--- a/contrib/python-zstandard/zstd/zstd.h Sun Apr 08 01:08:43 2018 +0200
+++ b/contrib/python-zstandard/zstd/zstd.h Mon Apr 09 10:13:29 2018 -0700
@@ -2,11 +2,11 @@
* Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
* All rights reserved.
*
- * This source code is licensed under the BSD-style license found in the
- * LICENSE file in the root directory of this source tree. An additional grant
- * of patent rights can be found in the PATENTS file in the same directory.
+ * This source code is licensed under both the BSD-style license (found in the
+ * LICENSE file in the root directory of this source tree) and the GPLv2 (found
+ * in the COPYING file in the root directory of this source tree).
+ * You may select, at your option, one of the above-listed licenses.
*/
-
#if defined (__cplusplus)
extern "C" {
#endif
@@ -19,10 +19,12 @@
/* ===== ZSTDLIB_API : control library symbols visibility ===== */
-#if defined(__GNUC__) && (__GNUC__ >= 4)
-# define ZSTDLIB_VISIBILITY __attribute__ ((visibility ("default")))
-#else
-# define ZSTDLIB_VISIBILITY
+#ifndef ZSTDLIB_VISIBILITY
+# if defined(__GNUC__) && (__GNUC__ >= 4)
+# define ZSTDLIB_VISIBILITY __attribute__ ((visibility ("default")))
+# else
+# define ZSTDLIB_VISIBILITY
+# endif
#endif
#if defined(ZSTD_DLL_EXPORT) && (ZSTD_DLL_EXPORT==1)
# define ZSTDLIB_API __declspec(dllexport) ZSTDLIB_VISIBILITY
@@ -36,117 +38,147 @@
/*******************************************************************************************************
Introduction
- zstd, short for Zstandard, is a fast lossless compression algorithm, targeting real-time compression scenarios
- at zlib-level and better compression ratios. The zstd compression library provides in-memory compression and
- decompression functions. The library supports compression levels from 1 up to ZSTD_maxCLevel() which is 22.
- Levels >= 20, labelled `--ultra`, should be used with caution, as they require more memory.
+ zstd, short for Zstandard, is a fast lossless compression algorithm,
+ targeting real-time compression scenarios at zlib-level and better compression ratios.
+ The zstd compression library provides in-memory compression and decompression functions.
+ The library supports compression levels from 1 up to ZSTD_maxCLevel() which is currently 22.
+ Levels >= 20, labeled `--ultra`, should be used with caution, as they require more memory.
Compression can be done in:
- a single step (described as Simple API)
- - a single step, reusing a context (described as Explicit memory management)
+ - a single step, reusing a context (described as Explicit context)
- unbounded multiple steps (described as Streaming compression)
- The compression ratio achievable on small data can be highly improved using compression with a dictionary in:
+ The compression ratio achievable on small data can be highly improved using a dictionary in:
- a single step (described as Simple dictionary API)
- - a single step, reusing a dictionary (described as Fast dictionary API)
+ - a single step, reusing a dictionary (described as Bulk-processing dictionary API)
Advanced experimental functions can be accessed using #define ZSTD_STATIC_LINKING_ONLY before including zstd.h.
- These APIs shall never be used with a dynamic library.
+ Advanced experimental APIs shall never be used with a dynamic library.
They are not "stable", their definition may change in the future. Only static linking is allowed.
*********************************************************************************************************/
/*------ Version ------*/
#define ZSTD_VERSION_MAJOR 1
-#define ZSTD_VERSION_MINOR 1
-#define ZSTD_VERSION_RELEASE 3
+#define ZSTD_VERSION_MINOR 3
+#define ZSTD_VERSION_RELEASE 4
+
+#define ZSTD_VERSION_NUMBER (ZSTD_VERSION_MAJOR *100*100 + ZSTD_VERSION_MINOR *100 + ZSTD_VERSION_RELEASE)
+ZSTDLIB_API unsigned ZSTD_versionNumber(void); /**< useful to check dll version */
#define ZSTD_LIB_VERSION ZSTD_VERSION_MAJOR.ZSTD_VERSION_MINOR.ZSTD_VERSION_RELEASE
#define ZSTD_QUOTE(str) #str
#define ZSTD_EXPAND_AND_QUOTE(str) ZSTD_QUOTE(str)
#define ZSTD_VERSION_STRING ZSTD_EXPAND_AND_QUOTE(ZSTD_LIB_VERSION)
-
-#define ZSTD_VERSION_NUMBER (ZSTD_VERSION_MAJOR *100*100 + ZSTD_VERSION_MINOR *100 + ZSTD_VERSION_RELEASE)
-ZSTDLIB_API unsigned ZSTD_versionNumber(void); /**< library version number; to be used when checking dll version */
+ZSTDLIB_API const char* ZSTD_versionString(void); /* added in v1.3.0 */
/***************************************
* Simple API
***************************************/
/*! ZSTD_compress() :
- Compresses `src` content as a single zstd compressed frame into already allocated `dst`.
- Hint : compression runs faster if `dstCapacity` >= `ZSTD_compressBound(srcSize)`.
- @return : compressed size written into `dst` (<= `dstCapacity),
- or an error code if it fails (which can be tested using ZSTD_isError()). */
+ * Compresses `src` content as a single zstd compressed frame into already allocated `dst`.
+ * Hint : compression runs faster if `dstCapacity` >= `ZSTD_compressBound(srcSize)`.
+ * @return : compressed size written into `dst` (<= `dstCapacity),
+ * or an error code if it fails (which can be tested using ZSTD_isError()). */
ZSTDLIB_API size_t ZSTD_compress( void* dst, size_t dstCapacity,
const void* src, size_t srcSize,
int compressionLevel);
/*! ZSTD_decompress() :
- `compressedSize` : must be the _exact_ size of a single compressed frame.
- `dstCapacity` is an upper bound of originalSize.
- If user cannot imply a maximum upper bound, it's better to use streaming mode to decompress data.
- @return : the number of bytes decompressed into `dst` (<= `dstCapacity`),
- or an errorCode if it fails (which can be tested using ZSTD_isError()). */
+ * `compressedSize` : must be the _exact_ size of some number of compressed and/or skippable frames.
+ * `dstCapacity` is an upper bound of originalSize to regenerate.
+ * If user cannot imply a maximum upper bound, it's better to use streaming mode to decompress data.
+ * @return : the number of bytes decompressed into `dst` (<= `dstCapacity`),
+ * or an errorCode if it fails (which can be tested using ZSTD_isError()). */
ZSTDLIB_API size_t ZSTD_decompress( void* dst, size_t dstCapacity,
const void* src, size_t compressedSize);
+/*! ZSTD_getFrameContentSize() : added in v1.3.0
+ * `src` should point to the start of a ZSTD encoded frame.
+ * `srcSize` must be at least as large as the frame header.
+ * hint : any size >= `ZSTD_frameHeaderSize_max` is large enough.
+ * @return : - decompressed size of the frame in `src`, if known
+ * - ZSTD_CONTENTSIZE_UNKNOWN if the size cannot be determined
+ * - ZSTD_CONTENTSIZE_ERROR if an error occurred (e.g. invalid magic number, srcSize too small)
+ * note 1 : a 0 return value means the frame is valid but "empty".
+ * note 2 : decompressed size is an optional field, it may not be present, typically in streaming mode.
+ * When `return==ZSTD_CONTENTSIZE_UNKNOWN`, data to decompress could be any size.
+ * In which case, it's necessary to use streaming mode to decompress data.
+ * Optionally, application can rely on some implicit limit,
+ * as ZSTD_decompress() only needs an upper bound of decompressed size.
+ * (For example, data could be necessarily cut into blocks <= 16 KB).
+ * note 3 : decompressed size is always present when compression is done with ZSTD_compress()
+ * note 4 : decompressed size can be very large (64-bits value),
+ * potentially larger than what local system can handle as a single memory segment.
+ * In which case, it's necessary to use streaming mode to decompress data.
+ * note 5 : If source is untrusted, decompressed size could be wrong or intentionally modified.
+ * Always ensure return value fits within application's authorized limits.
+ * Each application can set its own limits.
+ * note 6 : This function replaces ZSTD_getDecompressedSize() */
+#define ZSTD_CONTENTSIZE_UNKNOWN (0ULL - 1)
+#define ZSTD_CONTENTSIZE_ERROR (0ULL - 2)
+ZSTDLIB_API unsigned long long ZSTD_getFrameContentSize(const void *src, size_t srcSize);
+
/*! ZSTD_getDecompressedSize() :
-* 'src' is the start of a zstd compressed frame.
-* @return : content size to be decompressed, as a 64-bits value _if known_, 0 otherwise.
-* note 1 : decompressed size is an optional field, that may not be present, especially in streaming mode.
-* When `return==0`, data to decompress could be any size.
-* In which case, it's necessary to use streaming mode to decompress data.
-* Optionally, application can still use ZSTD_decompress() while relying on implied limits.
-* (For example, data may be necessarily cut into blocks <= 16 KB).
-* note 2 : decompressed size is always present when compression is done with ZSTD_compress()
-* note 3 : decompressed size can be very large (64-bits value),
-* potentially larger than what local system can handle as a single memory segment.
-* In which case, it's necessary to use streaming mode to decompress data.
-* note 4 : If source is untrusted, decompressed size could be wrong or intentionally modified.
-* Always ensure result fits within application's authorized limits.
-* Each application can set its own limits.
-* note 5 : when `return==0`, if precise failure cause is needed, use ZSTD_getFrameParams() to know more. */
+ * NOTE: This function is now obsolete, in favor of ZSTD_getFrameContentSize().
+ * Both functions work the same way, but ZSTD_getDecompressedSize() blends
+ * "empty", "unknown" and "error" results to the same return value (0),
+ * while ZSTD_getFrameContentSize() gives them separate return values.
+ * `src` is the start of a zstd compressed frame.
+ * @return : content size to be decompressed, as a 64-bits value _if known and not empty_, 0 otherwise. */
ZSTDLIB_API unsigned long long ZSTD_getDecompressedSize(const void* src, size_t srcSize);
/*====== Helper functions ======*/
-ZSTDLIB_API int ZSTD_maxCLevel(void); /*!< maximum compression level available */
-ZSTDLIB_API size_t ZSTD_compressBound(size_t srcSize); /*!< maximum compressed size in worst case scenario */
+#define ZSTD_COMPRESSBOUND(srcSize) ((srcSize) + ((srcSize)>>8) + (((srcSize) < (128<<10)) ? (((128<<10) - (srcSize)) >> 11) /* margin, from 64 to 0 */ : 0)) /* this formula ensures that bound(A) + bound(B) <= bound(A+B) as long as A and B >= 128 KB */
+ZSTDLIB_API size_t ZSTD_compressBound(size_t srcSize); /*!< maximum compressed size in worst case single-pass scenario */
ZSTDLIB_API unsigned ZSTD_isError(size_t code); /*!< tells if a `size_t` function result is an error code */
ZSTDLIB_API const char* ZSTD_getErrorName(size_t code); /*!< provides readable string from an error code */
+ZSTDLIB_API int ZSTD_maxCLevel(void); /*!< maximum compression level available */
/***************************************
-* Explicit memory management
+* Explicit context
***************************************/
/*= Compression context
-* When compressing many times,
-* it is recommended to allocate a context just once, and re-use it for each successive compression operation.
-* This will make workload friendlier for system's memory.
-* Use one context per thread for parallel execution in multi-threaded environments. */
+ * When compressing many times,
+ * it is recommended to allocate a context just once, and re-use it for each successive compression operation.
+ * This will make workload friendlier for system's memory.
+ * Use one context per thread for parallel execution in multi-threaded environments. */
typedef struct ZSTD_CCtx_s ZSTD_CCtx;
ZSTDLIB_API ZSTD_CCtx* ZSTD_createCCtx(void);
ZSTDLIB_API size_t ZSTD_freeCCtx(ZSTD_CCtx* cctx);
/*! ZSTD_compressCCtx() :
- Same as ZSTD_compress(), requires an allocated ZSTD_CCtx (see ZSTD_createCCtx()). */
-ZSTDLIB_API size_t ZSTD_compressCCtx(ZSTD_CCtx* ctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize, int compressionLevel);
+ * Same as ZSTD_compress(), requires an allocated ZSTD_CCtx (see ZSTD_createCCtx()). */
+ZSTDLIB_API size_t ZSTD_compressCCtx(ZSTD_CCtx* ctx,
+ void* dst, size_t dstCapacity,
+ const void* src, size_t srcSize,
+ int compressionLevel);
-/*= Decompression context */
+/*= Decompression context
+ * When decompressing many times,
+ * it is recommended to allocate a context only once,
+ * and re-use it for each successive compression operation.
