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updated fse version

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Yann Collet
2016-03-04 19:26:59 +01:00
parent 4ec2998b1f
commit 944d0d2285
2 changed files with 100 additions and 117 deletions
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lib/fse.h
+74 -90
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@@ -1,7 +1,7 @@
/* ******************************************************************
FSE : Finite State Entropy coder
header file
Copyright (C) 2013-2015, Yann Collet.
FSE : Finite State Entropy codec
Public Prototypes declaration
Copyright (C) 2013-2016, Yann Collet.
BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
@@ -30,7 +30,6 @@
You can contact the author at :
- Source repository : https://github.com/Cyan4973/FiniteStateEntropy
- Public forum : https://groups.google.com/forum/#!forum/lz4c
****************************************************************** */
#ifndef FSE_H
#define FSE_H
@@ -40,8 +39,8 @@ extern "C" {
#endif
/* *****************************************
* Includes
/*-*****************************************
* Dependencies
******************************************/
#include <stddef.h> /* size_t, ptrdiff_t */
@@ -49,32 +48,32 @@ extern "C" {
/*-****************************************
* FSE simple functions
******************************************/
size_t FSE_compress(void* dst, size_t maxDstSize,
const void* src, size_t srcSize);
size_t FSE_decompress(void* dst, size_t maxDstSize,
const void* cSrc, size_t cSrcSize);
/*!
FSE_compress():
/*! FSE_compress() :
Compress content of buffer 'src', of size 'srcSize', into destination buffer 'dst'.
'dst' buffer must be already allocated. Compression runs faster is maxDstSize >= FSE_compressBound(srcSize)
return : size of compressed data (<= maxDstSize)
'dst' buffer must be already allocated. Compression runs faster is dstCapacity >= FSE_compressBound(srcSize).
@return : size of compressed data (<= dstCapacity).
Special values : if return == 0, srcData is not compressible => Nothing is stored within dst !!!
if return == 1, srcData is a single byte symbol * srcSize times. Use RLE compression instead.
if FSE_isError(return), compression failed (more details using FSE_getErrorName())
*/
size_t FSE_compress(void* dst, size_t dstCapacity,
const void* src, size_t srcSize);
FSE_decompress():
/*! FSE_decompress():
Decompress FSE data from buffer 'cSrc', of size 'cSrcSize',
into already allocated destination buffer 'dst', of size 'maxDstSize'.
return : size of regenerated data (<= maxDstSize)
or an error code, which can be tested using FSE_isError()
into already allocated destination buffer 'dst', of size 'dstCapacity'.
@return : size of regenerated data (<= maxDstSize),
or an error code, which can be tested using FSE_isError() .
** Important ** : FSE_decompress() doesn't decompress non-compressible nor RLE data !!!
** Important ** : FSE_decompress() does not decompress non-compressible nor RLE data !!!
Why ? : making this distinction requires a header.
Header management is intentionally delegated to the user layer, which can better manage special cases.
*/
size_t FSE_decompress(void* dst, size_t dstCapacity,
const void* cSrc, size_t cSrcSize);
/* *****************************************
/*-*****************************************
* Tool functions
******************************************/
size_t FSE_compressBound(size_t size); /* maximum compressed size */
@@ -84,14 +83,13 @@ unsigned FSE_isError(size_t code); /* tells if a return value is an er
const char* FSE_getErrorName(size_t code); /* provides error code string (useful for debugging) */
/* *****************************************
/*-*****************************************
* FSE advanced functions
******************************************/
/*!
FSE_compress2():
/*! FSE_compress2() :
Same as FSE_compress(), but allows the selection of 'maxSymbolValue' and 'tableLog'
Both parameters can be defined as '0' to mean : use default value
return : size of compressed data
@return : size of compressed data
Special values : if return == 0, srcData is not compressible => Nothing is stored within cSrc !!!
if return == 1, srcData is a single byte symbol * srcSize times. Use RLE compression.
if FSE_isError(return), it's an error code.
@@ -99,7 +97,7 @@ FSE_compress2():
size_t FSE_compress2 (void* dst, size_t dstSize, const void* src, size_t srcSize, unsigned maxSymbolValue, unsigned tableLog);
/* *****************************************
/*-*****************************************
* FSE detailed API
******************************************/
/*!
@@ -122,65 +120,56 @@ or to save and provide normalized distribution using external method.
