Subject: [Boost-commit] svn:boost r72940 - in sandbox/bloom_filter/trunk/boost/bloom_filter: . hash
From: cpp.cabrera_at_[hidden]
Date: 2011-07-06 20:17:40
Author: alejandro
Date: 2011-07-06 20:17:39 EDT (Wed, 06 Jul 2011)
New Revision: 72940
URL: http://svn.boost.org/trac/boost/changeset/72940
Log:
Added an implementation of murmurhash3, with appropriate header comments. This new Hasher dispatches at compile-time to the appropriate hash function.
Added:
sandbox/bloom_filter/trunk/boost/bloom_filter/hash/.gitignore (contents, props changed)
sandbox/bloom_filter/trunk/boost/bloom_filter/hash/murmurhash3.hpp (contents, props changed)
Text files modified:
sandbox/bloom_filter/trunk/boost/bloom_filter/counting_bloom.hpp | 1 +
1 files changed, 1 insertions(+), 0 deletions(-)
Modified: sandbox/bloom_filter/trunk/boost/bloom_filter/counting_bloom.hpp
==============================================================================
--- sandbox/bloom_filter/trunk/boost/bloom_filter/counting_bloom.hpp (original)
+++ sandbox/bloom_filter/trunk/boost/bloom_filter/counting_bloom.hpp 2011-07-06 20:17:39 EDT (Wed, 06 Jul 2011)
@@ -59,6 +59,7 @@
// can have internal fragmentation if the calculation for
// bins_per_slot has a remainder. The severity of the internal
// fragmentation is equal to the remainder * the number of slots.
+ // this check prevents internal fragmentation
BOOST_STATIC_ASSERT( ((sizeof(Block) * 8) % BitsPerBin) == 0);
// a slot is one element position in the array
Added: sandbox/bloom_filter/trunk/boost/bloom_filter/hash/.gitignore
==============================================================================
--- (empty file)
+++ sandbox/bloom_filter/trunk/boost/bloom_filter/hash/.gitignore 2011-07-06 20:17:39 EDT (Wed, 06 Jul 2011)
@@ -0,0 +1 @@
+test
Added: sandbox/bloom_filter/trunk/boost/bloom_filter/hash/murmurhash3.hpp
==============================================================================
--- (empty file)
+++ sandbox/bloom_filter/trunk/boost/bloom_filter/hash/murmurhash3.hpp 2011-07-06 20:17:39 EDT (Wed, 06 Jul 2011)
@@ -0,0 +1,412 @@
+//////////////////////////////////////////////////////////////////////////////
+//
+// (C) Copyright Alejandro Cabrera 2011.
+// Distributed under the Boost
+// Software License, Version 1.0.
+// (See accompanying file LICENSE_1_0.txt or
+// copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+// See http://www.boost.org/libs/bloom_filter for documentation.
+//
+//////////////////////////////////////////////////////////////////////////////
+
+// Note by original author - Austin Appleby
+//-----------------------------------------------------------------------------
+// MurmurHash3 was written by Austin Appleby, and is placed in the public
+// domain. The author hereby disclaims copyright to this source code.
+
+// Note - The x86 and x64 versions do _not_ produce the same results, as the
+// algorithms are optimized for their respective platforms. You can still
+// compile and run any of them on any platform, but your performance with the
+// non-native version will be less than optimal.
+
+/**
+ * Note by Alejandro Cabrera:
+ *
+ * I've made a few contributions to this implementation of murmurhash3.
+ * One makes the implementation more readily portable by using
+ * boost/cstdlib and boost/cstdint instead of relying on stdint.h
+ * and stdlib.h to be present on a given platform. I've also removed
+ * platform-specific macros from this version.
