| 1 |
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| 2 | |
| 3 | * Copyright (c) Meta Platforms, Inc. and affiliates.
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| 4 | * All rights reserved.
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| 5 | *
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| 6 | * This source code is licensed under both the BSD-style license (found in the
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| 7 | * LICENSE file in the root directory of https://github.com/facebook/zstd) and
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| 8 | * the GPLv2 (found in the COPYING file in the root directory of
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| 9 | * https://github.com/facebook/zstd). You may select, at your option, one of the
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| 10 | * above-listed licenses.
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| 11 |
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| 12 |
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| 13 | #ifndef LINUX_ZSTD_H
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| 14 | #define LINUX_ZSTD_H
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| 15 |
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| 16 | |
| 17 | * This is a kernel-style API that wraps the upstream zstd API, which cannot be
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| 18 | * used directly because the symbols aren't exported. It exposes the minimal
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| 19 | * functionality which is currently required by users of zstd in the kernel.
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| 20 | * Expose extra functions from lib/zstd/zstd.h as needed.
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| 21 |
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| 22 |
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| 23 | |
| 24 | #include <linux/types.h>
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| 25 | #include <linux/zstd_errors.h>
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| 26 | #include <linux/zstd_lib.h>
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| 27 |
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| 28 | |
| 29 | |
| 30 | * zstd_compress_bound() - maximum compressed size in worst case scenario
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| 31 | * @src_size: The size of the data to compress.
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| 32 | *
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| 33 | * Return: The maximum compressed size in the worst case scenario.
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| 34 |
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| 35 | size_t zstd_compress_bound(size_t src_size);
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| 36 |
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| 37 | |
| 38 | * zstd_is_error() - tells if a size_t function result is an error code
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| 39 | * @code: The function result to check for error.
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| 40 | *
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| 41 | * Return: Non-zero iff the code is an error.
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| 42 |
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| 43 | unsigned int zstd_is_error(size_t code);
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| 44 |
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| 45 | |
| 46 | * enum zstd_error_code - zstd error codes
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| 47 |
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| 48 | typedef ZSTD_ErrorCode zstd_error_code;
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| 49 |
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| 50 | |
| 51 | * zstd_get_error_code() - translates an error function result to an error code
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| 52 | * @code: The function result for which zstd_is_error(code) is true.
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| 53 | *
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| 54 | * Return: A unique error code for this error.
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| 55 |
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| 56 | zstd_error_code zstd_get_error_code(size_t code);
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| 57 |
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| 58 | |
| 59 | * zstd_get_error_name() - translates an error function result to a string
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| 60 | * @code: The function result for which zstd_is_error(code) is true.
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| 61 | *
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| 62 | * Return: An error string corresponding to the error code.
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| 63 |
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| 64 | const char *zstd_get_error_name(size_t code);
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| 65 |
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| 66 | |
| 67 | * zstd_min_clevel() - minimum allowed compression level
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| 68 | *
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| 69 | * Return: The minimum allowed compression level.
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| 70 |
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| 71 | int zstd_min_clevel(void);
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| 72 |
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| 73 | |
| 74 | * zstd_max_clevel() - maximum allowed compression level
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| 75 | *
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| 76 | * Return: The maximum allowed compression level.
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| 77 |
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| 78 | int zstd_max_clevel(void);
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| 79 |
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| 80 | |
| 81 | * zstd_default_clevel() - default compression level
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| 82 | *
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| 83 | * Return: Default compression level.
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| 84 |
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| 85 | int zstd_default_clevel(void);
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| 86 |
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| 87 | |
| 88 | * struct zstd_custom_mem - custom memory allocation
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| 89 |
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| 90 | typedef ZSTD_customMem zstd_custom_mem;
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| 91 |
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| 92 | |
| 93 | * struct zstd_dict_load_method - Dictionary load method.
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| 94 | * See zstd_lib.h.
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| 95 |
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| 96 | typedef ZSTD_dictLoadMethod_e zstd_dict_load_method;
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| 97 |
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| 98 | |
| 99 | * struct zstd_dict_content_type - Dictionary context type.
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| 100 | * See zstd_lib.h.
