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e0c1b49f | 1 | /* SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause */ |
73f3d1b4 | 2 | /* |
cf30f6a5 | 3 | * Copyright (c) Yann Collet, Facebook, Inc. |
73f3d1b4 NT |
4 | * All rights reserved. |
5 | * | |
cf30f6a5 NT |
6 | * This source code is licensed under both the BSD-style license (found in the |
7 | * LICENSE file in the root directory of https://github.com/facebook/zstd) and | |
8 | * the GPLv2 (found in the COPYING file in the root directory of | |
9 | * https://github.com/facebook/zstd). You may select, at your option, one of the | |
10 | * above-listed licenses. | |
73f3d1b4 NT |
11 | */ |
12 | ||
cf30f6a5 NT |
13 | #ifndef LINUX_ZSTD_H |
14 | #define LINUX_ZSTD_H | |
73f3d1b4 | 15 | |
cf30f6a5 NT |
16 | /** |
17 | * This is a kernel-style API that wraps the upstream zstd API, which cannot be | |
18 | * used directly because the symbols aren't exported. It exposes the minimal | |
19 | * functionality which is currently required by users of zstd in the kernel. | |
20 | * Expose extra functions from lib/zstd/zstd.h as needed. | |
21 | */ | |
73f3d1b4 | 22 | |
cf30f6a5 NT |
23 | /* ====== Dependency ====== */ |
24 | #include <linux/types.h> | |
e0c1b49f | 25 | #include <linux/zstd_errors.h> |
cf30f6a5 | 26 | #include <linux/zstd_lib.h> |
73f3d1b4 | 27 | |
cf30f6a5 NT |
28 | /* ====== Helper Functions ====== */ |
29 | /** | |
30 | * zstd_compress_bound() - maximum compressed size in worst case scenario | |
31 | * @src_size: The size of the data to compress. | |
73f3d1b4 | 32 | * |
cf30f6a5 NT |
33 | * Return: The maximum compressed size in the worst case scenario. |
34 | */ | |
35 | size_t zstd_compress_bound(size_t src_size); | |
73f3d1b4 NT |
36 | |
37 | /** | |
cf30f6a5 NT |
38 | * zstd_is_error() - tells if a size_t function result is an error code |
39 | * @code: The function result to check for error. | |
73f3d1b4 | 40 | * |
cf30f6a5 NT |
41 | * Return: Non-zero iff the code is an error. |
42 | */ | |
43 | unsigned int zstd_is_error(size_t code); | |
44 | ||
45 | /** | |
46 | * enum zstd_error_code - zstd error codes | |
73f3d1b4 | 47 | */ |
cf30f6a5 | 48 | typedef ZSTD_ErrorCode zstd_error_code; |
73f3d1b4 NT |
49 | |
50 | /** | |
cf30f6a5 NT |
51 | * zstd_get_error_code() - translates an error function result to an error code |
52 | * @code: The function result for which zstd_is_error(code) is true. | |
73f3d1b4 | 53 | * |
cf30f6a5 | 54 | * Return: A unique error code for this error. |
73f3d1b4 | 55 | */ |
cf30f6a5 NT |
56 | zstd_error_code zstd_get_error_code(size_t code); |
57 | ||
73f3d1b4 | 58 | /** |
cf30f6a5 NT |
59 | * zstd_get_error_name() - translates an error function result to a string |
60 | * @code: The function result for which zstd_is_error(code) is true. | |
73f3d1b4 | 61 | * |
cf30f6a5 | 62 | * Return: An error string corresponding to the error code. |
73f3d1b4 | 63 | */ |
cf30f6a5 NT |
64 | const char *zstd_get_error_name(size_t code); |
65 | ||
73f3d1b4 | 66 | /** |
cf30f6a5 | 67 | * zstd_min_clevel() - minimum allowed compression level |
73f3d1b4 | 68 | * |
cf30f6a5 | 69 | * Return: The minimum allowed compression level. |
73f3d1b4 | 70 | */ |
cf30f6a5 NT |
71 | int zstd_min_clevel(void); |
72 | ||
73f3d1b4 | 73 | /** |
