Commit 902c8ce7 authored by Baptiste Daroussin's avatar Baptiste Daroussin
Browse files

Import zstd 1.3.1

parent 4ab113e3
......@@ -39,4 +39,4 @@ outlined on that page and do not file a public issue.
## License
By contributing to Zstandard, you agree that your contributions will be licensed
under the [LICENSE](LICENSE) file in the root directory of this source tree.
under both the [LICENSE](LICENSE) file and the [COPYING](COPYING) file in the root directory of this source tree.
......@@ -74,12 +74,9 @@ zstdmt:
zlibwrapper:
$(MAKE) -C $(ZWRAPDIR) test
.PHONY: shortest
shortest:
$(MAKE) -C $(TESTDIR) $@
.PHONY: test
test:
.PHONY: test shortest
test shortest:
$(MAKE) -C $(PRGDIR) allVariants
$(MAKE) -C $(TESTDIR) $@
.PHONY: examples
......@@ -146,6 +143,11 @@ gcc6build: clean
gcc-6 -v
CC=gcc-6 $(MAKE) all MOREFLAGS="-Werror"
.PHONY: gcc7build
gcc7build: clean
gcc-7 -v
CC=gcc-7 $(MAKE) all MOREFLAGS="-Werror"
.PHONY: clangbuild
clangbuild: clean
clang -v
......@@ -180,7 +182,7 @@ ppc64fuzz: clean
CC=powerpc-linux-gnu-gcc QEMU_SYS=qemu-ppc64-static MOREFLAGS="-m64 -static" FUZZER_FLAGS=--no-big-tests $(MAKE) -C $(TESTDIR) fuzztest
gpptest: clean
CC=g++ $(MAKE) -C $(PRGDIR) all CFLAGS="-O3 -Wall -Wextra -Wundef -Wshadow -Wcast-align -Werror"
CC=$(CXX) $(MAKE) -C $(PRGDIR) all CFLAGS="-O3 -Wall -Wextra -Wundef -Wshadow -Wcast-align -Werror"
gcc5test: clean
gcc-5 -v
......
v1.3.1
New license : BSD + GPLv2
perf: substantially decreased memory usage in Multi-threading mode, thanks to reports by Tino Reichardt (@mcmilk)
perf: Multi-threading supports up to 256 threads. Cap at 256 when more are requested (#760)
cli : improved and fixed --list command, by @ib (#772)
cli : command -vV to list supported formats, by @ib (#771)
build : fixed binary variants, reported by @svenha (#788)
build : fix Visual compilation for non x86/x64 targets, reported by Greg Slazinski (@GregSlazinski) (#718)
API exp : breaking change : ZSTD_getframeHeader() provides more information
API exp : breaking change : pinned down values of error codes
doc : fixed huffman example, by Ulrich Kunitz (@ulikunitz)
new : contrib/adaptive-compression, I/O driven compression strength, by Paul Cruz (@paulcruz74)
new : contrib/long_distance_matching, statistics by Stella Lau (@stellamplau)
updated : contrib/linux-kernel, by Nick Terrell (@terrelln)
v1.3.0
cli : new : `--list` command, by Paul Cruz
cli : changed : xz/lzma support enabled by default
......
Additional Grant of Patent Rights Version 2
"Software" means the Zstandard software distributed by Facebook, Inc.
Facebook, Inc. ("Facebook") hereby grants to each recipient of the Software
("you") a perpetual, worldwide, royalty-free, non-exclusive, irrevocable
(subject to the termination provision below) license under any Necessary
Claims, to make, have made, use, sell, offer to sell, import, and otherwise
transfer the Software. For avoidance of doubt, no license is granted under
Facebook’s rights in any patent claims that are infringed by (i) modifications
to the Software made by you or any third party or (ii) the Software in
combination with any software or other technology.