+ *
+ * I've also placed the implementation in the boost::hash namespace and
+ * changed the function names from -> to:
+ * - MurmurHash3_x86_32 -> murmurhash3_x86_32
+ * - MurmurHash3_x86_128 -> murmurhash3_x86_128
+ * - MurmurHash3_x64_128 -> murmurhash3_x64_128
+ *
+ * Finally, I've provided a unifying Hasher based on Murmur Hash 3:
+ * - murmurhash3<T, Seed=0, Use128Mode=True>
+ *
+ * This Hasher performs compile-time dispatch to the appropriate
+ * murmurhash function based on the template parameters and whether
+ * the compilation target is 64-bit or not.
+ */
+#include <boost/cstdint.hpp>
+
+namespace boost {
+ namespace hash {
+
+ // forward declarations
+ namespace detail {
+ void murmurhash3_x86_32 ( const void *const key, const size_t len,
+ const size_t seed, const void * out );
+ void murmurhash3_x86_128 ( const void *const key, const size_t len,
+ const size_t seed, const void * out );
+ void murmurhash3_x64_128 ( const void *const key, const size_t len,
+ const size_t seed, const void * out );
+ template <bool, bool>
+ struct murmurhash3_dispatch;
+
+ struct Is64Bit {
+ static const bool value = (sizeof(size_t) == 8);
+ };
+ }
+
+ template <typename T, size_t Seed = 0, bool Use128Mode = true>
+ struct murmurhash3 {
+ typedef detail::murmurhash3_dispatch<detail::Is64Bit::value,
+ Use128Mode> dispatch_type;
+ size_t operator()(const T& t) {
+ static dispatch_type dispatcher;
+ size_t out[2] = {0,0};
+
+ dispatcher(&t, sizeof(T), Seed, &out);
+
+ return out[1];
+ }
+ };
+
+ namespace detail {
+
+ template <bool _64Bit = true, bool Use128Mode = true>
+ struct murmurhash3_dispatch {
+ void operator()(const void *const data, const size_t len,
+ const size_t seed, const void *out) {
+ murmurhash3_x64_128(data, len, seed, out);
+ }
+ };
+
+ template <>
+ struct murmurhash3_dispatch<true, true> {
+ void operator()(const void *const data, const size_t len,
+ const size_t seed, const void *out) {
+ murmurhash3_x64_128(data, len, seed, out);
+ }
+ };
+
+ template <>
+ struct murmurhash3_dispatch<false, false> {
+ void operator()(const void *const data, const size_t len,
+ const size_t seed, const void *out) {
+ murmurhash3_x86_32(data, len, seed, out);
+ }
+ };
+
+ template <>
+ struct murmurhash3_dispatch<false, true> {
+ void operator()(const void *const data, const size_t len,
+ const size_t seed, const void *out) {
+ murmurhash3_x86_128(data, len, seed, out);
+ }
+ };
+
+ inline uint32_t rotl32(const uint32_t x, const int8_t r)
+ {
+ return (x << r) | (x >> (32 - r));
+ }
+
+ inline uint64_t rotl64(const uint64_t x, const int8_t r)
+ {
+ return (x << r) | (x >> (64 - r));
+ }
+
+ //-----------------------------------------------------------------------------
+ // Block read - if your platform needs to do endian-swapping or can only