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| 101 |
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| 102 | typedef ZSTD_dictContentType_e zstd_dict_content_type;
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| 103 |
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| 104 | |
| 105 |
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| 106 | |
| 107 | * enum zstd_strategy - zstd compression search strategy
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| 108 | *
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| 109 | * From faster to stronger. See zstd_lib.h.
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| 110 |
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| 111 | typedef ZSTD_strategy zstd_strategy;
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| 112 |
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| 113 | |
| 114 | * struct zstd_compression_parameters - zstd compression parameters
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| 115 | * @windowLog: Log of the largest match distance. Larger means more
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| 116 | * compression, and more memory needed during decompression.
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| 117 | * @chainLog: Fully searched segment. Larger means more compression,
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| 118 | * slower, and more memory (useless for fast).
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| 119 | * @hashLog: Dispatch table. Larger means more compression,
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| 120 | * slower, and more memory.
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| 121 | * @searchLog: Number of searches. Larger means more compression and slower.
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| 122 | * @searchLength: Match length searched. Larger means faster decompression,
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| 123 | * sometimes less compression.
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| 124 | * @targetLength: Acceptable match size for optimal parser (only). Larger means
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| 125 | * more compression, and slower.
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| 126 | * @strategy: The zstd compression strategy.
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| 127 | *
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| 128 | * See zstd_lib.h.
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| 129 |
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| 130 | typedef ZSTD_compressionParameters zstd_compression_parameters;
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| 131 |
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| 132 | |
| 133 | * struct zstd_frame_parameters - zstd frame parameters
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| 134 | * @contentSizeFlag: Controls whether content size will be present in the
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| 135 | * frame header (when known).
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| 136 | * @checksumFlag: Controls whether a 32-bit checksum is generated at the
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| 137 | * end of the frame for error detection.
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| 138 | * @noDictIDFlag: Controls whether dictID will be saved into the frame
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| 139 | * header when using dictionary compression.
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| 140 | *
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| 141 | * The default value is all fields set to 0. See zstd_lib.h.
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| 142 |
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| 143 | typedef ZSTD_frameParameters zstd_frame_parameters;
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| 144 |
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| 145 | |
| 146 | * struct zstd_parameters - zstd parameters
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| 147 | * @cParams: The compression parameters.
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| 148 | * @fParams: The frame parameters.
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| 149 |
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| 150 | typedef ZSTD_parameters zstd_parameters;
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| 151 |
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| 152 | |
| 153 | * zstd_get_params() - returns zstd_parameters for selected level
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| 154 | * @level: The compression level
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| 155 | * @estimated_src_size: The estimated source size to compress or 0
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| 156 | * if unknown.
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| 157 | *
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| 158 | * Return: The selected zstd_parameters.
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| 159 |
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| 160 | zstd_parameters zstd_get_params(int level,
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| 161 | unsigned long long estimated_src_size);
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| 162 |
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| 163 | |
| 164 | * zstd_get_cparams() - returns zstd_compression_parameters for selected level
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| 165 | * @level: The compression level
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| 166 | * @estimated_src_size: The estimated source size to compress or 0
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| 167 | * if unknown.
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| 168 | * @dict_size: Dictionary size.
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| 169 | *
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| 170 | * Return: The selected zstd_compression_parameters.
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| 171 |
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| 172 | zstd_compression_parameters zstd_get_cparams(int level,
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| 173 | unsigned long long estimated_src_size, size_t dict_size);
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| 174 |
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| 175 | typedef ZSTD_CCtx zstd_cctx;
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| 176 | typedef ZSTD_cParameter zstd_cparameter;
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| 177 |
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| 178 | |
| 179 | * zstd_cctx_set_param() - sets a compression parameter
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| 180 | * @cctx: The context. Must have been initialized with zstd_init_cctx().
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| 181 | * @param: The parameter to set.
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| 182 | * @value: The value to set the parameter to.
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| 183 | *
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| 184 | * Return: Zero or an error, which can be checked using zstd_is_error().
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| 185 |
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| 186 | size_t zstd_cctx_set_param(zstd_cctx *cctx, zstd_cparameter param, int value);
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| 187 |
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| 188 | |
| 189 |
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| 190 | |
| 191 | * zstd_cctx_workspace_bound() - max memory needed to initialize a zstd_cctx
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| 192 | * @parameters: The compression parameters to be used.