The license granted hereunder will terminate, automatically and without notice,
if you (or any of your subsidiaries, corporate affiliates or agents) initiate
directly or indirectly, or take a direct financial interest in, any Patent
Assertion: (i) against Facebook or any of its subsidiaries or corporate
affiliates, (ii) against any party if such Patent Assertion arises in whole or
in part from any software, technology, product or service of Facebook or any of
its subsidiaries or corporate affiliates, or (iii) against any party relating
to the Software. Notwithstanding the foregoing, if Facebook or any of its
subsidiaries or corporate affiliates files a lawsuit alleging patent
infringement against you in the first instance, and you respond by filing a
patent infringement counterclaim in that lawsuit against that party that is
unrelated to the Software, the license granted hereunder will not terminate
under section (i) of this paragraph due to such counterclaim.
A "Necessary Claim" is a claim of a patent owned by Facebook that is
necessarily infringed by the Software standing alone.
A "Patent Assertion" is any lawsuit or other action alleging direct, indirect,
or contributory infringement or inducement to infringe any patent, including a
cross-claim or counterclaim.
......@@ -134,12 +134,12 @@ Going into `build` directory, you will find additional possibilities :
### Status
Zstandard is currently deployed within Facebook. It is used daily to compress and decompress very large amounts of data in multiple formats and use cases.
Zstandard is currently deployed within Facebook. It is used continuously to compress large amounts of data in multiple formats and use cases.
Zstandard is considered safe for production environments.
### License
Zstandard is [BSD-licensed](LICENSE). We also provide an [additional patent grant](PATENTS).
Zstandard is dual-licensed under [BSD](LICENSE) and [GPLv2](COPYING).
### Contributing
......
......@@ -3,7 +3,7 @@ dependencies:
- sudo dpkg --add-architecture i386
- sudo add-apt-repository -y ppa:ubuntu-toolchain-r/test; sudo apt-get -y -qq update
- sudo apt-get -y install gcc-powerpc-linux-gnu gcc-arm-linux-gnueabi libc6-dev-armel-cross gcc-aarch64-linux-gnu libc6-dev-arm64-cross
- sudo apt-get -y install libstdc++-6-dev clang gcc g++ gcc-5 gcc-6 zlib1g-dev liblzma-dev
- sudo apt-get -y install libstdc++-7-dev clang gcc g++ gcc-5 gcc-6 gcc-7 zlib1g-dev liblzma-dev
- sudo apt-get -y install linux-libc-dev:i386 libc6-dev-i386
test:
......@@ -45,7 +45,7 @@ test:
parallel: true
- ? |
if [[ "$CIRCLE_NODE_INDEX" == "0" ]] ; then make ppc64build && make clean; fi &&
if [[ "$CIRCLE_NODE_TOTAL" < "2" ]] || [[ "$CIRCLE_NODE_INDEX" == "1" ]]; then true && make clean; fi #could add another test here
if [[ "$CIRCLE_NODE_TOTAL" < "2" ]] || [[ "$CIRCLE_NODE_INDEX" == "1" ]]; then make gcc7build && make clean; fi #could add another test here
:
parallel: true
- ? |
......@@ -64,7 +64,7 @@ test:
#- gcc -v; make -C tests test32 MOREFLAGS="-I/usr/include/x86_64-linux-gnu" && make clean
#- make uasan && make clean
#- make asan32 && make clean
#- make -C tests test32 CC=clang MOREFLAGS="-g -fsanitize=address -I/usr/include/x86_64-linux-gnu"
#- make -C tests test32 CC=clang MOREFLAGS="-g -fsanitize=address -I/usr/include/x86_64-linux-gnu"
# Valgrind tests
#- CFLAGS="-O1 -g" make -C zlibWrapper valgrindTest && make clean
#- make -C tests valgrindTest && make clean
......
......@@ -87,7 +87,7 @@ int main(int argc, char **argv) {
}
size_t decompressed_size = ZSTD_get_decompressed_size(input, input_size);
if (decompressed_size == -1) {
if (decompressed_size == (size_t)-1) {
decompressed_size = MAX_COMPRESSION_RATIO * input_size;
fprintf(stderr, "WARNING: Compressed data does not contain "
"decompressed size, going to assume the compression "
......@@ -106,9 +106,15 @@ int main(int argc, char **argv) {
return 1;
}
dictionary_t* const parsed_dict = create_dictionary();
if (dict) {
parse_dictionary(parsed_dict, dict, dict_size);
}
size_t decompressed =
ZSTD_decompress_with_dict(output, decompressed_size,
input, input_size, dict, dict_size);
input, input_size, parsed_dict);
free_dictionary(parsed_dict);
write_file(argv[2], output, decompressed);
......@@ -117,4 +123,3 @@ int main(int argc, char **argv) {
free(dict);
input = output = dict = NULL;
}
This diff is collapsed.
