Initial commit

1 files changed, 148 insertions, 0 deletions

diff --git a/compr_zlib.c b/compr_zlib.c
new file mode 100644
index 0000000..167946e
--- /dev/null
+++ b/compr_zlib.c
@@ -0,0 +1,148 @@
+/*
+ * JFFS2 -- Journalling Flash File System, Version 2.
+ *
+ * Copyright (C) 2001 Red Hat, Inc.
+ *
+ * Created by David Woodhouse <dwmw2@cambridge.redhat.com>
+ *
+ * The original JFFS, from which the design for JFFS2 was derived,
+ * was designed and implemented by Axis Communications AB.
+ *
+ * The contents of this file are subject to the Red Hat eCos Public
+ * License Version 1.1 (the "Licence"); you may not use this file
+ * except in compliance with the Licence.  You may obtain a copy of
+ * the Licence at http://www.redhat.com/
+ *
+ * Software distributed under the Licence is distributed on an "AS IS"
+ * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied.
+ * See the Licence for the specific language governing rights and
+ * limitations under the Licence.
+ *
+ * The Original Code is JFFS2 - Journalling Flash File System, version 2
+ *
+ * Alternatively, the contents of this file may be used under the
+ * terms of the GNU General Public License version 2 (the "GPL"), in
+ * which case the provisions of the GPL are applicable instead of the
+ * above.  If you wish to allow the use of your version of this file
+ * only under the terms of the GPL and not to allow others to use your
+ * version of this file under the RHEPL, indicate your decision by
+ * deleting the provisions above and replace them with the notice and
+ * other provisions required by the GPL.  If you do not delete the
+ * provisions above, a recipient may use your version of this file
+ * under either the RHEPL or the GPL.
+ *
+ * $Id: compr_zlib.c,v 1.4 2005/11/07 11:15:09 gleixner Exp $
+ *
+ */
+
+#include <stdint.h>
+#include <zlib.h>
+#include <stdio.h>
+#include <asm/types.h>
+#include <linux/jffs2.h>
+#include "compr.h"
+
+#define min(x,y) ((x)<(y)?(x):(y))
+
+	/* Plan: call deflate() with avail_in == *sourcelen,
+		avail_out = *dstlen - 12 and flush == Z_FINISH.
+		If it doesn't manage to finish,	call it again with
+		avail_in == 0 and avail_out set to the remaining 12
+		bytes for it to clean up.
+	   Q: Is 12 bytes sufficient?
+	*/
+#define STREAM_END_SPACE 12
+
+int jffs2_zlib_compress(unsigned char *data_in, unsigned char *cpage_out,
+		   uint32_t *sourcelen, uint32_t *dstlen, void *model)
+{
+	z_stream strm;
+	int ret;
+
+	if (*dstlen <= STREAM_END_SPACE)
+		return -1;
+
+	strm.zalloc = (void *)0;
+	strm.zfree = (void *)0;
+
+	if (Z_OK != deflateInit(&strm, 3)) {
+		return -1;
+	}
+	strm.next_in = data_in;
+	strm.total_in = 0;
+
+	strm.next_out = cpage_out;
+	strm.total_out = 0;
+
+	while (strm.total_out < *dstlen - STREAM_END_SPACE && strm.total_in < *sourcelen) {
+		strm.avail_out = *dstlen - (strm.total_out + STREAM_END_SPACE);
+		strm.avail_in = min((unsigned)(*sourcelen-strm.total_in), strm.avail_out);
+		ret = deflate(&strm, Z_PARTIAL_FLUSH);
+		if (ret != Z_OK) {
+			deflateEnd(&strm);
+			return -1;
+		}
+	}
+	strm.avail_out += STREAM_END_SPACE;
+	strm.avail_in = 0;
+	ret = deflate(&strm, Z_FINISH);
+	if (ret != Z_STREAM_END) {
+		deflateEnd(&strm);
+		return -1;
+	}
+	deflateEnd(&strm);
+
+	if (strm.total_out >= strm.total_in)
+		return -1;
+
+
+	*dstlen = strm.total_out;
+	*sourcelen = strm.total_in;
+	return 0;
+}
+
+int jffs2_zlib_decompress(unsigned char *data_in, unsigned char *cpage_out,
+		      uint32_t srclen, uint32_t destlen, void *model)
+{
+	z_stream strm;
+	int ret;
+
+	strm.zalloc = (void *)0;
+	strm.zfree = (void *)0;
+
+	if (Z_OK != inflateInit(&strm)) {
+		return 1;
+	}
+	strm.next_in = data_in;
+	strm.avail_in = srclen;
+	strm.total_in = 0;
+
+	strm.next_out = cpage_out;
+	strm.avail_out = destlen;
+	strm.total_out = 0;
+
+	while((ret = inflate(&strm, Z_FINISH)) == Z_OK)
+		;
+
+	inflateEnd(&strm);
+        return 0;
+}
+
+static struct jffs2_compressor jffs2_zlib_comp = {
+    .priority = JFFS2_ZLIB_PRIORITY,
+    .name = "zlib",
+    .disabled = 0,
+    .compr = JFFS2_COMPR_ZLIB,
+    .compress = &jffs2_zlib_compress,
+    .decompress = &jffs2_zlib_decompress,
+};
+
+int jffs2_zlib_init(void)
+{
+    return jffs2_register_compressor(&jffs2_zlib_comp);
+}
+
+void jffs2_zlib_exit(void)
+{
+    jffs2_unregister_compressor(&jffs2_zlib_comp);
+}