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-rw-r--r--xlators/cluster/dht/src/dht-hashfn-tea.c146
1 files changed, 146 insertions, 0 deletions
diff --git a/xlators/cluster/dht/src/dht-hashfn-tea.c b/xlators/cluster/dht/src/dht-hashfn-tea.c
new file mode 100644
index 000000000..8437b4955
--- /dev/null
+++ b/xlators/cluster/dht/src/dht-hashfn-tea.c
@@ -0,0 +1,146 @@
+/*
+ Copyright (c) 2008 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);
+ }
+
+ if ((len % 16) == 0) {
+ goto done;
+ }
+
+ 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);
+
+done:
+ 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