zlib 0.71

compress.c

@@ -0,0 +1,55 @@
+/* compress.c -- compress a memory buffer
+ * Copyright (C) 1995 Jean-loup Gailly.
+ * For conditions of distribution and use, see copyright notice in zlib.h 
+ */
+
+/* $Id: compress.c,v 1.4 1995/04/10 15:52:04 jloup Exp $ */
+
+#include "zlib.h"
+
+/* ===========================================================================
+     Compresses the source buffer into the destination buffer.  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 8 bytes. Upon exit, destLen is the actual size of the
+   compressed buffer.
+     This function can be used to compress a whole file at once if the
+   input file is mmap'ed.
+     compress 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.
+*/
+int compress (dest, destLen, source, sourceLen)
+    Byte *dest;
+    uLong *destLen;
+    Byte *source;
+    uLong sourceLen;
+{
+    z_stream stream;
+    int err;
+
+    stream.next_in = source;
+    stream.avail_in = (uInt)sourceLen;
+    /* Check for source > 64K on 16-bit machine: */
+    if ((uLong)stream.avail_in != sourceLen) return Z_BUF_ERROR;
+
+    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;
+
+    err = deflateInit(&stream, Z_DEFAULT_COMPRESSION);
+    if (err != Z_OK) return err;
+
+    err = deflate(&stream, Z_FINISH);
+    if (err != Z_OK) {
+	deflateEnd(&stream);
+	return err;
+    }
+    *destLen = stream.total_out;
+
+    err = deflateEnd(&stream);
+    return err;
+}