalid maxBlockSize).
+ */
+LZ4LIB_API int LZ4_decoderRingBufferSize(int maxBlockSize);
+#define LZ4_DECODER_RING_BUFFER_SIZE(maxBlockSize) (65536 + 14 + (maxBlockSize)) /* for static allocation; maxBlockSize presumed valid */
+
+/*! LZ4_decompress_*_continue() :
+ * These decoding functions allow decompression of consecutive blocks in "streaming" mode.
+ * A block is an unsplittable entity, it must be presented entirely to a decompression function.
+ * Decompression functions only accepts one block at a time.
+ * The last 64KB of previously decoded data *must* remain available and unmodified at the memory position where they were decoded.
+ * If less than 64KB of data has been decoded, all the data must be present.
+ *
+ * Special : if decompression side sets a ring buffer, it must respect one of the following conditions :
+ * - Decompression buffer size is _at least_ LZ4_decoderRingBufferSize(maxBlockSize).
+ * maxBlockSize is the maximum size of any single block. It can have any value > 16 bytes.
+ * In which case, encoding and decoding buffers do not need to be synchronized.
+ * Actually, data can be produced by any source compliant with LZ4 format specification, and respecting maxBlockSize.
+ * - Synchronized mode :
+ * Decompression buffer size is _exactly_ the same as compression buffer size,
+ * and follows exactly same update rule (block boundaries at same positions),
+ * and decoding function is provided with exact decompressed size of each block (exception for last block of the stream),
+ * _then_ decoding & encoding ring buffer can have any size, including small ones ( < 64 KB).
+ * - Decompression buffer is larger than encoding buffer, by a minimum of maxBlockSize more bytes.
+ * In which case, encoding and decoding buffers do not need to be synchronized,
+ * and encoding ring buffer can have any size, including small ones ( < 64 KB).
+ *
+ * Whenever these conditions are not possible,
+ * save the last 64KB of decoded data into a safe buffer where it can't be modified during decompression,
+ * 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* source, char* dest, int compressedSize, int maxDecompressedSize);
-LZ4LIB_API int LZ4_decompress_fast_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* source, char* dest, int originalSize);
+LZ4LIB_API int LZ4_decompress_safe_continue (LZ4_streamDecode_t* LZ4_streamDecode, const char* src, char* dst, int srcSize, int dstCapacity);
/*! LZ4_decompress_*_usingDict() :
* These decoding functions work the same as
* a combination of LZ4_setStreamDecode() followed by LZ4_decompress_*_continue()
* They are stand-alone, and don't need an LZ4_streamDecode_t structure.
+ * 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* source, char* dest, int compressedSize, int maxDecompressedSize, const char* dictStart, int dictSize);
-LZ4LIB_API int LZ4_decompress_fast_usingDict (const char* source, char* dest, int originalSize, 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);
+#endif /* LZ4_H_2983827168210 */
-/*^**********************************************
+
+/*^*************************************
* !!!!!! STATIC LINKING ONLY !!!!!!
- ***********************************************/
-/*-************************************
- * Private definitions
- **************************************
- * Do not use these definitions.
- * They are exposed to allow static allocation of `LZ4_stream_t` and `LZ4_streamDecode_t`.
- * Using these definitions will expose code to API and/or ABI break in future versions of the library.
- **************************************/
+ ***************************************/
+
+/*-****************************************************************************
+ * Experimental section
+ *
+ * Symbols declared in this section must be considered unstable. Their
+ * signatures or semantics may change, or they may be removed altogether in the
+ * future. They are therefore only safe to depend on when the caller is
+ * 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
+
+#ifndef LZ4_STATIC_3504398509
+#define LZ4_STATIC_3504398509
+
+#ifdef LZ4_PUBLISH_STATIC_FUNCTIONS
+#define LZ4LIB_STATIC_API LZ4LIB_API
+#else
+#define LZ4LIB_STATIC_API
+#endif
+
+
+/*! LZ4_compress_fast_extState_fastReset() :
+ * A variant of LZ4_compress_fast_extState().
+ *
+ * Using this variant avoids an expensive initialization step.
+ * 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 initialized").
+ * From a high level, the difference is that
+ * this function initializes the provided state with a call to something like LZ4_resetStream_fast()
+ * while LZ4_compress_fast_extState() starts with a call to LZ4_resetStream().
+ */
+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() :
+ * This is an experimental API that allows
+ * efficient use of a static dictionary many times.
+ *
+ * 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
+ * working LZ4_stream_t, this function introduces a no-copy setup mechanism,
+ * in which the working stream references the dictionary stream in-place.
+ *
+ * Several assumptions are made about the state of the dictionary stream.
+ * Currently, only streams which have been prepared by LZ4_loadDict() should
+ * be expected to work.
