opencv

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/* compress.c -- compress a memory buffer
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 * Copyright (C) 1995-2005, 2014, 2016 Jean-loup Gailly, Mark Adler
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 * For conditions of distribution and use, see copyright notice in zlib.h
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 */
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#include "zbuild.h"
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#include "zutil.h"
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/* ===========================================================================
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 *  Architecture-specific hooks.
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 */
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#ifdef S390_DFLTCC_DEFLATE
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#  include "arch/s390/dfltcc_common.h"
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#else
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/* Returns the upper bound on compressed data length based on uncompressed data length, assuming default settings.
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 * Zero means that arch-specific deflation code behaves identically to the regular zlib-ng algorithms. */
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#  define DEFLATE_BOUND_COMPLEN(source_len) 0
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#endif
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/* ===========================================================================
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     Compresses the source buffer into the destination buffer. The level
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   parameter has the same meaning as in deflateInit.  sourceLen is the byte
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   length of the source buffer. Upon entry, destLen is the total size of the
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   destination buffer, which must be at least 0.1% larger than sourceLen plus
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   12 bytes. Upon exit, destLen is the actual size of the compressed buffer.
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     compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
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   memory, Z_BUF_ERROR if there was not enough room in the output buffer,
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   Z_STREAM_ERROR if the level parameter is invalid.
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*/
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int Z_EXPORT PREFIX(compress2)(unsigned char *dest, z_uintmax_t *destLen, const unsigned char *source,
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                        z_uintmax_t sourceLen, int level) {
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    PREFIX3(stream) stream;
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    int err;
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    const unsigned int max = (unsigned int)-1;
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    z_size_t left;
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    left = *destLen;
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    *destLen = 0;
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    stream.zalloc = NULL;
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    stream.zfree = NULL;
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    stream.opaque = NULL;
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    err = PREFIX(deflateInit)(&stream, level);
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    if (err != Z_OK)
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        return err;
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    stream.next_out = dest;
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    stream.avail_out = 0;
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    stream.next_in = (z_const unsigned char *)source;
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    stream.avail_in = 0;
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    do {
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        if (stream.avail_out == 0) {
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            stream.avail_out = left > (unsigned long)max ? max : (unsigned int)left;
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            left -= stream.avail_out;
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        }
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        if (stream.avail_in == 0) {
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            stream.avail_in = sourceLen > (unsigned long)max ? max : (unsigned int)sourceLen;
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            sourceLen -= stream.avail_in;
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        }
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        err = PREFIX(deflate)(&stream, sourceLen ? Z_NO_FLUSH : Z_FINISH);
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    } while (err == Z_OK);
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    *destLen = stream.total_out;
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    PREFIX(deflateEnd)(&stream);
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    return err == Z_STREAM_END ? Z_OK : err;
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}
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/* ===========================================================================
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 */
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int Z_EXPORT PREFIX(compress)(unsigned char *dest, z_uintmax_t *destLen, const unsigned char *source, z_uintmax_t sourceLen) {
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    return PREFIX(compress2)(dest, destLen, source, sourceLen, Z_DEFAULT_COMPRESSION);
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}
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/* ===========================================================================
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   If the default memLevel or windowBits for deflateInit() is changed, then
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   this function needs to be updated.
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 */
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z_uintmax_t Z_EXPORT PREFIX(compressBound)(z_uintmax_t sourceLen) {
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    z_uintmax_t complen = DEFLATE_BOUND_COMPLEN(sourceLen);
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    if (complen > 0)
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        /* Architecture-specific code provided an upper bound. */
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        return complen + ZLIB_WRAPLEN;
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#ifndef NO_QUICK_STRATEGY
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    return sourceLen                       /* The source size itself */
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      + (sourceLen == 0 ? 1 : 0)           /* Always at least one byte for any input */
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      + (sourceLen < 9 ? 1 : 0)            /* One extra byte for lengths less than 9 */
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      + DEFLATE_QUICK_OVERHEAD(sourceLen)  /* Source encoding overhead, padded to next full byte */
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      + DEFLATE_BLOCK_OVERHEAD             /* Deflate block overhead bytes */
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      + ZLIB_WRAPLEN;                      /* zlib wrapper */
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#else
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    return sourceLen + (sourceLen >> 4) + 7 + ZLIB_WRAPLEN;
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#endif
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}
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