+ * This will make workload friendlier for system's memory.
+ * Use one context per thread for parallel execution. */
typedef struct ZSTD_DCtx_s ZSTD_DCtx;
ZSTDLIB_API ZSTD_DCtx* ZSTD_createDCtx(void);
ZSTDLIB_API size_t ZSTD_freeDCtx(ZSTD_DCtx* dctx);
/*! ZSTD_decompressDCtx() :
-* Same as ZSTD_decompress(), requires an allocated ZSTD_DCtx (see ZSTD_createDCtx()). */
-ZSTDLIB_API size_t ZSTD_decompressDCtx(ZSTD_DCtx* ctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
+ * Same as ZSTD_decompress(), requires an allocated ZSTD_DCtx (see ZSTD_createDCtx()) */
+ZSTDLIB_API size_t ZSTD_decompressDCtx(ZSTD_DCtx* ctx,
+ void* dst, size_t dstCapacity,
+ const void* src, size_t srcSize);
/**************************
* Simple dictionary API
***************************/
/*! ZSTD_compress_usingDict() :
-* Compression using a predefined Dictionary (see dictBuilder/zdict.h).
-* Note : This function loads the dictionary, resulting in significant startup delay.
-* Note : When `dict == NULL || dictSize < 8` no dictionary is used. */
+ * Compression using a predefined Dictionary (see dictBuilder/zdict.h).
+ * Note : This function loads the dictionary, resulting in significant startup delay.
+ * Note : When `dict == NULL || dictSize < 8` no dictionary is used. */
ZSTDLIB_API size_t ZSTD_compress_usingDict(ZSTD_CCtx* ctx,
void* dst, size_t dstCapacity,
const void* src, size_t srcSize,
@@ -154,36 +186,38 @@
int compressionLevel);
/*! ZSTD_decompress_usingDict() :
-* Decompression using a predefined Dictionary (see dictBuilder/zdict.h).
-* Dictionary must be identical to the one used during compression.
-* Note : This function loads the dictionary, resulting in significant startup delay.
-* Note : When `dict == NULL || dictSize < 8` no dictionary is used. */
+ * Decompression using a predefined Dictionary (see dictBuilder/zdict.h).
+ * Dictionary must be identical to the one used during compression.
+ * Note : This function loads the dictionary, resulting in significant startup delay.
+ * Note : When `dict == NULL || dictSize < 8` no dictionary is used. */
ZSTDLIB_API size_t ZSTD_decompress_usingDict(ZSTD_DCtx* dctx,
void* dst, size_t dstCapacity,
const void* src, size_t srcSize,
const void* dict,size_t dictSize);
-/****************************
-* Fast dictionary API
-****************************/
+/**********************************
+ * Bulk processing dictionary API
+ *********************************/
typedef struct ZSTD_CDict_s ZSTD_CDict;
/*! ZSTD_createCDict() :
-* When compressing multiple messages / blocks with the same dictionary, it's recommended to load it just once.
-* ZSTD_createCDict() will create a digested dictionary, ready to start future compression operations without startup delay.
-* ZSTD_CDict can be created once and used by multiple threads concurrently, as its usage is read-only.
-* `dictBuffer` can be released after ZSTD_CDict creation, as its content is copied within CDict */
-ZSTDLIB_API ZSTD_CDict* ZSTD_createCDict(const void* dictBuffer, size_t dictSize, int compressionLevel);
+ * When compressing multiple messages / blocks with the same dictionary, it's recommended to load it just once.
+ * ZSTD_createCDict() will create a digested dictionary, ready to start future compression operations without startup delay.
+ * ZSTD_CDict can be created once and shared by multiple threads concurrently, since its usage is read-only.
+ * `dictBuffer` can be released after ZSTD_CDict creation, since its content is copied within CDict */
+ZSTDLIB_API ZSTD_CDict* ZSTD_createCDict(const void* dictBuffer, size_t dictSize,
+ int compressionLevel);
/*! ZSTD_freeCDict() :
-* Function frees memory allocated by ZSTD_createCDict(). */
+ * Function frees memory allocated by ZSTD_createCDict(). */
ZSTDLIB_API size_t ZSTD_freeCDict(ZSTD_CDict* CDict);
/*! ZSTD_compress_usingCDict() :
-* Compression using a digested Dictionary.
-* Faster startup than ZSTD_compress_usingDict(), recommended when same dictionary is used multiple times.
-* Note that compression level is decided during dictionary creation. */
+ * Compression using a digested Dictionary.
+ * Faster startup than ZSTD_compress_usingDict(), recommended when same dictionary is used multiple times.
+ * Note that compression level is decided during dictionary creation.
+ * Frame parameters are hardcoded (dictID=yes, contentSize=yes, checksum=no) */
ZSTDLIB_API size_t ZSTD_compress_usingCDict(ZSTD_CCtx* cctx,
void* dst, size_t dstCapacity,
const void* src, size_t srcSize,
@@ -193,17 +227,17 @@
typedef struct ZSTD_DDict_s ZSTD_DDict;
/*! ZSTD_createDDict() :
-* Create a digested dictionary, ready to start decompression operation without startup delay.
-* dictBuffer can be released after DDict creation, as its content is copied inside DDict */
+ * Create a digested dictionary, ready to start decompression operation without startup delay.
+ * dictBuffer can be released after DDict creation, as its content is copied inside DDict */
ZSTDLIB_API ZSTD_DDict* ZSTD_createDDict(const void* dictBuffer, size_t dictSize);
/*! ZSTD_freeDDict() :
-* Function frees memory allocated with ZSTD_createDDict() */
+ * Function frees memory allocated with ZSTD_createDDict() */
ZSTDLIB_API size_t ZSTD_freeDDict(ZSTD_DDict* ddict);
/*! ZSTD_decompress_usingDDict() :
-* Decompression using a digested Dictionary.
-* Faster startup than ZSTD_decompress_usingDict(), recommended when same dictionary is used multiple times. */
+ * Decompression using a digested Dictionary.
+ * Faster startup than ZSTD_decompress_usingDict(), recommended when same dictionary is used multiple times. */
ZSTDLIB_API size_t ZSTD_decompress_usingDDict(ZSTD_DCtx* dctx,
void* dst, size_t dstCapacity,
const void* src, size_t srcSize,
@@ -260,17 +294,22 @@
* ZSTD_endStream() instructs to finish a frame.
* It will perform a flush and write frame epilogue.
* The epilogue is required for decoders to consider a frame completed.
-* Similar to ZSTD_flushStream(), it may not be able to flush the full content if `output->size` is too small.
+* ZSTD_endStream() may not be able to flush full data if `output->size` is too small.
* In which case, call again ZSTD_endStream() to complete the flush.
-* @return : nb of bytes still present within internal buffer (0 if it's empty, hence compression completed)
+* @return : 0 if frame fully completed and fully flushed,
+ or >0 if some data is still present within internal buffer
+ (value is minimum size estimation for remaining data to flush, but it could be more)
* or an error code, which can be tested using ZSTD_isError().
*
* *******************************************************************/
-typedef struct ZSTD_CStream_s ZSTD_CStream;
+typedef ZSTD_CCtx ZSTD_CStream; /**< CCtx and CStream are now effectively same object (>= v1.3.0) */
+ /* Continue to distinguish them for compatibility with versions <= v1.2.0 */
+/*===== ZSTD_CStream management functions =====*/
ZSTDLIB_API ZSTD_CStream* ZSTD_createCStream(void);
ZSTDLIB_API size_t ZSTD_freeCStream(ZSTD_CStream* zcs);
+/*===== Streaming compression functions =====*/
ZSTDLIB_API size_t ZSTD_initCStream(ZSTD_CStream* zcs, int compressionLevel);
ZSTDLIB_API size_t ZSTD_compressStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output, ZSTD_inBuffer* input);
ZSTDLIB_API size_t ZSTD_flushStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output);
@@ -303,10 +342,13 @@
* The return value is a suggested next input size (a hint to improve latency) that will never load more than the current frame.
* *******************************************************************************/
-typedef struct ZSTD_DStream_s ZSTD_DStream;
+typedef ZSTD_DCtx ZSTD_DStream; /**< DCtx and DStream are now effectively same object (>= v1.3.0) */
+ /* For compatibility with versions <= v1.2.0, continue to consider them separated. */
+/*===== ZSTD_DStream management functions =====*/
ZSTDLIB_API ZSTD_DStream* ZSTD_createDStream(void);
ZSTDLIB_API size_t ZSTD_freeDStream(ZSTD_DStream* zds);
+/*===== Streaming decompression functions =====*/
ZSTDLIB_API size_t ZSTD_initDStream(ZSTD_DStream* zds);
ZSTDLIB_API size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inBuffer* input);
@@ -316,47 +358,55 @@
#endif /* ZSTD_H_235446 */
-#if defined(ZSTD_STATIC_LINKING_ONLY) && !defined(ZSTD_H_ZSTD_STATIC_LINKING_ONLY)
-#define ZSTD_H_ZSTD_STATIC_LINKING_ONLY
/****************************************************************************************
* START OF ADVANCED AND EXPERIMENTAL FUNCTIONS
* The definitions in this section are considered experimental.
- * They should never be used with a dynamic library, as they may change in the future.
- * They are provided for advanced usages.
+ * They should never be used with a dynamic library, as prototypes may change in the future.
+ * They are provided for advanced scenarios.
* Use them only in association with static linking.
