lib/hmap.h \
lib/hmapx.c \
lib/hmapx.h \
+ lib/jhash.c \
+ lib/jhash.h \
lib/json.c \
lib/json.h \
lib/jsonrpc.c \
#include "csum.h"
#include "dynamic-string.h"
#include "hash.h"
+#include "jhash.h"
#include "match.h"
#include "ofpbuf.h"
#include "openflow/openflow.h"
fields.tp_port = flow->tp_src ^ flow->tp_dst;
}
}
- return hash_bytes(&fields, sizeof fields, basis);
+ return jhash_bytes(&fields, sizeof fields, basis);
}
/* Hashes the portions of 'flow' designated by 'fields'. */
switch (fields) {
case NX_HASH_FIELDS_ETH_SRC:
- return hash_bytes(flow->dl_src, sizeof flow->dl_src, basis);
+ return jhash_bytes(flow->dl_src, sizeof flow->dl_src, basis);
case NX_HASH_FIELDS_SYMMETRIC_L4:
return flow_hash_symmetric_l4(flow, basis);
/*
- * Copyright (c) 2008, 2009, 2010, 2012 Nicira, Inc.
+ * Copyright (c) 2008, 2009, 2010, 2012, 2013 Nicira, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
#include <string.h>
#include "unaligned.h"
-/* Returns the hash of the 'n' 32-bit words at 'p', starting from 'basis'.
- * 'p' must be properly aligned. */
-uint32_t
-hash_words(const uint32_t *p, size_t n, uint32_t basis)
-{
- uint32_t a, b, c;
-
- a = b = c = 0xdeadbeef + (((uint32_t) n) << 2) + basis;
-
- while (n > 3) {
- a += p[0];
- b += p[1];
- c += p[2];
- hash_mix(&a, &b, &c);
- n -= 3;
- p += 3;
- }
-
- switch (n) {
- case 3:
- c += p[2];
- /* fall through */
- case 2:
- b += p[1];
- /* fall through */
- case 1:
- a += p[0];
- hash_final(&a, &b, &c);
- /* fall through */
- case 0:
- break;
- }
- return c;
-}
-
/* Returns the hash of 'a', 'b', and 'c'. */
uint32_t
hash_3words(uint32_t a, uint32_t b, uint32_t c)
{
- a += 0xdeadbeef;
- b += 0xdeadbeef;
- c += 0xdeadbeef;
- hash_final(&a, &b, &c);
- return c;
-}
-
-/* Returns the hash of 'a' and 'b'. */
-uint32_t
-hash_2words(uint32_t a, uint32_t b)
-{
- return hash_3words(a, b, 0);
+ return mhash_finish(mhash_add(mhash_add(mhash_add(a, 0), b), c), 12);
}
/* Returns the hash of the 'n' bytes at 'p', starting from 'basis'. */
hash_bytes(const void *p_, size_t n, uint32_t basis)
{
const uint8_t *p = p_;
- uint32_t a, b, c;
-
- a = b = c = 0xdeadbeef + n + basis;
+ size_t orig_n = n;
+ uint32_t hash;
- while (n >= 12) {
- a += get_unaligned_u32((uint32_t *) p);
- b += get_unaligned_u32((uint32_t *) (p + 4));
- c += get_unaligned_u32((uint32_t *) (p + 8));
- hash_mix(&a, &b, &c);
- n -= 12;
- p += 12;
+ hash = basis;
+ while (n >= 4) {
+ hash = mhash_add(hash, get_unaligned_u32((const uint32_t *) p));
+ n -= 4;
+ p += 4;
}
if (n) {
- uint32_t tmp[3];
+ uint32_t tmp = 0;
- tmp[0] = tmp[1] = tmp[2] = 0;
- memcpy(tmp, p, n);
- a += tmp[0];
- b += tmp[1];
- c += tmp[2];
- hash_final(&a, &b, &c);
+ memcpy(&tmp, p, n);
+ hash = mhash_add__(hash, tmp);
}
- return c;
+ return mhash_finish(hash, orig_n);
}
/* Returns the hash of the 'n' 32-bit words at 'p', starting from 'basis'.
* 'p' must be properly aligned. */
uint32_t
-mhash_words(const uint32_t p[], size_t n_words, uint32_t basis)
+hash_words(const uint32_t p[], size_t n_words, uint32_t basis)
{
uint32_t hash;
size_t i;
}
return mhash_finish(hash, n_words * 4);
}
+
+uint32_t
+hash_double(double x, uint32_t basis)
+{
+ uint32_t value[2];
+ BUILD_ASSERT_DECL(sizeof x == sizeof value);
+
+ memcpy(value, &x, sizeof value);
+ return hash_3words(value[0], value[1], basis);
+}
/*
- * Copyright (c) 2008, 2009, 2010, 2012 Nicira, Inc.