+ // handle aligned reads, do the conversion here
+
+ uint32_t getblock(const uint32_t *const p, const size_t i)
+ {
+ return p[i];
+ }
+
+ uint64_t getblock(const uint64_t *const p, const size_t i)
+ {
+ return p[i];
+ }
+
+ //-----------------------------------------------------------------------------
+ // Finalization mix - force all bits of a hash block to avalanche
+
+ uint32_t fmix(const uint32_t val)
+ {
+ uint32_t h = val;
+
+ h ^= h >> 16;
+ h *= 0x85ebca6b;
+ h ^= h >> 13;
+ h *= 0xc2b2ae35;
+ h ^= h >> 16;
+
+ return h;
+ }
+
+ //----------
+
+ uint64_t fmix(const uint64_t val)
+ {
+ uint64_t k = val;
+
+ k ^= k >> 33;
+ k *= 0xff51afd7ed558ccd;
+ k ^= k >> 33;
+ k *= 0xc4ceb9fe1a85ec53;
+ k ^= k >> 33;
+
+ return k;
+ }
+
+ //-----------------------------------------------------------------------------
+
+ void murmurhash3_x86_32 ( const void *const key, const size_t len,
+ const size_t seed, const void * out )
+ {
+ const uint8_t *const data = static_cast<const uint8_t*>(key);
+ const int nblocks = len / 4;
+
+ uint32_t h1 = seed;
+
+ static const uint32_t c1 = 0xcc9e2d51;
+ static const uint32_t c2 = 0x1b873593;
+
+ //----------
+ // body
+
+ const uint32_t *const blocks = reinterpret_cast<const uint32_t *>(data + nblocks*4);
+
+ for(int i = -nblocks; i; i++)
+ {
+ uint32_t k1 = getblock(blocks,i);
+
+ k1 *= c1;
+ k1 = rotl32(k1,15);
+ k1 *= c2;
+
+ h1 ^= k1;
+ h1 = rotl32(h1,13);
+ h1 = h1*5+0xe6546b64;
+ }
+
+ //----------
+ // tail
+
+ const uint8_t *const tail = static_cast<const uint8_t*>(data + nblocks*4);
+
+ uint32_t k1 = 0;
+
+ switch(len & 3)
+ {
+ case 3: k1 ^= tail[2] << 16;
+ case 2: k1 ^= tail[1] << 8;
+ case 1: k1 ^= tail[0];
+ k1 *= c1; k1 = rotl32(k1,15); k1 *= c2; h1 ^= k1;
+ };
+
+ //----------
+ // finalization
+
+ h1 ^= len;
+
+ h1 = fmix(h1);
+
+ ((uint32_t*)out)[1] = h1;
+ }
+
+ //-----------------------------------------------------------------------------
+
+ void murmurhash3_x86_128(const void *const key, const size_t len,
+ const size_t seed, const void *out )
+ {
+ const uint8_t *const data = static_cast<const uint8_t*>(key);
+ const int nblocks = len / 16;
+
+ uint32_t h1 = seed;
+ uint32_t h2 = seed;
+ uint32_t h3 = seed;
+ uint32_t h4 = seed;
+
+ static const uint32_t c1 = 0x239b961b;
+ static const uint32_t c2 = 0xab0e9789;
+ static const uint32_t c3 = 0x38b34ae5;
+ static const uint32_t c4 = 0xa1e38b93;
+
+ //----------
+ // body
+
+ const uint32_t *const blocks = reinterpret_cast<const uint32_t *>(data + nblocks*16);
+
+ for(int i = -nblocks; i; i++)
+ {
+ uint32_t k1 = getblock(blocks,i*4+0);
+ uint32_t k2 = getblock(blocks,i*4+1);
+ uint32_t k3 = getblock(blocks,i*4+2);
+ uint32_t k4 = getblock(blocks,i*4+3);
+
