X-Git-Url: https://git.lizzy.rs/?a=blobdiff_plain;f=compress.c;h=e2db404abf888bd2c85844985b5ae9784b955c63;hb=e9a52aa129efe3834383e415580716a7c4027f8d;hp=be9ef64c76c275db43352de5c3e98a2a08e48346;hpb=56bcb184fac036a45cb8937238d51778d0a796aa;p=zlib.git

diff --git a/compress.c b/compress.c
index be9ef64..e2db404 100644
--- a/compress.c
+++ b/compress.c
@@ -1,56 +1,86 @@
 /* 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 
+ * Copyright (C) 1995-2005, 2014, 2016 Jean-loup Gailly, Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
  */
 
-/* $Id: compress.c,v 1.6 1995/05/03 17:27:08 jloup Exp $ */
+/* @(#) $Id$ */
 
+#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 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;
+    const uInt max = (uInt)-1;
+    uLong left;
 
-    stream.next_in = (Bytef*)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;
+    left = *destLen;
+    *destLen = 0;
 
     stream.zalloc = (alloc_func)0;
     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);
-    if (err != Z_STREAM_END) {
-        deflateEnd(&stream);
-        return err == Z_OK ? Z_BUF_ERROR : err;
-    }
+    stream.next_out = dest;
+    stream.avail_out = 0;
+    stream.next_in = (z_const Bytef *)source;
+    stream.avail_in = 0;
+
+    do {
+        if (stream.avail_out == 0) {
+            stream.avail_out = left > (uLong)max ? max : (uInt)left;
+            left -= stream.avail_out;
+        }
+        if (stream.avail_in == 0) {
+            stream.avail_in = sourceLen > (uLong)max ? max : (uInt)sourceLen;
+            sourceLen -= stream.avail_in;
+        }
+        err = deflate(&stream, sourceLen ? Z_NO_FLUSH : Z_FINISH);
+    } while (err == Z_OK);
+
     *destLen = stream.total_out;
+    deflateEnd(&stream);
+    return err == Z_STREAM_END ? Z_OK : 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);
+}
 
-    err = deflateEnd(&stream);
-    return err;
+/* ===========================================================================
+     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;
 }