......@@ -7,10 +7,52 @@
* of patent rights can be found in the PATENTS file in the same directory.
*/
/******* EXPOSED TYPES ********************************************************/
/*
* Contains the parsed contents of a dictionary
* This includes Huffman and FSE tables used for decoding and data on offsets
*/
typedef struct dictionary_s dictionary_t;
/******* END EXPOSED TYPES ****************************************************/
/******* DECOMPRESSION FUNCTIONS **********************************************/
/// Zstandard decompression functions.
/// `dst` must point to a space at least as large as the reconstructed output.
size_t ZSTD_decompress(void *const dst, const size_t dst_len,
const void *const src, const size_t src_len);
const void *const src, const size_t src_len);
/// If `dict != NULL` and `dict_len >= 8`, does the same thing as
/// `ZSTD_decompress` but uses the provided dict
size_t ZSTD_decompress_with_dict(void *const dst, const size_t dst_len,
const void *const src, const size_t src_len,
const void *const dict, const size_t dict_len);
const void *const src, const size_t src_len,
dictionary_t* parsed_dict);
/// Get the decompressed size of an input stream so memory can be allocated in
/// advance
/// Returns -1 if the size can't be determined
/// Assumes decompression of a single frame
size_t ZSTD_get_decompressed_size(const void *const src, const size_t src_len);
/******* END DECOMPRESSION FUNCTIONS ******************************************/
/******* DICTIONARY MANAGEMENT ***********************************************/
/*
* Return a valid dictionary_t pointer for use with dictionary initialization
* or decompression
*/
dictionary_t* create_dictionary();
/*
* Parse a provided dictionary blob for use in decompression
* `src` -- must point to memory space representing the dictionary
* `src_len` -- must provide the dictionary size
* `dict` -- will contain the parsed contents of the dictionary and
* can be used for decompression
*/
void parse_dictionary(dictionary_t *const dict, const void *src,
size_t src_len);
/*
* Free internal Huffman tables, FSE tables, and dictionary content
*/
void free_dictionary(dictionary_t *const dict);
/******* END DICTIONARY MANAGEMENT *******************************************/
......@@ -16,7 +16,7 @@ Distribution of this document is unlimited.
### Version
0.2.5 (31/03/17)
0.2.6 (19/08/17)
Introduction
......@@ -106,7 +106,7 @@ The structure of a single Zstandard frame is following:
| `Magic_Number` | `Frame_Header` |`Data_Block`| [More data blocks] | [`Content_Checksum`] |
|:--------------:|:--------------:|:----------:| ------------------ |:--------------------:|
| 4 bytes | 2-14 bytes | n bytes | | 0-4 bytes |
| 4 bytes | 2-14 bytes | n bytes | | 0-4 bytes |
__`Magic_Number`__
......@@ -1249,23 +1249,30 @@ Consequently, a last byte of `0` is not possible.
And the final-bit-flag itself is not part of the useful bitstream.
Hence, the last byte contains between 0 and 7 useful bits.
For example, if the literal sequence "0145" was encoded using the prefix codes above,
it would be encoded as:
```
00000001 01110000
```
Starting from the end,
it's possible to read the bitstream in a __little-endian__ fashion,
keeping track of already used bits. Since the bitstream is encoded in reverse
order, starting from the end read symbols in forward order.
For example, if the literal sequence "0145" was encoded using above prefix code,
it would be encoded (in reverse order) as:
|Symbol | 5 | 4 | 1 | 0 | Padding |
|--------|------|------|----|---|---------|
|Encoding|`0000`|`0001`|`01`|`1`| `10000` |
|Encoding|`0000`|`0001`|`01`|`1`| `00001` |
Starting from the end,
it's possible to read the bitstream in a __little-endian__ fashion,
keeping track of already used bits. Since the bitstream is encoded in reverse
order, by starting at the end the symbols can be read in forward order.