/* *** COMPRESSION *** */
/*!
FSE_count():
Provides the precise count of each byte within a table 'count'
'count' is a table of unsigned int, of minimum size (*maxSymbolValuePtr+1).
*maxSymbolValuePtr will be updated if detected smaller than initial value.
@return : the count of the most frequent symbol (which is not identified)
if return == srcSize, there is only one symbol.
Can also return an error code, which can be tested with FSE_isError() */
/*! FSE_count():
Provides the precise count of each byte within a table 'count'.
'count' is a table of unsigned int, of minimum size (*maxSymbolValuePtr+1).
*maxSymbolValuePtr will be updated if detected smaller than initial value.
@return : the count of the most frequent symbol (which is not identified).
if return == srcSize, there is only one symbol.
Can also return an error code, which can be tested with FSE_isError(). */
size_t FSE_count(unsigned* count, unsigned* maxSymbolValuePtr, const void* src, size_t srcSize);
/*!
FSE_optimalTableLog():
dynamically downsize 'tableLog' when conditions are met.
It saves CPU time, by using smaller tables, while preserving or even improving compression ratio.
return : recommended tableLog (necessarily <= initial 'tableLog') */
/*! FSE_optimalTableLog():
dynamically downsize 'tableLog' when conditions are met.
It saves CPU time, by using smaller tables, while preserving or even improving compression ratio.
@return : recommended tableLog (necessarily <= initial 'tableLog') */
unsigned FSE_optimalTableLog(unsigned tableLog, size_t srcSize, unsigned maxSymbolValue);
/*!
FSE_normalizeCount():
normalize counters so that sum(count[]) == Power_of_2 (2^tableLog)
'normalizedCounter' is a table of short, of minimum size (maxSymbolValue+1).
return : tableLog,
or an errorCode, which can be tested using FSE_isError() */
/*! FSE_normalizeCount():
normalize counts so that sum(count[]) == Power_of_2 (2^tableLog)
'normalizedCounter' is a table of short, of minimum size (maxSymbolValue+1).
@return : tableLog,
or an errorCode, which can be tested using FSE_isError() */
size_t FSE_normalizeCount(short* normalizedCounter, unsigned tableLog, const unsigned* count, size_t srcSize, unsigned maxSymbolValue);
/*!
FSE_NCountWriteBound():
Provides the maximum possible size of an FSE normalized table, given 'maxSymbolValue' and 'tableLog'
Typically useful for allocation purpose. */
/*! FSE_NCountWriteBound():
Provides the maximum possible size of an FSE normalized table, given 'maxSymbolValue' and 'tableLog'.
Typically useful for allocation purpose. */
size_t FSE_NCountWriteBound(unsigned maxSymbolValue, unsigned tableLog);
/*!
FSE_writeNCount():
Compactly save 'normalizedCounter' into 'buffer'.
return : size of the compressed table
or an errorCode, which can be tested using FSE_isError() */
/*! FSE_writeNCount():
Compactly save 'normalizedCounter' into 'buffer'.
@return : size of the compressed table,
or an errorCode, which can be tested using FSE_isError(). */
size_t FSE_writeNCount (void* buffer, size_t bufferSize, const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog);
/*!
Constructor and Destructor of type FSE_CTable
Note that its size depends on 'tableLog' and 'maxSymbolValue' */
/*! Constructor and Destructor of FSE_CTable.
Note that FSE_CTable size depends on 'tableLog' and 'maxSymbolValue' */
typedef unsigned FSE_CTable; /* don't allocate that. It's only meant to be more restrictive than void* */
FSE_CTable* FSE_createCTable (unsigned tableLog, unsigned maxSymbolValue);
void FSE_freeCTable (FSE_CTable* ct);
/*!
FSE_buildCTable():
Builds @ct, which must be already allocated, using FSE_createCTable()
return : 0
or an errorCode, which can be tested using FSE_isError() */
/*! FSE_buildCTable():
Builds `ct`, which must be already allocated, using FSE_createCTable().
@return : 0, or an errorCode, which can be tested using FSE_isError() */
size_t FSE_buildCTable(FSE_CTable* ct, const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog);
/*!
FSE_compress_usingCTable():
Compress @src using @ct into @dst which must be already allocated
return : size of compressed data (<= @dstCapacity)
or 0 if compressed data could not fit into @dst
or an errorCode, which can be tested using FSE_isError() */
/*! FSE_compress_usingCTable():
Compress `src` using `ct` into `dst` which must be already allocated.