cf30f6a5 | 74 | * zstd_max_clevel() - maximum allowed compression level |
73f3d1b4 | 75 | * |
cf30f6a5 | 76 | * Return: The maximum allowed compression level. |
73f3d1b4 | 77 | */ |
cf30f6a5 NT |
78 | int zstd_max_clevel(void); |
79 | ||
80 | /* ====== Parameter Selection ====== */ | |
73f3d1b4 NT |
81 | |
82 | /** | |
cf30f6a5 | 83 | * enum zstd_strategy - zstd compression search strategy |
73f3d1b4 | 84 | * |
cf30f6a5 | 85 | * From faster to stronger. See zstd_lib.h. |
73f3d1b4 | 86 | */ |
cf30f6a5 | 87 | typedef ZSTD_strategy zstd_strategy; |
73f3d1b4 NT |
88 | |
89 | /** | |
cf30f6a5 | 90 | * struct zstd_compression_parameters - zstd compression parameters |
73f3d1b4 NT |
91 | * @windowLog: Log of the largest match distance. Larger means more |
92 | * compression, and more memory needed during decompression. | |
cf30f6a5 NT |
93 | * @chainLog: Fully searched segment. Larger means more compression, |
94 | * slower, and more memory (useless for fast). | |
73f3d1b4 NT |
95 | * @hashLog: Dispatch table. Larger means more compression, |
96 | * slower, and more memory. | |
97 | * @searchLog: Number of searches. Larger means more compression and slower. | |
98 | * @searchLength: Match length searched. Larger means faster decompression, | |
99 | * sometimes less compression. | |
100 | * @targetLength: Acceptable match size for optimal parser (only). Larger means | |
101 | * more compression, and slower. | |
102 | * @strategy: The zstd compression strategy. | |
cf30f6a5 NT |
103 | * |
104 | * See zstd_lib.h. | |
73f3d1b4 | 105 | */ |
cf30f6a5 | 106 | typedef ZSTD_compressionParameters zstd_compression_parameters; |
73f3d1b4 NT |
107 | |
108 | /** | |
cf30f6a5 NT |
109 | * struct zstd_frame_parameters - zstd frame parameters |
110 | * @contentSizeFlag: Controls whether content size will be present in the | |
111 | * frame header (when known). | |
112 | * @checksumFlag: Controls whether a 32-bit checksum is generated at the | |
113 | * end of the frame for error detection. | |
114 | * @noDictIDFlag: Controls whether dictID will be saved into the frame | |
115 | * header when using dictionary compression. | |
73f3d1b4 | 116 | * |
cf30f6a5 | 117 | * The default value is all fields set to 0. See zstd_lib.h. |
73f3d1b4 | 118 | */ |
cf30f6a5 | 119 | typedef ZSTD_frameParameters zstd_frame_parameters; |
73f3d1b4 NT |
120 | |
121 | /** | |
cf30f6a5 | 122 | * struct zstd_parameters - zstd parameters |
73f3d1b4 NT |
123 | * @cParams: The compression parameters. |
124 | * @fParams: The frame parameters. | |
125 | */ | |
cf30f6a5 | 126 | typedef ZSTD_parameters zstd_parameters; |
73f3d1b4 NT |
127 | |
128 | /** | |
cf30f6a5 NT |
129 | * zstd_get_params() - returns zstd_parameters for selected level |
130 | * @level: The compression level | |
131 | * @estimated_src_size: The estimated source size to compress or 0 | |
132 | * if unknown. | |
73f3d1b4 | 133 | * |
cf30f6a5 | 134 | * Return: The selected zstd_parameters. |
73f3d1b4 | 135 | */ |
cf30f6a5 NT |
136 | zstd_parameters zstd_get_params(int level, |
137 | unsigned long long estimated_src_size); | |
73f3d1b4 | 138 | |
cf30f6a5 | 139 | /* ====== Single-pass Compression ====== */ |
73f3d1b4 | 140 | |
cf30f6a5 | 141 | typedef ZSTD_CCtx zstd_cctx; |
73f3d1b4 NT |
142 | |