Resulting in following 2-bytes bitstream :
```
00010000 00001101
```
Here is an alternative representation with the symbol codes separated by underscore:
```
0001_0000 00001_1_01
```
Reading the last `Max_Number_of_Bits` bits,
it's then possible to compare extracted value to decoding table,
Reading highest `Max_Number_of_Bits` bits,
it's possible to compare extracted value to decoding table,
determining the symbol to decode and number of bits to discard.
The process continues up to reading the required number of symbols per stream.
......@@ -1516,12 +1523,13 @@ to crosscheck that an implementation build its decoding tables correctly.
Version changes
---------------
- 0.2.6 : fixed an error in huffman example, by Ulrich Kunitz
- 0.2.5 : minor typos and clarifications
- 0.2.4 : section restructuring, by Sean Purcell
- 0.2.3 : clarified several details, by Sean Purcell
- 0.2.2 : added predefined codes, by Johannes Rudolph
- 0.2.1 : clarify field names, by Przemyslaw Skibinski
- 0.2.0 : numerous format adjustments for zstd v0.8
- 0.2.0 : numerous format adjustments for zstd v0.8+
- 0.1.2 : limit Huffman tree depth to 11 bits
- 0.1.1 : reserved dictID ranges
- 0.1.0 : initial release
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>zstd 1.3.0 Manual</title>
<title>zstd 1.3.1 Manual</title>
</head>
<body>
<h1>zstd 1.3.0 Manual</h1>
<h1>zstd 1.3.1 Manual</h1>
<hr>
<a name="Contents"></a><h2>Contents</h2>
<ol>
......@@ -73,27 +73,41 @@
or an errorCode if it fails (which can be tested using ZSTD_isError()).
</p></pre><BR>
<pre><b>unsigned long long ZSTD_getDecompressedSize(const void* src, size_t srcSize);
</b><p> NOTE: This function is planned to be obsolete, in favor of ZSTD_getFrameContentSize().
ZSTD_getFrameContentSize() works the same way,
returning the decompressed size of a single frame,
but distinguishes empty frames from frames with an unknown size, or errors.
'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, it may not be present, typically in streaming mode.
When `return==0`, data to decompress could be any size.
<pre><b>#define ZSTD_CONTENTSIZE_UNKNOWN (0ULL - 1)
#define ZSTD_CONTENTSIZE_ERROR (0ULL - 2)
unsigned long long ZSTD_getFrameContentSize(const void *src, size_t srcSize);
</b><p> `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 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),
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 4 : If source is untrusted, decompressed size could be wrong or intentionally modified.
Always ensure result fits within application's authorized limits.
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 5 : when `return==0`, if precise failure cause is needed, use ZSTD_getFrameHeader() to know more.
note 6 : This function replaces ZSTD_getDecompressedSize()
</p></pre><BR>
<pre><b>unsigned long long ZSTD_getDecompressedSize(const void* src, size_t srcSize);
</b><p> 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 in the same return value (0),
while ZSTD_getFrameContentSize() distinguishes them.
'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.
</p></pre><BR>
<h3>Helper functions</h3><pre></pre><b><pre>int ZSTD_maxCLevel(void); </b>/*!< maximum compression level available */<b>
......@@ -298,8 +312,8 @@ size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inB
<pre><b>size_t ZSTD_DStreamOutSize(void); </b>/*!< recommended size for output buffer. Guarantee to successfully flush at least one complete block in all circumstances. */<b>
</b></pre><BR>
<a name="Chapter10"></a><h2>START OF ADVANCED AND EXPERIMENTAL FUNCTIONS</h2><pre> 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.
