xref: /linux/lib/zstd/decompress/zstd_decompress_block.h (revision e61f33273ca755b3e2ebee4520a76097199dc7a8)
1 /* SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause */
2 /*
3  * Copyright (c) Meta Platforms, Inc. and affiliates.
4  * All rights reserved.
5  *
6  * This source code is licensed under both the BSD-style license (found in the
7  * LICENSE file in the root directory of this source tree) and the GPLv2 (found
8  * in the COPYING file in the root directory of this source tree).
9  * You may select, at your option, one of the above-listed licenses.
10  */
11 
12 
13 #ifndef ZSTD_DEC_BLOCK_H
14 #define ZSTD_DEC_BLOCK_H
15 
16 /*-*******************************************************
17  *  Dependencies
18  *********************************************************/
19 #include "../common/zstd_deps.h"   /* size_t */
20 #include <linux/zstd.h>    /* DCtx, and some public functions */
21 #include "../common/zstd_internal.h"  /* blockProperties_t, and some public functions */
22 #include "zstd_decompress_internal.h"  /* ZSTD_seqSymbol */
23 
24 
25 /* ===   Prototypes   === */
26 
27 /* note: prototypes already published within `zstd.h` :
28  * ZSTD_decompressBlock()
29  */
30 
31 /* note: prototypes already published within `zstd_internal.h` :
32  * ZSTD_getcBlockSize()
33  * ZSTD_decodeSeqHeaders()
34  */
35 
36 
37  /* Streaming state is used to inform allocation of the literal buffer */
38 typedef enum {
39     not_streaming = 0,
40     is_streaming = 1
41 } streaming_operation;
42 
43 /* ZSTD_decompressBlock_internal() :
44  * decompress block, starting at `src`,
45  * into destination buffer `dst`.
46  * @return : decompressed block size,
47  *           or an error code (which can be tested using ZSTD_isError())
48  */
49 size_t ZSTD_decompressBlock_internal(ZSTD_DCtx* dctx,
50                                void* dst, size_t dstCapacity,
51                          const void* src, size_t srcSize, const streaming_operation streaming);
52 
53 /* ZSTD_buildFSETable() :
54  * generate FSE decoding table for one symbol (ll, ml or off)
55  * this function must be called with valid parameters only
56  * (dt is large enough, normalizedCounter distribution total is a power of 2, max is within range, etc.)
57  * in which case it cannot fail.
58  * The workspace must be 4-byte aligned and at least ZSTD_BUILD_FSE_TABLE_WKSP_SIZE bytes, which is
59  * defined in zstd_decompress_internal.h.
60  * Internal use only.
61  */
62 void ZSTD_buildFSETable(ZSTD_seqSymbol* dt,
63              const short* normalizedCounter, unsigned maxSymbolValue,
64              const U32* baseValue, const U8* nbAdditionalBits,
65                    unsigned tableLog, void* wksp, size_t wkspSize,
66                    int bmi2);
67 
68 /* Internal definition of ZSTD_decompressBlock() to avoid deprecation warnings. */
69 size_t ZSTD_decompressBlock_deprecated(ZSTD_DCtx* dctx,
70                             void* dst, size_t dstCapacity,
71                       const void* src, size_t srcSize);
72 
73 
74 #endif /* ZSTD_DEC_BLOCK_H */
75