143 | /** | |
cf30f6a5 NT |
144 | * zstd_cctx_workspace_bound() - max memory needed to initialize a zstd_cctx |
145 | * @parameters: The compression parameters to be used. | |
73f3d1b4 NT |
146 | * |
147 | * If multiple compression parameters might be used, the caller must call | |
cf30f6a5 | 148 | * zstd_cctx_workspace_bound() for each set of parameters and use the maximum |
73f3d1b4 NT |
149 | * size. |
150 | * | |
cf30f6a5 NT |
151 | * Return: A lower bound on the size of the workspace that is passed to |
152 | * zstd_init_cctx(). | |
73f3d1b4 | 153 | */ |
cf30f6a5 | 154 | size_t zstd_cctx_workspace_bound(const zstd_compression_parameters *parameters); |
73f3d1b4 NT |
155 | |
156 | /** | |
cf30f6a5 NT |
157 | * zstd_init_cctx() - initialize a zstd compression context |
158 | * @workspace: The workspace to emplace the context into. It must outlive | |
159 | * the returned context. | |
160 | * @workspace_size: The size of workspace. Use zstd_cctx_workspace_bound() to | |
161 | * determine how large the workspace must be. | |
73f3d1b4 | 162 | * |
cf30f6a5 | 163 | * Return: A zstd compression context or NULL on error. |
73f3d1b4 | 164 | */ |
cf30f6a5 | 165 | zstd_cctx *zstd_init_cctx(void *workspace, size_t workspace_size); |
73f3d1b4 NT |
166 | |
167 | /** | |
cf30f6a5 NT |
168 | * zstd_compress_cctx() - compress src into dst with the initialized parameters |
169 | * @cctx: The context. Must have been initialized with zstd_init_cctx(). | |
170 | * @dst: The buffer to compress src into. | |
171 | * @dst_capacity: The size of the destination buffer. May be any size, but | |
172 | * ZSTD_compressBound(srcSize) is guaranteed to be large enough. | |
173 | * @src: The data to compress. | |
174 | * @src_size: The size of the data to compress. | |
175 | * @parameters: The compression parameters to be used. | |
73f3d1b4 | 176 | * |
cf30f6a5 NT |
177 | * Return: The compressed size or an error, which can be checked using |
178 | * zstd_is_error(). | |
73f3d1b4 | 179 | */ |
cf30f6a5 NT |
180 | size_t zstd_compress_cctx(zstd_cctx *cctx, void *dst, size_t dst_capacity, |
181 | const void *src, size_t src_size, const zstd_parameters *parameters); | |
73f3d1b4 | 182 | |
cf30f6a5 | 183 | /* ====== Single-pass Decompression ====== */ |
73f3d1b4 | 184 | |
cf30f6a5 | 185 | typedef ZSTD_DCtx zstd_dctx; |
73f3d1b4 NT |
186 | |
187 | /** | |
cf30f6a5 | 188 | * zstd_dctx_workspace_bound() - max memory needed to initialize a zstd_dctx |
73f3d1b4 | 189 | * |
cf30f6a5 NT |
190 | * Return: A lower bound on the size of the workspace that is passed to |
191 | * zstd_init_dctx(). | |
73f3d1b4 | 192 | */ |
cf30f6a5 | 193 | size_t zstd_dctx_workspace_bound(void); |
73f3d1b4 NT |
194 | |
195 | /** | |
cf30f6a5 NT |
196 | * zstd_init_dctx() - initialize a zstd decompression context |
197 | * @workspace: The workspace to emplace the context into. It must outlive | |
198 | * the returned context. | |
199 | * @workspace_size: The size of workspace. Use zstd_dctx_workspace_bound() to | |
200 | * determine how large the workspace must be. | |
73f3d1b4 | 201 | * |
cf30f6a5 | 202 | * Return: A zstd decompression context or NULL on error. |
73f3d1b4 | 203 | */ |
cf30f6a5 | 204 | zstd_dctx *zstd_init_dctx(void *workspace, size_t workspace_size); |