<BR></pre>
......@@ -330,13 +344,6 @@ size_t ZSTD_decompressStream(ZSTD_DStream* zds, ZSTD_outBuffer* output, ZSTD_inB
ZSTD_frameParameters fParams;
} ZSTD_parameters;
</b></pre><BR>
<pre><b>typedef struct {
unsigned long long frameContentSize;
size_t windowSize;
unsigned dictID;
unsigned checksumFlag;
} ZSTD_frameHeader;
</b></pre><BR>
<h3>Custom memory allocation functions</h3><pre></pre><b><pre>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;
......@@ -348,26 +355,15 @@ static const ZSTD_customMem ZSTD_defaultCMem = { NULL, NULL, NULL };
<pre><b>size_t ZSTD_findFrameCompressedSize(const void* src, size_t srcSize);
</b><p> `src` should point to the start of a ZSTD encoded frame or skippable frame
`srcSize` must be at least as large as the frame
@return : the compressed size of the frame pointed to by `src`,
@return : the compressed size of the first frame starting at `src`,
suitable to pass to `ZSTD_decompress` or similar,
or an error code if given invalid input.
</p></pre><BR>
<pre><b>#define ZSTD_CONTENTSIZE_UNKNOWN (0ULL - 1)
#define ZSTD_CONTENTSIZE_ERROR (0ULL - 2)
unsigned long long ZSTD_getFrameContentSize(const void *src, size_t srcSize);
</b><p> `src` should point to the start of a ZSTD encoded frame.
`srcSize` must be at least as large as the frame header.
A value >= `ZSTD_frameHeaderSize_max` is guaranteed to be large enough.
@return : - decompressed size of the frame pointed to be `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)
or an error code if input is invalid
</p></pre><BR>
<pre><b>unsigned long long ZSTD_findDecompressedSize(const void* src, size_t srcSize);
</b><p> `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 `srcSize` bytes after `src`)
(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
......@@ -375,8 +371,6 @@ unsigned long long ZSTD_getFrameContentSize(const void *src, size_t srcSize);
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.
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.
......@@ -385,7 +379,7 @@ unsigned long long ZSTD_getFrameContentSize(const void *src, size_t srcSize);
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 efficient as most of the data is skipped,
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.
</p></pre><BR>
......@@ -483,14 +477,15 @@ size_t ZSTD_estimateDDictSize(size_t dictSize, unsigned byReference);
It is important that dictBuffer outlives CDict, it must remain read accessible throughout the lifetime of CDict
</p></pre><BR>
<pre><b>typedef enum { ZSTD_dm_auto=0, </b>/* dictionary is "full" if it starts with ZSTD_MAGIC_DICTIONARY, rawContent otherwize */<b>
<pre><b>typedef enum { ZSTD_dm_auto=0, </b>/* dictionary is "full" if it starts with ZSTD_MAGIC_DICTIONARY, otherwise it is "rawContent" */<b>
ZSTD_dm_rawContent, </b>/* ensures dictionary is always loaded as rawContent, even if it starts with ZSTD_MAGIC_DICTIONARY */<b>
ZSTD_dm_fullDict </b>/* refuses to load a dictionary if it does not respect Zstandard's specification */<b>
} ZSTD_dictMode_e;
</b></pre><BR>
<pre><b>ZSTD_CDict* ZSTD_createCDict_advanced(const void* dict, size_t dictSize,
unsigned byReference, ZSTD_dictMode_e dictMode,
ZSTD_compressionParameters cParams, ZSTD_customMem customMem);
ZSTD_compressionParameters cParams,
ZSTD_customMem customMem);
</b><p> Create a ZSTD_CDict using external alloc and free, and customized compression parameters
</p></pre><BR>
......@@ -760,7 +755,16 @@ size_t ZSTD_copyCCtx(ZSTD_CCtx* cctx, const ZSTD_CCtx* preparedCCtx, unsigned lo
It also returns Frame Size as fparamsPtr->frameContentSize.
