| 1 | /* |
| 2 | * Copyright (c) Meta Platforms, Inc. and affiliates. |
| 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 ZSTD_ZLIBWRAPPER_H |
| 12 | #define ZSTD_ZLIBWRAPPER_H |
| 13 | |
| 14 | #if defined (__cplusplus) |
| 15 | extern "C" { |
| 16 | #endif |
| 17 | |
| 18 | |
| 19 | #define ZLIB_CONST |
| 20 | #define Z_PREFIX |
| 21 | #define ZLIB_INTERNAL /* disables gz*64 functions but fixes zlib 1.2.4 with Z_PREFIX */ |
| 22 | #include <zlib.h> |
| 23 | |
| 24 | #if !defined(z_const) |
| 25 | #define z_const |
| 26 | #endif |
| 27 | |
| 28 | #if !defined(_Z_OF) |
| 29 | #define _Z_OF OF |
| 30 | #endif |
| 31 | |
| 32 | /* returns a string with version of zstd library */ |
| 33 | const char * zstdVersion(void); |
| 34 | |
| 35 | |
| 36 | /*** COMPRESSION ***/ |
| 37 | /* ZWRAP_useZSTDcompression() enables/disables zstd compression during runtime. |
| 38 | By default zstd compression is disabled. To enable zstd compression please use one of the methods: |
| 39 | - compilation with the additional option -DZWRAP_USE_ZSTD=1 |
| 40 | - using '#define ZWRAP_USE_ZSTD 1' in source code before '#include "zstd_zlibwrapper.h"' |
| 41 | - calling ZWRAP_useZSTDcompression(1) |
| 42 | All above-mentioned methods will enable zstd compression for all threads. |
| 43 | Be aware that ZWRAP_useZSTDcompression() is not thread-safe and may lead to a race condition. */ |
| 44 | void ZWRAP_useZSTDcompression(int turn_on); |
| 45 | |
| 46 | /* checks if zstd compression is turned on */ |
| 47 | int ZWRAP_isUsingZSTDcompression(void); |
| 48 | |
| 49 | /* Changes a pledged source size for a given compression stream. |
| 50 | It will change ZSTD compression parameters what may improve compression speed and/or ratio. |
| 51 | The function should be called just after deflateInit() or deflateReset() and before deflate() or deflateSetDictionary(). |
| 52 | It's only helpful when data is compressed in blocks. |
| 53 | There will be no change in case of deflateInit() or deflateReset() immediately followed by deflate(strm, Z_FINISH) |
| 54 | as this case is automatically detected. */ |
| 55 | int ZWRAP_setPledgedSrcSize(z_streamp strm, unsigned long long pledgedSrcSize); |
| 56 | |
| 57 | /* Similar to deflateReset but preserves dictionary set using deflateSetDictionary. |
| 58 | It should improve compression speed because there will be less calls to deflateSetDictionary |
| 59 | When using zlib compression this method redirects to deflateReset. */ |
| 60 | int ZWRAP_deflateReset_keepDict(z_streamp strm); |
| 61 | |
| 62 | |
| 63 | |
| 64 | /*** DECOMPRESSION ***/ |
| 65 | typedef enum { ZWRAP_FORCE_ZLIB, ZWRAP_AUTO } ZWRAP_decompress_type; |
| 66 | |
| 67 | /* ZWRAP_setDecompressionType() enables/disables automatic recognition of zstd/zlib compressed data during runtime. |
| 68 | By default auto-detection of zstd and zlib streams in enabled (ZWRAP_AUTO). |
| 69 | Forcing zlib decompression with ZWRAP_setDecompressionType(ZWRAP_FORCE_ZLIB) slightly improves |
| 70 | decompression speed of zlib-encoded streams. |
| 71 | Be aware that ZWRAP_setDecompressionType() is not thread-safe and may lead to a race condition. */ |
| 72 | void ZWRAP_setDecompressionType(ZWRAP_decompress_type type); |
| 73 | |
| 74 | /* checks zstd decompression type */ |
| 75 | ZWRAP_decompress_type ZWRAP_getDecompressionType(void); |
| 76 | |
| 77 | /* Checks if zstd decompression is used for a given stream. |
| 78 | If will return 1 only when inflate() was called and zstd header was detected. */ |
| 79 | int ZWRAP_isUsingZSTDdecompression(z_streamp strm); |
| 80 | |
| 81 | /* Similar to inflateReset but preserves dictionary set using inflateSetDictionary. |
| 82 | inflate() will return Z_NEED_DICT only for the first time what will improve decompression speed. |
| 83 | For zlib streams this method redirects to inflateReset. */ |
| 84 | int ZWRAP_inflateReset_keepDict(z_streamp strm); |
| 85 | |
| 86 | |
| 87 | #if defined (__cplusplus) |
| 88 | } |
| 89 | #endif |
| 90 | |
| 91 | #endif /* ZSTD_ZLIBWRAPPER_H */ |