73f3d1b4 NT |
205 | |
206 | /** | |
cf30f6a5 NT |
207 | * zstd_decompress_dctx() - decompress zstd compressed src into dst |
208 | * @dctx: The decompression context. | |
209 | * @dst: The buffer to decompress src into. | |
210 | * @dst_capacity: The size of the destination buffer. Must be at least as large | |
211 | * as the decompressed size. If the caller cannot upper bound the | |
212 | * decompressed size, then it's better to use the streaming API. | |
213 | * @src: The zstd compressed data to decompress. Multiple concatenated | |
214 | * frames and skippable frames are allowed. | |
215 | * @src_size: The exact size of the data to decompress. | |
73f3d1b4 | 216 | * |
cf30f6a5 NT |
217 | * Return: The decompressed size or an error, which can be checked using |
218 | * zstd_is_error(). | |
73f3d1b4 | 219 | */ |
cf30f6a5 NT |
220 | size_t zstd_decompress_dctx(zstd_dctx *dctx, void *dst, size_t dst_capacity, |
221 | const void *src, size_t src_size); | |
73f3d1b4 | 222 | |
cf30f6a5 | 223 | /* ====== Streaming Buffers ====== */ |
73f3d1b4 NT |
224 | |
225 | /** | |
cf30f6a5 | 226 | * struct zstd_in_buffer - input buffer for streaming |
73f3d1b4 NT |
227 | * @src: Start of the input buffer. |
228 | * @size: Size of the input buffer. | |
229 | * @pos: Position where reading stopped. Will be updated. | |
230 | * Necessarily 0 <= pos <= size. | |
cf30f6a5 NT |
231 | * |
232 | * See zstd_lib.h. | |
73f3d1b4 | 233 | */ |
cf30f6a5 | 234 | typedef ZSTD_inBuffer zstd_in_buffer; |
73f3d1b4 NT |
235 | |
236 | /** | |
cf30f6a5 | 237 | * struct zstd_out_buffer - output buffer for streaming |
73f3d1b4 NT |
238 | * @dst: Start of the output buffer. |
239 | * @size: Size of the output buffer. | |
240 | * @pos: Position where writing stopped. Will be updated. | |
241 | * Necessarily 0 <= pos <= size. | |
cf30f6a5 NT |
242 | * |
243 | * See zstd_lib.h. | |
73f3d1b4 | 244 | */ |
cf30f6a5 | 245 | typedef ZSTD_outBuffer zstd_out_buffer; |
73f3d1b4 | 246 | |
cf30f6a5 | 247 | /* ====== Streaming Compression ====== */ |
73f3d1b4 | 248 | |
cf30f6a5 | 249 | typedef ZSTD_CStream zstd_cstream; |
73f3d1b4 NT |
250 | |
251 | /** | |
cf30f6a5 NT |
252 | * zstd_cstream_workspace_bound() - memory needed to initialize a zstd_cstream |
253 | * @cparams: The compression parameters to be used for compression. | |
73f3d1b4 NT |
254 | * |
255 | * Return: A lower bound on the size of the workspace that is passed to | |
cf30f6a5 | 256 | * zstd_init_cstream(). |
73f3d1b4 | 257 | */ |
cf30f6a5 | 258 | size_t zstd_cstream_workspace_bound(const zstd_compression_parameters *cparams); |
73f3d1b4 | 259 | |
73f3d1b4 | 260 | /** |
cf30f6a5 NT |
261 | * zstd_init_cstream() - initialize a zstd streaming compression context |
262 | * @parameters The zstd parameters to use for compression. | |
263 | * @pledged_src_size: If params.fParams.contentSizeFlag == 1 then the caller | |
264 | * must pass the source size (zero means empty source). | |
265 | * Otherwise, the caller may optionally pass the source | |
266 | * size, or zero if unknown. | |
267 | * @workspace: The workspace to emplace the context into. It must outlive | |
268 | * the returned context. | |
269 | * @workspace_size: The size of workspace. | |
270 | * Use zstd_cstream_workspace_bound(params->cparams) to | |
