mirror of
https://github.com/facebook/zstd.git
synced 2025-11-04 00:02:59 -05:00
9da3b215ec
Now uses ZDICT_DICTSIZE_MIN and ZDICT_CONTENTSIZE_MIN from zdict.h. Also : reduced values to 256 and 128 respectively
202 lines
10 KiB
C++
202 lines
10 KiB
C++
/**
|
|
* Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
|
|
* All rights reserved.
|
|
*
|
|
* This source code is licensed under the BSD-style license found in the
|
|
* LICENSE file in the root directory of this source tree. An additional grant
|
|
* of patent rights can be found in the PATENTS file in the same directory.
|
|
*/
|
|
|
|
#ifndef DICTBUILDER_H_001
|
|
#define DICTBUILDER_H_001
|
|
|
|
#if defined (__cplusplus)
|
|
extern "C" {
|
|
#endif
|
|
|
|
|
|
/*====== Dependencies ======*/
|
|
#include <stddef.h> /* size_t */
|
|
|
|
|
|
/* ===== ZDICTLIB_API : control library symbols visibility ===== */
|
|
#if defined(__GNUC__) && (__GNUC__ >= 4)
|
|
# define ZDICTLIB_VISIBILITY __attribute__ ((visibility ("default")))
|
|
#else
|
|
# define ZDICTLIB_VISIBILITY
|
|
#endif
|
|
#if defined(ZSTD_DLL_EXPORT) && (ZSTD_DLL_EXPORT==1)
|
|
# define ZDICTLIB_API __declspec(dllexport) ZDICTLIB_VISIBILITY
|
|
#elif defined(ZSTD_DLL_IMPORT) && (ZSTD_DLL_IMPORT==1)
|
|
# define ZDICTLIB_API __declspec(dllimport) ZDICTLIB_VISIBILITY /* It isn't required but allows to generate better code, saving a function pointer load from the IAT and an indirect jump.*/
|
|
#else
|
|
# define ZDICTLIB_API ZDICTLIB_VISIBILITY
|
|
#endif
|
|
|
|
|
|
/*! ZDICT_trainFromBuffer() :
|
|
Train a dictionary from an array of samples.
|
|
Samples must be stored concatenated in a single flat buffer `samplesBuffer`,
|
|
supplied with an array of sizes `samplesSizes`, providing the size of each sample, in order.
|
|
The resulting dictionary will be saved into `dictBuffer`.
|
|
@return : size of dictionary stored into `dictBuffer` (<= `dictBufferCapacity`)
|
|
or an error code, which can be tested with ZDICT_isError().
|
|
Tips : In general, a reasonable dictionary has a size of ~ 100 KB.
|
|
It's obviously possible to target smaller or larger ones, just by specifying different `dictBufferCapacity`.
|
|
In general, it's recommended to provide a few thousands samples, but this can vary a lot.
|
|
It's recommended that total size of all samples be about ~x100 times the target size of dictionary.
|
|
*/
|
|
ZDICTLIB_API size_t ZDICT_trainFromBuffer(void* dictBuffer, size_t dictBufferCapacity,
|
|
const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples);
|
|
|
|
|
|
/*====== Helper functions ======*/
|
|
ZDICTLIB_API unsigned ZDICT_getDictID(const void* dictBuffer, size_t dictSize); /**< extracts dictID; @return zero if error (not a valid dictionary) */
|
|
ZDICTLIB_API unsigned ZDICT_isError(size_t errorCode);
|
|
ZDICTLIB_API const char* ZDICT_getErrorName(size_t errorCode);
|
|
|
|
|
|
|
|
#ifdef ZDICT_STATIC_LINKING_ONLY
|
|
|
|
/* ====================================================================================
|
|
* 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.
|
|
* ==================================================================================== */
|
|
|
|
typedef struct {
|
|
unsigned selectivityLevel; /* 0 means default; larger => select more => larger dictionary */
|
|
int compressionLevel; /* 0 means default; target a specific zstd compression level */
|
|
unsigned notificationLevel; /* Write to stderr; 0 = none (default); 1 = errors; 2 = progression; 3 = details; 4 = debug; */
|
|
unsigned dictID; /* 0 means auto mode (32-bits random value); other : force dictID value */
|
|
unsigned reserved[2]; /* reserved space for future parameters */
|
|
} ZDICT_params_t;
|
|
|
|
|
|
/*! ZDICT_trainFromBuffer_advanced() :
|
|
Same as ZDICT_trainFromBuffer() with control over more parameters.
