1 /*
2  * Copyright (c) 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 
12 
13 /* *************************************
14 *  Dependencies
15 ***************************************/
16 #define ZBUFF_STATIC_LINKING_ONLY
17 #include "zbuff.h"
18 #include "../common/error_private.h"
19 
20 
21 /*-***********************************************************
22 *  Streaming compression
23 *
24 *  A ZBUFF_CCtx object is required to track streaming operation.
25 *  Use ZBUFF_createCCtx() and ZBUFF_freeCCtx() to create/release resources.
26 *  Use ZBUFF_compressInit() to start a new compression operation.
27 *  ZBUFF_CCtx objects can be reused multiple times.
28 *
29 *  Use ZBUFF_compressContinue() repetitively to consume your input.
30 *  *srcSizePtr and *dstCapacityPtr can be any size.
31 *  The function will report how many bytes were read or written by modifying *srcSizePtr and *dstCapacityPtr.
32 *  Note that it may not consume the entire input, in which case it's up to the caller to call again the function with remaining input.
33 *  The content of dst will be overwritten (up to *dstCapacityPtr) at each function call, so save its content if it matters or change dst .
34 *  @return : a hint to preferred nb of bytes to use as input for next function call (it's only a hint, to improve latency)
35 *            or an error code, which can be tested using ZBUFF_isError().
36 *
37 *  ZBUFF_compressFlush() can be used to instruct ZBUFF to compress and output whatever remains within its buffer.
38 *  Note that it will not output more than *dstCapacityPtr.
39 *  Therefore, some content might still be left into its internal buffer if dst buffer is too small.
40 *  @return : nb of bytes still present into internal buffer (0 if it's empty)
41 *            or an error code, which can be tested using ZBUFF_isError().
42 *
43 *  ZBUFF_compressEnd() instructs to finish a frame.
44 *  It will perform a flush and write frame epilogue.
45 *  Similar to ZBUFF_compressFlush(), it may not be able to output the entire internal buffer content if *dstCapacityPtr is too small.
46 *  @return : nb of bytes still present into internal buffer (0 if it's empty)
47 *            or an error code, which can be tested using ZBUFF_isError().
48 *
49 *  Hint : recommended buffer sizes (not compulsory)
50 *  input : ZSTD_BLOCKSIZE_MAX (128 KB), internal unit size, it improves latency to use this value.
51 *  output : ZSTD_compressBound(ZSTD_BLOCKSIZE_MAX) + ZSTD_blockHeaderSize + ZBUFF_endFrameSize : ensures it's always possible to write/flush/end a full block at best speed.
52 * ***********************************************************/
53 
54 ZBUFF_CCtx* ZBUFF_createCCtx(void)
55 {
56     return ZSTD_createCStream();
57 }
58 
59 ZBUFF_CCtx* ZBUFF_createCCtx_advanced(ZSTD_customMem customMem)
60 {
61     return ZSTD_createCStream_advanced(customMem);
62 }
63 
64 size_t ZBUFF_freeCCtx(ZBUFF_CCtx* zbc)
65 {
66     return ZSTD_freeCStream(zbc);
67 }
68 
69 
70 /* ======   Initialization   ====== */
71 
72 size_t ZBUFF_compressInit_advanced(ZBUFF_CCtx* zbc,
73                                    const void* dict, size_t dictSize,
74                                    ZSTD_parameters params, unsigned long long pledgedSrcSize)
75 {
76     if (pledgedSrcSize==0) pledgedSrcSize = ZSTD_CONTENTSIZE_UNKNOWN;  /* preserve "0 == unknown" behavior */
77     FORWARD_IF_ERROR(ZSTD_CCtx_reset(zbc, ZSTD_reset_session_only), "");
78     FORWARD_IF_ERROR(ZSTD_CCtx_setPledgedSrcSize(zbc, pledgedSrcSize), "");