271 | * determine how large the workspace must be. | |
73f3d1b4 | 272 | * |
cf30f6a5 | 273 | * Return: The zstd streaming compression context or NULL on error. |
73f3d1b4 | 274 | */ |
cf30f6a5 NT |
275 | zstd_cstream *zstd_init_cstream(const zstd_parameters *parameters, |
276 | unsigned long long pledged_src_size, void *workspace, size_t workspace_size); | |
73f3d1b4 NT |
277 | |
278 | /** | |
cf30f6a5 NT |
279 | * zstd_reset_cstream() - reset the context using parameters from creation |
280 | * @cstream: The zstd streaming compression context to reset. | |
281 | * @pledged_src_size: Optionally the source size, or zero if unknown. | |
73f3d1b4 NT |
282 | * |
283 | * Resets the context using the parameters from creation. Skips dictionary | |
cf30f6a5 | 284 | * loading, since it can be reused. If `pledged_src_size` is non-zero the frame |
73f3d1b4 NT |
285 | * content size is always written into the frame header. |
286 | * | |
cf30f6a5 NT |
287 | * Return: Zero or an error, which can be checked using |
288 | * zstd_is_error(). | |
73f3d1b4 | 289 | */ |
cf30f6a5 NT |
290 | size_t zstd_reset_cstream(zstd_cstream *cstream, |
291 | unsigned long long pledged_src_size); | |
292 | ||
73f3d1b4 | 293 | /** |
cf30f6a5 NT |
294 | * zstd_compress_stream() - streaming compress some of input into output |
295 | * @cstream: The zstd streaming compression context. | |
296 | * @output: Destination buffer. `output->pos` is updated to indicate how much | |
297 | * compressed data was written. | |
298 | * @input: Source buffer. `input->pos` is updated to indicate how much data | |
299 | * was read. Note that it may not consume the entire input, in which | |
300 | * case `input->pos < input->size`, and it's up to the caller to | |
301 | * present remaining data again. | |
73f3d1b4 NT |
302 | * |
303 | * The `input` and `output` buffers may be any size. Guaranteed to make some | |
304 | * forward progress if `input` and `output` are not empty. | |
305 | * | |
cf30f6a5 NT |
306 | * Return: A hint for the number of bytes to use as the input for the next |
307 | * function call or an error, which can be checked using | |
308 | * zstd_is_error(). | |
73f3d1b4 | 309 | */ |
cf30f6a5 NT |
310 | size_t zstd_compress_stream(zstd_cstream *cstream, zstd_out_buffer *output, |
311 | zstd_in_buffer *input); | |
312 | ||
73f3d1b4 | 313 | /** |
cf30f6a5 NT |
314 | * zstd_flush_stream() - flush internal buffers into output |
315 | * @cstream: The zstd streaming compression context. | |
316 | * @output: Destination buffer. `output->pos` is updated to indicate how much | |
317 | * compressed data was written. | |
73f3d1b4 | 318 | * |
cf30f6a5 NT |
319 | * zstd_flush_stream() must be called until it returns 0, meaning all the data |
320 | * has been flushed. Since zstd_flush_stream() causes a block to be ended, | |
73f3d1b4 NT |
321 | * calling it too often will degrade the compression ratio. |
322 | * | |
cf30f6a5 NT |
323 | * Return: The number of bytes still present within internal buffers or an |
324 | * error, which can be checked using zstd_is_error(). | |
73f3d1b4 | 325 | */ |
cf30f6a5 | 326 | size_t zstd_flush_stream(zstd_cstream *cstream, zstd_out_buffer *output); |
73f3d1b4 NT |
327 | |
328 | /** | |
cf30f6a5 NT |