<BR></pre>
<h3>Buffer-less streaming decompression functions</h3><pre></pre><b><pre>size_t ZSTD_getFrameHeader(ZSTD_frameHeader* zfhPtr, const void* src, size_t srcSize); </b>/**< doesn't consume input */<b>
<h3>Buffer-less streaming decompression functions</h3><pre></pre><b><pre>typedef enum { ZSTD_frame, ZSTD_skippableFrame } ZSTD_frameType_e;
typedef struct {
unsigned long long frameContentSize; </b>/* ZSTD_CONTENTSIZE_UNKNOWN means this field is not available. 0 means "empty" */<b>
unsigned long long windowSize; </b>/* can be very large, up to <= frameContentSize */<b>
ZSTD_frameType_e frameType; </b>/* if == ZSTD_skippableFrame, frameContentSize is the size of skippable content */<b>
unsigned headerSize;
unsigned dictID;
unsigned checksumFlag;
} ZSTD_frameHeader;
size_t ZSTD_getFrameHeader(ZSTD_frameHeader* zfhPtr, const void* src, size_t srcSize); </b>/**< doesn't consume input */<b>
size_t ZSTD_decompressBegin(ZSTD_DCtx* dctx);
size_t ZSTD_decompressBegin_usingDict(ZSTD_DCtx* dctx, const void* dict, size_t dictSize);
size_t ZSTD_decompressBegin_usingDDict(ZSTD_DCtx* dctx, const ZSTD_DDict* ddict);
......@@ -809,7 +813,9 @@ void ZSTD_copyDCtx(ZSTD_DCtx* dctx, const ZSTD_DCtx* preparedDCtx);
* Special: value 0 means "do not change strategy". */
</b>/* frame parameters */<b>
ZSTD_p_contentSizeFlag=200, </b>/* Content size is written into frame header _whenever known_ (default:1) */<b>
ZSTD_p_contentSizeFlag=200, </b>/* Content size is written into frame header _whenever known_ (default:1)<b>
* note that content size must be known at the beginning,
* it is sent using ZSTD_CCtx_setPledgedSrcSize() */
ZSTD_p_checksumFlag, </b>/* A 32-bits checksum of content is written at end of frame (default:0) */<b>
ZSTD_p_dictIDFlag, </b>/* When applicable, dictID of dictionary is provided in frame header (default:1) */<b>
......
......@@ -80,9 +80,9 @@ extern "C" {
* bitStream encoding API (write forward)
********************************************/
/* bitStream can mix input from multiple sources.
* A critical property of these streams is that they encode and decode in **reverse** direction.
* So the first bit sequence you add will be the last to be read, like a LIFO stack.
*/
* A critical property of these streams is that they encode and decode in **reverse** direction.
* So the first bit sequence you add will be the last to be read, like a LIFO stack.
*/
typedef struct
{
size_t bitContainer;
......@@ -203,7 +203,7 @@ static const unsigned BIT_mask[] = { 0, 1, 3, 7, 0xF, 0x1F, 0x3F, 0x7F,
/*! BIT_initCStream() :
* `dstCapacity` must be > sizeof(size_t)
* @return : 0 if success,
otherwise an error code (can be tested using ERR_isError() ) */
* otherwise an error code (can be tested using ERR_isError()) */
MEM_STATIC size_t BIT_initCStream(BIT_CStream_t* bitC,
void* startPtr, size_t dstCapacity)
{
......@@ -217,8 +217,8 @@ MEM_STATIC size_t BIT_initCStream(BIT_CStream_t* bitC,
}
/*! BIT_addBits() :
can add up to 26 bits into `bitC`.
Does not check for register overflow ! */
* can add up to 26 bits into `bitC`.
* Note : does not check for register overflow ! */
MEM_STATIC void BIT_addBits(BIT_CStream_t* bitC,
size_t value, unsigned nbBits)
{
......@@ -268,7 +268,7 @@ MEM_STATIC void BIT_flushBits(BIT_CStream_t* bitC)
/*! BIT_closeCStream() :
* @return : size of CStream, in bytes,
or 0 if it could not fit into dstBuffer */
* or 0 if it could not fit into dstBuffer */
MEM_STATIC size_t BIT_closeCStream(BIT_CStream_t* bitC)
{
BIT_addBitsFast(bitC, 1, 1); /* endMark */
......@@ -279,14 +279,14 @@ MEM_STATIC size_t BIT_closeCStream(BIT_CStream_t* bitC)
/*-********************************************************
* bitStream decoding
* bitStream decoding
**********************************************************/
/*! BIT_initDStream() :
* Initialize a BIT_DStream_t.
* `bitD` : a pointer to an already allocated BIT_DStream_t structure.
* `srcSize` must be the *exact* size of the bitStream, in bytes.
