From 95f34e056a10f1645c4e40ac82c348995d7a92d2 Mon Sep 17 00:00:00 2001 From: Przemyslaw Skibinski Date: Tue, 6 Dec 2016 11:36:24 +0100 Subject: [PATCH 1/7] zlibWrapper/README.md: updated info about gzip file access functions --- zlibWrapper/Makefile | 4 ++-- zlibWrapper/README.md | 22 +++++++++++++--------- 2 files changed, 15 insertions(+), 11 deletions(-) diff --git a/zlibWrapper/Makefile b/zlibWrapper/Makefile index a0e641d94..5a6378767 100644 --- a/zlibWrapper/Makefile +++ b/zlibWrapper/Makefile @@ -42,10 +42,10 @@ test: example fitblk example_zstd fitblk_zstd zwrapbench minigzip minigzip_zstd ./fitblk_zstd 40960 <$(TEST_FILE) @echo ---- minigzip start ---- ./minigzip_zstd example$(EXT) - cp example$(EXT).gz example$(EXT)_zstd.gz + #cp example$(EXT).gz example$(EXT)_zstd.gz ./minigzip_zstd -d example$(EXT).gz ./minigzip example$(EXT) - cp example$(EXT).gz example$(EXT)_gz.gz + #cp example$(EXT).gz example$(EXT)_gz.gz ./minigzip_zstd -d example$(EXT).gz @echo ---- minigzip end ---- ./zwrapbench -qb3B1K $(TEST_FILE) diff --git a/zlibWrapper/README.md b/zlibWrapper/README.md index cbf1b1b30..164b69ace 100644 --- a/zlibWrapper/README.md +++ b/zlibWrapper/README.md @@ -10,6 +10,8 @@ To build the zstd wrapper for zlib the following files are required: - a static or dynamic zlib library - zlibWrapper/zstd_zlibwrapper.h - zlibWrapper/zstd_zlibwrapper.c +- zlibWrapper/gz*.c files (gzclose.c, gzlib.c, gzread.c, gzwrite.c) +- zlibWrapper/gz*.h files (gzcompatibility.h, gzguts.h) - a static or dynamic zstd library The first two files are required by all projects using zlib and they are not included with the zstd distribution. @@ -22,26 +24,26 @@ Let's assume that your project that uses zlib is compiled with: ```gcc project.o -lz``` To compile the zstd wrapper with your project you have to do the following: -- change all references with ```#include "zlib.h"``` to ```#include "zstd_zlibwrapper.h"``` -- compile your project with `zstd_zlibwrapper.c` and a static or dynamic zstd library +- change all references with `#include "zlib.h"` to `#include "zstd_zlibwrapper.h"` +- compile your project with `zstd_zlibwrapper.c`, `gz*.c` and a static or dynamic zstd library The linking should be changed to: -```gcc project.o zstd_zlibwrapper.o -lz -lzstd``` +```gcc project.o zstd_zlibwrapper.o gz*.c -lz -lzstd``` #### Enabling zstd compression within your project After embedding the zstd wrapper within your project the zstd library is turned off by default. Your project should work as before with zlib. There are two options to enable zstd compression: -- compilation with ```-DZWRAP_USE_ZSTD=1``` (or using ```#define ZWRAP_USE_ZSTD 1``` before ```#include "zstd_zlibwrapper.h"```) -- using the ```void ZWRAP_useZSTDcompression(int turn_on)``` function (declared in ```#include "zstd_zlibwrapper.h"```) +- compilation with `-DZWRAP_USE_ZSTD=1` (or using `#define ZWRAP_USE_ZSTD 1` before `#include "zstd_zlibwrapper.h"`) +- using the `void ZWRAP_useZSTDcompression(int turn_on)` function (declared in `#include "zstd_zlibwrapper.h"`) During decompression zlib and zstd streams are automatically detected and decompressed using a proper library. This behavior can be changed using `ZWRAP_setDecompressionType(ZWRAP_FORCE_ZLIB)` what will make zlib decompression slightly faster. #### Example -We have take the file ```test/example.c``` from [the zlib library distribution](http://zlib.net/) and copied it to [zlibWrapper/examples/example.c](examples/example.c). +We have take the file `test/example.c` from [the zlib library distribution](http://zlib.net/) and copied it to [zlibWrapper/examples/example.c](examples/example.c). After compilation and execution it shows the following results: ``` zlib version 1.2.8 = 0x1280, compile flags = 0x65 @@ -53,13 +55,15 @@ large_inflate(): OK after inflateSync(): hello, hello! inflate with dictionary: hello, hello! ``` -Then we have changed ```#include "zlib.h"``` to ```#include "zstd_zlibwrapper.h"```, compiled the [example.c](examples/example.c) file -with ```-DZWRAP_USE_ZSTD=1``` and linked with additional ```zstd_zlibwrapper.o -lzstd```. -We were forced to turn off the following functions: ```test_gzio```, ```test_flush```, ```test_sync``` which use currently unsupported features. +Then we have changed `#include "zlib.h"` to `#include "zstd_zlibwrapper.h"`, compiled the [example.c](examples/example.c) file +with `-DZWRAP_USE_ZSTD=1` and linked with additional `zstd_zlibwrapper.o gz*.c -lzstd`. +We were forced to turn off the following functions: `test_flush`, `test_sync` which use currently unsupported features. After running it shows the following results: ``` zlib version 1.2.8 = 0x1280, compile flags = 0x65 uncompress(): hello, hello! +gzread(): hello, hello! +gzgets() after gzseek: hello! inflate(): hello, hello! large_inflate(): OK inflate with dictionary: hello, hello! From abd9ec0d5386d28d047446bf117dadcf8bc1bbf0 Mon Sep 17 00:00:00 2001 From: Przemyslaw Skibinski Date: Wed, 7 Dec 2016 11:13:20 +0100 Subject: [PATCH 2/7] gen_html: comments of type /*= and /**= can be longer than a single line --- contrib/gen_html/.gitignore | 1 + contrib/gen_html/gen_html.cpp | 47 +-- contrib/gen_html/zstd_manual.html | 564 ------------------------------ 3 files changed, 26 insertions(+), 586 deletions(-) delete mode 100644 contrib/gen_html/zstd_manual.html diff --git a/contrib/gen_html/.gitignore b/contrib/gen_html/.gitignore index ccf28c1d6..344611428 100644 --- a/contrib/gen_html/.gitignore +++ b/contrib/gen_html/.gitignore @@ -1,2 +1,3 @@ # make artefact gen_html +zstd_manual.html diff --git a/contrib/gen_html/gen_html.cpp b/contrib/gen_html/gen_html.cpp index d3ab265a6..987b7917b 100644 --- a/contrib/gen_html/gen_html.cpp +++ b/contrib/gen_html/gen_html.cpp @@ -133,36 +133,28 @@ int main(int argc, char *argv[]) { continue; } - /* comments of type /*= and /**= mean: use a

header and show also all functions until first empty line */ - if ((line.substr(0,3) == "/*=" || line.substr(0,4) == "/**=") && line.find("*/")!=string::npos) { - trim_comments(line); - trim(line, "= "); - sout << "