329 | * zstd_end_stream() - flush internal buffers into output and end the frame |
330 | * @cstream: The zstd streaming compression context. | |
331 | * @output: Destination buffer. `output->pos` is updated to indicate how much | |
332 | * compressed data was written. | |
73f3d1b4 | 333 | * |
cf30f6a5 NT |
334 | * zstd_end_stream() must be called until it returns 0, meaning all the data has |
335 | * been flushed and the frame epilogue has been written. | |
73f3d1b4 | 336 | * |
cf30f6a5 NT |
337 | * Return: The number of bytes still present within internal buffers or an |
338 | * error, which can be checked using zstd_is_error(). | |
73f3d1b4 | 339 | */ |
cf30f6a5 | 340 | size_t zstd_end_stream(zstd_cstream *cstream, zstd_out_buffer *output); |
73f3d1b4 | 341 | |
cf30f6a5 | 342 | /* ====== Streaming Decompression ====== */ |
73f3d1b4 | 343 | |
cf30f6a5 | 344 | typedef ZSTD_DStream zstd_dstream; |
73f3d1b4 NT |
345 | |
346 | /** | |
cf30f6a5 NT |
347 | * zstd_dstream_workspace_bound() - memory needed to initialize a zstd_dstream |
348 | * @max_window_size: The maximum window size allowed for compressed frames. | |
73f3d1b4 | 349 | * |
cf30f6a5 NT |
350 | * Return: A lower bound on the size of the workspace that is passed |
351 | * to zstd_init_dstream(). | |
73f3d1b4 | 352 | */ |
cf30f6a5 | 353 | size_t zstd_dstream_workspace_bound(size_t max_window_size); |
73f3d1b4 NT |
354 | |
355 | /** | |
cf30f6a5 NT |
356 | * zstd_init_dstream() - initialize a zstd streaming decompression context |
357 | * @max_window_size: The maximum window size allowed for compressed frames. | |
358 | * @workspace: The workspace to emplace the context into. It must outlive | |
359 | * the returned context. | |
360 | * @workspaceSize: The size of workspace. | |
361 | * Use zstd_dstream_workspace_bound(max_window_size) to | |
362 | * determine how large the workspace must be. | |
73f3d1b4 | 363 | * |
cf30f6a5 | 364 | * Return: The zstd streaming decompression context. |
73f3d1b4 | 365 | */ |
cf30f6a5 NT |
366 | zstd_dstream *zstd_init_dstream(size_t max_window_size, void *workspace, |
367 | size_t workspace_size); | |
73f3d1b4 | 368 | |
73f3d1b4 | 369 | /** |
cf30f6a5 NT |
370 | * zstd_reset_dstream() - reset the context using parameters from creation |
371 | * @dstream: The zstd streaming decompression context to reset. | |
73f3d1b4 NT |
372 | * |
373 | * Resets the context using the parameters from creation. Skips dictionary | |
374 | * loading, since it can be reused. | |
375 | * | |
cf30f6a5 | 376 | * Return: Zero or an error, which can be checked using zstd_is_error(). |
73f3d1b4 | 377 | */ |
cf30f6a5 NT |
378 | size_t zstd_reset_dstream(zstd_dstream *dstream); |
379 | ||
73f3d1b4 | 380 | /** |
cf30f6a5 NT |
381 | * zstd_decompress_stream() - streaming decompress some of input into output |
382 | * @dstream: The zstd streaming decompression context. | |
383 | * @output: Destination buffer. `output.pos` is updated to indicate how much | |
384 | * decompressed data was written. | |
385 | * @input: Source buffer. `input.pos` is updated to indicate how much data was | |
386 | * read. Note that it may not consume the entire input, in which case | |
387 | * `input.pos < input.size`, and it's up to the caller to present | |
388 | * remaining data again. | |
