1/*
2 * Copyright (c) 2016-present, Yann Collet, Facebook, Inc.
3 * All rights reserved.
4 *
5 * This source code is licensed under both the BSD-style license (found in the
6 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
7 * in the COPYING file in the root directory of this source tree).
8 * You may select, at your option, one of the above-listed licenses.
9 */
10
11#ifndef DICTBUILDER_H_001
12#define DICTBUILDER_H_001
13
14#if defined (__cplusplus)
15extern "C" {
16#endif
17
18
19/*====== Dependencies ======*/
20#include <stddef.h> /* size_t */
21
22
23/* ===== ZDICTLIB_API : control library symbols visibility ===== */
24#ifndef ZDICTLIB_VISIBILITY
25# if defined(__GNUC__) && (__GNUC__ >= 4)
26# define ZDICTLIB_VISIBILITY __attribute__ ((visibility ("default")))
27# else
28# define ZDICTLIB_VISIBILITY
29# endif
30#endif
31#if defined(ZSTD_DLL_EXPORT) && (ZSTD_DLL_EXPORT==1)
32# define ZDICTLIB_API __declspec(dllexport) ZDICTLIB_VISIBILITY
33#elif defined(ZSTD_DLL_IMPORT) && (ZSTD_DLL_IMPORT==1)
34# 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.*/
35#else
36# define ZDICTLIB_API ZDICTLIB_VISIBILITY
37#endif
38
39
40/*! ZDICT_trainFromBuffer():
41 * Train a dictionary from an array of samples.
42 * Redirect towards ZDICT_optimizeTrainFromBuffer_cover() single-threaded, with d=8 and steps=4.
43 * Samples must be stored concatenated in a single flat buffer `samplesBuffer`,
44 * supplied with an array of sizes `samplesSizes`, providing the size of each sample, in order.
45 * The resulting dictionary will be saved into `dictBuffer`.
46 * @return: size of dictionary stored into `dictBuffer` (<= `dictBufferCapacity`)
47 * or an error code, which can be tested with ZDICT_isError().
48 * Note: ZDICT_trainFromBuffer() requires about 9 bytes of memory for each input byte.
49 * Tips: In general, a reasonable dictionary has a size of ~ 100 KB.
50 * It's possible to select smaller or larger size, just by specifying `dictBufferCapacity`.
51 * In general, it's recommended to provide a few thousands samples, though this can vary a lot.
52 * It's recommended that total size of all samples be about ~x100 times the target size of dictionary.
53 */
54ZDICTLIB_API size_t ZDICT_trainFromBuffer(void* dictBuffer, size_t dictBufferCapacity,
55 const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples);
56
57
58/*====== Helper functions ======*/
59ZDICTLIB_API unsigned ZDICT_getDictID(const void* dictBuffer, size_t dictSize); /**< extracts dictID; @return zero if error (not a valid dictionary) */
60ZDICTLIB_API unsigned ZDICT_isError(size_t errorCode);
61ZDICTLIB_API const char* ZDICT_getErrorName(size_t errorCode);
62
63
64
65#ifdef ZDICT_STATIC_LINKING_ONLY
66
67/* ====================================================================================
68 * The definitions in this section are considered experimental.
69 * They should never be used with a dynamic library, as they may change in the future.
70 * They are provided for advanced usages.
71 * Use them only in association with static linking.
72 * ==================================================================================== */
73
74typedef struct {
75 int compressionLevel; /* optimize for a specific zstd compression level; 0 means default */
76 unsigned notificationLevel; /* Write log to stderr; 0 = none (default); 1 = errors; 2 = progression; 3 = details; 4 = debug; */
77 unsigned dictID; /* force dictID value; 0 means auto mode (32-bits random value) */
78} ZDICT_params_t;
79
80/*! ZDICT_cover_params_t:
81 * k and d are the only required parameters.
82 * For others, value 0 means default.