" << line << "

";
-            lines = get_lines(input, ++linenum, "");
-            for (l=0; l

" << endl; - continue; + spos = line.find("/**="); + if (spos==string::npos) { + spos = line.find("/*!"); + if (spos==string::npos) + spos = line.find("/**"); + if (spos==string::npos) + spos = line.find("/*-"); + if (spos==string::npos) + spos = line.find("/*="); + if (spos==string::npos) + continue; + exclam = line[spos+2]; } + else exclam = '='; - spos = line.find("/*!"); - if (spos==string::npos) - spos = line.find("/**"); - if (spos==string::npos) - spos = line.find("/*-"); - - if (spos==string::npos) - continue; - - exclam = line[spos+2]; comments = get_lines(input, linenum, "*/"); if (!comments.empty()) comments[0] = line.substr(spos+3); if (!comments.empty()) comments[comments.size()-1] = comments[comments.size()-1].substr(0, comments[comments.size()-1].find("*/")); for (l=0; l
" << endl << endl; + } else if (exclam == '=') { /* comments of type /*= and /**= mean: use a

header and show also all functions until first empty line */ + sout << "

" << comments[0] << "

";
+            for (l=1; l
";
+            lines = get_lines(input, ++linenum, "");
+            for (l=0; l
" << endl;
         } else { /* comments of type /** and /*- mean: this is a comment; use a 
 header for the first line */
             if (comments.empty()) continue;
 
diff --git a/contrib/gen_html/zstd_manual.html b/contrib/gen_html/zstd_manual.html
deleted file mode 100644
index d6465c0b4..000000000
--- a/contrib/gen_html/zstd_manual.html
+++ /dev/null
@@ -1,564 +0,0 @@
-
-
-
-zstd 1.1.2 Manual
-
-
-
zstd 1.1.2 Manual

-

-
Contents

-
    
-
  1. Introduction
    2. 
-
  2. Version
    3. 
-
  3. Simple API
    4. 
-
  4. Explicit memory management
    5. 
-
  5. Simple dictionary API
    6. 
-
  6. Fast dictionary API
    7. 
-
  7. Streaming
    8. 
-
  8. Streaming compression - HowTo
    9. 
-
  9. Streaming decompression - HowTo
    10. 
-
  10. START OF ADVANCED AND EXPERIMENTAL FUNCTIONS
    11. 
-
  11. Advanced types
    12. 
-
  12. Advanced compression functions
    13. 
-
  13. Advanced decompression functions
    14. 
-
  14. Advanced streaming functions
    15. 
-
  15. Buffer-less and synchronous inner streaming functions
    16. 
-
  16. Buffer-less streaming compression (synchronous mode)
    17. 
-
  17. Buffer-less streaming decompression (synchronous mode)
    18. 
-
  18. Block functions
    19. 
-

-

-
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.
-  Compression can be done in:
-    - a single step (described as Simple API)
-    - a single step, reusing a context (described as Explicit memory management)
-    - unbounded multiple steps (described as Streaming compression)
-  The compression ratio achievable on small data can be highly improved using compression with a dictionary in:
-    - a single step (described as Simple dictionary API)
-    - a single step, reusing a dictionary (described as Fast 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.
-  They are not "stable", their definition may change in the future. Only static linking is allowed.
-

-
-
Version

-
-
unsigned ZSTD_versionNumber(void);   /**< library version number; to be used when checking dll version  */
-


-
Simple API

-
-
size_t ZSTD_compress( void* dst, size_t dstCapacity,
-                            const void* src, size_t srcSize,
-                                  int compressionLevel);
-
    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()). 
-


-
-
size_t ZSTD_decompress( void* dst, size_t dstCapacity,
-                              const void* src, size_t compressedSize);
-
    `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()). 
-


-
-
unsigned long long ZSTD_getDecompressedSize(const void* src, size_t srcSize);
-
   '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. 
-


-
-
Helper functions
int         ZSTD_maxCLevel(void);               /*!< maximum compression level available */
-size_t      ZSTD_compressBound(size_t srcSize); /*!< maximum compressed size in worst case scenario */
-unsigned    ZSTD_isError(size_t code);          /*!< tells if a `size_t` function result is an error code */
-const char* ZSTD_getErrorName(size_t code);     /*!< provides readable string from an error code */
-


-
Explicit memory management

-
-
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()). 
-


-
-
Decompression context
typedef struct ZSTD_DCtx_s ZSTD_DCtx;
-ZSTD_DCtx* ZSTD_createDCtx(void);
-size_t     ZSTD_freeDCtx(ZSTD_DCtx* dctx);
-


-
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()). 
-


-
-
Simple dictionary API

-
-
size_t ZSTD_compress_usingDict(ZSTD_CCtx* ctx,
-                                           void* dst, size_t dstCapacity,
-                                     const void* src, size_t srcSize,
-                                     const void* dict,size_t dictSize,
-                                           int compressionLevel);
-
   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. 
-


-
-
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);
-
   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. 
-


-
-
Fast dictionary API

-
-
ZSTD_CDict* ZSTD_createCDict(const void* dict, 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 used by multiple threads concurrently, as its usage is read-only.
-   `dict` can be released after ZSTD_CDict creation. 
-


-
-
size_t      ZSTD_freeCDict(ZSTD_CDict* CDict);
-
   Function frees memory allocated by ZSTD_createCDict(). 
-


-
-
size_t ZSTD_compress_usingCDict(ZSTD_CCtx* cctx,
-                                            void* dst, size_t dstCapacity,
-                                      const void* src, size_t srcSize,
-                                      const ZSTD_CDict* cdict);
-
   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. 
-


