*** empty log message ***

os/frisbee/imagehdr.h

+
+#include <sys/types.h>
+
+/*
+ * Magic number when image is compressed
+ */
+#define COMPRESSED_MAGIC	0x69696969
+
+/*
+ * Each compressed block of the file has this little header on it.
+ * Since each subblock is independently compressed, we need to know
+ * its internal size (it will probably be shorter than 1MB) since we
+ * have to know exactly how much to give the inflator.
+ */
+struct blockhdr {
+	int		magic;
+	unsigned long   size;		/* Size of compressed part */
+	int		blockindex;
+	int		blocktotal;
+	int		regionsize;
+	int		regioncount;
+};
+
+/*
+ * This little struct defines the pair. Each number is in sectors. An array
+ * of these come after the header above, and is padded to a 1K boundry.
+ * The region says where to write the next part of the input file, which is
+ * how we skip over parts of the disk that do not need to be written
+ * (swap, free FS blocks).
+ */
+struct region {
+	unsigned long	start;
+	unsigned long	size;
+};
+
+/*
+ * In the new model, each sub region has its own region header info.
+ * But there is no easy way to tell how many regions before compressing.
+ * Just leave a page, and hope that 512 regions is enough!
+ *
+ * This number must be a multiple of the NFS read size in netdisk.
+ */
+#define DEFAULTREGIONSIZE	(1024 * 4)
+
+/*
+ * Ah, the frisbee protocol. The new world order is to break up the
+ * file into fixed 1MB chunks, with the region info prepended to each
+ * chunk so that it can be layed down on disk independently of all the
+ * chunks in the file. 
+ */
+#define SUBBLOCKSIZE		(1024 * 1024)
+#define SUBBLOCKMAX		(SUBBLOCKSIZE - DEFAULTREGIONSIZE)