summaryrefslogtreecommitdiffstats
path: root/src/zstd/examples/streaming_memory_usage.c
blob: 37dd660e4a64efcb8329680297acbcdf66baaa63 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
/*
 * Copyright (c) 2017-2020, Yann Collet, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under both the BSD-style license (found in the
 * LICENSE file in the root directory of this source tree) and the GPLv2 (found
 * in the COPYING file in the root directory of this source tree).
 * You may select, at your option, one of the above-listed licenses.
 */


/*===   Tuning parameter   ===*/
#ifndef MAX_TESTED_LEVEL
#define MAX_TESTED_LEVEL 12
#endif


/*===   Dependencies   ===*/
#include <stdio.h>     // printf
#define ZSTD_STATIC_LINKING_ONLY
#include <zstd.h>      // presumes zstd library is installed
#include "common.h"    // Helper functions, CHECK(), and CHECK_ZSTD()


/*===   functions   ===*/

/*! readU32FromChar() :
    @return : unsigned integer value read from input in `char` format
    allows and interprets K, KB, KiB, M, MB and MiB suffix.
    Will also modify `*stringPtr`, advancing it to position where it stopped reading.
    Note : function result can overflow if digit string > MAX_UINT */
static unsigned readU32FromChar(const char** stringPtr)
{
    unsigned result = 0;
    while ((**stringPtr >='0') && (**stringPtr <='9'))
        result *= 10, result += **stringPtr - '0', (*stringPtr)++ ;
    if ((**stringPtr=='K') || (**stringPtr=='M')) {
        result <<= 10;
        if (**stringPtr=='M') result <<= 10;
        (*stringPtr)++ ;
        if (**stringPtr=='i') (*stringPtr)++;
        if (**stringPtr=='B') (*stringPtr)++;
    }
    return result;
}


int main(int argc, char const *argv[]) {

    printf("\n Zstandard (v%s) memory usage for streaming : \n\n", ZSTD_versionString());

    unsigned wLog = 0;
    if (argc > 1) {
        const char* valStr = argv[1];
        wLog = readU32FromChar(&valStr);
    }

    int compressionLevel;
    for (compressionLevel = 1; compressionLevel <= MAX_TESTED_LEVEL; compressionLevel++) {
#define INPUT_SIZE 5
#define COMPRESSED_SIZE 128
        char const dataToCompress[INPUT_SIZE] = "abcde";
        char compressedData[COMPRESSED_SIZE];
        char decompressedData[INPUT_SIZE];
        /* the ZSTD_CCtx_params structure is a way to save parameters and use
         * them across multiple contexts. We use them here so we can call the
         * function ZSTD_estimateCStreamSize_usingCCtxParams().
         */
        ZSTD_CCtx_params* const cctxParams = ZSTD_createCCtxParams();
        CHECK(cctxParams != NULL, "ZSTD_createCCtxParams() failed!");

        /* Set the compression level. */
        CHECK_ZSTD( ZSTD_CCtxParams_setParameter(cctxParams, ZSTD_c_compressionLevel, compressionLevel) );
        /* Set the window log.
         * The value 0 means use the default window log, which is equivalent to
         * not setting it.
         */
        CHECK_ZSTD( ZSTD_CCtxParams_setParameter(cctxParams, ZSTD_c_windowLog, wLog) );

        /* Force the compressor to allocate the maximum memory size for a given
         * level by not providing the pledged source size, or calling
         * ZSTD_compressStream2() with ZSTD_e_end.
         */
        ZSTD_CCtx* const cctx = ZSTD_createCCtx();
        CHECK(cctx != NULL, "ZSTD_createCCtx() failed!");
        CHECK_ZSTD( ZSTD_CCtx_setParametersUsingCCtxParams(cctx, cctxParams) );
        size_t compressedSize;
        {
            ZSTD_inBuffer inBuff = { dataToCompress, sizeof(dataToCompress), 0 };
            ZSTD_outBuffer outBuff = { compressedData, sizeof(compressedData), 0 };
            CHECK_ZSTD( ZSTD_compressStream(cctx, &outBuff, &inBuff) );
            size_t const remaining = ZSTD_endStream(cctx, &outBuff);
            CHECK_ZSTD(remaining);
            CHECK(remaining == 0, "Frame not flushed!");
            compressedSize = outBuff.pos;
        }

        ZSTD_DCtx* const dctx = ZSTD_createDCtx();
        CHECK(dctx != NULL, "ZSTD_createDCtx() failed!");
        /* Set the maximum allowed window log.
         * The value 0 means use the default window log, which is equivalent to
         * not setting it.
         */
        CHECK_ZSTD( ZSTD_DCtx_setParameter(dctx, ZSTD_d_windowLogMax, wLog) );
        /* forces decompressor to use maximum memory size, since the
         * decompressed size is not stored in the frame header.
         */
        {   ZSTD_inBuffer inBuff = { compressedData, compressedSize, 0 };
            ZSTD_outBuffer outBuff = { decompressedData, sizeof(decompressedData), 0 };
            size_t const remaining = ZSTD_decompressStream(dctx, &outBuff, &inBuff);
            CHECK_ZSTD(remaining);
            CHECK(remaining == 0, "Frame not complete!");
            CHECK(outBuff.pos == sizeof(dataToCompress), "Bad decompression!");
        }

        size_t const cstreamSize = ZSTD_sizeof_CStream(cctx);
        size_t const cstreamEstimatedSize = ZSTD_estimateCStreamSize_usingCCtxParams(cctxParams);
        size_t const dstreamSize = ZSTD_sizeof_DStream(dctx);
        size_t const dstreamEstimatedSize = ZSTD_estimateDStreamSize_fromFrame(compressedData, compressedSize);

        CHECK(cstreamSize <= cstreamEstimatedSize, "Compression mem (%u) > estimated (%u)",
                (unsigned)cstreamSize, (unsigned)cstreamEstimatedSize);
        CHECK(dstreamSize <= dstreamEstimatedSize, "Decompression mem (%u) > estimated (%u)",
                (unsigned)dstreamSize, (unsigned)dstreamEstimatedSize);

        printf("Level %2i : Compression Mem = %5u KB (estimated : %5u KB) ; Decompression Mem = %4u KB (estimated : %5u KB)\n",
                compressionLevel,
                (unsigned)(cstreamSize>>10), (unsigned)(cstreamEstimatedSize>>10),
                (unsigned)(dstreamSize>>10), (unsigned)(dstreamEstimatedSize>>10));

        ZSTD_freeDCtx(dctx);
        ZSTD_freeCCtx(cctx);
        ZSTD_freeCCtxParams(cctxParams);
        if (wLog) break;  /* single test */
    }
    return 0;
}