79 
80     FORWARD_IF_ERROR(ZSTD_checkCParams(params.cParams), "");
81     FORWARD_IF_ERROR(ZSTD_CCtx_setParameter(zbc, ZSTD_c_windowLog, params.cParams.windowLog), "");
82     FORWARD_IF_ERROR(ZSTD_CCtx_setParameter(zbc, ZSTD_c_hashLog, params.cParams.hashLog), "");
83     FORWARD_IF_ERROR(ZSTD_CCtx_setParameter(zbc, ZSTD_c_chainLog, params.cParams.chainLog), "");
84     FORWARD_IF_ERROR(ZSTD_CCtx_setParameter(zbc, ZSTD_c_searchLog, params.cParams.searchLog), "");
85     FORWARD_IF_ERROR(ZSTD_CCtx_setParameter(zbc, ZSTD_c_minMatch, params.cParams.minMatch), "");
86     FORWARD_IF_ERROR(ZSTD_CCtx_setParameter(zbc, ZSTD_c_targetLength, params.cParams.targetLength), "");
87     FORWARD_IF_ERROR(ZSTD_CCtx_setParameter(zbc, ZSTD_c_strategy, params.cParams.strategy), "");
88 
89     FORWARD_IF_ERROR(ZSTD_CCtx_setParameter(zbc, ZSTD_c_contentSizeFlag, params.fParams.contentSizeFlag), "");
90     FORWARD_IF_ERROR(ZSTD_CCtx_setParameter(zbc, ZSTD_c_checksumFlag, params.fParams.checksumFlag), "");
91     FORWARD_IF_ERROR(ZSTD_CCtx_setParameter(zbc, ZSTD_c_dictIDFlag, params.fParams.noDictIDFlag), "");
92 
93     FORWARD_IF_ERROR(ZSTD_CCtx_loadDictionary(zbc, dict, dictSize), "");
94     return 0;
95 }
96 
97 size_t ZBUFF_compressInitDictionary(ZBUFF_CCtx* zbc, const void* dict, size_t dictSize, int compressionLevel)
98 {
99     FORWARD_IF_ERROR(ZSTD_CCtx_reset(zbc, ZSTD_reset_session_only), "");
100     FORWARD_IF_ERROR(ZSTD_CCtx_setParameter(zbc, ZSTD_c_compressionLevel, compressionLevel), "");
101     FORWARD_IF_ERROR(ZSTD_CCtx_loadDictionary(zbc, dict, dictSize), "");
102     return 0;
103 }
104 
105 size_t ZBUFF_compressInit(ZBUFF_CCtx* zbc, int compressionLevel)
106 {
107     return ZSTD_initCStream(zbc, compressionLevel);
108 }
109 
110 /* ======   Compression   ====== */
111 
112 
113 size_t ZBUFF_compressContinue(ZBUFF_CCtx* zbc,
114                               void* dst, size_t* dstCapacityPtr,
115                         const void* src, size_t* srcSizePtr)
116 {
117     size_t result;
118     ZSTD_outBuffer outBuff;
119     ZSTD_inBuffer inBuff;
120     outBuff.dst = dst;
121     outBuff.pos = 0;
122     outBuff.size = *dstCapacityPtr;
123     inBuff.src = src;
124     inBuff.pos = 0;
125     inBuff.size = *srcSizePtr;
126     result = ZSTD_compressStream(zbc, &outBuff, &inBuff);
127     *dstCapacityPtr = outBuff.pos;
128     *srcSizePtr = inBuff.pos;
129     return result;
130 }
131 
132 
133 
134 /* ======   Finalize   ====== */
135 
136 size_t ZBUFF_compressFlush(ZBUFF_CCtx* zbc, void* dst, size_t* dstCapacityPtr)
137 {
138     size_t result;
139     ZSTD_outBuffer outBuff;
140     outBuff.dst = dst;
141     outBuff.pos = 0;
142     outBuff.size = *dstCapacityPtr;
143     result = ZSTD_flushStream(zbc, &outBuff);
144     *dstCapacityPtr = outBuff.pos;
145     return result;
146 }
147 
148 
149 size_t ZBUFF_compressEnd(ZBUFF_CCtx* zbc, void* dst, size_t* dstCapacityPtr)
150 {
151     size_t result;
152     ZSTD_outBuffer outBuff;
153     outBuff.dst = dst;
154     outBuff.pos = 0;
155     outBuff.size = *dstCapacityPtr;
156     result = ZSTD_endStream(zbc, &outBuff);
157     *dstCapacityPtr = outBuff.pos;
158     return result;
159 }
160 
161 
162 
163 /* *************************************
164 *  Tool functions
165 ***************************************/
166 size_t ZBUFF_recommendedCInSize(void)  { return ZSTD_CStreamInSize(); }
167 size_t ZBUFF_recommendedCOutSize(void) { return ZSTD_CStreamOutSize(); }
168