83 */
84typedef struct {
85 unsigned k; /* Segment size : constraint: 0 < k : Reasonable range [16, 2048+] */
86 unsigned d; /* dmer size : constraint: 0 < d <= k : Reasonable range [6, 16] */
87 unsigned steps; /* Number of steps : Only used for optimization : 0 means default (32) : Higher means more parameters checked */
88 unsigned nbThreads; /* Number of threads : constraint: 0 < nbThreads : 1 means single-threaded : Only used for optimization : Ignored if ZSTD_MULTITHREAD is not defined */
89 ZDICT_params_t zParams;
90} ZDICT_cover_params_t;
91
92
93/*! ZDICT_trainFromBuffer_cover():
94 * Train a dictionary from an array of samples using the COVER algorithm.
95 * Samples must be stored concatenated in a single flat buffer `samplesBuffer`,
96 * supplied with an array of sizes `samplesSizes`, providing the size of each sample, in order.
97 * The resulting dictionary will be saved into `dictBuffer`.
98 * @return: size of dictionary stored into `dictBuffer` (<= `dictBufferCapacity`)
99 * or an error code, which can be tested with ZDICT_isError().
100 * Note: ZDICT_trainFromBuffer_cover() requires about 9 bytes of memory for each input byte.
101 * Tips: In general, a reasonable dictionary has a size of ~ 100 KB.
102 * It's possible to select smaller or larger size, just by specifying `dictBufferCapacity`.
103 * In general, it's recommended to provide a few thousands samples, though this can vary a lot.
104 * It's recommended that total size of all samples be about ~x100 times the target size of dictionary.
105 */
106ZDICTLIB_API size_t ZDICT_trainFromBuffer_cover(
107 void *dictBuffer, size_t dictBufferCapacity,
108 const void *samplesBuffer, const size_t *samplesSizes, unsigned nbSamples,
109 ZDICT_cover_params_t parameters);
110
111/*! ZDICT_optimizeTrainFromBuffer_cover():
112 * The same requirements as above hold for all the parameters except `parameters`.
113 * This function tries many parameter combinations and picks the best parameters.
114 * `*parameters` is filled with the best parameters found,
115 * dictionary constructed with those parameters is stored in `dictBuffer`.
116 *
117 * All of the parameters d, k, steps are optional.
118 * If d is non-zero then we don't check multiple values of d, otherwise we check d = {6, 8, 10, 12, 14, 16}.
119 * if steps is zero it defaults to its default value.
120 * If k is non-zero then we don't check multiple values of k, otherwise we check steps values in [16, 2048].
121 *
122 * @return: size of dictionary stored into `dictBuffer` (<= `dictBufferCapacity`)
123 * or an error code, which can be tested with ZDICT_isError().
124 * On success `*parameters` contains the parameters selected.
125 * Note: ZDICT_optimizeTrainFromBuffer_cover() 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.
126 */
127ZDICTLIB_API size_t ZDICT_optimizeTrainFromBuffer_cover(
128 void* dictBuffer, size_t dictBufferCapacity,
129 const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples,
130 ZDICT_cover_params_t* parameters);
131
132/*! ZDICT_finalizeDictionary():
133 * Given a custom content as a basis for dictionary, and a set of samples,
134 * finalize dictionary by adding headers and statistics.
135 *
136 * Samples must be stored concatenated in a flat buffer `samplesBuffer`,
137 * supplied with an array of sizes `samplesSizes`, providing the size of each sample in order.
138 *
139 * dictContentSize must be >= ZDICT_CONTENTSIZE_MIN bytes.
140 * maxDictSize must be >= dictContentSize, and must be >= ZDICT_DICTSIZE_MIN bytes.
141 *
142 * @return: size of dictionary stored into `dictBuffer` (<= `dictBufferCapacity`),
143 * or an error code, which can be tested by ZDICT_isError().
144 * Note: ZDICT_finalizeDictionary() will push notifications into stderr if instructed to, using notificationLevel>0.