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| 193 | *
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| 194 | * If multiple compression parameters might be used, the caller must call
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| 195 | * zstd_cctx_workspace_bound() for each set of parameters and use the maximum
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| 196 | * size.
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| 197 | *
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| 198 | * Return: A lower bound on the size of the workspace that is passed to
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| 199 | * zstd_init_cctx().
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| 200 |
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| 201 | size_t zstd_cctx_workspace_bound(const zstd_compression_parameters *parameters);
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| 202 |
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| 203 | |
| 204 | * zstd_cctx_workspace_bound_with_ext_seq_prod() - max memory needed to
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| 205 | * initialize a zstd_cctx when using the block-level external sequence
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| 206 | * producer API.
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| 207 | * @parameters: The compression parameters to be used.
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| 208 | *
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| 209 | * If multiple compression parameters might be used, the caller must call
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| 210 | * this function for each set of parameters and use the maximum size.
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| 211 | *
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| 212 | * Return: A lower bound on the size of the workspace that is passed to
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| 213 | * zstd_init_cctx().
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| 214 |
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| 215 | size_t zstd_cctx_workspace_bound_with_ext_seq_prod(const zstd_compression_parameters *parameters);
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| 216 |
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| 217 | |
| 218 | * zstd_init_cctx() - initialize a zstd compression context
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| 219 | * @workspace: The workspace to emplace the context into. It must outlive
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| 220 | * the returned context.
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| 221 | * @workspace_size: The size of workspace. Use zstd_cctx_workspace_bound() to
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| 222 | * determine how large the workspace must be.
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| 223 | *
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| 224 | * Return: A zstd compression context or NULL on error.
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| 225 |
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| 226 | zstd_cctx *zstd_init_cctx(void *workspace, size_t workspace_size);
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| 227 |
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| 228 | |
| 229 | * zstd_compress_cctx() - compress src into dst with the initialized parameters
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| 230 | * @cctx: The context. Must have been initialized with zstd_init_cctx().
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| 231 | * @dst: The buffer to compress src into.
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| 232 | * @dst_capacity: The size of the destination buffer. May be any size, but
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| 233 | * ZSTD_compressBound(srcSize) is guaranteed to be large enough.
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| 234 | * @src: The data to compress.
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| 235 | * @src_size: The size of the data to compress.
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| 236 | * @parameters: The compression parameters to be used.
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| 237 | *
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| 238 | * Return: The compressed size or an error, which can be checked using
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| 239 | * zstd_is_error().
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| 240 |
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| 241 | size_t zstd_compress_cctx(zstd_cctx *cctx, void *dst, size_t dst_capacity,
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| 242 | const void *src, size_t src_size, const zstd_parameters *parameters);
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| 243 |
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| 244 | |
| 245 | * zstd_create_cctx_advanced() - Create compression context
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| 246 | * @custom_mem: Custom allocator.
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| 247 | *
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| 248 | * Return: NULL on error, pointer to compression context otherwise.
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| 249 |
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| 250 | zstd_cctx *zstd_create_cctx_advanced(zstd_custom_mem custom_mem);
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| 251 |
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| 252 | |
| 253 | * zstd_free_cctx() - Free compression context
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| 254 | * @cdict: Pointer to compression context.
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| 255 | *
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| 256 | * Return: Always 0.
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| 257 |
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| 258 | size_t zstd_free_cctx(zstd_cctx* cctx);
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| 259 |
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| 260 | |
| 261 | * struct zstd_cdict - Compression dictionary.
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| 262 | * See zstd_lib.h.
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| 263 |
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| 264 | typedef ZSTD_CDict zstd_cdict;
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| 265 |
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| 266 | |
| 267 | * zstd_create_cdict_byreference() - Create compression dictionary
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| 268 | * @dict: Pointer to dictionary buffer.
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| 269 | * @dict_size: Size of the dictionary buffer.
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| 270 | * @dict_load_method: Dictionary load method.
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| 271 | * @dict_content_type: Dictionary content type.
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| 272 | * @custom_mem: Memory allocator.
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| 273 | *
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| 274 | * Note, this uses @dict by reference (ZSTD_dlm_byRef), so it should be
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| 275 | * free before zstd_cdict is destroyed.
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| 276 | *
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| 277 | * Return: NULL on error, pointer to compression dictionary
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| 278 | * otherwise.