+ *
+ * Alternatively, the provided dictionaryStream may be NULL,
+ * in which case any existing dictionary stream is unset.
+ *
+ * If a dictionary is provided, it replaces any pre-existing stream history.
+ * The dictionary contents are the only history that can be referenced and
+ * logically immediately precede the data compressed in the first subsequent
+ * compression call.
+ *
+ * The dictionary will only remain attached to the working stream through the
+ * first compression call, at the end of which it is cleared. The dictionary
+ * stream (and source buffer) must remain in-place / accessible / unchanged
+ * through the completion of the first compression call on the 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
+
+#define LZ4_COMPRESS_INPLACE_MARGIN (LZ4_DISTANCE_MAX + 32) /* LZ4_DISTANCE_MAX can be safely replaced by srcSize when it's smaller */
+#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)) */
+
+#endif /* LZ4_STATIC_3504398509 */
+#endif /* LZ4_STATIC_LINKING_ONLY */
+
+
+
+#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_HASHTABLESIZE (1 << LZ4_MEMORY_USAGE)
#define LZ4_HASH_SIZE_U32 (1 << LZ4_HASHLOG) /* required as macro for static allocation */
@@ -332,14 +560,16 @@ LZ4LIB_API int LZ4_decompress_fast_usingDict (const char* source, char* dest, in
#if defined(__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
#include <stdint.h>
-typedef struct {
+typedef struct LZ4_stream_t_internal LZ4_stream_t_internal;
+struct LZ4_stream_t_internal {
uint32_t hashTable[LZ4_HASH_SIZE_U32];
uint32_t currentOffset;
- uint32_t initCheck;
+ uint16_t dirty;
+ uint16_t tableType;
const uint8_t* dictionary;
- uint8_t* bufferStart; /* obsolete, used for slideInputBuffer */
+ const LZ4_stream_t_internal* dictCtx;
uint32_t dictSize;
-} LZ4_stream_t_internal;
+};
typedef struct {
const uint8_t* externalDict;
@@ -350,49 +580,67 @@ typedef struct {
#else
-typedef struct {
+typedef struct LZ4_stream_t_internal LZ4_stream_t_internal;
+struct LZ4_stream_t_internal {
unsigned int hashTable[LZ4_HASH_SIZE_U32];
unsigned int currentOffset;
- unsigned int initCheck;
+ unsigned short dirty;
+ unsigned short tableType;
const unsigned char* dictionary;
- unsigned char* bufferStart; /* obsolete, used for slideInputBuffer */
+ const LZ4_stream_t_internal* dictCtx;
unsigned int dictSize;
-} LZ4_stream_t_internal;
+};
typedef struct {
const unsigned char* externalDict;
- size_t extDictSize;
const unsigned char* prefixEnd;
+ size_t extDictSize;
size_t prefixSize;
} LZ4_streamDecode_t_internal;
#endif
-/*!
- * LZ4_stream_t :
- * information structure to track an LZ4 stream.
- * init this structure before first use.
- * note : only use in association with static linking !
- * this definition is not API/ABI safe,
- * and may change in a future version !
+/*! LZ4_stream_t :
+ * information structure to track an LZ4 stream.
+ * LZ4_stream_t can also be created using LZ4_createStream(), which is recommended.
+ * The structure definition can be convenient for static allocation
+ * (on stack, or as part of larger structure).
+ * 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))
union LZ4_stream_u {
unsigned long long table[LZ4_STREAMSIZE_U64];
LZ4_stream_t_internal internal_donotuse;
} ; /* 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 :
- * information structure to track an LZ4 stream during decompression.
- * init this structure using LZ4_setStreamDecode (or memset()) before first use
- * note : only use in association with static linking !
- * this definition is not API/ABI safe,
- * and may change in a future version !
+
+/*! LZ4_streamDecode_t :
+ * information structure to track an LZ4 stream during decompression.
+ * init this structure using LZ4_setStreamDecode() before first use.
+ * note : only use in association with static linking !
+ * this definition is not API/ABI safe,
+ * 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))
union LZ4_streamDecode_u {
unsigned long long table[LZ4_STREAMDECODESIZE_U64];
@@ -400,15 +648,22 @@ union LZ4_streamDecode_u {
} ; /* previously typedef'd to LZ4_streamDecode_t */
-/*=************************************
+
+/*-************************************
* Obsolete Functions
**************************************/
-/* Deprecation warnings */
-/* Should these warnings be a problem,
- it is generally possible to disable them,
- typically with -Wno-deprecated-declarations for gcc
- or _CRT_SECURE_NO_WARNINGS in Visual.
- Otherwise, it's also possible to define LZ4_DISABLE_DEPRECATE_WARNINGS */
+
+/*! Deprecation warnings
+ *
+ * Deprecated functions make the compiler generate a warning when invoked.
