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55 lines
1.7 KiB
55 lines
1.7 KiB
/* compress.c -- compress a memory buffer |
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* Copyright (C) 1995 Jean-loup Gailly. |
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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: compress.c,v 1.5 1995/04/29 17:18:43 jloup Exp $ */ |
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#include "zlib.h" |
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/* =========================================================================== |
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Compresses 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 |
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size of the destination buffer, which must be at least 0.1% larger than |
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sourceLen plus 8 bytes. Upon exit, destLen is the actual size of the |
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compressed buffer. |
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This function can be used to compress a whole file at once if the |
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input file is mmap'ed. |
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compress returns Z_OK if success, Z_MEM_ERROR if there was not |
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enough memory, Z_BUF_ERROR if there was not enough room in the output |
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buffer. |
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*/ |
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int compress (dest, destLen, source, sourceLen) |
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Byte *dest; |
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uLong *destLen; |
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Byte *source; |
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uLong sourceLen; |
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{ |
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z_stream stream; |
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int err; |
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stream.next_in = source; |
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stream.avail_in = (uInt)sourceLen; |
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/* Check for source > 64K on 16-bit machine: */ |
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if ((uLong)stream.avail_in != sourceLen) return Z_BUF_ERROR; |
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stream.next_out = dest; |
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stream.avail_out = (uInt)*destLen; |
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if ((uLong)stream.avail_out != *destLen) return Z_BUF_ERROR; |
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stream.zalloc = (alloc_func)0; |
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stream.zfree = (free_func)0; |
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err = deflateInit(&stream, Z_DEFAULT_COMPRESSION); |
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if (err != Z_OK) return err; |
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err = deflate(&stream, Z_FINISH); |
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if (err != Z_STREAM_END) { |
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deflateEnd(&stream); |
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return err == Z_OK ? Z_BUF_ERROR : err; |
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} |
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*destLen = stream.total_out; |
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err = deflateEnd(&stream); |
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return err; |
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}
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