* ***************************************************************************************/
+#if defined(ZSTD_STATIC_LINKING_ONLY) && !defined(ZSTD_H_ZSTD_STATIC_LINKING_ONLY)
+#define ZSTD_H_ZSTD_STATIC_LINKING_ONLY
+
/* --- Constants ---*/
#define ZSTD_MAGICNUMBER 0xFD2FB528 /* >= v0.8.0 */
#define ZSTD_MAGIC_SKIPPABLE_START 0x184D2A50U
+#define ZSTD_MAGIC_DICTIONARY 0xEC30A437 /* >= v0.7.0 */
-#define ZSTD_WINDOWLOG_MAX_32 25
-#define ZSTD_WINDOWLOG_MAX_64 27
-#define ZSTD_WINDOWLOG_MAX ((U32)(MEM_32bits() ? ZSTD_WINDOWLOG_MAX_32 : ZSTD_WINDOWLOG_MAX_64))
-#define ZSTD_WINDOWLOG_MIN 10
-#define ZSTD_HASHLOG_MAX ZSTD_WINDOWLOG_MAX
-#define ZSTD_HASHLOG_MIN 6
-#define ZSTD_CHAINLOG_MAX (ZSTD_WINDOWLOG_MAX+1)
-#define ZSTD_CHAINLOG_MIN ZSTD_HASHLOG_MIN
-#define ZSTD_HASHLOG3_MAX 17
-#define ZSTD_SEARCHLOG_MAX (ZSTD_WINDOWLOG_MAX-1)
-#define ZSTD_SEARCHLOG_MIN 1
-#define ZSTD_SEARCHLENGTH_MAX 7 /* only for ZSTD_fast, other strategies are limited to 6 */
-#define ZSTD_SEARCHLENGTH_MIN 3 /* only for ZSTD_btopt, other strategies are limited to 4 */
-#define ZSTD_TARGETLENGTH_MIN 4
-#define ZSTD_TARGETLENGTH_MAX 999
+#define ZSTD_WINDOWLOG_MAX_32 30
+#define ZSTD_WINDOWLOG_MAX_64 31
+#define ZSTD_WINDOWLOG_MAX ((unsigned)(sizeof(size_t) == 4 ? ZSTD_WINDOWLOG_MAX_32 : ZSTD_WINDOWLOG_MAX_64))
+#define ZSTD_WINDOWLOG_MIN 10
+#define ZSTD_HASHLOG_MAX ((ZSTD_WINDOWLOG_MAX < 30) ? ZSTD_WINDOWLOG_MAX : 30)
+#define ZSTD_HASHLOG_MIN 6
+#define ZSTD_CHAINLOG_MAX_32 29
+#define ZSTD_CHAINLOG_MAX_64 30
+#define ZSTD_CHAINLOG_MAX ((unsigned)(sizeof(size_t) == 4 ? ZSTD_CHAINLOG_MAX_32 : ZSTD_CHAINLOG_MAX_64))
+#define ZSTD_CHAINLOG_MIN ZSTD_HASHLOG_MIN
+#define ZSTD_HASHLOG3_MAX 17
+#define ZSTD_SEARCHLOG_MAX (ZSTD_WINDOWLOG_MAX-1)
+#define ZSTD_SEARCHLOG_MIN 1
+#define ZSTD_SEARCHLENGTH_MAX 7 /* only for ZSTD_fast, other strategies are limited to 6 */
+#define ZSTD_SEARCHLENGTH_MIN 3 /* only for ZSTD_btopt, other strategies are limited to 4 */
+#define ZSTD_TARGETLENGTH_MIN 1 /* only used by btopt, btultra and btfast */
+#define ZSTD_LDM_MINMATCH_MIN 4
+#define ZSTD_LDM_MINMATCH_MAX 4096
+#define ZSTD_LDM_BUCKETSIZELOG_MAX 8
-#define ZSTD_FRAMEHEADERSIZE_MAX 18 /* for static allocation */
-#define ZSTD_FRAMEHEADERSIZE_MIN 6
-static const size_t ZSTD_frameHeaderSize_prefix = 5;
+#define ZSTD_FRAMEHEADERSIZE_PREFIX 5 /* minimum input size to know frame header size */
+#define ZSTD_FRAMEHEADERSIZE_MIN 6
+#define ZSTD_FRAMEHEADERSIZE_MAX 18 /* for static allocation */
+static const size_t ZSTD_frameHeaderSize_prefix = ZSTD_FRAMEHEADERSIZE_PREFIX;
static const size_t ZSTD_frameHeaderSize_min = ZSTD_FRAMEHEADERSIZE_MIN;
static const size_t ZSTD_frameHeaderSize_max = ZSTD_FRAMEHEADERSIZE_MAX;
static const size_t ZSTD_skippableHeaderSize = 8; /* magic number + skippable frame length */
/*--- Advanced types ---*/
-typedef enum { ZSTD_fast, ZSTD_dfast, ZSTD_greedy, ZSTD_lazy, ZSTD_lazy2, ZSTD_btlazy2, ZSTD_btopt, ZSTD_btopt2 } ZSTD_strategy; /* from faster to stronger */
+typedef enum { ZSTD_fast=1, ZSTD_dfast, ZSTD_greedy, ZSTD_lazy, ZSTD_lazy2,
+ ZSTD_btlazy2, ZSTD_btopt, ZSTD_btultra } ZSTD_strategy; /* from faster to stronger */
typedef struct {
unsigned windowLog; /**< largest match distance : larger == more compression, more memory needed during decompression */
@@ -379,35 +429,190 @@
ZSTD_frameParameters fParams;
} ZSTD_parameters;
-/*= Custom memory allocation functions */
+typedef struct ZSTD_CCtx_params_s ZSTD_CCtx_params;
+
+typedef enum {
+ ZSTD_dct_auto=0, /* dictionary is "full" when starting with ZSTD_MAGIC_DICTIONARY, otherwise it is "rawContent" */
+ ZSTD_dct_rawContent, /* ensures dictionary is always loaded as rawContent, even if it starts with ZSTD_MAGIC_DICTIONARY */
+ ZSTD_dct_fullDict /* refuses to load a dictionary if it does not respect Zstandard's specification */
+} ZSTD_dictContentType_e;
+
+typedef enum {
+ ZSTD_dlm_byCopy = 0, /**< Copy dictionary content internally */
+ ZSTD_dlm_byRef, /**< Reference dictionary content -- the dictionary buffer must outlive its users. */
+} ZSTD_dictLoadMethod_e;
+
+
+
+/***************************************
+* Frame size functions
+***************************************/
+
+/*! ZSTD_findFrameCompressedSize() :
+ * `src` should point to the start of a ZSTD encoded frame or skippable frame
+ * `srcSize` must be >= first frame size
+ * @return : the compressed size of the first frame starting at `src`,
+ * suitable to pass to `ZSTD_decompress` or similar,
+ * or an error code if input is invalid */
+ZSTDLIB_API size_t ZSTD_findFrameCompressedSize(const void* src, size_t srcSize);
+
+/*! ZSTD_findDecompressedSize() :
+ * `src` should point the start of a series of ZSTD encoded and/or skippable frames
+ * `srcSize` must be the _exact_ size of this series
+ * (i.e. there should be a frame boundary exactly at `srcSize` bytes after `src`)
+ * @return : - decompressed size of all data in all successive frames
+ * - if the decompressed size cannot be determined: ZSTD_CONTENTSIZE_UNKNOWN
+ * - if an error occurred: ZSTD_CONTENTSIZE_ERROR
+ *
+ * note 1 : decompressed size is an optional field, that may not be present, especially in streaming mode.
+ * When `return==ZSTD_CONTENTSIZE_UNKNOWN`, data to decompress could be any size.
+ * In which case, it's necessary to use streaming mode to decompress data.
+ * note 2 : decompressed size is always present when compression is done with ZSTD_compress()
+ * note 3 : decompressed size can be very large (64-bits value),
+ * potentially larger than what local system can handle as a single memory segment.
+ * In which case, it's necessary to use streaming mode to decompress data.
+ * note 4 : If source is untrusted, decompressed size could be wrong or intentionally modified.
+ * Always ensure result fits within application's authorized limits.
+ * Each application can set its own limits.
+ * note 5 : ZSTD_findDecompressedSize handles multiple frames, and so it must traverse the input to
+ * read each contained frame header. This is fast as most of the data is skipped,
+ * however it does mean that all frame data must be present and valid. */
+ZSTDLIB_API unsigned long long ZSTD_findDecompressedSize(const void* src, size_t srcSize);
+
+/*! ZSTD_frameHeaderSize() :
+* `src` should point to the start of a ZSTD frame
+* `srcSize` must be >= ZSTD_frameHeaderSize_prefix.
+* @return : size of the Frame Header */
+ZSTDLIB_API size_t ZSTD_frameHeaderSize(const void* src, size_t srcSize);
+
+
+/***************************************
+* Memory management
+***************************************/
+
+/*! ZSTD_sizeof_*() :
+ * These functions give the current memory usage of selected object.
+ * Object memory usage can evolve when re-used. */
+ZSTDLIB_API size_t ZSTD_sizeof_CCtx(const ZSTD_CCtx* cctx);
+ZSTDLIB_API size_t ZSTD_sizeof_DCtx(const ZSTD_DCtx* dctx);
+ZSTDLIB_API size_t ZSTD_sizeof_CStream(const ZSTD_CStream* zcs);
+ZSTDLIB_API size_t ZSTD_sizeof_DStream(const ZSTD_DStream* zds);
+ZSTDLIB_API size_t ZSTD_sizeof_CDict(const ZSTD_CDict* cdict);
+ZSTDLIB_API size_t ZSTD_sizeof_DDict(const ZSTD_DDict* ddict);
+
+/*! ZSTD_estimate*() :
+ * These functions make it possible to estimate memory usage
+ * of a future {D,C}Ctx, before its creation.
+ * ZSTD_estimateCCtxSize() will provide a budget large enough for any compression level up to selected one.
+ * It will also consider src size to be arbitrarily "large", which is worst case.
+ * If srcSize is known to always be small, ZSTD_estimateCCtxSize_usingCParams() can provide a tighter estimation.
+ * ZSTD_estimateCCtxSize_usingCParams() can be used in tandem with ZSTD_getCParams() to create cParams from compressionLevel.
+ * ZSTD_estimateCCtxSize_usingCCtxParams() can be used in tandem with ZSTD_CCtxParam_setParameter(). Only single-threaded compression is supported. This function will return an error code if ZSTD_p_nbWorkers is >= 1.
+ * Note : CCtx size estimation is only correct for single-threaded compression. */
+ZSTDLIB_API size_t ZSTD_estimateCCtxSize(int compressionLevel);
+ZSTDLIB_API size_t ZSTD_estimateCCtxSize_usingCParams(ZSTD_compressionParameters cParams);
+ZSTDLIB_API size_t ZSTD_estimateCCtxSize_usingCCtxParams(const ZSTD_CCtx_params* params);
+ZSTDLIB_API size_t ZSTD_estimateDCtxSize(void);
+
+/*! ZSTD_estimateCStreamSize() :
+ * ZSTD_estimateCStreamSize() will provide a budget large enough for any compression level up to selected one.
+ * It will also consider src size to be arbitrarily "large", which is worst case.
+ * If srcSize is known to always be small, ZSTD_estimateCStreamSize_usingCParams() can provide a tighter estimation.
+ * ZSTD_estimateCStreamSize_usingCParams() can be used in tandem with ZSTD_getCParams() to create cParams from compressionLevel.
+ * ZSTD_estimateCStreamSize_usingCCtxParams() can be used in tandem with ZSTD_CCtxParam_setParameter(). Only single-threaded compression is supported. This function will return an error code if ZSTD_p_nbWorkers is >= 1.
+ * Note : CStream size estimation is only correct for single-threaded compression.
+ * ZSTD_DStream memory budget depends on window Size.
+ * This information can be passed manually, using ZSTD_estimateDStreamSize,
+ * or deducted from a valid frame Header, using ZSTD_estimateDStreamSize_fromFrame();
+ * Note : if streaming is init with function ZSTD_init?Stream_usingDict(),
+ * an internal ?Dict will be created, which additional size is not estimated here.
+ * In this case, get total size by adding ZSTD_estimate?DictSize */
+ZSTDLIB_API size_t ZSTD_estimateCStreamSize(int compressionLevel);
+ZSTDLIB_API size_t ZSTD_estimateCStreamSize_usingCParams(ZSTD_compressionParameters cParams);
+ZSTDLIB_API size_t ZSTD_estimateCStreamSize_usingCCtxParams(const ZSTD_CCtx_params* params);
+ZSTDLIB_API size_t ZSTD_estimateDStreamSize(size_t windowSize);
+ZSTDLIB_API size_t ZSTD_estimateDStreamSize_fromFrame(const void* src, size_t srcSize);
+
+/*! ZSTD_estimate?DictSize() :
+ * ZSTD_estimateCDictSize() will bet that src size is relatively "small", and content is copied, like ZSTD_createCDict().
+ * ZSTD_estimateCDictSize_advanced() makes it possible to control compression parameters precisely, like ZSTD_createCDict_advanced().
+ * Note : dictionaries created by reference (`ZSTD_dlm_byRef`) are logically smaller.
+ */
+ZSTDLIB_API size_t ZSTD_estimateCDictSize(size_t dictSize, int compressionLevel);
+ZSTDLIB_API size_t ZSTD_estimateCDictSize_advanced(size_t dictSize, ZSTD_compressionParameters cParams, ZSTD_dictLoadMethod_e dictLoadMethod);
+ZSTDLIB_API size_t ZSTD_estimateDDictSize(size_t dictSize, ZSTD_dictLoadMethod_e dictLoadMethod);
+
+/*! ZSTD_initStatic*() :
+ * Initialize an object using a pre-allocated fixed-size buffer.
+ * workspace: The memory area to emplace the object into.
+ * Provided pointer *must be 8-bytes aligned*.
+ * Buffer must outlive object.
+ * workspaceSize: Use ZSTD_estimate*Size() to determine
+ * how large workspace must be to support target scenario.
+ * @return : pointer to object (same address as workspace, just different type),
+ * or NULL if error (size too small, incorrect alignment, etc.)
+ * Note : zstd will never resize nor malloc() when using a static buffer.
+ * If the object requires more memory than available,
+ * zstd will just error out (typically ZSTD_error_memory_allocation).
+ * Note 2 : there is no corresponding "free" function.
+ * Since workspace is allocated externally, it must be freed externally too.
+ * Note 3 : cParams : use ZSTD_getCParams() to convert a compression level
+ * into its associated cParams.
+ * Limitation 1 : currently not compatible with internal dictionary creation, triggered by
+ * ZSTD_CCtx_loadDictionary(), ZSTD_initCStream_usingDict() or ZSTD_initDStream_usingDict().
+ * Limitation 2 : static cctx currently not compatible with multi-threading.
+ * Limitation 3 : static dctx is incompatible with legacy support.