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| 279 |
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| 280 | zstd_cdict *zstd_create_cdict_byreference(const void *dict, size_t dict_size,
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| 281 | zstd_compression_parameters cparams,
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| 282 | zstd_custom_mem custom_mem);
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| 283 |
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| 284 | |
| 285 | * zstd_free_cdict() - Free compression dictionary
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| 286 | * @cdict: Pointer to compression dictionary.
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| 287 | *
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| 288 | * Return: Always 0.
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| 289 |
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| 290 | size_t zstd_free_cdict(zstd_cdict* cdict);
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| 291 |
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| 292 | |
| 293 | * zstd_compress_using_cdict() - compress src into dst using a dictionary
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| 294 | * @cctx: The context. Must have been initialized with zstd_init_cctx().
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| 295 | * @dst: The buffer to compress src into.
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| 296 | * @dst_capacity: The size of the destination buffer. May be any size, but
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| 297 | * ZSTD_compressBound(srcSize) is guaranteed to be large enough.
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| 298 | * @src: The data to compress.
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| 299 | * @src_size: The size of the data to compress.
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| 300 | * @cdict: The dictionary to be used.
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| 301 | *
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| 302 | * Return: The compressed size or an error, which can be checked using
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| 303 | * zstd_is_error().
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| 304 |
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| 305 | size_t zstd_compress_using_cdict(zstd_cctx *cctx, void *dst,
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| 306 | size_t dst_capacity, const void *src, size_t src_size,
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| 307 | const zstd_cdict *cdict);
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| 308 |
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| 309 | |
| 310 |
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| 311 | typedef ZSTD_DCtx zstd_dctx;
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| 312 |
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| 313 | |
| 314 | * zstd_dctx_workspace_bound() - max memory needed to initialize a zstd_dctx
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| 315 | *
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| 316 | * Return: A lower bound on the size of the workspace that is passed to
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| 317 | * zstd_init_dctx().
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| 318 |
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| 319 | size_t zstd_dctx_workspace_bound(void);
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| 320 |
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| 321 | |
| 322 | * zstd_init_dctx() - initialize a zstd decompression context
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| 323 | * @workspace: The workspace to emplace the context into. It must outlive
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| 324 | * the returned context.
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| 325 | * @workspace_size: The size of workspace. Use zstd_dctx_workspace_bound() to
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| 326 | * determine how large the workspace must be.
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| 327 | *
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| 328 | * Return: A zstd decompression context or NULL on error.
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| 329 |
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| 330 | zstd_dctx *zstd_init_dctx(void *workspace, size_t workspace_size);
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| 331 |
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| 332 | |
| 333 | * zstd_decompress_dctx() - decompress zstd compressed src into dst
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| 334 | * @dctx: The decompression context.
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| 335 | * @dst: The buffer to decompress src into.
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| 336 | * @dst_capacity: The size of the destination buffer. Must be at least as large
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| 337 | * as the decompressed size. If the caller cannot upper bound the
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| 338 | * decompressed size, then it's better to use the streaming API.
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| 339 | * @src: The zstd compressed data to decompress. Multiple concatenated
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| 340 | * frames and skippable frames are allowed.
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| 341 | * @src_size: The exact size of the data to decompress.
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| 342 | *
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| 343 | * Return: The decompressed size or an error, which can be checked using
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| 344 | * zstd_is_error().
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| 345 |
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| 346 | size_t zstd_decompress_dctx(zstd_dctx *dctx, void *dst, size_t dst_capacity,
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| 347 | const void *src, size_t src_size);
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| 348 |
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| 349 | |
| 350 | * struct zstd_ddict - Decompression dictionary.
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| 351 | * See zstd_lib.h.
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| 352 |
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| 353 | typedef ZSTD_DDict zstd_ddict;
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| 354 |
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| 355 | |
| 356 | * zstd_create_ddict_byreference() - Create decompression dictionary
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| 357 | * @dict: Pointer to dictionary buffer.
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| 358 | * @dict_size: Size of the dictionary buffer.
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| 359 | * @dict_load_method: Dictionary load method.
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| 360 | * @dict_content_type: Dictionary content type.
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| 361 | * @custom_mem: Memory allocator.
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| 362 | *
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| 363 | * Note, this uses @dict by reference (ZSTD_dlm_byRef), so it should be
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| 364 | * free before zstd_ddict is destroyed.