-
-
ZSTD_DDict* ZSTD_createDDict(const void* dict, size_t dictSize);
-
   Create a digested dictionary, ready to start decompression operation without startup delay.
-   `dict` can be released after creation. 
-


-
-
size_t      ZSTD_freeDDict(ZSTD_DDict* ddict);
-
   Function frees memory allocated with ZSTD_createDDict() 
-


-
-
size_t ZSTD_decompress_usingDDict(ZSTD_DCtx* dctx,
-                                              void* dst, size_t dstCapacity,
-                                        const void* src, size_t srcSize,
-                                        const ZSTD_DDict* ddict);
-
   Decompression using a digested Dictionary.
-   Faster startup than ZSTD_decompress_usingDict(), recommended when same dictionary is used multiple times. 
-


-
-
Streaming

-
-
typedef struct ZSTD_inBuffer_s {
-  const void* src;    /**< start of input buffer */
-  size_t size;        /**< size of input buffer */
-  size_t pos;         /**< position where reading stopped. Will be updated. Necessarily 0 <= pos <= size */
-} ZSTD_inBuffer;
-


-
typedef struct ZSTD_outBuffer_s {
-  void*  dst;         /**< start of output buffer */
-  size_t size;        /**< size of output buffer */
-  size_t pos;         /**< position where writing stopped. Will be updated. Necessarily 0 <= pos <= size */
-} ZSTD_outBuffer;
-


-
Streaming compression - HowTo
-  A ZSTD_CStream object is required to track streaming operation.
-  Use ZSTD_createCStream() and ZSTD_freeCStream() to create/release resources.
-  ZSTD_CStream objects can be reused multiple times on consecutive compression operations.
-  It is recommended to re-use ZSTD_CStream in situations where many streaming operations will be achieved consecutively,
-  since it will play nicer with system's memory, by re-using already allocated memory.
-  Use one separate ZSTD_CStream per thread for parallel execution.
-
-  Start a new compression by initializing ZSTD_CStream.
-  Use ZSTD_initCStream() to start a new compression operation.
-  Use ZSTD_initCStream_usingDict() for a compression which requires a dictionary.
-
-  Use ZSTD_compressStream() repetitively to consume input stream.
-  The function will automatically update both `pos` fields.
-  Note that it may not consume the entire input, in which case `pos < size`,
-  and it's up to the caller to present again remaining data.
-  @return : a size hint, preferred nb of bytes to use as input for next function call
-           (it's just a hint, to help latency a little, any other value will work fine)
-           (note : the size hint is guaranteed to be <= ZSTD_CStreamInSize() )
-            or an error code, which can be tested using ZSTD_isError().
-
-  At any moment, it's possible to flush whatever data remains within buffer, using ZSTD_flushStream().
-  `output->pos` will be updated.
-  Note some content might still be left within internal buffer if `output->size` is too small.
-  @return : nb of bytes still present within internal buffer (0 if it's empty)
-            or an error code, which can be tested using ZSTD_isError().
-
-  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.
-  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)
-            or an error code, which can be tested using ZSTD_isError().
-
- 
-

-
-
Streaming compression functions
typedef struct ZSTD_CStream_s ZSTD_CStream;
-ZSTD_CStream* ZSTD_createCStream(void);
-size_t ZSTD_freeCStream(ZSTD_CStream* zcs);
-size_t ZSTD_initCStream(ZSTD_CStream* zcs, int compressionLevel);
-size_t ZSTD_compressStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output, ZSTD_inBuffer* input);
-size_t ZSTD_flushStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output);
-size_t ZSTD_endStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output);
-


-
size_t ZSTD_CStreamInSize(void);    /**< recommended size for input buffer */
-


-
size_t ZSTD_CStreamOutSize(void);   /**< recommended size for output buffer. Guarantee to successfully flush at least one complete compressed block in all circumstances. */
-


-
Streaming decompression - HowTo
-  A ZSTD_DStream object is required to track streaming operations.
-  Use ZSTD_createDStream() and ZSTD_freeDStream() to create/release resources.
-  ZSTD_DStream objects can be re-used multiple times.
-
-  Use ZSTD_initDStream() to start a new decompression operation,
-   or ZSTD_initDStream_usingDict() if decompression requires a dictionary.
-   @return : recommended first input size
-
-  Use ZSTD_decompressStream() repetitively to consume your input.
-  The function will update both `pos` fields.
-  If `input.pos < input.size`, some input has not been consumed.
-  It's up to the caller to present again remaining data.
-  If `output.pos < output.size`, decoder has flushed everything it could.
-  @return : 0 when a frame is completely decoded and fully flushed,
-            an error code, which can be tested using ZSTD_isError(),
-            any other value > 0, which means there is still some decoding to do to complete current frame.
-            The return value is a suggested next input size (a hint to improve latency) that will never load more than the current frame.
- 
-

-
-
Streaming decompression functions
typedef struct ZSTD_DStream_s ZSTD_DStream;
-ZSTD_DStream* ZSTD_createDStream(void);
-size_t ZSTD_freeDStream(ZSTD_DStream* zds);
-size_t ZSTD_initDStream(ZSTD_DStream* zds);
-size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inBuffer* input);
-


-
size_t ZSTD_DStreamInSize(void);    /*!< recommended size for input buffer */
-


-
size_t ZSTD_DStreamOutSize(void);   /*!< recommended size for output buffer. Guarantee to successfully flush at least one complete block in all circumstances. */
-


-
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.
- Use them only in association with static linking.
- 
-

-
-
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 struct {
-    unsigned windowLog;      /**< largest match distance : larger == more compression, more memory needed during decompression */
-    unsigned chainLog;       /**< fully searched segment : larger == more compression, slower, more memory (useless for fast) */
-    unsigned hashLog;        /**< dispatch table : larger == faster, more memory */
-    unsigned searchLog;      /**< nb of searches : larger == more compression, slower */
-    unsigned searchLength;   /**< match length searched : larger == faster decompression, sometimes less compression */
-    unsigned targetLength;   /**< acceptable match size for optimal parser (only) : larger == more compression, slower */
-    ZSTD_strategy strategy;
-} ZSTD_compressionParameters;
-