+ */
+ZSTDLIB_API ZSTD_CCtx* ZSTD_initStaticCCtx(void* workspace, size_t workspaceSize);
+ZSTDLIB_API ZSTD_CStream* ZSTD_initStaticCStream(void* workspace, size_t workspaceSize); /**< same as ZSTD_initStaticCCtx() */
+
+ZSTDLIB_API ZSTD_DCtx* ZSTD_initStaticDCtx(void* workspace, size_t workspaceSize);
+ZSTDLIB_API ZSTD_DStream* ZSTD_initStaticDStream(void* workspace, size_t workspaceSize); /**< same as ZSTD_initStaticDCtx() */
+
+ZSTDLIB_API const ZSTD_CDict* ZSTD_initStaticCDict(
+ void* workspace, size_t workspaceSize,
+ const void* dict, size_t dictSize,
+ ZSTD_dictLoadMethod_e dictLoadMethod,
+ ZSTD_dictContentType_e dictContentType,
+ ZSTD_compressionParameters cParams);
+
+ZSTDLIB_API const ZSTD_DDict* ZSTD_initStaticDDict(
+ void* workspace, size_t workspaceSize,
+ const void* dict, size_t dictSize,
+ ZSTD_dictLoadMethod_e dictLoadMethod,
+ ZSTD_dictContentType_e dictContentType);
+
+/*! Custom memory allocation :
+ * These prototypes make it possible to pass your own allocation/free functions.
+ * ZSTD_customMem is provided at creation time, using ZSTD_create*_advanced() variants listed below.
+ * All allocation/free operations will be completed using these custom variants instead of regular <stdlib.h> ones.
+ */
typedef void* (*ZSTD_allocFunction) (void* opaque, size_t size);
typedef void (*ZSTD_freeFunction) (void* opaque, void* address);
typedef struct { ZSTD_allocFunction customAlloc; ZSTD_freeFunction customFree; void* opaque; } ZSTD_customMem;
+static ZSTD_customMem const ZSTD_defaultCMem = { NULL, NULL, NULL }; /**< this constant defers to stdlib's functions */
+
+ZSTDLIB_API ZSTD_CCtx* ZSTD_createCCtx_advanced(ZSTD_customMem customMem);
+ZSTDLIB_API ZSTD_CStream* ZSTD_createCStream_advanced(ZSTD_customMem customMem);
+ZSTDLIB_API ZSTD_DCtx* ZSTD_createDCtx_advanced(ZSTD_customMem customMem);
+ZSTDLIB_API ZSTD_DStream* ZSTD_createDStream_advanced(ZSTD_customMem customMem);
+
+ZSTDLIB_API ZSTD_CDict* ZSTD_createCDict_advanced(const void* dict, size_t dictSize,
+ ZSTD_dictLoadMethod_e dictLoadMethod,
+ ZSTD_dictContentType_e dictContentType,
+ ZSTD_compressionParameters cParams,
+ ZSTD_customMem customMem);
+
+ZSTDLIB_API ZSTD_DDict* ZSTD_createDDict_advanced(const void* dict, size_t dictSize,
+ ZSTD_dictLoadMethod_e dictLoadMethod,
+ ZSTD_dictContentType_e dictContentType,
+ ZSTD_customMem customMem);
+
/***************************************
* Advanced compression functions
***************************************/
-/*! ZSTD_estimateCCtxSize() :
- * Gives the amount of memory allocated for a ZSTD_CCtx given a set of compression parameters.
- * `frameContentSize` is an optional parameter, provide `0` if unknown */
-ZSTDLIB_API size_t ZSTD_estimateCCtxSize(ZSTD_compressionParameters cParams);
-
-/*! ZSTD_createCCtx_advanced() :
- * Create a ZSTD compression context using external alloc and free functions */
-ZSTDLIB_API ZSTD_CCtx* ZSTD_createCCtx_advanced(ZSTD_customMem customMem);
-
-/*! ZSTD_sizeofCCtx() :
- * Gives the amount of memory used by a given ZSTD_CCtx */
-ZSTDLIB_API size_t ZSTD_sizeof_CCtx(const ZSTD_CCtx* cctx);
-
-typedef enum {
- ZSTD_p_forceWindow /* Force back-references to remain < windowSize, even when referencing Dictionary content (default:0)*/
-} ZSTD_CCtxParameter;
-/*! ZSTD_setCCtxParameter() :
- * Set advanced parameters, selected through enum ZSTD_CCtxParameter
- * @result : 0, or an error code (which can be tested with ZSTD_isError()) */
-ZSTDLIB_API size_t ZSTD_setCCtxParameter(ZSTD_CCtx* cctx, ZSTD_CCtxParameter param, unsigned value);
/*! ZSTD_createCDict_byReference() :
* Create a digested dictionary for compression
@@ -415,15 +620,6 @@
* It is important that dictBuffer outlives CDict, it must remain read accessible throughout the lifetime of CDict */
ZSTDLIB_API ZSTD_CDict* ZSTD_createCDict_byReference(const void* dictBuffer, size_t dictSize, int compressionLevel);
-/*! ZSTD_createCDict_advanced() :
- * Create a ZSTD_CDict using external alloc and free, and customized compression parameters */
-ZSTDLIB_API ZSTD_CDict* ZSTD_createCDict_advanced(const void* dict, size_t dictSize, unsigned byReference,
- ZSTD_parameters params, ZSTD_customMem customMem);
-
-/*! ZSTD_sizeof_CDict() :
- * Gives the amount of memory used by a given ZSTD_sizeof_CDict */
-ZSTDLIB_API size_t ZSTD_sizeof_CDict(const ZSTD_CDict* cdict);
-
/*! ZSTD_getCParams() :
* @return ZSTD_compressionParameters structure for a selected compression level and estimated srcSize.
* `estimatedSrcSize` value is optional, select 0 if not known */
@@ -431,7 +627,7 @@
/*! ZSTD_getParams() :
* same as ZSTD_getCParams(), but @return a full `ZSTD_parameters` object instead of sub-component `ZSTD_compressionParameters`.
-* All fields of `ZSTD_frameParameters` are set to default (0) */
+* All fields of `ZSTD_frameParameters` are set to default : contentSize=1, checksum=0, noDictID=0 */
ZSTDLIB_API ZSTD_parameters ZSTD_getParams(int compressionLevel, unsigned long long estimatedSrcSize, size_t dictSize);
/*! ZSTD_checkCParams() :
@@ -439,17 +635,24 @@
ZSTDLIB_API size_t ZSTD_checkCParams(ZSTD_compressionParameters params);
/*! ZSTD_adjustCParams() :
-* optimize params for a given `srcSize` and `dictSize`.
-* both values are optional, select `0` if unknown. */
+ * optimize params for a given `srcSize` and `dictSize`.
+ * both values are optional, select `0` if unknown. */
ZSTDLIB_API ZSTD_compressionParameters ZSTD_adjustCParams(ZSTD_compressionParameters cPar, unsigned long long srcSize, size_t dictSize);
/*! ZSTD_compress_advanced() :
-* Same as ZSTD_compress_usingDict(), with fine-tune control of each compression parameter */
-ZSTDLIB_API size_t ZSTD_compress_advanced (ZSTD_CCtx* ctx,
- void* dst, size_t dstCapacity,
- const void* src, size_t srcSize,
- const void* dict,size_t dictSize,
- ZSTD_parameters params);
+* Same as ZSTD_compress_usingDict(), with fine-tune control over each compression parameter */
+ZSTDLIB_API size_t ZSTD_compress_advanced (ZSTD_CCtx* cctx,
+ void* dst, size_t dstCapacity,
+ const void* src, size_t srcSize,
+ const void* dict,size_t dictSize,
+ ZSTD_parameters params);
+
+/*! ZSTD_compress_usingCDict_advanced() :
+* Same as ZSTD_compress_usingCDict(), with fine-tune control over frame parameters */
+ZSTDLIB_API size_t ZSTD_compress_usingCDict_advanced(ZSTD_CCtx* cctx,
+ void* dst, size_t dstCapacity,
+ const void* src, size_t srcSize,
+ const ZSTD_CDict* cdict, ZSTD_frameParameters fParams);
/*--- Advanced decompression functions ---*/
@@ -461,30 +664,13 @@
* Note 3 : Skippable Frame Identifiers are considered valid. */
ZSTDLIB_API unsigned ZSTD_isFrame(const void* buffer, size_t size);
-/*! ZSTD_estimateDCtxSize() :
- * Gives the potential amount of memory allocated to create a ZSTD_DCtx */
-ZSTDLIB_API size_t ZSTD_estimateDCtxSize(void);
-
-/*! ZSTD_createDCtx_advanced() :
- * Create a ZSTD decompression context using external alloc and free functions */
-ZSTDLIB_API ZSTD_DCtx* ZSTD_createDCtx_advanced(ZSTD_customMem customMem);
-
-/*! ZSTD_sizeof_DCtx() :
- * Gives the amount of memory used by a given ZSTD_DCtx */
-ZSTDLIB_API size_t ZSTD_sizeof_DCtx(const ZSTD_DCtx* dctx);
-
/*! ZSTD_createDDict_byReference() :
* Create a digested dictionary, ready to start decompression operation without startup delay.
- * Dictionary content is simply referenced, and therefore stays in dictBuffer.
- * It is important that dictBuffer outlives DDict, it must remain read accessible throughout the lifetime of DDict */
+ * Dictionary content is referenced, and therefore stays in dictBuffer.
+ * It is important that dictBuffer outlives DDict,
+ * it must remain read accessible throughout the lifetime of DDict */
ZSTDLIB_API ZSTD_DDict* ZSTD_createDDict_byReference(const void* dictBuffer, size_t dictSize);
-ZSTDLIB_API ZSTD_DDict* ZSTD_createDDict_advanced(const void* dict, size_t dictSize,
- unsigned byReference, ZSTD_customMem customMem);
-
-/*! ZSTD_sizeof_DDict() :
- * Gives the amount of memory used by a given ZSTD_DDict */
-ZSTDLIB_API size_t ZSTD_sizeof_DDict(const ZSTD_DDict* ddict);
/*! ZSTD_getDictID_fromDict() :
* Provides the dictID stored within dictionary.
@@ -507,7 +693,7 @@
* Note : this use case also happens when using a non-conformant dictionary.
* - `srcSize` is too small, and as a result, the frame header could not be decoded (only possible if `srcSize < ZSTD_FRAMEHEADERSIZE_MAX`).
* - This is not a Zstandard frame.
- * When identifying the exact failure cause, it's possible to used ZSTD_getFrameParams(), which will provide a more precise error code. */
+ * When identifying the exact failure cause, it's possible to use ZSTD_getFrameHeader(), which will provide a more precise error code. */
ZSTDLIB_API unsigned ZSTD_getDictID_fromFrame(const void* src, size_t srcSize);
@@ -516,32 +702,55 @@
********************************************************************/
/*===== Advanced Streaming compression functions =====*/
-ZSTDLIB_API ZSTD_CStream* ZSTD_createCStream_advanced(ZSTD_customMem customMem);
-ZSTDLIB_API size_t ZSTD_initCStream_srcSize(ZSTD_CStream* zcs, int compressionLevel, unsigned long long pledgedSrcSize); /**< pledgedSrcSize must be correct */
-ZSTDLIB_API size_t ZSTD_initCStream_usingDict(ZSTD_CStream* zcs, const void* dict, size_t dictSize, int compressionLevel); /**< note: a dict will not be used if dict == NULL or dictSize < 8 */
+ZSTDLIB_API size_t ZSTD_initCStream_srcSize(ZSTD_CStream* zcs, int compressionLevel, unsigned long long pledgedSrcSize); /**< pledgedSrcSize must be correct. If it is not known at init time, use ZSTD_CONTENTSIZE_UNKNOWN. Note that, for compatibility with older programs, "0" also disables frame content size field. It may be enabled in the future. */
+ZSTDLIB_API size_t ZSTD_initCStream_usingDict(ZSTD_CStream* zcs, const void* dict, size_t dictSize, int compressionLevel); /**< creates of an internal CDict (incompatible with static CCtx), except if dict == NULL or dictSize < 8, in which case no dict is used. Note: dict is loaded with ZSTD_dm_auto (treated as a full zstd dictionary if it begins with ZSTD_MAGIC_DICTIONARY, else as raw content) and ZSTD_dlm_byCopy.*/
ZSTDLIB_API size_t ZSTD_initCStream_advanced(ZSTD_CStream* zcs, const void* dict, size_t dictSize,
- ZSTD_parameters params, unsigned long long pledgedSrcSize); /**< pledgedSrcSize is optional and can be zero == unknown */
+ ZSTD_parameters params, unsigned long long pledgedSrcSize); /**< pledgedSrcSize must be correct. If srcSize is not known at init time, use value ZSTD_CONTENTSIZE_UNKNOWN. dict is loaded with ZSTD_dm_auto and ZSTD_dlm_byCopy. */
ZSTDLIB_API size_t ZSTD_initCStream_usingCDict(ZSTD_CStream* zcs, const ZSTD_CDict* cdict); /**< note : cdict will just be referenced, and must outlive compression session */
-ZSTDLIB_API size_t ZSTD_resetCStream(ZSTD_CStream* zcs, unsigned long long pledgedSrcSize); /**< re-use compression parameters from previous init; skip dictionary loading stage; zcs must be init at least once before */
-ZSTDLIB_API size_t ZSTD_sizeof_CStream(const ZSTD_CStream* zcs);
+ZSTDLIB_API size_t ZSTD_initCStream_usingCDict_advanced(ZSTD_CStream* zcs, const ZSTD_CDict* cdict, ZSTD_frameParameters fParams, unsigned long long pledgedSrcSize); /**< same as ZSTD_initCStream_usingCDict(), with control over frame parameters. pledgedSrcSize must be correct. If srcSize is not known at init time, use value ZSTD_CONTENTSIZE_UNKNOWN. */
+
+/*! ZSTD_resetCStream() :
+ * start a new compression job, using same parameters from previous job.