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| 365 | *
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| 366 | * Return: NULL on error, pointer to decompression dictionary
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| 367 | * otherwise.
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| 368 |
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| 369 | zstd_ddict *zstd_create_ddict_byreference(const void *dict, size_t dict_size,
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| 370 | zstd_custom_mem custom_mem);
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| 371 | |
| 372 | * zstd_free_ddict() - Free decompression dictionary
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| 373 | * @dict: Pointer to the dictionary.
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| 374 | *
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| 375 | * Return: Always 0.
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| 376 |
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| 377 | size_t zstd_free_ddict(zstd_ddict *ddict);
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| 378 |
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| 379 | |
| 380 | * zstd_create_dctx_advanced() - Create decompression context
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| 381 | * @custom_mem: Custom allocator.
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| 382 | *
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| 383 | * Return: NULL on error, pointer to decompression context otherwise.
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| 384 |
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| 385 | zstd_dctx *zstd_create_dctx_advanced(zstd_custom_mem custom_mem);
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| 386 |
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| 387 | |
| 388 | * zstd_free_dctx() -- Free decompression context
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| 389 | * @dctx: Pointer to decompression context.
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| 390 | * Return: Always 0.
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| 391 |
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| 392 | size_t zstd_free_dctx(zstd_dctx *dctx);
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| 393 |
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| 394 | |
| 395 | * zstd_decompress_using_ddict() - decompress src into dst using a dictionary
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| 396 | * @dctx: The decompression context.
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| 397 | * @dst: The buffer to decompress src into.
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| 398 | * @dst_capacity: The size of the destination buffer. Must be at least as large
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| 399 | * as the decompressed size. If the caller cannot upper bound the
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| 400 | * decompressed size, then it's better to use the streaming API.
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| 401 | * @src: The zstd compressed data to decompress. Multiple concatenated
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| 402 | * frames and skippable frames are allowed.
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| 403 | * @src_size: The exact size of the data to decompress.
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| 404 | * @ddict: The dictionary to be used.
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| 405 | *
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| 406 | * Return: The decompressed size or an error, which can be checked using
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| 407 | * zstd_is_error().
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| 408 |
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| 409 | size_t zstd_decompress_using_ddict(zstd_dctx *dctx,
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| 410 | void *dst, size_t dst_capacity, const void *src, size_t src_size,
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| 411 | const zstd_ddict *ddict);
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| 412 |
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| 413 |
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| 414 | |
| 415 |
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| 416 | |
| 417 | * struct zstd_in_buffer - input buffer for streaming
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| 418 | * @src: Start of the input buffer.
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| 419 | * @size: Size of the input buffer.
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| 420 | * @pos: Position where reading stopped. Will be updated.
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| 421 | * Necessarily 0 <= pos <= size.
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| 422 | *
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| 423 | * See zstd_lib.h.
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| 424 |
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| 425 | typedef ZSTD_inBuffer zstd_in_buffer;
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| 426 |
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| 427 | |
| 428 | * struct zstd_out_buffer - output buffer for streaming
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| 429 | * @dst: Start of the output buffer.
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| 430 | * @size: Size of the output buffer.
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| 431 | * @pos: Position where writing stopped. Will be updated.
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| 432 | * Necessarily 0 <= pos <= size.
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| 433 | *
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| 434 | * See zstd_lib.h.
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| 435 |
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| 436 | typedef ZSTD_outBuffer zstd_out_buffer;
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| 437 |
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| 438 | |
| 439 |
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| 440 | typedef ZSTD_CStream zstd_cstream;
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| 441 |
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| 442 | |
| 443 | * zstd_cstream_workspace_bound() - memory needed to initialize a zstd_cstream
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| 444 | * @cparams: The compression parameters to be used for compression.
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| 445 | *
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| 446 | * Return: A lower bound on the size of the workspace that is passed to
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| 447 | * zstd_init_cstream().
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| 448 |
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| 449 | size_t zstd_cstream_workspace_bound(const zstd_compression_parameters *cparams);
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| 450 |
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| 451 | |
| 452 | * zstd_cstream_workspace_bound_with_ext_seq_prod() - memory needed to initialize
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| 453 | * a zstd_cstream when using the block-level external sequence producer API.
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| 454 | * @cparams: The compression parameters to be used for compression.