-
typedef struct {
-    unsigned contentSizeFlag; /**< 1: content size will be in frame header (if known). */
-    unsigned checksumFlag;    /**< 1: will generate a 22-bits checksum at end of frame, to be used for error detection by decompressor */
-    unsigned noDictIDFlag;    /**< 1: no dict ID will be saved into frame header (if dictionary compression) */
-} ZSTD_frameParameters;
-


-
typedef struct {
-    ZSTD_compressionParameters cParams;
-    ZSTD_frameParameters fParams;
-} ZSTD_parameters;
-


-
Custom memory allocation functions
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;
-


-
Advanced compression functions

-
-
size_t ZSTD_estimateCCtxSize(ZSTD_compressionParameters cParams);
-
  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 
-


-
-
ZSTD_CCtx* ZSTD_createCCtx_advanced(ZSTD_customMem customMem);
-
  Create a ZSTD compression context using external alloc and free functions 
-


-
-
size_t ZSTD_sizeof_CCtx(const ZSTD_CCtx* cctx);
-
  Gives the amount of memory used by a given ZSTD_CCtx 
-


-
-
ZSTD_CDict* ZSTD_createCDict_advanced(const void* dict, size_t dictSize,
-                                                  ZSTD_parameters params, ZSTD_customMem customMem);
-
  Create a ZSTD_CDict using external alloc and free, and customized compression parameters 
-


-
-
size_t ZSTD_sizeof_CDict(const ZSTD_CDict* cdict);
-
  Gives the amount of memory used by a given ZSTD_sizeof_CDict 
-


-
-
ZSTD_parameters ZSTD_getParams(int compressionLevel, unsigned long long srcSize, size_t dictSize);
-
   same as ZSTD_getCParams(), but @return a full `ZSTD_parameters` object instead of a `ZSTD_compressionParameters`.
-   All fields of `ZSTD_frameParameters` are set to default (0) 
-


-
-
ZSTD_compressionParameters ZSTD_getCParams(int compressionLevel, unsigned long long srcSize, size_t dictSize);
-
   @return ZSTD_compressionParameters structure for a selected compression level and srcSize.
-   `srcSize` value is optional, select 0 if not known 
-


-
-
size_t ZSTD_checkCParams(ZSTD_compressionParameters params);
-
   Ensure param values remain within authorized range 
-


-
-
ZSTD_compressionParameters ZSTD_adjustCParams(ZSTD_compressionParameters cPar, unsigned long long srcSize, size_t dictSize);
-
   optimize params for a given `srcSize` and `dictSize`.
-   both values are optional, select `0` if unknown. 
-


-
-
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 of each compression parameter 
-


-
-
Advanced decompression functions

-
-
unsigned ZSTD_isFrame(const void* buffer, size_t size);
-
  Tells if the content of `buffer` starts with a valid Frame Identifier.
-  Note : Frame Identifier is 4 bytes. If `size < 4`, @return will always be 0.
-  Note 2 : Legacy Frame Identifiers are considered valid only if Legacy Support is enabled.
-  Note 3 : Skippable Frame Identifiers are considered valid. 
-


-
-
size_t ZSTD_estimateDCtxSize(void);
-
  Gives the potential amount of memory allocated to create a ZSTD_DCtx 
-


-
-
ZSTD_DCtx* ZSTD_createDCtx_advanced(ZSTD_customMem customMem);
-
  Create a ZSTD decompression context using external alloc and free functions 
-


-
-
size_t ZSTD_sizeof_DCtx(const ZSTD_DCtx* dctx);
-
  Gives the amount of memory used by a given ZSTD_DCtx 
-


-
-
size_t ZSTD_sizeof_DDict(const ZSTD_DDict* ddict);
-
  Gives the amount of memory used by a given ZSTD_DDict 
-


-
-
unsigned ZSTD_getDictID_fromDict(const void* dict, size_t dictSize);
-
  Provides the dictID stored within dictionary.
-  if @return == 0, the dictionary is not conformant with Zstandard specification.
-  It can still be loaded, but as a content-only dictionary. 
-


-
-
unsigned ZSTD_getDictID_fromDDict(const ZSTD_DDict* ddict);
-
  Provides the dictID of the dictionary loaded into `ddict`.
-  If @return == 0, the dictionary is not conformant to Zstandard specification, or empty.
-  Non-conformant dictionaries can still be loaded, but as content-only dictionaries. 
-


-
-
unsigned ZSTD_getDictID_fromFrame(const void* src, size_t srcSize);
-
  Provides the dictID required to decompressed the frame stored within `src`.
-  If @return == 0, the dictID could not be decoded.
-  This could for one of the following reasons :
-  - The frame does not require a dictionary to be decoded (most common case).
-  - The frame was built with dictID intentionally removed. Whatever dictionary is necessary is a hidden information.
-    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. 
-


-
-
Advanced streaming functions

-
-
Advanced Streaming compression functions
ZSTD_CStream* ZSTD_createCStream_advanced(ZSTD_customMem customMem);
-size_t ZSTD_initCStream_usingDict(ZSTD_CStream* zcs, const void* dict, size_t dictSize, int compressionLevel);
-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 */
-size_t ZSTD_initCStream_usingCDict(ZSTD_CStream* zcs, const ZSTD_CDict* cdict);  /**< note : cdict will just be referenced, and must outlive compression session */
-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 */
-size_t ZSTD_sizeof_CStream(const ZSTD_CStream* zcs);
-


-
Advanced Streaming decompression functions
typedef enum { ZSTDdsp_maxWindowSize } ZSTD_DStreamParameter_e;
-ZSTD_DStream* ZSTD_createDStream_advanced(ZSTD_customMem customMem);
-size_t ZSTD_initDStream_usingDict(ZSTD_DStream* zds, const void* dict, size_t dictSize);
-size_t ZSTD_setDStreamParameter(ZSTD_DStream* zds, ZSTD_DStreamParameter_e paramType, unsigned paramValue);
-size_t ZSTD_initDStream_usingDDict(ZSTD_DStream* zds, const ZSTD_DDict* ddict);  /**< note : ddict will just be referenced, and must outlive decompression session */
-size_t ZSTD_resetDStream(ZSTD_DStream* zds);  /**< re-use decompression parameters from previous init; saves dictionary loading */
-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
- 
-