+ * Copyright (c) 2008, 2009, 2010, 2012, 2013 Nicira, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
extern "C" {
#endif
-/* This is the public domain lookup3 hash by Bob Jenkins from
- * http://burtleburtle.net/bob/c/lookup3.c, modified for style. */
-
static inline uint32_t
hash_rot(uint32_t x, int k)
{
return (x << k) | (x >> (32 - k));
}
-static inline void
-hash_mix(uint32_t *a, uint32_t *b, uint32_t *c)
+uint32_t hash_words(const uint32_t data[], size_t n_words, uint32_t basis);
+uint32_t hash_bytes(const void *, size_t n_bytes, uint32_t basis);
+
+static inline uint32_t hash_int(uint32_t x, uint32_t basis);
+static inline uint32_t hash_2words(uint32_t, uint32_t);
+uint32_t hash_3words(uint32_t, uint32_t, uint32_t);
+
+static inline uint32_t hash_boolean(bool x, uint32_t basis);
+uint32_t hash_double(double, uint32_t basis);
+
+static inline uint32_t hash_pointer(const void *, uint32_t basis);
+static inline uint32_t hash_string(const char *, uint32_t basis);
+
+/* Murmurhash by Austin Appleby,
+ * from http://code.google.com/p/smhasher/source/browse/trunk/MurmurHash3.cpp.
+ *
+ * The upstream license there says:
+ *
+ * // MurmurHash3 was written by Austin Appleby, and is placed in the public
+ * // domain. The author hereby disclaims copyright to this source code.
+ *
+ * See hash_words() for sample usage. */
+
+static inline uint32_t mhash_add__(uint32_t hash, uint32_t data)
{
- *a -= *c; *a ^= hash_rot(*c, 4); *c += *b;
- *b -= *a; *b ^= hash_rot(*a, 6); *a += *c;
- *c -= *b; *c ^= hash_rot(*b, 8); *b += *a;
- *a -= *c; *a ^= hash_rot(*c, 16); *c += *b;
- *b -= *a; *b ^= hash_rot(*a, 19); *a += *c;
- *c -= *b; *c ^= hash_rot(*b, 4); *b += *a;
+ data *= 0xcc9e2d51;
+ data = hash_rot(data, 15);
+ data *= 0x1b873593;
+ return hash ^ data;
}
-static inline void
-hash_final(uint32_t *a, uint32_t *b, uint32_t *c)
+static inline uint32_t mhash_add(uint32_t hash, uint32_t data)
{
- *c ^= *b; *c -= hash_rot(*b, 14);
- *a ^= *c; *a -= hash_rot(*c, 11);
- *b ^= *a; *b -= hash_rot(*a, 25);
- *c ^= *b; *c -= hash_rot(*b, 16);
- *a ^= *c; *a -= hash_rot(*c, 4);
- *b ^= *a; *b -= hash_rot(*a, 14);
- *c ^= *b; *c -= hash_rot(*b, 24);
+ hash = mhash_add__(hash, data);
+ hash = hash_rot(hash, 13);
+ return hash * 5 + 0xe6546b64;
}
-uint32_t hash_words(const uint32_t *, size_t n_word, uint32_t basis);
-uint32_t hash_2words(uint32_t, uint32_t);
-uint32_t hash_3words(uint32_t, uint32_t, uint32_t);
-uint32_t hash_bytes(const void *, size_t n_bytes, uint32_t basis);
+static inline uint32_t mhash_finish(uint32_t hash, size_t n_bytes)
+{
+ hash ^= n_bytes;
+ hash ^= hash >> 16;
+ hash *= 0x85ebca6b;
+ hash ^= hash >> 13;
+ hash *= 0xc2b2ae35;
+ hash ^= hash >> 16;
+ return hash;
+}
static inline uint32_t hash_string(const char *s, uint32_t basis)
{
return hash_bytes(s, strlen(s), basis);
}
-/* This is Bob Jenkins' integer hash from
- * http://burtleburtle.net/bob/hash/integer.html, modified for style.