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| 455 | *
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| 456 | * Return: A lower bound on the size of the workspace that is passed to
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| 457 | * zstd_init_cstream().
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| 458 |
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| 459 | size_t zstd_cstream_workspace_bound_with_ext_seq_prod(const zstd_compression_parameters *cparams);
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| 460 |
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| 461 | |
| 462 | * zstd_init_cstream() - initialize a zstd streaming compression context
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| 463 | * @parameters The zstd parameters to use for compression.
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| 464 | * @pledged_src_size: If params.fParams.contentSizeFlag == 1 then the caller
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| 465 | * must pass the source size (zero means empty source).
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| 466 | * Otherwise, the caller may optionally pass the source
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| 467 | * size, or zero if unknown.
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| 468 | * @workspace: The workspace to emplace the context into. It must outlive
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| 469 | * the returned context.
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| 470 | * @workspace_size: The size of workspace.
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| 471 | * Use zstd_cstream_workspace_bound(params->cparams) to
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| 472 | * determine how large the workspace must be.
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| 473 | *
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| 474 | * Return: The zstd streaming compression context or NULL on error.
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| 475 |
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| 476 | zstd_cstream *zstd_init_cstream(const zstd_parameters *parameters,
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| 477 | unsigned long long pledged_src_size, void *workspace, size_t workspace_size);
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| 478 |
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| 479 | |
| 480 | * zstd_reset_cstream() - reset the context using parameters from creation
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| 481 | * @cstream: The zstd streaming compression context to reset.
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| 482 | * @pledged_src_size: Optionally the source size, or zero if unknown.
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| 483 | *
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| 484 | * Resets the context using the parameters from creation. Skips dictionary
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| 485 | * loading, since it can be reused. If `pledged_src_size` is non-zero the frame
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| 486 | * content size is always written into the frame header.
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| 487 | *
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| 488 | * Return: Zero or an error, which can be checked using
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| 489 | * zstd_is_error().
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| 490 |
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| 491 | size_t zstd_reset_cstream(zstd_cstream *cstream,
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| 492 | unsigned long long pledged_src_size);
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| 493 |
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| 494 | |
| 495 | * zstd_compress_stream() - streaming compress some of input into output
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| 496 | * @cstream: The zstd streaming compression context.
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| 497 | * @output: Destination buffer. `output->pos` is updated to indicate how much
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| 498 | * compressed data was written.
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| 499 | * @input: Source buffer. `input->pos` is updated to indicate how much data
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| 500 | * was read. Note that it may not consume the entire input, in which
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| 501 | * case `input->pos < input->size`, and it's up to the caller to
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| 502 | * present remaining data again.
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| 503 | *
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| 504 | * The `input` and `output` buffers may be any size. Guaranteed to make some
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| 505 | * forward progress if `input` and `output` are not empty.
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| 506 | *
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| 507 | * Return: A hint for the number of bytes to use as the input for the next
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| 508 | * function call or an error, which can be checked using
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| 509 | * zstd_is_error().
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| 510 |
|
| 511 | size_t zstd_compress_stream(zstd_cstream *cstream, zstd_out_buffer *output,
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| 512 | zstd_in_buffer *input);
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| 513 |
|
| 514 | |
| 515 | * zstd_flush_stream() - flush internal buffers into output
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| 516 | * @cstream: The zstd streaming compression context.
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| 517 | * @output: Destination buffer. `output->pos` is updated to indicate how much
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| 518 | * compressed data was written.
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| 519 | *
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| 520 | * zstd_flush_stream() must be called until it returns 0, meaning all the data
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| 521 | * has been flushed. Since zstd_flush_stream() causes a block to be ended,
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| 522 | * calling it too often will degrade the compression ratio.
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| 523 | *
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| 524 | * Return: The number of bytes still present within internal buffers or an
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| 525 | * error, which can be checked using zstd_is_error().
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| 526 |
|
| 527 | size_t zstd_flush_stream(zstd_cstream *cstream, zstd_out_buffer *output);
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| 528 |
|
| 529 | |
| 530 | * zstd_end_stream() - flush internal buffers into output and end the frame
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| 531 | * @cstream: The zstd streaming compression context.
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| 532 | * @output: Destination buffer. `output->pos` is updated to indicate how much
|
| 533 | * compressed data was written.