73f3d1b4 NT |
389 | * |
390 | * The `input` and `output` buffers may be any size. Guaranteed to make some | |
391 | * forward progress if `input` and `output` are not empty. | |
cf30f6a5 | 392 | * zstd_decompress_stream() will not consume the last byte of the frame until |
73f3d1b4 NT |
393 | * the entire frame is flushed. |
394 | * | |
cf30f6a5 NT |
395 | * Return: Returns 0 iff a frame is completely decoded and fully flushed. |
396 | * Otherwise returns a hint for the number of bytes to use as the | |
397 | * input for the next function call or an error, which can be checked | |
398 | * using zstd_is_error(). The size hint will never load more than the | |
399 | * frame. | |
73f3d1b4 | 400 | */ |
cf30f6a5 NT |
401 | size_t zstd_decompress_stream(zstd_dstream *dstream, zstd_out_buffer *output, |
402 | zstd_in_buffer *input); | |
73f3d1b4 | 403 | |
cf30f6a5 | 404 | /* ====== Frame Inspection Functions ====== */ |
73f3d1b4 NT |
405 | |
406 | /** | |
cf30f6a5 NT |
407 | * zstd_find_frame_compressed_size() - returns the size of a compressed frame |
408 | * @src: Source buffer. It should point to the start of a zstd encoded | |
409 | * frame or a skippable frame. | |
410 | * @src_size: The size of the source buffer. It must be at least as large as the | |
411 | * size of the frame. | |
73f3d1b4 | 412 | * |
cf30f6a5 NT |
413 | * Return: The compressed size of the frame pointed to by `src` or an error, |
414 | * which can be check with zstd_is_error(). | |
415 | * Suitable to pass to ZSTD_decompress() or similar functions. | |
73f3d1b4 | 416 | */ |
cf30f6a5 | 417 | size_t zstd_find_frame_compressed_size(const void *src, size_t src_size); |
73f3d1b4 NT |
418 | |
419 | /** | |
cf30f6a5 | 420 | * struct zstd_frame_params - zstd frame parameters stored in the frame header |
e0c1b49f NT |
421 | * @frameContentSize: The frame content size, or ZSTD_CONTENTSIZE_UNKNOWN if not |
422 | * present. | |
73f3d1b4 | 423 | * @windowSize: The window size, or 0 if the frame is a skippable frame. |
e0c1b49f NT |
424 | * @blockSizeMax: The maximum block size. |
425 | * @frameType: The frame type (zstd or skippable) | |
426 | * @headerSize: The size of the frame header. | |
73f3d1b4 NT |
427 | * @dictID: The dictionary id, or 0 if not present. |
428 | * @checksumFlag: Whether a checksum was used. | |
e0c1b49f NT |
429 | * |
430 | * See zstd_lib.h. | |
73f3d1b4 | 431 | */ |
e0c1b49f | 432 | typedef ZSTD_frameHeader zstd_frame_header; |
73f3d1b4 NT |
433 | |
434 | /** | |
cf30f6a5 NT |
435 | * zstd_get_frame_header() - extracts parameters from a zstd or skippable frame |
436 | * @params: On success the frame parameters are written here. | |
437 | * @src: The source buffer. It must point to a zstd or skippable frame. | |
438 | * @src_size: The size of the source buffer. | |
73f3d1b4 | 439 | * |
cf30f6a5 NT |
440 | * Return: 0 on success. If more data is required it returns how many bytes |
441 | * must be provided to make forward progress. Otherwise it returns | |
442 | * an error, which can be checked using zstd_is_error(). | |
73f3d1b4 | 443 | */ |
cf30f6a5 NT |
444 | size_t zstd_get_frame_header(zstd_frame_header *params, const void *src, |
445 | size_t src_size); | |
73f3d1b4 | 446 | |
cf30f6a5 | 447 | #endif /* LINUX_ZSTD_H */ |