-
-
Buffer-less streaming compression (synchronous mode)
-  A ZSTD_CCtx object is required to track streaming operations.
-  Use ZSTD_createCCtx() / ZSTD_freeCCtx() to manage resource.
-  ZSTD_CCtx object can be re-used multiple times within successive compression operations.
-
-  Start by initializing a context.
-  Use ZSTD_compressBegin(), or ZSTD_compressBegin_usingDict() for dictionary compression,
-  or ZSTD_compressBegin_advanced(), for finer parameter control.
-  It's also possible to duplicate a reference context which has already been initialized, using ZSTD_copyCCtx()
-
-  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.
-  - 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.
-  - ZSTD_compressContinue() presumes prior input ***is still accessible and unmodified*** (up to maximum distance size, see WindowLog).
-    It remembers all previous contiguous blocks, plus one separated memory segment (which can itself consists of multiple contiguous blocks)
-  - ZSTD_compressContinue() detects that prior input has been overwritten when `src` buffer overlaps.
-    In which case, it will "discard" the relevant memory section from its history.
-
-  Finish a frame with ZSTD_compressEnd(), which will write the last block(s) and optional checksum.
-  It's possible to use a NULL,0 src content, in which case, it will write a final empty block to end the frame,
-  Without last block mark, frames will be considered unfinished (broken) by decoders.
-
-  You can then reuse `ZSTD_CCtx` (ZSTD_compressBegin()) to compress some new frame.
-

-
-
Buffer-less streaming compression functions
size_t ZSTD_compressBegin(ZSTD_CCtx* cctx, int compressionLevel);
-size_t ZSTD_compressBegin_usingDict(ZSTD_CCtx* cctx, const void* dict, size_t dictSize, int compressionLevel);
-size_t ZSTD_compressBegin_advanced(ZSTD_CCtx* cctx, const void* dict, size_t dictSize, ZSTD_parameters params, unsigned long long pledgedSrcSize);
-size_t ZSTD_copyCCtx(ZSTD_CCtx* cctx, const ZSTD_CCtx* preparedCCtx, unsigned long long pledgedSrcSize);
-size_t ZSTD_compressContinue(ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
-size_t ZSTD_compressEnd(ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
-


-
Buffer-less streaming decompression (synchronous mode)
-  A ZSTD_DCtx object is required to track streaming operations.
-  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.
-           >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().
-
-  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.
-  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.
-
-  Note : it's possible to know if next input to present is a header or a block, using ZSTD_nextInputType().
-  This information is not required to properly decode a frame.
-
-  == 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 :
-  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.
-

-
-
typedef struct {
-    unsigned long long frameContentSize;
-    unsigned windowSize;
-    unsigned dictID;
-    unsigned checksumFlag;
-} ZSTD_frameParams;
-


-
Buffer-less streaming decompression functions
size_t ZSTD_getFrameParams(ZSTD_frameParams* fparamsPtr, const void* src, size_t srcSize);   /**< doesn't consume input, see details below */
-size_t ZSTD_decompressBegin(ZSTD_DCtx* dctx);
-size_t ZSTD_decompressBegin_usingDict(ZSTD_DCtx* dctx, const void* dict, size_t dictSize);
-void   ZSTD_copyDCtx(ZSTD_DCtx* dctx, const ZSTD_DCtx* preparedDCtx);
-size_t ZSTD_nextSrcSizeToDecompress(ZSTD_DCtx* dctx);
-size_t ZSTD_decompressContinue(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
-typedef enum { ZSTDnit_frameHeader, ZSTDnit_blockHeader, ZSTDnit_block, ZSTDnit_lastBlock, ZSTDnit_checksum, ZSTDnit_skippableFrame } ZSTD_nextInputType_e;
-ZSTD_nextInputType_e ZSTD_nextInputType(ZSTD_DCtx* dctx);
-


-
Block functions
-    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.
-
-    A few rules to respect :
-    - 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.
-    - 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.
-

-
-
Raw zstd block functions
size_t ZSTD_getBlockSizeMax(ZSTD_CCtx* cctx);
-size_t ZSTD_compressBlock  (ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
-size_t ZSTD_decompressBlock(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
-size_t ZSTD_insertBlock(ZSTD_DCtx* dctx, const void* blockStart, size_t blockSize);  /**< insert block into `dctx` history. Useful for uncompressed blocks */
-


-
-

From 4da53219a07c07c3a3e1456c5acc74fa9faa3f73 Mon Sep 17 00:00:00 2001
From: Przemyslaw Skibinski 
Date: Wed, 7 Dec 2016 11:18:40 +0100
Subject: [PATCH 3/7] zstd Manual updated to 1.1.2

---
 contrib/gen_html/gen_html.cpp |  1 +
 doc/zstd_manual.html          | 91 +++++++++++++++++++++++++----------
 lib/zstd.h                    |  2 +-
 3 files changed, 67 insertions(+), 27 deletions(-)

diff --git a/contrib/gen_html/gen_html.cpp b/contrib/gen_html/gen_html.cpp
index 987b7917b..22ff65b10 100644
--- a/contrib/gen_html/gen_html.cpp
+++ b/contrib/gen_html/gen_html.cpp
@@ -176,6 +176,7 @@ int main(int argc, char *argv[]) {
             }
             sout << "

" << endl << endl;
         } else if (exclam == '=') { /* comments of type /*= and /**= mean: use a 
 header and show also all functions until first empty line */
+            trim(comments[0], " ");
             sout << "
" << comments[0] << "
";
             for (l=1; l
 
 
-zstd 1.1.1 Manual
+zstd 1.1.2 Manual
 
 
-
zstd 1.1.1 Manual

+
zstd 1.1.2 Manual

 

 
Contents

 
    
@@ -48,7 +48,7 @@
 
 
    Version
    
 
-
    unsigned ZSTD_versionNumber (void);  /**< returns version number of ZSTD */
+
    unsigned ZSTD_versionNumber(void);   /**< library version number; to be used when checking dll version */
 

    
 
    Simple API
    
 
@@ -88,21 +88,29 @@
     note 5 : when `return==0`, if precise failure cause is needed, use ZSTD_getFrameParams() to know more. 
 