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| 534 | *
|
| 535 | * zstd_end_stream() must be called until it returns 0, meaning all the data has
|
| 536 | * been flushed and the frame epilogue has been written.
|
| 537 | *
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| 538 | * Return: The number of bytes still present within internal buffers or an
|
| 539 | * error, which can be checked using zstd_is_error().
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| 540 |
|
| 541 | size_t zstd_end_stream(zstd_cstream *cstream, zstd_out_buffer *output);
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| 542 |
|
| 543 | |
| 544 |
|
| 545 | typedef ZSTD_DStream zstd_dstream;
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| 546 |
|
| 547 | |
| 548 | * zstd_dstream_workspace_bound() - memory needed to initialize a zstd_dstream
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| 549 | * @max_window_size: The maximum window size allowed for compressed frames.
|
| 550 | *
|
| 551 | * Return: A lower bound on the size of the workspace that is passed
|
| 552 | * to zstd_init_dstream().
|
| 553 |
|
| 554 | size_t zstd_dstream_workspace_bound(size_t max_window_size);
|
| 555 |
|
| 556 | |
| 557 | * zstd_init_dstream() - initialize a zstd streaming decompression context
|
| 558 | * @max_window_size: The maximum window size allowed for compressed frames.
|
| 559 | * @workspace: The workspace to emplace the context into. It must outlive
|
| 560 | * the returned context.
|
| 561 | * @workspaceSize: The size of workspace.
|
| 562 | * Use zstd_dstream_workspace_bound(max_window_size) to
|
| 563 | * determine how large the workspace must be.
|
| 564 | *
|
| 565 | * Return: The zstd streaming decompression context.
|
| 566 |
|
| 567 | zstd_dstream *zstd_init_dstream(size_t max_window_size, void *workspace,
|
| 568 | size_t workspace_size);
|
| 569 |
|
| 570 | |
| 571 | * zstd_reset_dstream() - reset the context using parameters from creation
|
| 572 | * @dstream: The zstd streaming decompression context to reset.
|
| 573 | *
|
| 574 | * Resets the context using the parameters from creation. Skips dictionary
|
| 575 | * loading, since it can be reused.
|
| 576 | *
|
| 577 | * Return: Zero or an error, which can be checked using zstd_is_error().
|
| 578 |
|
| 579 | size_t zstd_reset_dstream(zstd_dstream *dstream);
|
| 580 |
|
| 581 | |
| 582 | * zstd_decompress_stream() - streaming decompress some of input into output
|
| 583 | * @dstream: The zstd streaming decompression context.
|
| 584 | * @output: Destination buffer. `output.pos` is updated to indicate how much
|
| 585 | * decompressed data was written.
|
| 586 | * @input: Source buffer. `input.pos` is updated to indicate how much data was
|
| 587 | * read. Note that it may not consume the entire input, in which case
|
| 588 | * `input.pos < input.size`, and it's up to the caller to present
|
| 589 | * remaining data again.
|
| 590 | *
|
| 591 | * The `input` and `output` buffers may be any size. Guaranteed to make some
|
| 592 | * forward progress if `input` and `output` are not empty.
|
| 593 | * zstd_decompress_stream() will not consume the last byte of the frame until
|
| 594 | * the entire frame is flushed.
|
| 595 | *
|
| 596 | * Return: Returns 0 iff a frame is completely decoded and fully flushed.
|
| 597 | * Otherwise returns a hint for the number of bytes to use as the
|
| 598 | * input for the next function call or an error, which can be checked
|
| 599 | * using zstd_is_error(). The size hint will never load more than the
|
| 600 | * frame.
|
| 601 |
|
| 602 | size_t zstd_decompress_stream(zstd_dstream *dstream, zstd_out_buffer *output,
|
| 603 | zstd_in_buffer *input);
|
| 604 |
|
| 605 | |
| 606 |
|
| 607 | |
| 608 | * zstd_find_frame_compressed_size() - returns the size of a compressed frame
|
| 609 | * @src: Source buffer. It should point to the start of a zstd encoded
|
| 610 | * frame or a skippable frame.
|
| 611 | * @src_size: The size of the source buffer. It must be at least as large as the
|
| 612 | * size of the frame.
|
| 613 | *
|
| 614 | * Return: The compressed size of the frame pointed to by `src` or an error,
|
| 615 | * which can be check with zstd_is_error().
