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/* uncompr.c -- decompress a memory buffer |
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* Copyright (C) 1995-2026 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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/* @(#) $Id$ */ |
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#define ZLIB_INTERNAL |
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#include "zlib.h" |
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/* =========================================================================== |
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Decompresses the source buffer into the destination buffer. *sourceLen is |
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the byte length of the source buffer. Upon entry, *destLen is the total size |
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of the destination buffer, which must be large enough to hold the entire |
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uncompressed data. (The size of the uncompressed data must have been saved |
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previously by the compressor and transmitted to the decompressor by some |
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mechanism outside the scope of this compression library.) Upon exit, |
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*destLen is the size of the decompressed data and *sourceLen is the number |
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of source bytes consumed. Upon return, source + *sourceLen points to the |
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first unused input byte. |
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uncompress 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, or |
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Z_DATA_ERROR if the input data was corrupted, including if the input data is |
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an incomplete zlib stream. |
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The _z versions of the functions take size_t length arguments. |
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*/ |
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int ZEXPORT uncompress2_z(Bytef *dest, z_size_t *destLen, const Bytef *source, |
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z_size_t *sourceLen) { |
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z_stream stream; |
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int err; |
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const uInt max = (uInt)-1; |
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z_size_t len, left; |
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if (sourceLen == NULL || (*sourceLen > 0 && source == NULL) || |
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destLen == NULL || (*destLen > 0 && dest == NULL)) |
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return Z_STREAM_ERROR; |
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len = *sourceLen; |
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left = *destLen; |
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if (left == 0 && dest == Z_NULL) |
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dest = (Bytef *)&stream.reserved; /* next_out cannot be NULL */ |
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stream.next_in = (z_const Bytef *)source; |
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stream.avail_in = 0; |
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stream.zalloc = (alloc_func)0; |
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stream.zfree = (free_func)0; |
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stream.opaque = (voidpf)0; |
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err = inflateInit(&stream); |
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if (err != Z_OK) return err; |
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stream.next_out = dest; |
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stream.avail_out = 0; |
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do { |
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if (stream.avail_out == 0) { |
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stream.avail_out = left > (z_size_t)max ? max : (uInt)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 = len > (z_size_t)max ? max : (uInt)len; |
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len -= stream.avail_in; |
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} |
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err = inflate(&stream, Z_NO_FLUSH); |
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} while (err == Z_OK); |
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/* Set len and left to the unused input data and unused output space. Set |
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*sourceLen to the amount of input consumed. Set *destLen to the amount |
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of data produced. */ |
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len += stream.avail_in; |
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left += stream.avail_out; |
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*sourceLen -= len; |
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*destLen -= left; |
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inflateEnd(&stream); |
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return err == Z_STREAM_END ? Z_OK : |
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err == Z_NEED_DICT ? Z_DATA_ERROR : |
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err == Z_BUF_ERROR && len == 0 ? Z_DATA_ERROR : |
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err; |
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} |
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int ZEXPORT uncompress2(Bytef *dest, uLongf *destLen, const Bytef *source, |
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uLong *sourceLen) { |
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int ret; |
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z_size_t got = *destLen, used = *sourceLen; |
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ret = uncompress2_z(dest, &got, source, &used); |
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*sourceLen = (uLong)used; |
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*destLen = (uLong)got; |
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return ret; |
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} |
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int ZEXPORT uncompress_z(Bytef *dest, z_size_t *destLen, const Bytef *source, |
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z_size_t sourceLen) { |
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z_size_t used = sourceLen; |
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return uncompress2_z(dest, destLen, source, &used); |
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} |
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int ZEXPORT uncompress(Bytef *dest, uLongf *destLen, const Bytef *source, |
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uLong sourceLen) { |
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uLong used = sourceLen; |
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return uncompress2(dest, destLen, source, &used); |
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} |
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