    
 
-
    Helper functions
    int         ZSTD_maxCLevel(void);               /*!< maximum compression level available */
+
    Helper functions
    int         ZSTD_maxCLevel(void);               /*!< maximum compression level available */
 size_t      ZSTD_compressBound(size_t srcSize); /*!< maximum compressed size in worst case scenario */
 unsigned    ZSTD_isError(size_t code);          /*!< tells if a `size_t` function result is an error code */
 const char* ZSTD_getErrorName(size_t code);     /*!< provides readable string from an error code */
-

    
+

    
 
    Explicit memory management
    
 
+
    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. 
+
    typedef struct ZSTD_CCtx_s ZSTD_CCtx;
+ZSTD_CCtx* ZSTD_createCCtx(void);
+size_t     ZSTD_freeCCtx(ZSTD_CCtx* cctx);
+

    
 
    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()). 
 

    
 
-
    Decompression context
    typedef struct ZSTD_DCtx_s ZSTD_DCtx;
+
    Decompression context
    typedef struct ZSTD_DCtx_s ZSTD_DCtx;
 ZSTD_DCtx* ZSTD_createDCtx(void);
 size_t     ZSTD_freeDCtx(ZSTD_DCtx* dctx);
-

    
+

    
 
    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()). 
 

    
@@ -220,14 +228,14 @@ size_t     ZSTD_freeDCtx(ZSTD_DCtx* dctx);
  
 

 
-
Streaming compression functions
typedef struct ZSTD_CStream_s ZSTD_CStream;
+
Streaming compression functions
typedef struct ZSTD_CStream_s ZSTD_CStream;
 ZSTD_CStream* ZSTD_createCStream(void);
 size_t ZSTD_freeCStream(ZSTD_CStream* zcs);
 size_t ZSTD_initCStream(ZSTD_CStream* zcs, int compressionLevel);
 size_t ZSTD_compressStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output, ZSTD_inBuffer* input);
 size_t ZSTD_flushStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output);
 size_t ZSTD_endStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output);
-


+


 
size_t ZSTD_CStreamInSize(void);    /**< recommended size for input buffer */
 


 
size_t ZSTD_CStreamOutSize(void);   /**< recommended size for output buffer. Guarantee to successfully flush at least one complete compressed block in all circumstances. */
@@ -248,17 +256,17 @@ size_t ZSTD_endStream(ZSTD_CStream* zcs, ZSTD_outBuffer* output);
   If `output.pos < output.size`, decoder has flushed everything it could.
   @return : 0 when a frame is completely decoded and fully flushed,
             an error code, which can be tested using ZSTD_isError(),
-            any other value > 0, which means there is still some work to do to complete the frame.
-            The return value is a suggested next input size (just an hint, to help latency).
+            any other value > 0, which means there is still some decoding to do to complete current frame.
+            The return value is a suggested next input size (a hint to improve latency) that will never load more than the current frame.
  
 

 
-
Streaming decompression functions
typedef struct ZSTD_DStream_s ZSTD_DStream;
+
Streaming decompression functions
typedef struct ZSTD_DStream_s ZSTD_DStream;
 ZSTD_DStream* ZSTD_createDStream(void);
 size_t ZSTD_freeDStream(ZSTD_DStream* zds);
 size_t ZSTD_initDStream(ZSTD_DStream* zds);
 size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inBuffer* input);
-


+


 
size_t ZSTD_DStreamInSize(void);    /*!< recommended size for input buffer */
 


 
size_t ZSTD_DStreamOutSize(void);   /*!< recommended size for output buffer. Guarantee to successfully flush at least one complete block in all circumstances. */
@@ -295,10 +303,10 @@ size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inB
     ZSTD_frameParameters fParams;
 } ZSTD_parameters;
 


-
Custom memory allocation functions
typedef void* (*ZSTD_allocFunction) (void* opaque, size_t size);
+
Custom memory allocation functions
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;
-


+


 
Advanced compression functions

 
 
size_t ZSTD_estimateCCtxSize(ZSTD_compressionParameters cParams);
@@ -352,6 +360,13 @@ typedef struct { ZSTD_allocFunction customAlloc; ZSTD_freeFunction customFree; v
 
 
Advanced decompression functions

 
+
unsigned ZSTD_isFrame(const void* buffer, size_t size);
+
  Tells if the content of `buffer` starts with a valid Frame Identifier.
+  Note : Frame Identifier is 4 bytes. If `size < 4`, @return will always be 0.
+  Note 2 : Legacy Frame Identifiers are considered valid only if Legacy Support is enabled.
+  Note 3 : Skippable Frame Identifiers are considered valid. 
+


+
 
size_t ZSTD_estimateDCtxSize(void);
 
  Gives the potential amount of memory allocated to create a ZSTD_DCtx 
 


@@ -368,24 +383,48 @@ typedef struct { ZSTD_allocFunction customAlloc; ZSTD_freeFunction customFree; v
 
  Gives the amount of memory used by a given ZSTD_DDict 
 


 
+
unsigned ZSTD_getDictID_fromDict(const void* dict, size_t dictSize);
+
  Provides the dictID stored within dictionary.
+  if @return == 0, the dictionary is not conformant with Zstandard specification.
+  It can still be loaded, but as a content-only dictionary. 
+


+
+
unsigned ZSTD_getDictID_fromDDict(const ZSTD_DDict* ddict);
+
  Provides the dictID of the dictionary loaded into `ddict`.
+  If @return == 0, the dictionary is not conformant to Zstandard specification, or empty.
+  Non-conformant dictionaries can still be loaded, but as content-only dictionaries. 
+


+
+
unsigned ZSTD_getDictID_fromFrame(const void* src, size_t srcSize);
+
  Provides the dictID required to decompressed the frame stored within `src`.
+  If @return == 0, the dictID could not be decoded.
+  This could for one of the following reasons :
+  - The frame does not require a dictionary to be decoded (most common case).
+  - The frame was built with dictID intentionally removed. Whatever dictionary is necessary is a hidden information.
+    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. 
+


+
 
Advanced streaming functions

 
-
Advanced Streaming compression functions
ZSTD_CStream* ZSTD_createCStream_advanced(ZSTD_customMem customMem);
+
Advanced Streaming compression functions
ZSTD_CStream* ZSTD_createCStream_advanced(ZSTD_customMem customMem);
 size_t ZSTD_initCStream_usingDict(ZSTD_CStream* zcs, const void* dict, size_t dictSize, int compressionLevel);
 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 */
 size_t ZSTD_initCStream_usingCDict(ZSTD_CStream* zcs, const ZSTD_CDict* cdict);  /**< note : cdict will just be referenced, and must outlive compression session */
 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 */
 size_t ZSTD_sizeof_CStream(const ZSTD_CStream* zcs);
-