145 * Note 2: dictBuffer and dictContent can overlap
146 */
147#define ZDICT_CONTENTSIZE_MIN 128
148#define ZDICT_DICTSIZE_MIN 256
149ZDICTLIB_API size_t ZDICT_finalizeDictionary(void* dictBuffer, size_t dictBufferCapacity,
150 const void* dictContent, size_t dictContentSize,
151 const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples,
152 ZDICT_params_t parameters);
153
154typedef struct {
155 unsigned selectivityLevel; /* 0 means default; larger => select more => larger dictionary */
156 ZDICT_params_t zParams;
157} ZDICT_legacy_params_t;
158
159/*! ZDICT_trainFromBuffer_legacy():
160 * Train a dictionary from an array of samples.
161 * Samples must be stored concatenated in a single flat buffer `samplesBuffer`,
162 * supplied with an array of sizes `samplesSizes`, providing the size of each sample, in order.
163 * The resulting dictionary will be saved into `dictBuffer`.
164 * `parameters` is optional and can be provided with values set to 0 to mean "default".
165 * @return: size of dictionary stored into `dictBuffer` (<= `dictBufferCapacity`)
166 * or an error code, which can be tested with ZDICT_isError().
167 * Tips: In general, a reasonable dictionary has a size of ~ 100 KB.
168 * It's possible to select smaller or larger size, just by specifying `dictBufferCapacity`.
169 * In general, it's recommended to provide a few thousands samples, though this can vary a lot.
170 * It's recommended that total size of all samples be about ~x100 times the target size of dictionary.
171 * Note: ZDICT_trainFromBuffer_legacy() will send notifications into stderr if instructed to, using notificationLevel>0.
172 */
173ZDICTLIB_API size_t ZDICT_trainFromBuffer_legacy(
174 void *dictBuffer, size_t dictBufferCapacity,
175 const void *samplesBuffer, const size_t *samplesSizes, unsigned nbSamples,
176 ZDICT_legacy_params_t parameters);
177
178/* Deprecation warnings */
179/* It is generally possible to disable deprecation warnings from compiler,
180 for example with -Wno-deprecated-declarations for gcc
181 or _CRT_SECURE_NO_WARNINGS in Visual.
182 Otherwise, it's also possible to manually define ZDICT_DISABLE_DEPRECATE_WARNINGS */
183#ifdef ZDICT_DISABLE_DEPRECATE_WARNINGS
184# define ZDICT_DEPRECATED(message) ZDICTLIB_API /* disable deprecation warnings */
185#else
186# define ZDICT_GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
187# if defined (__cplusplus) && (__cplusplus >= 201402) /* C++14 or greater */
188# define ZDICT_DEPRECATED(message) [[deprecated(message)]] ZDICTLIB_API
189# elif (ZDICT_GCC_VERSION >= 405) || defined(__clang__)
190# define ZDICT_DEPRECATED(message) ZDICTLIB_API __attribute__((deprecated(message)))
191# elif (ZDICT_GCC_VERSION >= 301)
192# define ZDICT_DEPRECATED(message) ZDICTLIB_API __attribute__((deprecated))
193# elif defined(_MSC_VER)
194# define ZDICT_DEPRECATED(message) ZDICTLIB_API __declspec(deprecated(message))
195# else
196# pragma message("WARNING: You need to implement ZDICT_DEPRECATED for this compiler")
197# define ZDICT_DEPRECATED(message) ZDICTLIB_API
198# endif
199#endif /* ZDICT_DISABLE_DEPRECATE_WARNINGS */
200
201ZDICT_DEPRECATED("use ZDICT_finalizeDictionary() instead")
202size_t ZDICT_addEntropyTablesFromBuffer(void* dictBuffer, size_t dictContentSize, size_t dictBufferCapacity,
203 const void* samplesBuffer, const size_t* samplesSizes, unsigned nbSamples);
204
205
206#endif /* ZDICT_STATIC_LINKING_ONLY */
207
208#if defined (__cplusplus)
209}
210#endif
211
212#endif /* DICTBUILDER_H_001 */
213