@return : size of compressed data (<= `dstCapacity`),
or 0 if compressed data could not fit into `dst`,
or an errorCode, which can be tested using FSE_isError() */
size_t FSE_compress_usingCTable (void* dst, size_t dstCapacity, const void* src, size_t srcSize, const FSE_CTable* ct);
/*!
@@ -221,7 +210,7 @@ If there is an error, both functions will return an ErrorCode (which can be test
'CTable' can then be used to compress 'src', with FSE_compress_usingCTable().
Similar to FSE_count(), the convention is that 'src' is assumed to be a table of char of size 'srcSize'
The function returns the size of compressed data (without header), necessarily <= @dstCapacity.
The function returns the size of compressed data (without header), necessarily <= `dstCapacity`.
If it returns '0', compressed data could not fit into 'dst'.
If there is an error, the function will return an ErrorCode (which can be tested using FSE_isError()).
*/
@@ -229,34 +218,29 @@ If there is an error, the function will return an ErrorCode (which can be tested
/* *** DECOMPRESSION *** */
/*!
FSE_readNCount():
Read compactly saved 'normalizedCounter' from 'rBuffer'.
return : size read from 'rBuffer'
or an errorCode, which can be tested using FSE_isError()
maxSymbolValuePtr[0] and tableLogPtr[0] will also be updated with their respective values */
/*! FSE_readNCount():
Read compactly saved 'normalizedCounter' from 'rBuffer'.
@return : size read from 'rBuffer',
or an errorCode, which can be tested using FSE_isError().
maxSymbolValuePtr[0] and tableLogPtr[0] will also be updated with their respective values */
size_t FSE_readNCount (short* normalizedCounter, unsigned* maxSymbolValuePtr, unsigned* tableLogPtr, const void* rBuffer, size_t rBuffSize);
/*!
Constructor and Destructor of type FSE_DTable
/*! Constructor and Destructor of FSE_DTable.
Note that its size depends on 'tableLog' */
typedef unsigned FSE_DTable; /* don't allocate that. It's just a way to be more restrictive than void* */
FSE_DTable* FSE_createDTable(unsigned tableLog);
void FSE_freeDTable(FSE_DTable* dt);
/*!
FSE_buildDTable():
Builds 'dt', which must be already allocated, using FSE_createDTable()
return : 0,
or an errorCode, which can be tested using FSE_isError() */
/*! FSE_buildDTable():
Builds 'dt', which must be already allocated, using FSE_createDTable().
return : 0, or an errorCode, which can be tested using FSE_isError() */
size_t FSE_buildDTable (FSE_DTable* dt, const short* normalizedCounter, unsigned maxSymbolValue, unsigned tableLog);
/*!
FSE_decompress_usingDTable():
Decompress compressed source @cSrc of size @cSrcSize using @dt
into @dst which must be already allocated.
return : size of regenerated data (necessarily <= @dstCapacity)
or an errorCode, which can be tested using FSE_isError() */
/*! FSE_decompress_usingDTable():
Decompress compressed source `cSrc` of size `cSrcSize` using `dt`
into `dst` which must be already allocated.
@return : size of regenerated data (necessarily <= `dstCapacity`),
or an errorCode, which can be tested using FSE_isError() */
size_t FSE_decompress_usingDTable(void* dst, size_t dstCapacity, const void* cSrc, size_t cSrcSize, const FSE_DTable* dt);
/*!
@@ -281,9 +265,9 @@ This is performed by the function FSE_buildDTable().
The space required by 'FSE_DTable' must be already allocated using FSE_createDTable().
If there is an error, the function will return an error code, which can be tested using FSE_isError().
'FSE_DTable' can then be used to decompress 'cSrc', with FSE_decompress_usingDTable().
'cSrcSize' must be strictly correct, otherwise decompression will fail.
FSE_decompress_usingDTable() result will tell how many bytes were regenerated (<=maxDstSize).
`FSE_DTable` can then be used to decompress `cSrc`, with FSE_decompress_usingDTable().
`cSrcSize` must be strictly correct, otherwise decompression will fail.
FSE_decompress_usingDTable() result will tell how many bytes were regenerated (<=`dstCapacity`).
If there is an error, the function will return an error code, which can be tested using FSE_isError(). (ex: dst buffer too small)
*/