|
|
`parameters` is optional and can be provided with values set to 0 to mean "default".
|
|
@return : size of dictionary stored into `dictBuffer` (<= `dictBufferSize`),
|
|
or an error code, which can be tested by ZDICT_isError().
|
|
note : ZDICT_trainFromBuffer_advanced() will send notifications into stderr if instructed to, using notificationLevel>0.
|
|
*/
|
|
ZDICTLIB_API size_t ZDICT_trainFromBuffer_advanced(void* dictBuffer, size_t dictBufferCapacity,
|
|
const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples,
|
|
ZDICT_params_t parameters);
|
|
|
|
/*! COVER_params_t :
|
|
For all values 0 means default.
|
|
kMin and d are the only required parameters.
|
|
*/
|
|
typedef struct {
|
|
unsigned k; /* Segment size : constraint: 0 < k : Reasonable range [16, 2048+] */
|
|
unsigned d; /* dmer size : constraint: 0 < d <= k : Reasonable range [6, 16] */
|
|
unsigned steps; /* Number of steps : Only used for optimization : 0 means default (32) : Higher means more parameters checked */
|
|
|
|
unsigned nbThreads; /* Number of threads : constraint: 0 < nbThreads : 1 means single-threaded : Only used for optimization : Ignored if ZSTD_MULTITHREAD is not defined */
|
|
unsigned notificationLevel; /* Write to stderr; 0 = none (default); 1 = errors; 2 = progression; 3 = details; 4 = debug; */
|
|
unsigned dictID; /* 0 means auto mode (32-bits random value); other : force dictID value */
|
|
int compressionLevel; /* 0 means default; target a specific zstd compression level */
|
|
} COVER_params_t;
|
|
|
|
|
|
/*! COVER_trainFromBuffer() :
|
|
Train a dictionary from an array of samples using the COVER algorithm.
|
|
Samples must be stored concatenated in a single flat buffer `samplesBuffer`,
|
|
supplied with an array of sizes `samplesSizes`, providing the size of each sample, in order.
|
|
The resulting dictionary will be saved into `dictBuffer`.
|
|
@return : size of dictionary stored into `dictBuffer` (<= `dictBufferCapacity`)
|
|
or an error code, which can be tested with ZDICT_isError().
|
|
Note : COVER_trainFromBuffer() requires about 9 bytes of memory for each input byte.
|
|
Tips : In general, a reasonable dictionary has a size of ~ 100 KB.
|
|
It's obviously possible to target smaller or larger ones, just by specifying different `dictBufferCapacity`.
|
|
In general, it's recommended to provide a few thousands samples, but this can vary a lot.
|
|
It's recommended that total size of all samples be about ~x100 times the target size of dictionary.
|
|
*/
|
|
ZDICTLIB_API size_t COVER_trainFromBuffer(void* dictBuffer, size_t dictBufferCapacity,
|
|
const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples,
|
|
COVER_params_t parameters);
|
|
|
|
/*! COVER_optimizeTrainFromBuffer() :
|
|
The same requirements as above hold for all the parameters except `parameters`.
|
|
This function tries many parameter combinations and picks the best parameters.
|
|
`*parameters` is filled with the best parameters found, and the dictionary
|
|
constructed with those parameters is stored in `dictBuffer`.
|
|
|
|
All of the parameters d, k, steps are optional.
|
|
If d is non-zero then we don't check multiple values of d, otherwise we check d = {6, 8, 10, 12, 14, 16}.
|
|
if steps is zero it defaults to its default value.
|
|
If k is non-zero then we don't check multiple values of k, otherwise we check steps values in [16, 2048].
|
|
|
|
@return : size of dictionary stored into `dictBuffer` (<= `dictBufferCapacity`)
|
|
or an error code, which can be tested with ZDICT_isError().
|
|
On success `*parameters` contains the parameters selected.