+ * This is typically useful to skip dictionary loading stage, since it will re-use it in-place..
+ * Note that zcs must be init at least once before using ZSTD_resetCStream().
+ * If pledgedSrcSize is not known at reset time, use macro ZSTD_CONTENTSIZE_UNKNOWN.
+ * If pledgedSrcSize > 0, its value must be correct, as it will be written in header, and controlled at the end.
+ * For the time being, pledgedSrcSize==0 is interpreted as "srcSize unknown" for compatibility with older programs,
+ * but it will change to mean "empty" in future version, so use macro ZSTD_CONTENTSIZE_UNKNOWN instead.
+ * @return : 0, or an error code (which can be tested using ZSTD_isError()) */
+ZSTDLIB_API size_t ZSTD_resetCStream(ZSTD_CStream* zcs, unsigned long long pledgedSrcSize);
+
+
+typedef struct {
+ unsigned long long ingested;
+ unsigned long long consumed;
+ unsigned long long produced;
+} ZSTD_frameProgression;
+
+/* ZSTD_getFrameProgression():
+ * tells how much data has been ingested (read from input)
+ * consumed (input actually compressed) and produced (output) for current frame.
+ * Therefore, (ingested - consumed) is amount of input data buffered internally, not yet compressed.
+ * Can report progression inside worker threads (multi-threading and non-blocking mode).
+ */
+ZSTD_frameProgression ZSTD_getFrameProgression(const ZSTD_CCtx* cctx);
+
/*===== Advanced Streaming decompression functions =====*/
typedef enum { DStream_p_maxWindowSize } ZSTD_DStreamParameter_e;
-ZSTDLIB_API ZSTD_DStream* ZSTD_createDStream_advanced(ZSTD_customMem customMem);
-ZSTDLIB_API size_t ZSTD_initDStream_usingDict(ZSTD_DStream* zds, const void* dict, size_t dictSize); /**< note: a dict will not be used if dict == NULL or dictSize < 8 */
-ZSTDLIB_API size_t ZSTD_setDStreamParameter(ZSTD_DStream* zds, ZSTD_DStreamParameter_e paramType, unsigned paramValue);
-ZSTDLIB_API size_t ZSTD_initDStream_usingDDict(ZSTD_DStream* zds, const ZSTD_DDict* ddict); /**< note : ddict will just be referenced, and must outlive decompression session */
+ZSTDLIB_API size_t ZSTD_setDStreamParameter(ZSTD_DStream* zds, ZSTD_DStreamParameter_e paramType, unsigned paramValue); /* obsolete : this API will be removed in a future version */
+ZSTDLIB_API size_t ZSTD_initDStream_usingDict(ZSTD_DStream* zds, const void* dict, size_t dictSize); /**< note: no dictionary will be used if dict == NULL or dictSize < 8 */
+ZSTDLIB_API size_t ZSTD_initDStream_usingDDict(ZSTD_DStream* zds, const ZSTD_DDict* ddict); /**< note : ddict is referenced, it must outlive decompression session */
ZSTDLIB_API size_t ZSTD_resetDStream(ZSTD_DStream* zds); /**< re-use decompression parameters from previous init; saves dictionary loading */
-ZSTDLIB_API size_t ZSTD_sizeof_DStream(const ZSTD_DStream* zds);
/*********************************************************************
* Buffer-less and synchronous inner streaming functions
*
* This is an advanced API, giving full control over buffer management, for users which need direct control over memory.
-* But it's also a complex one, with many restrictions (documented below).
-* Prefer using normal streaming API for an easier experience
+* But it's also a complex one, with several restrictions, documented below.
+* Prefer normal streaming API for an easier experience.
********************************************************************* */
/**
@@ -558,8 +767,8 @@
Then, consume your input using ZSTD_compressContinue().
There are some important considerations to keep in mind when using this advanced function :
- - ZSTD_compressContinue() has no internal buffer. It uses externally provided buffer only.
- - Interface is synchronous : input is consumed entirely and produce 1+ (or more) compressed blocks.
+ - ZSTD_compressContinue() has no internal buffer. It uses externally provided buffers only.
+ - Interface is synchronous : input is consumed entirely and produces 1+ compressed blocks.
- Caller must ensure there is enough space in `dst` to store compressed data under worst case scenario.
Worst case evaluation is provided by ZSTD_compressBound().
ZSTD_compressContinue() doesn't guarantee recover after a failed compression.
@@ -570,22 +779,23 @@
Finish a frame with ZSTD_compressEnd(), which will write the last block(s) and optional checksum.
It's possible to use srcSize==0, in which case, it will write a final empty block to end the frame.
- Without last block mark, frames will be considered unfinished (corrupted) by decoders.
+ Without last block mark, frames are considered unfinished (hence corrupted) by compliant decoders.
- `ZSTD_CCtx` object can be re-used (ZSTD_compressBegin()) to compress some new frame.
+ `ZSTD_CCtx` object can be re-used (ZSTD_compressBegin()) to compress again.
*/
/*===== Buffer-less streaming compression functions =====*/
ZSTDLIB_API size_t ZSTD_compressBegin(ZSTD_CCtx* cctx, int compressionLevel);
ZSTDLIB_API size_t ZSTD_compressBegin_usingDict(ZSTD_CCtx* cctx, const void* dict, size_t dictSize, int compressionLevel);
-ZSTDLIB_API size_t ZSTD_compressBegin_advanced(ZSTD_CCtx* cctx, const void* dict, size_t dictSize, ZSTD_parameters params, unsigned long long pledgedSrcSize);
-ZSTDLIB_API size_t ZSTD_copyCCtx(ZSTD_CCtx* cctx, const ZSTD_CCtx* preparedCCtx, unsigned long long pledgedSrcSize);
-ZSTDLIB_API size_t ZSTD_compressBegin_usingCDict(ZSTD_CCtx* cctx, const ZSTD_CDict* cdict, unsigned long long pledgedSrcSize);
+ZSTDLIB_API size_t ZSTD_compressBegin_advanced(ZSTD_CCtx* cctx, const void* dict, size_t dictSize, ZSTD_parameters params, unsigned long long pledgedSrcSize); /**< pledgedSrcSize : If srcSize is not known at init time, use ZSTD_CONTENTSIZE_UNKNOWN */
+ZSTDLIB_API size_t ZSTD_compressBegin_usingCDict(ZSTD_CCtx* cctx, const ZSTD_CDict* cdict); /**< note: fails if cdict==NULL */
+ZSTDLIB_API size_t ZSTD_compressBegin_usingCDict_advanced(ZSTD_CCtx* const cctx, const ZSTD_CDict* const cdict, ZSTD_frameParameters const fParams, unsigned long long const pledgedSrcSize); /* compression parameters are already set within cdict. pledgedSrcSize must be correct. If srcSize is not known, use macro ZSTD_CONTENTSIZE_UNKNOWN */
+ZSTDLIB_API size_t ZSTD_copyCCtx(ZSTD_CCtx* cctx, const ZSTD_CCtx* preparedCCtx, unsigned long long pledgedSrcSize); /**< note: if pledgedSrcSize is not known, use ZSTD_CONTENTSIZE_UNKNOWN */
+
ZSTDLIB_API size_t ZSTD_compressContinue(ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
ZSTDLIB_API size_t ZSTD_compressEnd(ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
-
/*-
Buffer-less streaming decompression (synchronous mode)
@@ -593,38 +803,54 @@
Use ZSTD_createDCtx() / ZSTD_freeDCtx() to manage it.
A ZSTD_DCtx object can be re-used multiple times.
- First typical operation is to retrieve frame parameters, using ZSTD_getFrameParams().
- It fills a ZSTD_frameParams structure which provide important information to correctly decode the frame,
- such as the minimum rolling buffer size to allocate to decompress data (`windowSize`),
- and the dictionary ID used.
- (Note : content size is optional, it may not be present. 0 means : content size unknown).
- Note that these values could be wrong, either because of data malformation, or because an attacker is spoofing deliberate false information.
- As a consequence, check that values remain within valid application range, especially `windowSize`, before allocation.
- Each application can set its own limit, depending on local restrictions. For extended interoperability, it is recommended to support at least 8 MB.
- Frame parameters are extracted from the beginning of the compressed frame.
- Data fragment must be large enough to ensure successful decoding, typically `ZSTD_frameHeaderSize_max` bytes.
- @result : 0 : successful decoding, the `ZSTD_frameParams` structure is correctly filled.
+ First typical operation is to retrieve frame parameters, using ZSTD_getFrameHeader().
+ Frame header is extracted from the beginning of compressed frame, so providing only the frame's beginning is enough.
+ Data fragment must be large enough to ensure successful decoding.
+ `ZSTD_frameHeaderSize_max` bytes is guaranteed to always be large enough.
+ @result : 0 : successful decoding, the `ZSTD_frameHeader` structure is correctly filled.
>0 : `srcSize` is too small, please provide at least @result bytes on next attempt.
errorCode, which can be tested using ZSTD_isError().
- Start decompression, with ZSTD_decompressBegin() or ZSTD_decompressBegin_usingDict().
- Alternatively, you can copy a prepared context, using ZSTD_copyDCtx().
+ It fills a ZSTD_frameHeader structure with important information to correctly decode the frame,
+ such as the dictionary ID, content size, or maximum back-reference distance (`windowSize`).
+ Note that these values could be wrong, either because of data corruption, or because a 3rd party deliberately spoofs false information.
+ As a consequence, check that values remain within valid application range.
+ For example, do not allocate memory blindly, check that `windowSize` is within expectation.
+ Each application can set its own limits, depending on local restrictions.
+ For extended interoperability, it is recommended to support `windowSize` of at least 8 MB.
+
+ ZSTD_decompressContinue() needs previous data blocks during decompression, up to `windowSize` bytes.
+ ZSTD_decompressContinue() is very sensitive to contiguity,
+ if 2 blocks don't follow each other, make sure that either the compressor breaks contiguity at the same place,
+ or that previous contiguous segment is large enough to properly handle maximum back-reference distance.
+ There are multiple ways to guarantee this condition.
+
+ The most memory efficient way is to use a round buffer of sufficient size.
+ Sufficient size is determined by invoking ZSTD_decodingBufferSize_min(),
+ which can @return an error code if required value is too large for current system (in 32-bits mode).
+ In a round buffer methodology, ZSTD_decompressContinue() decompresses each block next to previous one,
+ up to the moment there is not enough room left in the buffer to guarantee decoding another full block,
+ which maximum size is provided in `ZSTD_frameHeader` structure, field `blockSizeMax`.
+ At which point, decoding can resume from the beginning of the buffer.
+ Note that already decoded data stored in the buffer should be flushed before being overwritten.
+
+ There are alternatives possible, for example using two or more buffers of size `windowSize` each, though they consume more memory.
