Initial stab at Venti.

1 files changed, 40 insertions, 0 deletions

diff --git a/src/cmd/venti/whack.h b/src/cmd/venti/whack.h
new file mode 100644
index 00000000..fb966169
--- /dev/null
+++ b/src/cmd/venti/whack.h
@@ -0,0 +1,40 @@
+typedef struct Whack		Whack;
+typedef struct Unwhack		Unwhack;
+
+enum
+{
+	WhackStats	= 8,
+	WhackErrLen	= 64,		/* max length of error message from thwack or unthwack */
+	WhackMaxOff	= 16*1024,	/* max allowed offset */
+
+	HashLog		= 14,
+	HashSize	= 1<<HashLog,
+	HashMask	= HashSize - 1,
+
+	MinMatch	= 3,		/* shortest match possible */
+
+	MinDecode	= 8,		/* minimum bits to decode a match or lit; >= 8 */
+
+	MaxSeqMask	= 8,		/* number of bits in coding block mask */
+	MaxSeqStart	= 256		/* max offset of initial coding block */
+};
+
+struct Whack
+{
+	ushort		begin;			/* time of first byte in hash */
+	ushort		hash[HashSize];
+	ushort		next[WhackMaxOff];
+	uchar		*data;
+};
+
+struct Unwhack
+{
+	char		err[WhackErrLen];
+};
+
+void	whackinit(Whack*, int level);
+void	unwhackinit(Unwhack*);
+int	whack(Whack*, uchar *dst, uchar *src, int nsrc, ulong stats[WhackStats]);
+int	unwhack(Unwhack*, uchar *dst, int ndst, uchar *src, int nsrc);
+
+int	whackblock(uchar *dst, uchar *src, int ssize);