|
|
Note : COVER_optimizeTrainFromBuffer() requires about 8 bytes of memory for each input byte and additionally another 5 bytes of memory for each byte of memory for each thread.
|
|
*/
|
|
ZDICTLIB_API size_t COVER_optimizeTrainFromBuffer(void* dictBuffer, size_t dictBufferCapacity,
|
|
const void* samplesBuffer, const size_t *samplesSizes, unsigned nbSamples,
|
|
COVER_params_t *parameters);
|
|
|
|
/*! ZDICT_finalizeDictionary() :
|
|
|
|
Given a custom content as a basis for dictionary, and a set of samples,
|
|
finalize dictionary by adding headers and statistics.
|
|
|
|
Samples must be stored concatenated in a flat buffer `samplesBuffer`,
|
|
supplied with an array of sizes `samplesSizes`, providing the size of each sample in order.
|
|
|
|
dictContentSize must be >= ZDICT_CONTENTSIZE_MIN bytes.
|
|
maxDictSize must be >= dictContentSize, and must be >= ZDICT_DICTSIZE_MIN bytes.
|
|
|
|
@return : size of dictionary stored into `dictBuffer` (<= `dictBufferCapacity`),
|
|
or an error code, which can be tested by ZDICT_isError().
|
|
note : ZDICT_finalizeDictionary() will push notifications into stderr if instructed to, using notificationLevel>0.
|
|
note 2 : dictBuffer and dictContent can overlap
|
|
*/
|
|
#define ZDICT_CONTENTSIZE_MIN 128
|
|
#define ZDICT_DICTSIZE_MIN 256
|
|
ZDICTLIB_API size_t ZDICT_finalizeDictionary(void* dictBuffer, size_t dictBufferCapacity,
|
|
const void* dictContent, size_t dictContentSize,
|
|
const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples,
|
|
ZDICT_params_t parameters);
|
|
|
|
|
|
|
|
/* Deprecation warnings */
|
|
/* It is generally possible to disable deprecation warnings from compiler,
|
|
for example with -Wno-deprecated-declarations for gcc
|
|
or _CRT_SECURE_NO_WARNINGS in Visual.
|
|
Otherwise, it's also possible to manually define ZDICT_DISABLE_DEPRECATE_WARNINGS */
|
|
#ifdef ZDICT_DISABLE_DEPRECATE_WARNINGS
|
|
# define ZDICT_DEPRECATED(message) ZDICTLIB_API /* disable deprecation warnings */
|
|
#else
|
|
# define ZDICT_GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
|
|
# if defined (__cplusplus) && (__cplusplus >= 201402) /* C++14 or greater */
|
|
# define ZDICT_DEPRECATED(message) [[deprecated(message)]] ZDICTLIB_API
|
|
# elif (ZDICT_GCC_VERSION >= 405) || defined(__clang__)
|
|
# define ZDICT_DEPRECATED(message) ZDICTLIB_API __attribute__((deprecated(message)))
|
|
# elif (ZDICT_GCC_VERSION >= 301)
|
|
# define ZDICT_DEPRECATED(message) ZDICTLIB_API __attribute__((deprecated))
|
|
# elif defined(_MSC_VER)
|
|
# define ZDICT_DEPRECATED(message) ZDICTLIB_API __declspec(deprecated(message))
|
|
# else
|
|
# pragma message("WARNING: You need to implement ZDICT_DEPRECATED for this compiler")
|
|
# define ZDICT_DEPRECATED(message) ZDICTLIB_API
|
|
# endif
|
|
#endif /* ZDICT_DISABLE_DEPRECATE_WARNINGS */
|
|
|
|
ZDICT_DEPRECATED("use ZDICT_finalizeDictionary() instead")
|
|
size_t ZDICT_addEntropyTablesFromBuffer(void* dictBuffer, size_t dictContentSize, size_t dictBufferCapacity,
|
|
const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples);
|
|
|
|
|
|
#endif /* ZDICT_STATIC_LINKING_ONLY */
|
|
|
|
#if defined (__cplusplus)
|
|
}
|
|
#endif
|
|
|
|
#endif /* DICTBUILDER_H_001 */
|