+
+ Finally, if you control the compression process, you can also ignore all buffer size rules,
+ as long as the encoder and decoder progress in "lock-step",
+ aka use exactly the same buffer sizes, break contiguity at the same place, etc.
+
+ Once buffers are setup, start decompression, with ZSTD_decompressBegin().
+ If decompression requires a dictionary, use ZSTD_decompressBegin_usingDict() or ZSTD_decompressBegin_usingDDict().
Then use ZSTD_nextSrcSizeToDecompress() and ZSTD_decompressContinue() alternatively.
ZSTD_nextSrcSizeToDecompress() tells how many bytes to provide as 'srcSize' to ZSTD_decompressContinue().
ZSTD_decompressContinue() requires this _exact_ amount of bytes, or it will fail.
- @result of ZSTD_decompressContinue() is the number of bytes regenerated within 'dst' (necessarily <= dstCapacity).
- It can be zero, which is not an error; it just means ZSTD_decompressContinue() has decoded some metadata item.
+ @result of ZSTD_decompressContinue() is the number of bytes regenerated within 'dst' (necessarily <= dstCapacity).
+ It can be zero : it just means ZSTD_decompressContinue() has decoded some metadata item.
It can also be an error code, which can be tested with ZSTD_isError().
- ZSTD_decompressContinue() needs previous data blocks during decompression, up to `windowSize`.
- They should preferably be located contiguously, prior to current block.
- Alternatively, a round buffer of sufficient size is also possible. Sufficient size is determined by frame parameters.
- ZSTD_decompressContinue() is very sensitive to contiguity,
- if 2 blocks don't follow each other, make sure that either the compressor breaks contiguity at the same place,
- or that previous contiguous segment is large enough to properly handle maximum back-reference.
-
A frame is fully decoded when ZSTD_nextSrcSizeToDecompress() returns zero.
Context can then be reset to start a new decompression.
@@ -634,35 +860,505 @@
== Special case : skippable frames ==
Skippable frames allow integration of user-defined data into a flow of concatenated frames.
- Skippable frames will be ignored (skipped) by a decompressor. The format of skippable frames is as follows :
+ Skippable frames will be ignored (skipped) by decompressor.
+ The format of skippable frames is as follows :
a) Skippable frame ID - 4 Bytes, Little endian format, any value from 0x184D2A50 to 0x184D2A5F
b) Frame Size - 4 Bytes, Little endian format, unsigned 32-bits
c) Frame Content - any content (User Data) of length equal to Frame Size
- For skippable frames ZSTD_decompressContinue() always returns 0.
- For skippable frames ZSTD_getFrameParams() returns fparamsPtr->windowLog==0 what means that a frame is skippable.
- It also returns Frame Size as fparamsPtr->frameContentSize.
+ For skippable frames ZSTD_getFrameHeader() returns zfhPtr->frameType==ZSTD_skippableFrame.
+ For skippable frames ZSTD_decompressContinue() always returns 0 : it only skips the content.
*/
+/*===== Buffer-less streaming decompression functions =====*/
+typedef enum { ZSTD_frame, ZSTD_skippableFrame } ZSTD_frameType_e;
typedef struct {
- unsigned long long frameContentSize;
- unsigned windowSize;
+ unsigned long long frameContentSize; /* if == ZSTD_CONTENTSIZE_UNKNOWN, it means this field is not available. 0 means "empty" */
+ unsigned long long windowSize; /* can be very large, up to <= frameContentSize */
+ unsigned blockSizeMax;
+ ZSTD_frameType_e frameType; /* if == ZSTD_skippableFrame, frameContentSize is the size of skippable content */
+ unsigned headerSize;
unsigned dictID;
unsigned checksumFlag;
-} ZSTD_frameParams;
+} ZSTD_frameHeader;
+ZSTDLIB_API size_t ZSTD_getFrameHeader(ZSTD_frameHeader* zfhPtr, const void* src, size_t srcSize); /**< doesn't consume input */
+ZSTDLIB_API size_t ZSTD_decodingBufferSize_min(unsigned long long windowSize, unsigned long long frameContentSize); /**< when frame content size is not known, pass in frameContentSize == ZSTD_CONTENTSIZE_UNKNOWN */
-/*===== Buffer-less streaming decompression functions =====*/
-ZSTDLIB_API size_t ZSTD_getFrameParams(ZSTD_frameParams* fparamsPtr, const void* src, size_t srcSize); /**< doesn't consume input, see details below */
ZSTDLIB_API size_t ZSTD_decompressBegin(ZSTD_DCtx* dctx);
ZSTDLIB_API size_t ZSTD_decompressBegin_usingDict(ZSTD_DCtx* dctx, const void* dict, size_t dictSize);
-ZSTDLIB_API void ZSTD_copyDCtx(ZSTD_DCtx* dctx, const ZSTD_DCtx* preparedDCtx);
+ZSTDLIB_API size_t ZSTD_decompressBegin_usingDDict(ZSTD_DCtx* dctx, const ZSTD_DDict* ddict);
+
ZSTDLIB_API size_t ZSTD_nextSrcSizeToDecompress(ZSTD_DCtx* dctx);
ZSTDLIB_API size_t ZSTD_decompressContinue(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
+
+/* misc */
+ZSTDLIB_API void ZSTD_copyDCtx(ZSTD_DCtx* dctx, const ZSTD_DCtx* preparedDCtx);
typedef enum { ZSTDnit_frameHeader, ZSTDnit_blockHeader, ZSTDnit_block, ZSTDnit_lastBlock, ZSTDnit_checksum, ZSTDnit_skippableFrame } ZSTD_nextInputType_e;
ZSTDLIB_API ZSTD_nextInputType_e ZSTD_nextInputType(ZSTD_DCtx* dctx);
-/**
- Block functions
+
+
+/* ============================================ */
+/** New advanced API (experimental) */
+/* ============================================ */
+
+/* notes on API design :
+ * In this proposal, parameters are pushed one by one into an existing context,
+ * and then applied on all subsequent compression jobs.
+ * When no parameter is ever provided, CCtx is created with compression level ZSTD_CLEVEL_DEFAULT.
+ *
+ * This API is intended to replace all others advanced / experimental API entry points.
+ * But it stands a reasonable chance to become "stable", after a reasonable testing period.
+ */
+
+/* note on naming convention :
+ * Initially, the API favored names like ZSTD_setCCtxParameter() .
+ * In this proposal, convention is changed towards ZSTD_CCtx_setParameter() .
+ * The main driver is that it identifies more clearly the target object type.
+ * It feels clearer when considering multiple targets :
+ * ZSTD_CDict_setParameter() (rather than ZSTD_setCDictParameter())
+ * ZSTD_CCtxParams_setParameter() (rather than ZSTD_setCCtxParamsParameter() )
+ * etc...
+ */
+
+/* note on enum design :
+ * All enum will be pinned to explicit values before reaching "stable API" status */
+
+typedef enum {
+ /* Opened question : should we have a format ZSTD_f_auto ?
+ * Today, it would mean exactly the same as ZSTD_f_zstd1.
+ * But, in the future, should several formats become supported,
+ * on the compression side, it would mean "default format".
+ * On the decompression side, it would mean "automatic format detection",
+ * so that ZSTD_f_zstd1 would mean "accept *only* zstd frames".
+ * Since meaning is a little different, another option could be to define different enums for compression and decompression.
+ * This question could be kept for later, when there are actually multiple formats to support,
+ * but there is also the question of pinning enum values, and pinning value `0` is especially important */
+ ZSTD_f_zstd1 = 0, /* zstd frame format, specified in zstd_compression_format.md (default) */
+ ZSTD_f_zstd1_magicless, /* Variant of zstd frame format, without initial 4-bytes magic number.
+ * Useful to save 4 bytes per generated frame.
+ * Decoder cannot recognise automatically this format, requiring instructions. */
+} ZSTD_format_e;
+
+typedef enum {
+ /* compression format */
+ ZSTD_p_format = 10, /* See ZSTD_format_e enum definition.
+ * Cast selected format as unsigned for ZSTD_CCtx_setParameter() compatibility. */
+
+ /* compression parameters */
+ ZSTD_p_compressionLevel=100, /* Update all compression parameters according to pre-defined cLevel table
+ * Default level is ZSTD_CLEVEL_DEFAULT==3.
+ * Special: value 0 means "do not change cLevel".
+ * Note 1 : it's possible to pass a negative compression level by casting it to unsigned type.
+ * Note 2 : setting a level sets all default values of other compression parameters.
+ * Note 3 : setting compressionLevel automatically updates ZSTD_p_compressLiterals. */
+ ZSTD_p_windowLog, /* Maximum allowed back-reference distance, expressed as power of 2.
+ * Must be clamped between ZSTD_WINDOWLOG_MIN and ZSTD_WINDOWLOG_MAX.
+ * Special: value 0 means "use default windowLog".
+ * Note: Using a window size greater than ZSTD_MAXWINDOWSIZE_DEFAULT (default: 2^27)
+ * requires explicitly allowing such window size during decompression stage. */
+ ZSTD_p_hashLog, /* Size of the probe table, as a power of 2.
+ * Resulting table size is (1 << (hashLog+2)).
+ * Must be clamped between ZSTD_HASHLOG_MIN and ZSTD_HASHLOG_MAX.
+ * Larger tables improve compression ratio of strategies <= dFast,
+ * and improve speed of strategies > dFast.
+ * Special: value 0 means "use default hashLog". */
+ ZSTD_p_chainLog, /* Size of the full-search table, as a power of 2.
+ * Resulting table size is (1 << (chainLog+2)).
+ * Larger tables result in better and slower compression.
+ * This parameter is useless when using "fast" strategy.
+ * Special: value 0 means "use default chainLog". */
+ ZSTD_p_searchLog, /* Number of search attempts, as a power of 2.
+ * More attempts result in better and slower compression.
+ * This parameter is useless when using "fast" and "dFast" strategies.
+ * Special: value 0 means "use default searchLog". */
+ ZSTD_p_minMatch, /* Minimum size of searched matches (note : repCode matches can be smaller).
+ * Larger values make faster compression and decompression, but decrease ratio.
+ * Must be clamped between ZSTD_SEARCHLENGTH_MIN and ZSTD_SEARCHLENGTH_MAX.
+ * Note that currently, for all strategies < btopt, effective minimum is 4.
+ * , for all strategies > fast, effective maximum is 6.
+ * Special: value 0 means "use default minMatchLength". */
+ ZSTD_p_targetLength, /* Impact of this field depends on strategy.
+ * For strategies btopt & btultra:
+ * Length of Match considered "good enough" to stop search.
+ * Larger values make compression stronger, and slower.
+ * For strategy fast:
+ * Distance between match sampling.
+ * Larger values make compression faster, and weaker.
+ * Special: value 0 means "use default targetLength". */
+ ZSTD_p_compressionStrategy, /* See ZSTD_strategy enum definition.
+ * Cast selected strategy as unsigned for ZSTD_CCtx_setParameter() compatibility.
+ * The higher the value of selected strategy, the more complex it is,
+ * resulting in stronger and slower compression.
+ * Special: value 0 means "use default strategy". */
+
+ ZSTD_p_enableLongDistanceMatching=160, /* Enable long distance matching.
+ * This parameter is designed to improve compression ratio
+ * for large inputs, by finding large matches at long distance.
+ * It increases memory usage and window size.
+ * Note: enabling this parameter increases ZSTD_p_windowLog to 128 MB
+ * except when expressly set to a different value. */
+ ZSTD_p_ldmHashLog, /* Size of the table for long distance matching, as a power of 2.
+ * Larger values increase memory usage and compression ratio,
+ * but decrease compression speed.
+ * Must be clamped between ZSTD_HASHLOG_MIN and ZSTD_HASHLOG_MAX
+ * default: windowlog - 7.
+ * Special: value 0 means "automatically determine hashlog". */
+ ZSTD_p_ldmMinMatch, /* Minimum match size for long distance matcher.
+ * Larger/too small values usually decrease compression ratio.
+ * Must be clamped between ZSTD_LDM_MINMATCH_MIN and ZSTD_LDM_MINMATCH_MAX.
+ * Special: value 0 means "use default value" (default: 64). */
+ ZSTD_p_ldmBucketSizeLog, /* Log size of each bucket in the LDM hash table for collision resolution.
+ * Larger values improve collision resolution but decrease compression speed.
+ * The maximum value is ZSTD_LDM_BUCKETSIZELOG_MAX .
