Add #define ZLIB_CONST option to use const in the z_stream interface.

[zlib.git] / compress.c

diff --git a/compress.c b/compress.c
index 7be0b3de8753280c4fc6f4353637c19c8c973f50..ea4dfbe9d7b3ee2b7b380cc435973aca1976d4c0 100644 (file)
--- a/compress.c
+++ b/compress.c
@@ -1,29 +1,30 @@
 /* compress.c -- compress a memory buffer
- * Copyright (C) 1995-1998 Jean-loup Gailly.
- * For conditions of distribution and use, see copyright notice in zlib.h 
+ * Copyright (C) 1995-2005 Jean-loup Gailly.
+ * For conditions of distribution and use, see copyright notice in zlib.h
  */
 
 /* @(#) $Id$ */
 
+#define ZLIB_INTERNAL
 #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.
+     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 EXPORT compress (dest, destLen, source, sourceLen)
+int ZEXPORT compress2 (dest, destLen, source, sourceLen, level)
     Bytef *dest;
     uLongf *destLen;
     const Bytef *source;
     uLong sourceLen;
+    int level;
 {
     z_stream stream;
     int err;
@@ -42,7 +43,7 @@ int EXPORT compress (dest, destLen, source, sourceLen)
     stream.zfree = (free_func)0;
     stream.opaque = (voidpf)0;
 
-    err = deflateInit(&stream, Z_DEFAULT_COMPRESSION);
+    err = deflateInit(&stream, level);
     if (err != Z_OK) return err;
 
     err = deflate(&stream, Z_FINISH);
@@ -55,3 +56,25 @@ int EXPORT compress (dest, destLen, source, sourceLen)
     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) +
+           (sourceLen >> 25) + 13;
+}