-
Advanced Streaming decompression functions
typedef enum { ZSTDdsp_maxWindowSize } ZSTD_DStreamParameter_e;
+


+
Advanced Streaming decompression functions
typedef enum { ZSTDdsp_maxWindowSize } ZSTD_DStreamParameter_e;
 ZSTD_DStream* ZSTD_createDStream_advanced(ZSTD_customMem customMem);
 size_t ZSTD_initDStream_usingDict(ZSTD_DStream* zds, const void* dict, size_t dictSize);
 size_t ZSTD_setDStreamParameter(ZSTD_DStream* zds, ZSTD_DStreamParameter_e paramType, unsigned paramValue);
 size_t ZSTD_initDStream_usingDDict(ZSTD_DStream* zds, const ZSTD_DDict* ddict);  /**< note : ddict will just be referenced, and must outlive decompression session */
 size_t ZSTD_resetDStream(ZSTD_DStream* zds);  /**< re-use decompression parameters from previous init; saves dictionary loading */
 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).
@@ -422,13 +461,13 @@ size_t ZSTD_sizeof_DStream(const ZSTD_DStream* zds);
   You can then reuse `ZSTD_CCtx` (ZSTD_compressBegin()) to compress some new frame.
 

 
-
Buffer-less streaming compression functions
size_t ZSTD_compressBegin(ZSTD_CCtx* cctx, int compressionLevel);
+
Buffer-less streaming compression functions
size_t ZSTD_compressBegin(ZSTD_CCtx* cctx, int compressionLevel);
 size_t ZSTD_compressBegin_usingDict(ZSTD_CCtx* cctx, const void* dict, size_t dictSize, int compressionLevel);
 size_t ZSTD_compressBegin_advanced(ZSTD_CCtx* cctx, const void* dict, size_t dictSize, ZSTD_parameters params, unsigned long long pledgedSrcSize);
 size_t ZSTD_copyCCtx(ZSTD_CCtx* cctx, const ZSTD_CCtx* preparedCCtx, unsigned long long pledgedSrcSize);
 size_t ZSTD_compressContinue(ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
 size_t ZSTD_compressEnd(ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
-


+


 
Buffer-less streaming decompression (synchronous mode)
   A ZSTD_DCtx object is required to track streaming operations.
   Use ZSTD_createDCtx() / ZSTD_freeDCtx() to manage it.
@@ -472,7 +511,7 @@ size_t ZSTD_compressEnd(ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const vo
   Note : it's possible to know if next input to present is a header or a block, using ZSTD_nextInputType().
   This information is not required to properly decode a frame.
 
-  == Special case : skippable frames ==
+  == 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 :
@@ -491,7 +530,7 @@ size_t ZSTD_compressEnd(ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const vo
     unsigned checksumFlag;
 } ZSTD_frameParams;
 


-
Buffer-less streaming decompression functions
size_t ZSTD_getFrameParams(ZSTD_frameParams* fparamsPtr, const void* src, size_t srcSize);   /**< doesn't consume input, see details below */
+
Buffer-less streaming decompression functions
size_t ZSTD_getFrameParams(ZSTD_frameParams* fparamsPtr, const void* src, size_t srcSize);   /**< doesn't consume input, see details below */
 size_t ZSTD_decompressBegin(ZSTD_DCtx* dctx);
 size_t ZSTD_decompressBegin_usingDict(ZSTD_DCtx* dctx, const void* dict, size_t dictSize);
 void   ZSTD_copyDCtx(ZSTD_DCtx* dctx, const ZSTD_DCtx* preparedDCtx);
@@ -499,7 +538,7 @@ size_t ZSTD_nextSrcSizeToDecompress(ZSTD_DCtx* dctx);
 size_t ZSTD_decompressContinue(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
 typedef enum { ZSTDnit_frameHeader, ZSTDnit_blockHeader, ZSTDnit_block, ZSTDnit_lastBlock, ZSTDnit_checksum, ZSTDnit_skippableFrame } ZSTD_nextInputType_e;
 ZSTD_nextInputType_e ZSTD_nextInputType(ZSTD_DCtx* dctx);
-


+


 
Block functions
     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).
@@ -524,10 +563,10 @@ ZSTD_nextInputType_e ZSTD_nextInputType(ZSTD_DCtx* dctx);
         Use ZSTD_insertBlock() in such a case.
 

 
-
Raw zstd block functions
size_t ZSTD_getBlockSizeMax(ZSTD_CCtx* cctx);
+
Raw zstd block functions
size_t ZSTD_getBlockSizeMax(ZSTD_CCtx* cctx);
 size_t ZSTD_compressBlock  (ZSTD_CCtx* cctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
 size_t ZSTD_decompressBlock(ZSTD_DCtx* dctx, void* dst, size_t dstCapacity, const void* src, size_t srcSize);
 size_t ZSTD_insertBlock(ZSTD_DCtx* dctx, const void* blockStart, size_t blockSize);  /**< insert block into `dctx` history. Useful for uncompressed blocks */
-


+


 
 
diff --git a/lib/zstd.h b/lib/zstd.h
index 3989cc307..66ce13604 100644
--- a/lib/zstd.h
+++ b/lib/zstd.h
@@ -604,7 +604,7 @@ ZSTDLIB_API size_t ZSTD_compressEnd(ZSTD_CCtx* cctx, void* dst, size_t dstCapaci
   Note : it's possible to know if next input to present is a header or a block, using ZSTD_nextInputType().
   This information is not required to properly decode a frame.
 