+ * Special: value 0 means "use default value" (default: 3). */
+ ZSTD_p_ldmHashEveryLog, /* Frequency of inserting/looking up entries in the LDM hash table.
+ * Must be clamped between 0 and (ZSTD_WINDOWLOG_MAX - ZSTD_HASHLOG_MIN).
+ * Default is MAX(0, (windowLog - ldmHashLog)), optimizing hash table usage.
+ * Larger values improve compression speed.
+ * Deviating far from default value will likely result in a compression ratio decrease.
+ * Special: value 0 means "automatically determine hashEveryLog". */
+
+ /* frame parameters */
+ ZSTD_p_contentSizeFlag=200, /* Content size will be written into frame header _whenever known_ (default:1)
+ * Content size must be known at the beginning of compression,
+ * it is provided using ZSTD_CCtx_setPledgedSrcSize() */
+ ZSTD_p_checksumFlag, /* A 32-bits checksum of content is written at end of frame (default:0) */
+ ZSTD_p_dictIDFlag, /* When applicable, dictionary's ID is written into frame header (default:1) */
+
+ /* multi-threading parameters */
+ /* These parameters are only useful if multi-threading is enabled (ZSTD_MULTITHREAD).
+ * They return an error otherwise. */
+ ZSTD_p_nbWorkers=400, /* Select how many threads will be spawned to compress in parallel.
+ * When nbWorkers >= 1, triggers asynchronous mode :
+ * ZSTD_compress_generic() consumes some input, flush some output if possible, and immediately gives back control to caller,
+ * while compression work is performed in parallel, within worker threads.
+ * (note : a strong exception to this rule is when first invocation sets ZSTD_e_end : it becomes a blocking call).
+ * More workers improve speed, but also increase memory usage.
+ * Default value is `0`, aka "single-threaded mode" : no worker is spawned, compression is performed inside Caller's thread, all invocations are blocking */
+ ZSTD_p_jobSize, /* Size of a compression job. This value is enforced only in non-blocking mode.
+ * Each compression job is completed in parallel, so this value indirectly controls the nb of active threads.
+ * 0 means default, which is dynamically determined based on compression parameters.
+ * Job size must be a minimum of overlapSize, or 1 MB, whichever is largest.
+ * The minimum size is automatically and transparently enforced */
+ ZSTD_p_overlapSizeLog, /* Size of previous input reloaded at the beginning of each job.
+ * 0 => no overlap, 6(default) => use 1/8th of windowSize, >=9 => use full windowSize */
+
+ /* =================================================================== */
+ /* experimental parameters - no stability guaranteed */
+ /* =================================================================== */
+
+ ZSTD_p_compressLiterals=1000, /* control huffman compression of literals (enabled) by default.
+ * disabling it improves speed and decreases compression ratio by a large amount.
+ * note : this setting is automatically updated when changing compression level.
+ * positive compression levels set ZSTD_p_compressLiterals to 1.
+ * negative compression levels set ZSTD_p_compressLiterals to 0. */
+
+ ZSTD_p_forceMaxWindow=1100, /* Force back-reference distances to remain < windowSize,
+ * even when referencing into Dictionary content (default:0) */
+
+} ZSTD_cParameter;
+
+
+/*! ZSTD_CCtx_setParameter() :
+ * Set one compression parameter, selected by enum ZSTD_cParameter.
+ * Setting a parameter is generally only possible during frame initialization (before starting compression),
+ * except for a few exceptions which can be updated during compression: compressionLevel, hashLog, chainLog, searchLog, minMatch, targetLength and strategy.
+ * Note : when `value` is an enum, cast it to unsigned for proper type checking.
+ * @result : informational value (typically, value being set clamped correctly),
+ * or an error code (which can be tested with ZSTD_isError()). */
+ZSTDLIB_API size_t ZSTD_CCtx_setParameter(ZSTD_CCtx* cctx, ZSTD_cParameter param, unsigned value);
+
+/*! ZSTD_CCtx_setPledgedSrcSize() :
+ * Total input data size to be compressed as a single frame.
+ * This value will be controlled at the end, and result in error if not respected.
+ * @result : 0, or an error code (which can be tested with ZSTD_isError()).
+ * Note 1 : 0 means zero, empty.
+ * In order to mean "unknown content size", pass constant ZSTD_CONTENTSIZE_UNKNOWN.
+ * ZSTD_CONTENTSIZE_UNKNOWN is default value for any new compression job.
+ * Note 2 : If all data is provided and consumed in a single round,
+ * this value is overriden by srcSize instead. */
+ZSTDLIB_API size_t ZSTD_CCtx_setPledgedSrcSize(ZSTD_CCtx* cctx, unsigned long long pledgedSrcSize);
+
+/*! ZSTD_CCtx_loadDictionary() :
+ * Create an internal CDict from `dict` buffer.
+ * Decompression will have to use same dictionary.
+ * @result : 0, or an error code (which can be tested with ZSTD_isError()).
+ * Special: Adding a NULL (or 0-size) dictionary invalidates previous dictionary,
+ * meaning "return to no-dictionary mode".
+ * Note 1 : Dictionary will be used for all future compression jobs.
+ * To return to "no-dictionary" situation, load a NULL dictionary
+ * Note 2 : Loading a dictionary involves building tables, which are dependent on compression parameters.
+ * For this reason, compression parameters cannot be changed anymore after loading a dictionary.
+ * It's also a CPU consuming operation, with non-negligible impact on latency.
+ * Note 3 :`dict` content will be copied internally.
+ * Use ZSTD_CCtx_loadDictionary_byReference() to reference dictionary content instead.
+ * In such a case, dictionary buffer must outlive its users.
+ * Note 4 : Use ZSTD_CCtx_loadDictionary_advanced()
+ * to precisely select how dictionary content must be interpreted. */
+ZSTDLIB_API size_t ZSTD_CCtx_loadDictionary(ZSTD_CCtx* cctx, const void* dict, size_t dictSize);
+ZSTDLIB_API size_t ZSTD_CCtx_loadDictionary_byReference(ZSTD_CCtx* cctx, const void* dict, size_t dictSize);
+ZSTDLIB_API size_t ZSTD_CCtx_loadDictionary_advanced(ZSTD_CCtx* cctx, const void* dict, size_t dictSize, ZSTD_dictLoadMethod_e dictLoadMethod, ZSTD_dictContentType_e dictContentType);
+
+
+/*! ZSTD_CCtx_refCDict() :
+ * Reference a prepared dictionary, to be used for all next compression jobs.
+ * Note that compression parameters are enforced from within CDict,
+ * and supercede any compression parameter previously set within CCtx.
+ * The dictionary will remain valid for future compression jobs using same CCtx.
+ * @result : 0, or an error code (which can be tested with ZSTD_isError()).
+ * Special : adding a NULL CDict means "return to no-dictionary mode".
+ * Note 1 : Currently, only one dictionary can be managed.
+ * Adding a new dictionary effectively "discards" any previous one.
+ * Note 2 : CDict is just referenced, its lifetime must outlive CCtx. */
+ZSTDLIB_API size_t ZSTD_CCtx_refCDict(ZSTD_CCtx* cctx, const ZSTD_CDict* cdict);
+/*! ZSTD_CCtx_refPrefix() :
+ * Reference a prefix (single-usage dictionary) for next compression job.
+ * Decompression need same prefix to properly regenerate data.
+ * Prefix is **only used once**. Tables are discarded at end of compression job.
+ * Subsequent compression jobs will be done without prefix (if none is explicitly referenced).
+ * If there is a need to use same prefix multiple times, consider embedding it into a ZSTD_CDict instead.
+ * @result : 0, or an error code (which can be tested with ZSTD_isError()).
+ * Special: Adding any prefix (including NULL) invalidates any previous prefix or dictionary
+ * Note 1 : Prefix buffer is referenced. It must outlive compression job.
+ * Note 2 : Referencing a prefix involves building tables, which are dependent on compression parameters.
+ * It's a CPU consuming operation, with non-negligible impact on latency.
+ * Note 3 : By default, the prefix is treated as raw content (ZSTD_dm_rawContent).
+ * Use ZSTD_CCtx_refPrefix_advanced() to alter dictMode. */
+ZSTDLIB_API size_t ZSTD_CCtx_refPrefix(ZSTD_CCtx* cctx, const void* prefix, size_t prefixSize);
+ZSTDLIB_API size_t ZSTD_CCtx_refPrefix_advanced(ZSTD_CCtx* cctx, const void* prefix, size_t prefixSize, ZSTD_dictContentType_e dictContentType);
+
+/*! ZSTD_CCtx_reset() :
+ * Return a CCtx to clean state.
+ * Useful after an error, or to interrupt an ongoing compression job and start a new one.
+ * Any internal data not yet flushed is cancelled.
+ * Dictionary (if any) is dropped.
+ * All parameters are back to default values.
+ * It's possible to modify compression parameters after a reset.
+ */
+ZSTDLIB_API void ZSTD_CCtx_reset(ZSTD_CCtx* cctx);
+
+
+
+typedef enum {
+ ZSTD_e_continue=0, /* collect more data, encoder decides when to output compressed result, for optimal conditions */
+ ZSTD_e_flush, /* flush any data provided so far - frame will continue, future data can still reference previous data for better compression */
+ ZSTD_e_end /* flush any remaining data and close current frame. Any additional data starts a new frame. */
+} ZSTD_EndDirective;
+
+/*! ZSTD_compress_generic() :
+ * Behave about the same as ZSTD_compressStream. To note :
+ * - Compression parameters are pushed into CCtx before starting compression, using ZSTD_CCtx_setParameter()
+ * - Compression parameters cannot be changed once compression is started.
+ * - outpot->pos must be <= dstCapacity, input->pos must be <= srcSize
+ * - outpot->pos and input->pos will be updated. They are guaranteed to remain below their respective limit.
+ * - In single-thread mode (default), function is blocking : it completed its job before returning to caller.
+ * - In multi-thread mode, function is non-blocking : it just acquires a copy of input, and distribute job to internal worker threads,
+ * and then immediately returns, just indicating that there is some data remaining to be flushed.
+ * The function nonetheless guarantees forward progress : it will return only after it reads or write at least 1+ byte.
+ * - Exception : in multi-threading mode, if the first call requests a ZSTD_e_end directive, it is blocking : it will complete compression before giving back control to caller.
+ * - @return provides a minimum amount of data remaining to be flushed from internal buffers
+ * or an error code, which can be tested using ZSTD_isError().
+ * if @return != 0, flush is not fully completed, there is still some data left within internal buffers.
+ * This is useful for ZSTD_e_flush, since in this case more flushes are necessary to empty all buffers.
+ * For ZSTD_e_end, @return == 0 when internal buffers are fully flushed and frame is completed.
+ * - after a ZSTD_e_end directive, if internal buffer is not fully flushed (@return != 0),
+ * only ZSTD_e_end or ZSTD_e_flush operations are allowed.
+ * Before starting a new compression job, or changing compression parameters,
+ * it is required to fully flush internal buffers.
+ */
+ZSTDLIB_API size_t ZSTD_compress_generic (ZSTD_CCtx* cctx,
+ ZSTD_outBuffer* output,
+ ZSTD_inBuffer* input,
+ ZSTD_EndDirective endOp);
+
+
+/*! ZSTD_compress_generic_simpleArgs() :
+ * Same as ZSTD_compress_generic(),
+ * but using only integral types as arguments.
+ * Argument list is larger than ZSTD_{in,out}Buffer,
+ * but can be helpful for binders from dynamic languages
+ * which have troubles handling structures containing memory pointers.
+ */
+ZSTDLIB_API size_t ZSTD_compress_generic_simpleArgs (
+ ZSTD_CCtx* cctx,
+ void* dst, size_t dstCapacity, size_t* dstPos,
+ const void* src, size_t srcSize, size_t* srcPos,
+ ZSTD_EndDirective endOp);
+
+
+/*! ZSTD_CCtx_params :
+ * Quick howto :
+ * - ZSTD_createCCtxParams() : Create a ZSTD_CCtx_params structure
+ * - ZSTD_CCtxParam_setParameter() : Push parameters one by one into
+ * an existing ZSTD_CCtx_params structure.
+ * This is similar to
+ * ZSTD_CCtx_setParameter().
+ * - ZSTD_CCtx_setParametersUsingCCtxParams() : Apply parameters to
+ * an existing CCtx.
