summaryrefslogtreecommitdiffstats
path: root/zlib/compress.c
diff options
context:
space:
mode:
Diffstat (limited to 'zlib/compress.c')
-rw-r--r--zlib/compress.c57
1 files changed, 57 insertions, 0 deletions
diff --git a/zlib/compress.c b/zlib/compress.c
new file mode 100644
index 000000000..a4b393306
--- /dev/null
+++ b/zlib/compress.c
@@ -0,0 +1,57 @@
+/* compress.c -- compress a memory buffer
+ * Copyright (C) 1995-1996 Jean-loup Gailly.
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/* $Id$ */
+
+#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)
+ Bytef *dest;
+ uLongf *destLen;
+ const Bytef *source;
+ uLong sourceLen;
+{
+ 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, Z_DEFAULT_COMPRESSION);
+ 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;
+}