* @return : size of stream (== srcSize) or an errorCode if a problem is detected
*/
* Initialize a BIT_DStream_t.
* `bitD` : a pointer to an already allocated BIT_DStream_t structure.
* `srcSize` must be the *exact* size of the bitStream, in bytes.
* @return : size of stream (== srcSize), or an errorCode if a problem is detected
*/
MEM_STATIC size_t BIT_initDStream(BIT_DStream_t* bitD, const void* srcBuffer, size_t srcSize)
{
if (srcSize < 1) { memset(bitD, 0, sizeof(*bitD)); return ERROR(srcSize_wrong); }
......@@ -305,29 +305,30 @@ MEM_STATIC size_t BIT_initDStream(BIT_DStream_t* bitD, const void* srcBuffer, si
bitD->bitContainer = *(const BYTE*)(bitD->start);
switch(srcSize)
{
case 7: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[6]) << (sizeof(bitD->bitContainer)*8 - 16);
/* fall-through */
case 7: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[6]) << (sizeof(bitD->bitContainer)*8 - 16);
/* fall-through */
case 6: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[5]) << (sizeof(bitD->bitContainer)*8 - 24);
/* fall-through */
case 6: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[5]) << (sizeof(bitD->bitContainer)*8 - 24);
/* fall-through */
case 5: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[4]) << (sizeof(bitD->bitContainer)*8 - 32);
/* fall-through */
case 5: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[4]) << (sizeof(bitD->bitContainer)*8 - 32);
/* fall-through */
case 4: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[3]) << 24;
/* fall-through */
case 4: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[3]) << 24;
/* fall-through */
case 3: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[2]) << 16;
/* fall-through */
case 3: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[2]) << 16;
/* fall-through */
case 2: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[1]) << 8;
/* fall-through */
case 2: bitD->bitContainer += (size_t)(((const BYTE*)(srcBuffer))[1]) << 8;
/* fall-through */
default: break;
default: break;
}
{ BYTE const lastByte = ((const BYTE*)srcBuffer)[srcSize-1];
bitD->bitsConsumed = lastByte ? 8 - BIT_highbit32(lastByte) : 0;
if (lastByte == 0) return ERROR(corruption_detected); /* endMark not present */
}
{ BYTE const lastByte = ((const BYTE*)srcBuffer)[srcSize-1];
bitD->bitsConsumed = lastByte ? 8 - BIT_highbit32(lastByte) : 0;
if (lastByte == 0) return ERROR(GENERIC); /* endMark not present */ }
bitD->bitsConsumed += (U32)(sizeof(bitD->bitContainer) - srcSize)*8;
}
......@@ -363,9 +364,8 @@ MEM_STATIC size_t BIT_getLowerBits(size_t bitContainer, U32 const nbBits)
* local register is not modified.
* On 32-bits, maxNbBits==24.
* On 64-bits, maxNbBits==56.
* @return : value extracted
*/
MEM_STATIC size_t BIT_lookBits(const BIT_DStream_t* bitD, U32 nbBits)
* @return : value extracted */
MEM_STATIC size_t BIT_lookBits(const BIT_DStream_t* bitD, U32 nbBits)
{
#if defined(__BMI__) && defined(__GNUC__) /* experimental; fails if bitD->bitsConsumed + nbBits > sizeof(bitD->bitContainer)*8 */
return BIT_getMiddleBits(bitD->bitContainer, (sizeof(bitD->bitContainer)*8) - bitD->bitsConsumed - nbBits, nbBits);
......@@ -392,8 +392,7 @@ MEM_STATIC void BIT_skipBits(BIT_DStream_t* bitD, U32 nbBits)
/*! BIT_readBits() :
* Read (consume) next n bits from local register and update.
* Pay attention to not read more than nbBits contained into local register.
* @return : extracted value.
*/
* @return : extracted value. */
MEM_STATIC size_t BIT_readBits(BIT_DStream_t* bitD, U32 nbBits)
{
size_t const value = BIT_lookBits(bitD, nbBits);
......@@ -402,7 +401,7 @@ MEM_STATIC size_t BIT_readBits(BIT_DStream_t* bitD, U32 nbBits)
}
/*! BIT_readBitsFast() :