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-rw-r--r--lib/libz/compress.c79
1 files changed, 79 insertions, 0 deletions
diff --git a/lib/libz/compress.c b/lib/libz/compress.c
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+/* $OpenBSD: compress.c,v 1.6 2005/07/20 15:56:41 millert Exp $ */
+/* compress.c -- compress a memory buffer
+ * Copyright (C) 1995-2003 Jean-loup Gailly.
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+
+#define ZLIB_INTERNAL
+#include "zlib.h"
+
+/* ===========================================================================
+ Compresses the source buffer into the destination buffer. The level
+ parameter has the same meaning as in deflateInit. sourceLen is the byte
+ length of the source buffer. Upon entry, destLen is the total size of the
+ destination buffer, which must be at least 0.1% larger than sourceLen plus
+ 12 bytes. Upon exit, destLen is the actual size of the compressed buffer.
+
+ compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
+ memory, Z_BUF_ERROR if there was not enough room in the output buffer,
+ Z_STREAM_ERROR if the level parameter is invalid.
+*/
+int ZEXPORT compress2 (dest, destLen, source, sourceLen, level)
+ Bytef *dest;
+ uLongf *destLen;
+ const Bytef *source;
+ uLong sourceLen;
+ int level;
+{
+ z_stream stream;
+ int err;
+
+ stream.next_in = (Bytef*)source;
+ stream.avail_in = (uInt)sourceLen;
+#ifdef MAXSEG_64K
+ /* Check for source > 64K on 16-bit machine: */
+ if ((uLong)stream.avail_in != sourceLen) return Z_BUF_ERROR;
+#endif
+ stream.next_out = dest;
+ stream.avail_out = (uInt)*destLen;
+ if ((uLong)stream.avail_out != *destLen) return Z_BUF_ERROR;
+
+ stream.zalloc = (alloc_func)0;
+ stream.zfree = (free_func)0;
+ stream.opaque = (voidpf)0;
+
+ err = deflateInit(&stream, level);
+ if (err != Z_OK) return err;
+
+ err = deflate(&stream, Z_FINISH);
+ if (err != Z_STREAM_END) {
+ deflateEnd(&stream);
+ return err == Z_OK ? Z_BUF_ERROR : err;
+ }
+ *destLen = stream.total_out;
+
+ err = deflateEnd(&stream);
+ return err;
+}
+
+/* ===========================================================================
+ */
+int ZEXPORT compress (dest, destLen, source, sourceLen)
+ Bytef *dest;
+ uLongf *destLen;
+ const Bytef *source;
+ uLong sourceLen;
+{
+ return compress2(dest, destLen, source, sourceLen, Z_DEFAULT_COMPRESSION);
+}
+
+/* ===========================================================================
+ If the default memLevel or windowBits for deflateInit() is changed, then
+ this function needs to be updated.
+ */
+uLong ZEXPORT compressBound (sourceLen)
+ uLong sourceLen;
+{
+ return sourceLen + (sourceLen >> 12) + (sourceLen >> 14) + 11;
+}