moved dht_hashfn_tea() to libglusterfs/hashfn.c as gf_dm_hashfn() (dm - davies-meyer).

moved dht_hashfn_tea() to libglusterfs/src/hashfn.c as gf_dm_hashfn().

Signed-off-by: Anand V. Avati <avati@amp.gluster.com>

5 files changed, 110 insertions, 148 deletions

diff --git a/libglusterfs/src/hashfn.c b/libglusterfs/src/hashfn.c
index 810cc92495e..9ef8955a87d 100644
--- a/libglusterfs/src/hashfn.c
+++ b/libglusterfs/src/hashfn.c
@@ -29,6 +29,10 @@
 
 #define get16bits(d) (*((const uint16_t *) (d)))
 
+#define DM_DELTA 0x9E3779B9
+#define DM_FULLROUNDS 10        /* 32 is overkill, 16 is strong crypto */
+#define DM_PARTROUNDS 6	        /* 6 gets complete mixing */
+
 /*
   This is apparently the "fastest hash function for strings".
   Written by Paul Hsieh <http://www.azillionmonkeys.com/qed/hash.html>
@@ -87,3 +91,102 @@ uint32_t SuperFastHash (const char * data, int32_t len) {
 
   return hash;
 }
+
+
+/* Davies-Meyer hashing function implementation
+ */
+static int
+dm_round (int rounds, uint32_t *array, uint32_t *h0, uint32_t *h1)
+{
+	uint32_t sum = 0;
+	int      n = 0;
+	uint32_t b0  = 0;
+	uint32_t b1  = 0;
+
+	b0 = *h0;
+	b1 = *h1;
+
+	n = rounds;
+
+	do {
+		sum += DM_DELTA;
+		b0  += ((b1 << 4) + array[0])
+			^ (b1 + sum)
+			^ ((b1 >> 5) + array[1]);
+		b1  += ((b0 << 4) + array[2])
+			^ (b0 + sum)
+			^ ((b0 >> 5) + array[3]);
+	} while (--n);
+
+	*h0 += b0;
+	*h1 += b1;
+
+	return 0;
+}
+
+
+uint32_t
+__pad (int len)
+{
+	uint32_t pad = 0;
+
+	pad = (uint32_t) len | ((uint32_t) len << 8);
+	pad |= pad << 16;
+
+	return pad;
+}
+
+uint32_t
+gf_dm_hashfn (const char *msg, int len)
+{
+	uint32_t  h0 = 0x9464a485;
+	uint32_t  h1 = 0x542e1a94;
+	uint32_t  array[4];
+	uint32_t  pad = 0;
+	int       i = 0;
+	int       j = 0;
+	int       full_quads = 0;
+	int       full_words = 0;
+	int       full_bytes = 0;
+	uint32_t *intmsg = NULL;
+	int       word = 0;
+
+
+	intmsg = (uint32_t *) msg;
+	pad = __pad (len);
+
+	full_bytes   = len;
+	full_words   = len / 4;
+	full_quads   = len / 16;
+
+	for (i = 0; i < full_quads; i++) {
+		for (j = 0; j < 4; j++) {
+			word     = *intmsg;
+			array[j] = word;
+			intmsg++;
+			full_words--;
+			full_bytes -= 4;
+		}
+		dm_round (DM_PARTROUNDS, &array[0], &h0, &h1);
+	}
+
+	for (j = 0; j < 4; j++) {
+		if (full_words) {
+			word     = *intmsg;
+			array[j] = word;
+			intmsg++;
+			full_words--;
+			full_bytes -= 4;
+		} else {
+			array[j] = pad;
+			while (full_bytes) {
+				array[j] <<= 8;
+				array[j] |= msg[len - full_bytes];
+				full_bytes--;
+			}
+		}
+	}
+	dm_round (DM_FULLROUNDS, &array[0], &h0, &h1);
+
+	return h0 ^ h1;
+}
diff --git a/libglusterfs/src/hashfn.h b/libglusterfs/src/hashfn.h
index 1eea181f2a4..92481126d2d 100644
--- a/libglusterfs/src/hashfn.h
+++ b/libglusterfs/src/hashfn.h
@@ -30,4 +30,6 @@
 
 uint32_t SuperFastHash (const char * data, int32_t len);
 
+uint32_t gf_dm_hashfn (const char *msg, int len);
+
 #endif /* __HASHFN_H__ */
diff --git a/xlators/cluster/dht/src/Makefile.am b/xlators/cluster/dht/src/Makefile.am
index b7d07d137a6..d4e0752a585 100644
--- a/xlators/cluster/dht/src/Makefile.am
+++ b/xlators/cluster/dht/src/Makefile.am
@@ -4,7 +4,7 @@ xlatordir = $(libdir)/glusterfs/$(PACKAGE_VERSION)/xlator/cluster
 
 
 dht_common_source = dht-layout.c dht-helper.c dht-linkfile.c \
-		dht-selfheal.c dht-rename.c dht-hashfn.c dht-hashfn-tea.c
+		dht-selfheal.c dht-rename.c dht-hashfn.c
 