+ * These parameters will be applied to
+ * all subsequent compression jobs.
+ * - ZSTD_compress_generic() : Do compression using the CCtx.
+ * - ZSTD_freeCCtxParams() : Free the memory.
+ *
+ * This can be used with ZSTD_estimateCCtxSize_advanced_usingCCtxParams()
+ * for static allocation for single-threaded compression.
+ */
+ZSTDLIB_API ZSTD_CCtx_params* ZSTD_createCCtxParams(void);
+ZSTDLIB_API size_t ZSTD_freeCCtxParams(ZSTD_CCtx_params* params);
+
+
+/*! ZSTD_CCtxParams_reset() :
+ * Reset params to default values.
+ */
+ZSTDLIB_API size_t ZSTD_CCtxParams_reset(ZSTD_CCtx_params* params);
+
+/*! ZSTD_CCtxParams_init() :
+ * Initializes the compression parameters of cctxParams according to
+ * compression level. All other parameters are reset to their default values.
+ */
+ZSTDLIB_API size_t ZSTD_CCtxParams_init(ZSTD_CCtx_params* cctxParams, int compressionLevel);
+
+/*! ZSTD_CCtxParams_init_advanced() :
+ * Initializes the compression and frame parameters of cctxParams according to
+ * params. All other parameters are reset to their default values.
+ */
+ZSTDLIB_API size_t ZSTD_CCtxParams_init_advanced(ZSTD_CCtx_params* cctxParams, ZSTD_parameters params);
+
+
+/*! ZSTD_CCtxParam_setParameter() :
+ * Similar to ZSTD_CCtx_setParameter.
+ * Set one compression parameter, selected by enum ZSTD_cParameter.
+ * Parameters must be applied to a ZSTD_CCtx using ZSTD_CCtx_setParametersUsingCCtxParams().
+ * Note : when `value` is an enum, cast it to unsigned for proper type checking.
+ * @result : 0, or an error code (which can be tested with ZSTD_isError()).
+ */
+ZSTDLIB_API size_t ZSTD_CCtxParam_setParameter(ZSTD_CCtx_params* params, ZSTD_cParameter param, unsigned value);
+
+/*! ZSTD_CCtx_setParametersUsingCCtxParams() :
+ * Apply a set of ZSTD_CCtx_params to the compression context.
+ * This can be done even after compression is started,
+ * if nbWorkers==0, this will have no impact until a new compression is started.
+ * if nbWorkers>=1, new parameters will be picked up at next job,
+ * with a few restrictions (windowLog, pledgedSrcSize, nbWorkers, jobSize, and overlapLog are not updated).
+ */
+ZSTDLIB_API size_t ZSTD_CCtx_setParametersUsingCCtxParams(
+ ZSTD_CCtx* cctx, const ZSTD_CCtx_params* params);
+
+
+/*=== Advanced parameters for decompression API ===*/
+
+/* The following parameters must be set after creating a ZSTD_DCtx* (or ZSTD_DStream*) object,
+ * but before starting decompression of a frame.
+ */
+
+/*! ZSTD_DCtx_loadDictionary() :
+ * Create an internal DDict from dict buffer,
+ * to be used to decompress next frames.
+ * @result : 0, or an error code (which can be tested with ZSTD_isError()).
+ * Special : Adding a NULL (or 0-size) dictionary invalidates any previous dictionary,
+ * meaning "return to no-dictionary mode".
+ * Note 1 : `dict` content will be copied internally.
+ * Use ZSTD_DCtx_loadDictionary_byReference()
+ * to reference dictionary content instead.
+ * In which case, the dictionary buffer must outlive its users.
+ * Note 2 : Loading a dictionary involves building tables,
+ * which has a non-negligible impact on CPU usage and latency.
+ * Note 3 : Use ZSTD_DCtx_loadDictionary_advanced() to select
+ * how dictionary content will be interpreted and loaded.
+ */
+ZSTDLIB_API size_t ZSTD_DCtx_loadDictionary(ZSTD_DCtx* dctx, const void* dict, size_t dictSize);
+ZSTDLIB_API size_t ZSTD_DCtx_loadDictionary_byReference(ZSTD_DCtx* dctx, const void* dict, size_t dictSize);
+ZSTDLIB_API size_t ZSTD_DCtx_loadDictionary_advanced(ZSTD_DCtx* dctx, const void* dict, size_t dictSize, ZSTD_dictLoadMethod_e dictLoadMethod, ZSTD_dictContentType_e dictContentType);
+
+
+/*! ZSTD_DCtx_refDDict() :
+ * Reference a prepared dictionary, to be used to decompress next frames.
+ * The dictionary remains active for decompression of future frames using same DCtx.
+ * @result : 0, or an error code (which can be tested with ZSTD_isError()).
+ * Note 1 : Currently, only one dictionary can be managed.
+ * Referencing a new dictionary effectively "discards" any previous one.
+ * Special : adding a NULL DDict means "return to no-dictionary mode".
+ * Note 2 : DDict is just referenced, its lifetime must outlive its usage from DCtx.
+ */
+ZSTDLIB_API size_t ZSTD_DCtx_refDDict(ZSTD_DCtx* dctx, const ZSTD_DDict* ddict);
+
+
+/*! ZSTD_DCtx_refPrefix() :
+ * Reference a prefix (single-usage dictionary) for next compression job.
+ * Prefix is **only used once**. It must be explicitly referenced before each frame.
+ * If there is a need to use same prefix multiple times, consider embedding it into a ZSTD_DDict instead.
+ * @result : 0, or an error code (which can be tested with ZSTD_isError()).
+ * Note 1 : Adding any prefix (including NULL) invalidates any previously set prefix or dictionary
+ * Note 2 : Prefix buffer is referenced. It must outlive compression job.
+ * Note 3 : By default, the prefix is treated as raw content (ZSTD_dm_rawContent).
+ * Use ZSTD_CCtx_refPrefix_advanced() to alter dictMode.
+ * Note 4 : Referencing a raw content prefix has almost no cpu nor memory cost.
+ */
+ZSTDLIB_API size_t ZSTD_DCtx_refPrefix(ZSTD_DCtx* dctx, const void* prefix, size_t prefixSize);
+ZSTDLIB_API size_t ZSTD_DCtx_refPrefix_advanced(ZSTD_DCtx* dctx, const void* prefix, size_t prefixSize, ZSTD_dictContentType_e dictContentType);
+
+
+/*! ZSTD_DCtx_setMaxWindowSize() :
+ * Refuses allocating internal buffers for frames requiring a window size larger than provided limit.
+ * This is useful to prevent a decoder context from reserving too much memory for itself (potential attack scenario).
+ * This parameter is only useful in streaming mode, since no internal buffer is allocated in direct mode.
+ * By default, a decompression context accepts all window sizes <= (1 << ZSTD_WINDOWLOG_MAX)
+ * @return : 0, or an error code (which can be tested using ZSTD_isError()).
+ */
+ZSTDLIB_API size_t ZSTD_DCtx_setMaxWindowSize(ZSTD_DCtx* dctx, size_t maxWindowSize);
+
+
+/*! ZSTD_DCtx_setFormat() :
+ * Instruct the decoder context about what kind of data to decode next.
+ * This instruction is mandatory to decode data without a fully-formed header,
+ * such ZSTD_f_zstd1_magicless for example.
+ * @return : 0, or an error code (which can be tested using ZSTD_isError()).
+ */
+ZSTDLIB_API size_t ZSTD_DCtx_setFormat(ZSTD_DCtx* dctx, ZSTD_format_e format);
+
+
+/*! ZSTD_decompress_generic() :
+ * Behave the same as ZSTD_decompressStream.
+ * Decompression parameters cannot be changed once decompression is started.
+ * @return : an error code, which can be tested using ZSTD_isError()
+ * if >0, a hint, nb of expected input bytes for next invocation.
+ * `0` means : a frame has just been fully decoded and flushed.
+ */
+ZSTDLIB_API size_t ZSTD_decompress_generic(ZSTD_DCtx* dctx,
+ ZSTD_outBuffer* output,
+ ZSTD_inBuffer* input);
+
+
+/*! ZSTD_decompress_generic_simpleArgs() :
+ * Same as ZSTD_decompress_generic(),
+ * but using only integral types as arguments.
+ * Argument list is larger than ZSTD_{in,out}Buffer,
+ * but can be helpful for binders from dynamic languages
+ * which have troubles handling structures containing memory pointers.
+ */
+ZSTDLIB_API size_t ZSTD_decompress_generic_simpleArgs (
+ ZSTD_DCtx* dctx,
+ void* dst, size_t dstCapacity, size_t* dstPos,
+ const void* src, size_t srcSize, size_t* srcPos);
+
+
+/*! ZSTD_DCtx_reset() :
+ * Return a DCtx to clean state.
+ * If a decompression was ongoing, any internal data not yet flushed is cancelled.
+ * All parameters are back to default values, including sticky ones.
+ * Dictionary (if any) is dropped.
+ * Parameters can be modified again after a reset.
+ */
+ZSTDLIB_API void ZSTD_DCtx_reset(ZSTD_DCtx* dctx);
+
+
+
+/* ============================ */
+/** Block level API */
+/* ============================ */
+
+/*!
Block functions produce and decode raw zstd blocks, without frame metadata.
Frame metadata cost is typically ~18 bytes, which can be non-negligible for very small blocks (< 100 bytes).
User will have to take in charge required information to regenerate data, such as compressed and content sizes.
@@ -671,27 +1367,29 @@
- Compressing and decompressing require a context structure
+ Use ZSTD_createCCtx() and ZSTD_createDCtx()
- It is necessary to init context before starting
- + compression : ZSTD_compressBegin()
- + decompression : ZSTD_decompressBegin()
- + variants _usingDict() are also allowed
- + copyCCtx() and copyDCtx() work too
- - Block size is limited, it must be <= ZSTD_getBlockSizeMax()
- + If you need to compress more, cut data into multiple blocks
- + Consider using the regular ZSTD_compress() instead, as frame metadata costs become negligible when source size is large.
+ + compression : any ZSTD_compressBegin*() variant, including with dictionary
+ + decompression : any ZSTD_decompressBegin*() variant, including with dictionary
+ + copyCCtx() and copyDCtx() can be used too
+ - Block size is limited, it must be <= ZSTD_getBlockSize() <= ZSTD_BLOCKSIZE_MAX == 128 KB
+ + If input is larger than a block size, it's necessary to split input data into multiple blocks
+ + For inputs larger than a single block size, consider using the regular ZSTD_compress() instead.
+ Frame metadata is not that costly, and quickly becomes negligible as source size grows larger.
- When a block is considered not compressible enough, ZSTD_compressBlock() result will be zero.
In which case, nothing is produced into `dst`.
+ User must test for such outcome and deal directly with uncompressed data
+ ZSTD_decompressBlock() doesn't accept uncompressed data as input !!!
- + In case of multiple successive blocks, decoder must be informed of uncompressed block existence to follow proper history.
- Use ZSTD_insertBlock() in such a case.
+ + In case of multiple successive blocks, should some of them be uncompressed,
+ decoder must be informed of their existence in order to follow proper history.
+ Use ZSTD_insertBlock() for such a case.
*/
-#define ZSTD_BLOCKSIZE_ABSOLUTEMAX (128 * 1024) /* define, for static allocation */
+#define ZSTD_BLOCKSIZELOG_MAX 17
+#define ZSTD_BLOCKSIZE_MAX (1<<ZSTD_BLOCKSIZELOG_MAX) /* define, for static allocation */
/*===== Raw zstd block functions =====*/
-ZSTDLIB_API size_t ZSTD_getBlockSizeMax(ZSTD_CCtx* cctx);
+ZSTDLIB_API size_t ZSTD_getBlockSize (const ZSTD_CCtx* cctx);
ZSTDLIB_API size_t ZSTD_compressBlock (ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
ZSTDLIB_API size_t ZSTD_decompressBlock(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
-ZSTDLIB_API size_t ZSTD_insertBlock(ZSTD_DCtx* dctx, const void* blockStart, size_t blockSize); /**< insert block into `dctx` history. Useful for uncompressed blocks */
+ZSTDLIB_API size_t ZSTD_insertBlock (ZSTD_DCtx* dctx, const void* blockStart, size_t blockSize); /**< insert uncompressed block into `dctx` history. Useful for multi-blocks decompression. */
#endif /* ZSTD_H_ZSTD_STATIC_LINKING_ONLY */