patch-2.3.35 linux/fs/cramfs/uncompress.c

• Lines: 61
• Date: Tue Nov 23 14:43:51 1999
• Orig file: v2.3.34/linux/fs/cramfs/uncompress.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.34/linux/fs/cramfs/uncompress.c linux/fs/cramfs/uncompress.c
@@ -0,0 +1,60 @@
+/*
+ * uncompress.c
+ *
+ * (C) Copyright 1999 Linus Torvalds
+ *
+ * cramfs interfaces to the uncompression library. There's really just
+ * three entrypoints:
+ *
+ *  - cramfs_uncompress_init() - called to initialize the thing.
+ *  - cramfs_uncompress_exit() - tell me when you're done
+ *  - cramfs_uncompress_block() - uncompress a block.
+ *
+ * NOTE NOTE NOTE! The uncompression is entirely single-threaded. We
+ * only have one stream, and we'll initialize it only once even if it
+ * then is used by multiple filesystems.
+ */
+
+#include <linux/kernel.h>
+
+#include "inflate/zlib.h"
+
+static z_stream stream;
+static int initialized = 0;
+
+int cramfs_uncompress_block(void *dst, int dstlen, void *src, int srclen)
+{
+	int err;
+
+	stream.next_in = src;
+	stream.avail_in = srclen;
+
+	stream.next_out = dst;
+	stream.avail_out = dstlen;
+
+	inflateReset(&stream);
+
+	err = inflate(&stream, Z_FINISH);
+	if (err != Z_STREAM_END) {
+		printk("Error %d while decompressing!\n", err);
+		printk("%p(%d)->%p(%d)\n", src, srclen, dst, dstlen);
+	}
+	return stream.total_out;
+}
+
+int cramfs_uncompress_init(void)
+{
+	if (!initialized++) {
+		stream.next_in = NULL;
+		stream.avail_in = 0;
+		inflateInit(&stream);
+	}
+	return 0;
+}
+
+int cramfs_uncompress_exit(void)
+{
+	if (!--initialized)
+		inflateEnd(&stream);
+	return 0;
+}