|
| 616 | * Suitable to pass to ZSTD_decompress() or similar functions.
|
| 617 |
|
| 618 | size_t zstd_find_frame_compressed_size(const void *src, size_t src_size);
|
| 619 |
|
| 620 | |
| 621 | * zstd_register_sequence_producer() - exposes the zstd library function
|
| 622 | * ZSTD_registerSequenceProducer(). This is used for the block-level external
|
| 623 | * sequence producer API. See upstream zstd.h for detailed documentation.
|
| 624 |
|
| 625 | typedef ZSTD_sequenceProducer_F zstd_sequence_producer_f;
|
| 626 | void zstd_register_sequence_producer(
|
| 627 | zstd_cctx *cctx,
|
| 628 | void* sequence_producer_state,
|
| 629 | zstd_sequence_producer_f sequence_producer
|
| 630 | );
|
| 631 |
|
| 632 | |
| 633 | * struct zstd_frame_params - zstd frame parameters stored in the frame header
|
| 634 | * @frameContentSize: The frame content size, or ZSTD_CONTENTSIZE_UNKNOWN if not
|
| 635 | * present.
|
| 636 | * @windowSize: The window size, or 0 if the frame is a skippable frame.
|
| 637 | * @blockSizeMax: The maximum block size.
|
| 638 | * @frameType: The frame type (zstd or skippable)
|
| 639 | * @headerSize: The size of the frame header.
|
| 640 | * @dictID: The dictionary id, or 0 if not present.
|
| 641 | * @checksumFlag: Whether a checksum was used.
|
| 642 | *
|
| 643 | * See zstd_lib.h.
|
| 644 |
|
| 645 | typedef ZSTD_FrameHeader zstd_frame_header;
|
| 646 |
|
| 647 | |
| 648 | * zstd_get_frame_header() - extracts parameters from a zstd or skippable frame
|
| 649 | * @params: On success the frame parameters are written here.
|
| 650 | * @src: The source buffer. It must point to a zstd or skippable frame.
|
| 651 | * @src_size: The size of the source buffer.
|
| 652 | *
|
| 653 | * Return: 0 on success. If more data is required it returns how many bytes
|
| 654 | * must be provided to make forward progress. Otherwise it returns
|
| 655 | * an error, which can be checked using zstd_is_error().
|
| 656 |
|
| 657 | size_t zstd_get_frame_header(zstd_frame_header *params, const void *src,
|
| 658 | size_t src_size);
|
| 659 |
|
| 660 | |
| 661 | * struct zstd_sequence - a sequence of literals or a match
|
| 662 | *
|
| 663 | * @offset: The offset of the match
|
| 664 | * @litLength: The literal length of the sequence
|
| 665 | * @matchLength: The match length of the sequence
|
| 666 | * @rep: Represents which repeat offset is used
|
| 667 |
|
| 668 | typedef ZSTD_Sequence zstd_sequence;
|
| 669 |
|
| 670 | |
| 671 | * zstd_compress_sequences_and_literals() - compress an array of zstd_sequence and literals
|
| 672 | *
|
| 673 | * @cctx: The zstd compression context.
|
| 674 | * @dst: The buffer to compress the data into.
|
| 675 | * @dst_capacity: The size of the destination buffer.
|
| 676 | * @in_seqs: The array of zstd_sequence to compress.
|
| 677 | * @in_seqs_size: The number of sequences in in_seqs.
|
| 678 | * @literals: The literals associated to the sequences to be compressed.
|
| 679 | * @lit_size: The size of the literals in the literals buffer.
|
| 680 | * @lit_capacity: The size of the literals buffer.
|
| 681 | * @decompressed_size: The size of the input data
|
| 682 | *
|
| 683 | * Return: The compressed size or an error, which can be checked using
|
| 684 | * zstd_is_error().
|
| 685 |
|
| 686 | size_t zstd_compress_sequences_and_literals(zstd_cctx *cctx, void* dst, size_t dst_capacity,
|
| 687 | const zstd_sequence *in_seqs, size_t in_seqs_size,
|
| 688 | const void* literals, size_t lit_size, size_t lit_capacity,
|
| 689 | size_t decompressed_size);
|
| 690 |
|
| 691 | #endif
|