- *
- * This hash is faster than hash_2words(), but it isn't as good when 'basis' is
- * important. So use this function for speed or hash_2words() for hash
- * quality. */
static inline uint32_t hash_int(uint32_t x, uint32_t basis)
{
- x -= x << 6;
- x ^= x >> 17;
- x -= x << 9;
- x ^= x << 4;
- x += basis;
- x -= x << 3;
- x ^= x << 10;
- x ^= x >> 15;
- return x;
+ return hash_2words(x, basis);
}
/* An attempt at a useful 1-bit hash function. Has not been analyzed for
return (x ? P0 : P1) ^ hash_rot(basis, 1);
}
-static inline uint32_t hash_double(double x, uint32_t basis)
-{
- uint32_t value[2];
- BUILD_ASSERT_DECL(sizeof x == sizeof value);
-
- memcpy(value, &x, sizeof value);
- return hash_3words(value[0], value[1], basis);
-}
-
static inline uint32_t hash_pointer(const void *p, uint32_t basis)
{
/* Often pointers are hashed simply by casting to integer type, but that
return hash_int((uint32_t) (uintptr_t) p, basis);
}
-/* Murmurhash by Austin Appleby,
- * from http://code.google.com/p/smhasher/source/browse/trunk/MurmurHash3.cpp.
- *
- * The upstream license there says:
- *
- * // MurmurHash3 was written by Austin Appleby, and is placed in the public
- * // domain. The author hereby disclaims copyright to this source code.
- *
- * Murmurhash is faster and higher-quality than the Jenkins lookup3 hash. When
- * we have a little more familiarity with it, it's probably a good idea to
- * switch all of OVS to it.
- *
- * For now, we have this implementation here for use by code that needs a hash
- * that is convenient for use one word at a time, since the Jenkins lookup3
- * hash works three words at a time.
- *
- * See mhash_words() for sample usage. */
-
-uint32_t mhash_words(const uint32_t data[], size_t n_words, uint32_t basis);
-
-static inline uint32_t mhash_add(uint32_t hash, uint32_t data)
+static inline uint32_t hash_2words(uint32_t x, uint32_t y)
{
- data *= 0xcc9e2d51;
- data = hash_rot(data, 15);
- data *= 0x1b873593;
-
- hash ^= data;
- hash = hash_rot(hash, 13);
- return hash * 5 + 0xe6546b64;
-}
-
-static inline uint32_t mhash_finish(uint32_t hash, size_t n_bytes)
-{
- hash ^= n_bytes;
- hash ^= hash >> 16;
- hash *= 0x85ebca6b;
- hash ^= hash >> 13;
- hash *= 0xc2b2ae35;
- hash ^= hash >> 16;
- return hash;
+ return mhash_finish(mhash_add(mhash_add(x, 0), y), 4);
}
#ifdef __cplusplus
--- /dev/null
+/*
+ * Copyright (c) 2008, 2009, 2010, 2012 Nicira, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <config.h>
+#include "jhash.h"
+#include <string.h>
+#include "unaligned.h"
+
+/* This is the public domain lookup3 hash by Bob Jenkins from
+ * http://burtleburtle.net/bob/c/lookup3.c, modified for style. */
+
+static inline uint32_t
+jhash_rot(uint32_t x, int k)
+{
+ return (x << k) | (x >> (32 - k));
+}
+
+static inline void
+jhash_mix(uint32_t *a, uint32_t *b, uint32_t *c)
+{
+ *a -= *c; *a ^= jhash_rot(*c, 4); *c += *b;
+ *b -= *a; *b ^= jhash_rot(*a, 6); *a += *c;
+ *c -= *b; *c ^= jhash_rot(*b, 8); *b += *a;
+ *a -= *c; *a ^= jhash_rot(*c, 16); *c += *b;
+ *b -= *a; *b ^= jhash_rot(*a, 19); *a += *c;
+ *c -= *b; *c ^= jhash_rot(*b, 4); *b += *a;
+}
+
+static inline void
+jhash_final(uint32_t *a, uint32_t *b, uint32_t *c)
+{
+ *c ^= *b; *c -= jhash_rot(*b, 14);
+ *a ^= *c; *a -= jhash_rot(*c, 11);
+ *b ^= *a; *b -= jhash_rot(*a, 25);
+ *c ^= *b; *c -= jhash_rot(*b, 16);
+ *a ^= *c; *a -= jhash_rot(*c, 4);
+ *b ^= *a; *b -= jhash_rot(*a, 14);
+ *c ^= *b; *c -= jhash_rot(*b, 24);
+}
+
+/* Returns the Jenkins hash of the 'n' 32-bit words at 'p', starting from
+ * 'basis'. 'p' must be properly aligned.