+ * This is meant to invite users to update their source code.
+ * Should deprecation warnings be a problem, it is generally possible to disable them,
+ * 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
# define LZ4_DEPRECATED(message) /* disable deprecation warnings */
#else
@@ -428,36 +683,82 @@ union LZ4_streamDecode_u {
#endif /* LZ4_DISABLE_DEPRECATE_WARNINGS */
/* Obsolete compression functions */
-LZ4_DEPRECATED("use LZ4_compress_default() instead") int LZ4_compress (const char* source, char* dest, int sourceSize);
-LZ4_DEPRECATED("use LZ4_compress_default() instead") int LZ4_compress_limitedOutput (const char* source, char* dest, int sourceSize, int maxOutputSize);
-LZ4_DEPRECATED("use LZ4_compress_fast_extState() instead") int LZ4_compress_withState (void* state, const char* source, char* dest, int inputSize);
-LZ4_DEPRECATED("use LZ4_compress_fast_extState() instead") int LZ4_compress_limitedOutput_withState (void* state, const char* source, char* dest, int inputSize, int maxOutputSize);
-LZ4_DEPRECATED("use LZ4_compress_fast_continue() instead") int LZ4_compress_continue (LZ4_stream_t* LZ4_streamPtr, const char* source, char* dest, int inputSize);
-LZ4_DEPRECATED("use LZ4_compress_fast_continue() instead") int LZ4_compress_limitedOutput_continue (LZ4_stream_t* LZ4_streamPtr, const char* source, char* dest, int inputSize, int maxOutputSize);
+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* 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_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_limitedOutput_continue (LZ4_stream_t* LZ4_streamPtr, const char* source, char* dest, int inputSize, int maxOutputSize);
/* Obsolete decompression functions */
-/* These function names are completely deprecated and must no longer be used.
- They are only provided in lz4.c for compatibility with older programs.
- - LZ4_uncompress is the same as LZ4_decompress_fast
- - LZ4_uncompress_unknownOutputSize is the same as LZ4_decompress_safe
- These function prototypes are now disabled; uncomment them only if you really need them.
- It is highly recommended to stop using these prototypes and migrate to maintained ones */
-/* int LZ4_uncompress (const char* source, char* dest, int outputSize); */
-/* int LZ4_uncompress_unknownOutputSize (const char* source, char* dest, int isize, int maxOutputSize); */
-
-/* Obsolete streaming functions; use new streaming interface whenever possible */
-LZ4_DEPRECATED("use LZ4_createStream() instead") void* LZ4_create (char* inputBuffer);
-LZ4_DEPRECATED("use LZ4_createStream() instead") int LZ4_sizeofStreamState(void);
-LZ4_DEPRECATED("use LZ4_resetStream() instead") int LZ4_resetStreamState(void* state, char* inputBuffer);
-LZ4_DEPRECATED("use LZ4_saveDict() instead") char* LZ4_slideInputBuffer (void* state);
+LZ4_DEPRECATED("use LZ4_decompress_fast() instead") LZ4LIB_API int LZ4_uncompress (const char* source, char* dest, int outputSize);
+LZ4_DEPRECATED("use LZ4_decompress_safe() instead") LZ4LIB_API int LZ4_uncompress_unknownOutputSize (const char* source, char* dest, int isize, int maxOutputSize);
+
+/* Obsolete streaming functions; degraded functionality; do not use!
+ *
+ * In order to perform streaming compression, these functions depended on data
+ * that is no longer tracked in the state. They have been preserved as well as
+ * possible: using them will still produce a correct output. However, they don't
+ * actually retain any history between compression calls. The compression ratio
+ * achieved will therefore be no better than compressing each chunk
+ * independently.
+ */
+LZ4_DEPRECATED("Use LZ4_createStream() instead") LZ4LIB_API void* LZ4_create (char* inputBuffer);
+LZ4_DEPRECATED("Use LZ4_createStream() instead") LZ4LIB_API int LZ4_sizeofStreamState(void);
+LZ4_DEPRECATED("Use LZ4_resetStream() instead") LZ4LIB_API int LZ4_resetStreamState(void* state, char* inputBuffer);
+LZ4_DEPRECATED("Use LZ4_saveDict() instead") LZ4LIB_API char* LZ4_slideInputBuffer (void* state);
/* Obsolete streaming decoding functions */
-LZ4_DEPRECATED("use LZ4_decompress_safe_usingDict() instead") int LZ4_decompress_safe_withPrefix64k (const char* src, char* dst, int compressedSize, int maxDstSize);
-LZ4_DEPRECATED("use LZ4_decompress_fast_usingDict() instead") int LZ4_decompress_fast_withPrefix64k (const char* src, char* dst, int originalSize);
+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_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)
}
#endif
-
-#endif /* LZ4_H_2983827168210 */