-  == Special case : skippable frames ==
+  == 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 :

From 6323d0050fa1e2ebdb9c0fbbb3f2feb8c9500d63 Mon Sep 17 00:00:00 2001
From: Przemyslaw Skibinski 
Date: Thu, 8 Dec 2016 09:06:00 +0100
Subject: [PATCH 4/7] VS projects: restored zbuff for libzstd*

---
 build/VS2010/libzstd-dll/libzstd-dll.vcxproj | 3 +++
 build/VS2010/libzstd/libzstd.vcxproj         | 3 +++
 2 files changed, 6 insertions(+)

diff --git a/build/VS2010/libzstd-dll/libzstd-dll.vcxproj b/build/VS2010/libzstd-dll/libzstd-dll.vcxproj
index 81da84c7d..f85271970 100644
--- a/build/VS2010/libzstd-dll/libzstd-dll.vcxproj
+++ b/build/VS2010/libzstd-dll/libzstd-dll.vcxproj
@@ -29,6 +29,8 @@
     
     
     
+    
+    
     
     
     
@@ -47,6 +49,7 @@
     
     
     
+    
     
     
     
diff --git a/build/VS2010/libzstd/libzstd.vcxproj b/build/VS2010/libzstd/libzstd.vcxproj
index 661c20dfc..f5f30d733 100644
--- a/build/VS2010/libzstd/libzstd.vcxproj
+++ b/build/VS2010/libzstd/libzstd.vcxproj
@@ -29,6 +29,8 @@
     
     
     
+    
+    
     
     
     
@@ -47,6 +49,7 @@
     
     
     
+    
     
     
     

From 13de72e0cc499b7e509fb7b07d125e4af19de324 Mon Sep 17 00:00:00 2001
From: Przemyslaw Skibinski 
Date: Thu, 8 Dec 2016 10:43:55 +0100
Subject: [PATCH 5/7] programs\Makefile: use Linux paths

---
 programs/Makefile | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/programs/Makefile b/programs/Makefile
index e7ff3e5a0..2b89ddb57 100644
--- a/programs/Makefile
+++ b/programs/Makefile
@@ -56,8 +56,8 @@ endif
 # Define *.exe as extension for Windows systems
 ifneq (,$(filter Windows%,$(OS)))
 EXT =.exe
-RES64_FILE = windres\zstd64.res
-RES32_FILE = windres\zstd32.res
+RES64_FILE = windres/zstd64.res
+RES32_FILE = windres/zstd32.res
 ifneq (,$(filter x86_64%,$(shell $(CC) -dumpmachine)))
     RES_FILE = $(RES64_FILE)
 else
@@ -80,7 +80,7 @@ zstd  : CPPFLAGS += -DZSTD_LEGACY_SUPPORT=$(ZSTD_LEGACY_SUPPORT)
 zstd  : $(ZSTDDECOMP_O) $(ZSTD_FILES) $(ZSTDLEGACY_FILES) $(ZDICT_FILES) \
         zstdcli.c fileio.c bench.c datagen.c dibio.c
 ifneq (,$(filter Windows%,$(OS)))
-	windres\generate_res.bat
+	windres/generate_res.bat
 endif
 	$(CC) $(FLAGS) $^ $(RES_FILE) -o $@$(EXT) $(LDFLAGS)
 
@@ -89,7 +89,7 @@ zstd32 : CPPFLAGS += -DZSTD_LEGACY_SUPPORT=$(ZSTD_LEGACY_SUPPORT)
 zstd32 : $(ZSTDDIR)/decompress/zstd_decompress.c $(ZSTD_FILES) $(ZSTDLEGACY_FILES) $(ZDICT_FILES) \
         zstdcli.c fileio.c bench.c datagen.c dibio.c
 ifneq (,$(filter Windows%,$(OS)))
-	windres\generate_res.bat
+	windres/generate_res.bat
 endif
 	$(CC) -m32 $(FLAGS) $^ $(RES32_FILE) -o $@$(EXT)
 
@@ -136,7 +136,7 @@ gzstd: clean_decomp_o
     fi
 
 generate_res:
-	windres\generate_res.bat
+	windres/generate_res.bat
 
 clean:
 	$(MAKE) -C ../lib clean

From 128acb35dbcf5ca5de0a62a80815d7699b8a0d7b Mon Sep 17 00:00:00 2001
From: Przemyslaw Skibinski 
Date: Thu, 8 Dec 2016 10:49:59 +0100
Subject: [PATCH 6/7] improved MSYS support

---
 programs/windres/generate_res.bat | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/programs/windres/generate_res.bat b/programs/windres/generate_res.bat
index 76e47fa0a..7ff9aef51 100644
--- a/programs/windres/generate_res.bat
+++ b/programs/windres/generate_res.bat
@@ -6,6 +6,6 @@ IF ERRORLEVEL 1 (
     ECHO The windres.exe is missing. Ensure it is installed and placed in your PATH.
     EXIT /B
 ) ELSE (
-    windres.exe -I ..\lib -I windres -i windres\zstd.rc -O coff -F pe-x86-64 -o windres\zstd64.res
-    windres.exe -I ..\lib -I windres -i windres\zstd.rc -O coff -F pe-i386 -o windres\zstd32.res
+    windres.exe -I ../lib -I windres -i windres/zstd.rc -O coff -F pe-x86-64 -o windres/zstd64.res
+    windres.exe -I ../lib -I windres -i windres/zstd.rc -O coff -F pe-i386 -o windres/zstd32.res
 )

From 1d54feb171b279ff6dc121026a706605341e54c6 Mon Sep 17 00:00:00 2001
From: Przemyslaw Skibinski 
Date: Thu, 8 Dec 2016 14:00:09 +0100
Subject: [PATCH 7/7] use newer make with AppVeyor

---
 appveyor.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/appveyor.yml b/appveyor.yml
index f49d7cf42..27c83c04e 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -28,7 +28,7 @@ install:
       SET "CLANG_PARAMS=-C tests zstd fullbench fuzzer paramgrill datagen CC=clang MOREFLAGS="--target=x86_64-w64-mingw32 -Werror -Wconversion -Wno-sign-conversion"" &&
       SET "PATH_MINGW32=c:\MinGW\bin;c:\MinGW\usr\bin" &&
       SET "PATH_MINGW64=c:\msys64\mingw64\bin;c:\msys64\usr\bin" &&
-      COPY C:\MinGW\bin\mingw32-make.exe C:\MinGW\bin\make.exe &&
+      COPY C:\msys64\usr\bin\make.exe C:\MinGW\bin\make.exe &&
       COPY C:\MinGW\bin\gcc.exe C:\MinGW\bin\cc.exe
     ) else (
       IF [%PLATFORM%]==[x64] (SET ADDITIONALPARAM=/p:LibraryPath="C:\Program Files\Microsoft SDKs\Windows\v7.1\lib\x64;c:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\lib\amd64;C:\Program Files (x86)\Microsoft Visual Studio 10.0\;C:\Program Files (x86)\Microsoft Visual Studio 10.0\lib\amd64;")