 dht_la_SOURCES = $(dht_common_source) dht.c 
 
diff --git a/xlators/cluster/dht/src/dht-hashfn-tea.c b/xlators/cluster/dht/src/dht-hashfn-tea.c
deleted file mode 100644
index 3eca35dd4ad..00000000000
--- a/xlators/cluster/dht/src/dht-hashfn-tea.c
+++ /dev/null
@@ -1,141 +0,0 @@
-/*
-   Copyright (c) 2008-2009 Z RESEARCH, Inc. <http://www.zresearch.com>
-   This file is part of GlusterFS.
-
-   GlusterFS is free software; you can redistribute it and/or modify
-   it under the terms of the GNU General Public License as published
-   by the Free Software Foundation; either version 3 of the License,
-   or (at your option) any later version.
-
-   GlusterFS is distributed in the hope that it will be useful, but
-   WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-   General Public License for more details.
-
-   You should have received a copy of the GNU General Public License
-   along with this program.  If not, see
-   <http://www.gnu.org/licenses/>.
-*/
-
-
-#include <stdint.h>
-#include <stdio.h>
-#include <string.h>
-
-
-#define DELTA 0x9E3779B9
-#define FULLROUNDS 10		/* 32 is overkill, 16 is strong crypto */
-#define PARTROUNDS 6		/* 6 gets complete mixing */
-
-
-static int
-tearound (int rounds, uint32_t *array, uint32_t *h0, uint32_t *h1)
-{
-	uint32_t sum = 0;
-	int      n = 0;
-	uint32_t b0  = 0;
-	uint32_t b1  = 0;
-
-	b0 = *h0;
-	b1 = *h1;
-
-	n = rounds;
-
-	do {
-		sum += DELTA;
-		b0  += ((b1 << 4) + array[0])
-			^ (b1 + sum)
-			^ ((b1 >> 5) + array[1]);
-		b1  += ((b0 << 4) + array[2])
-			^ (b0 + sum)
-			^ ((b0 >> 5) + array[3]);
-	} while (--n);
-
-	*h0 += b0;
-	*h1 += b1;
-
-	return 0;
-}
-
-
-uint32_t
-__pad (int len)
-{
-	uint32_t pad = 0;
-
-	pad = (uint32_t) len | ((uint32_t) len << 8);
-	pad |= pad << 16;
-
-	return pad;
-}
-
-
-uint32_t
-dht_hashfn_tea (const char *msg, int len)
-{
-	uint32_t  h0 = 0x9464a485;
-	uint32_t  h1 = 0x542e1a94;
-	uint32_t  array[4];
-	uint32_t  pad = 0;
-	int       i = 0;
-	int       j = 0;
-	int       full_quads = 0;
-	int       full_words = 0;
-	int       full_bytes = 0;
-	uint32_t *intmsg = NULL;
-	int       word = 0;
-
-
-	intmsg = (uint32_t *) msg;
-	pad = __pad (len);
-
-	full_bytes   = len;
-	full_words   = len / 4;
-	full_quads   = len / 16;
-
-	for (i = 0; i < full_quads; i++) {
-		for (j = 0; j < 4; j++) {
-			word     = *intmsg;
-			array[j] = word;
-			intmsg++;
-			full_words--;
-			full_bytes -= 4;
-		}
-		tearound (PARTROUNDS, &array[0], &h0, &h1);
-	}
-
-	for (j = 0; j < 4; j++) {
-		if (full_words) {
-			word     = *intmsg;
-			array[j] = word;
-			intmsg++;
-			full_words--;
-			full_bytes -= 4;
-		} else {
-			array[j] = pad;
-			while (full_bytes) {
-				array[j] <<= 8;
-				array[j] |= msg[len - full_bytes];
-				full_bytes--;
-			}
-		}
-	}
-	tearound (FULLROUNDS, &array[0], &h0, &h1);
-
-	return h0 ^ h1;
-}
-
-
-#if 0
-int
-main (int argc, char *argv[])
-{
-	int i = 0;
-	int hashval = 0;
-
-	for (i = 1; i < argc; i++) {
-		hashval = tea (argv[i], strlen (argv[i]));
-		printf ("%s: %x\n", argv[i], hashval);
-	}
-}
-#endif
diff --git a/xlators/cluster/dht/src/dht-hashfn.c b/xlators/cluster/dht/src/dht-hashfn.c
index ee89eb61afd..31cb828a483 100644
--- a/xlators/cluster/dht/src/dht-hashfn.c
+++ b/xlators/cluster/dht/src/dht-hashfn.c
@@ -26,13 +26,11 @@
 #include "glusterfs.h"
 #include "xlator.h"
 #include "dht-common.h"
-
-
-uint32_t dht_hashfn_tea (const char *name, int len);
+#include "hashfn.h"
 
 
 typedef enum {
-	DHT_HASH_TYPE_TEA,
+	DHT_HASH_TYPE_DM,
 } dht_hashfn_type_t;
 
 
@@ -43,8 +41,8 @@ dht_hash_compute_internal (int type, const char *name, uint32_t *hash_p)
 	uint32_t hash = 0;
 
 	switch (type) {
-	case DHT_HASH_TYPE_TEA:
-		hash = dht_hashfn_tea (name, strlen (name));
+	case DHT_HASH_TYPE_DM:
+		hash = gf_dm_hashfn (name, strlen (name));
 		break;
 	default:
 		ret = -1;