+ *
+ * Use hash_words() instead, unless you're computing a hash function whose
+ * value is exposed "on the wire" so we don't want to change it. */
+uint32_t
+jhash_words(const uint32_t *p, size_t n, uint32_t basis)
+{
+ uint32_t a, b, c;
+
+ a = b = c = 0xdeadbeef + (((uint32_t) n) << 2) + basis;
+
+ while (n > 3) {
+ a += p[0];
+ b += p[1];
+ c += p[2];
+ jhash_mix(&a, &b, &c);
+ n -= 3;
+ p += 3;
+ }
+
+ switch (n) {
+ case 3:
+ c += p[2];
+ /* fall through */
+ case 2:
+ b += p[1];
+ /* fall through */
+ case 1:
+ a += p[0];
+ jhash_final(&a, &b, &c);
+ /* fall through */
+ case 0:
+ break;
+ }
+ return c;
+}
+
+/* Returns the Jenkins hash of the 'n' bytes at 'p', starting from 'basis'.
+ *
+ * Use jhash_bytes() instead, unless you're computing a hash function whose
+ * value is exposed "on the wire" so we don't want to change it. */
+uint32_t
+jhash_bytes(const void *p_, size_t n, uint32_t basis)
+{
+ const uint8_t *p = p_;
+ uint32_t a, b, c;
+
+ a = b = c = 0xdeadbeef + n + basis;
+
+ while (n >= 12) {
+ a += get_unaligned_u32((uint32_t *) p);
+ b += get_unaligned_u32((uint32_t *) (p + 4));
+ c += get_unaligned_u32((uint32_t *) (p + 8));
+ jhash_mix(&a, &b, &c);
+ n -= 12;
+ p += 12;
+ }
+
+ if (n) {
+ uint32_t tmp[3];
+
+ tmp[0] = tmp[1] = tmp[2] = 0;
+ memcpy(tmp, p, n);
+ a += tmp[0];
+ b += tmp[1];
+ c += tmp[2];
+ jhash_final(&a, &b, &c);
+ }
+
+ return c;
+}
--- /dev/null
+/*
+ * Copyright (c) 2008, 2009, 2010, 2012 Nicira, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef JHASH_H
+#define JHASH_H 1
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <string.h>
+#include "util.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* This is the public domain lookup3 hash by Bob Jenkins from
+ * http://burtleburtle.net/bob/c/lookup3.c, modified for style.
+ *
+ * Use the functions in hash.h instead if you can. These are here just for
+ * places where we've exposed a hash function "on the wire" and don't want it
+ * to change. */
+
+uint32_t jhash_words(const uint32_t *, size_t n_word, uint32_t basis);
+uint32_t jhash_bytes(const void *, size_t n_bytes, uint32_t basis);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* jhash.h */
#include <stdlib.h>
#include <string.h>
#include "hash.h"
+#include "jhash.h"
#undef NDEBUG
#include <assert.h>
}
static uint32_t
-mhash_words_cb(uint32_t input)
+jhash_words_cb(uint32_t input)
{
- return mhash_words(&input, 1, 0);
+ return jhash_words(&input, 1, 0);
}
static uint32_t
* independence must be a bad assumption :-)
*/
check_word_hash(hash_words_cb, "hash_words", 11);
- check_word_hash(mhash_words_cb, "mhash_words", 11);
+ check_word_hash(jhash_words_cb, "jhash_words", 11);
/* Check that all hash functions of with one 1-bit (or no 1-bits) set
* within three 32-bit words have different values in their lowest 12
* so we are doing pretty well to not have any collisions in 12 bits.
*/
check_3word_hash(hash_words, "hash_words");
- check_3word_hash(mhash_words, "mhash_words");
+ check_3word_hash(jhash_words, "jhash_words");
/* Check that all hashes computed with hash_int with one 1-bit (or no
* 1-bits) set within a single 32-bit word have different values in all
- * 14-bit consecutive runs.
+ * 12-bit consecutive runs.
*
* Given a random distribution, the probability of at least one collision
- * in any set of 14 bits is approximately
+ * in any set of 12 bits is approximately
*
- * 1 - ((2**14 - 1)/2**14)**C(33,2)
- * == 1 - (16,383/16,834)**528
- * =~ 0.031
+ * 1 - ((2**12 - 1)/2**12)**C(33,2)
+ * == 1 - (4,095/4,096)**528
+ * =~ 0.12
*
- * There are 18 ways to pick 14 consecutive bits in a 32-bit word, so if we
+ * There are 20 ways to pick 12 consecutive bits in a 32-bit word, so if we
* assumed independence then the chance of having no collisions in any of
- * those 14-bit runs would be (1-0.03)**18 =~ 0.56. This seems reasonable.
+ * those 12-bit runs would be (1-0.12)**20 =~ 0.078. This refutes our
+ * assumption of independence, which makes it seem like a good hash
+ * function.
*/
- check_word_hash(hash_int_cb, "hash_int", 14);
+ check_word_hash(hash_int_cb, "hash_int", 12);
return 0;
}
git://git.onelab.eu / sliver-openvswitch.git / commitdiff