+ k1 *= c1; k1 = rotl32(k1,15); k1 *= c2; h1 ^= k1;
+
+ h1 = rotl32(h1,19); h1 += h2; h1 = h1*5+0x561ccd1b;
+
+ k2 *= c2; k2 = rotl32(k2,16); k2 *= c3; h2 ^= k2;
+
+ h2 = rotl32(h2,17); h2 += h3; h2 = h2*5+0x0bcaa747;
+
+ k3 *= c3; k3 = rotl32(k3,17); k3 *= c4; h3 ^= k3;
+
+ h3 = rotl32(h3,15); h3 += h4; h3 = h3*5+0x96cd1c35;
+
+ k4 *= c4; k4 = rotl32(k4,18); k4 *= c1; h4 ^= k4;
+
+ h4 = rotl32(h4,13); h4 += h1; h4 = h4*5+0x32ac3b17;
+ }
+
+ //----------
+ // tail
+
+ const uint8_t *const tail = static_cast<const uint8_t*>(data + nblocks*16);
+
+ uint32_t k1 = 0;
+ uint32_t k2 = 0;
+ uint32_t k3 = 0;
+ uint32_t k4 = 0;
+
+ switch(len & 15)
+ {
+ case 15: k4 ^= tail[14] << 16;
+ case 14: k4 ^= tail[13] << 8;
+ case 13: k4 ^= tail[12] << 0;
+ k4 *= c4; k4 = rotl32(k4,18); k4 *= c1; h4 ^= k4;
+
+ case 12: k3 ^= tail[11] << 24;
+ case 11: k3 ^= tail[10] << 16;
+ case 10: k3 ^= tail[ 9] << 8;
+ case 9: k3 ^= tail[ 8] << 0;
+ k3 *= c3; k3 = rotl32(k3,17); k3 *= c4; h3 ^= k3;
+
+ case 8: k2 ^= tail[ 7] << 24;
+ case 7: k2 ^= tail[ 6] << 16;
+ case 6: k2 ^= tail[ 5] << 8;
+ case 5: k2 ^= tail[ 4] << 0;
+ k2 *= c2; k2 = rotl32(k2,16); k2 *= c3; h2 ^= k2;
+
+ case 4: k1 ^= tail[ 3] << 24;
+ case 3: k1 ^= tail[ 2] << 16;
+ case 2: k1 ^= tail[ 1] << 8;
+ case 1: k1 ^= tail[ 0] << 0;
+ k1 *= c1; k1 = rotl32(k1,15); k1 *= c2; h1 ^= k1;
+ };
+
+ //----------
+ // finalization
+
+ h1 ^= len; h2 ^= len; h3 ^= len; h4 ^= len;
+
+ h1 += h2; h1 += h3; h1 += h4;
+ h2 += h1; h3 += h1; h4 += h1;
+
+ h1 = fmix(h1);
+ h2 = fmix(h2);
+ h3 = fmix(h3);
+ h4 = fmix(h4);
+
+ h1 += h2; h1 += h3; h1 += h4;
+ h2 += h1; h3 += h1; h4 += h1;
+
+ ((uint32_t*)out)[0] = h1;
+ ((uint32_t*)out)[1] = h2;
+ ((uint32_t*)out)[2] = h3;
+ ((uint32_t*)out)[3] = h4;
+ }
+
+ //-----------------------------------------------------------------------------
+
+ void murmurhash3_x64_128(const void *const key, const size_t len,
+ const size_t seed, const void * out )
+ {
+ const uint8_t * data = static_cast<const uint8_t*>(key);
+ const int nblocks = len / 16;
+
+ uint64_t h1 = seed;
+ uint64_t h2 = seed;
+
+ static const uint64_t c1 = 0x87c37b91114253d5;
+ static const uint64_t c2 = 0x4cf5ad432745937f;
+
+ //----------
+ // body
+
+ const uint64_t *const blocks = reinterpret_cast<const uint64_t *>(data);
+
+ for(int i = 0; i < nblocks; i++)
+ {
+ uint64_t k1 = getblock(blocks,i*2+0);
+ uint64_t k2 = getblock(blocks,i*2+1);
+
+ k1 *= c1; k1 = rotl64(k1,31); k1 *= c2; h1 ^= k1;
+
+ h1 = rotl64(h1,27); h1 += h2; h1 = h1*5+0x52dce729;
+
+ k2 *= c2; k2 = rotl64(k2,33); k2 *= c1; h2 ^= k2;
+
+ h2 = rotl64(h2,31); h2 += h1; h2 = h2*5+0x38495ab5;
+ }
+
+ //----------
+ // tail
+
+ const uint8_t *const tail = static_cast<const uint8_t*>(data + nblocks*16);
+
+ uint64_t k1 = 0;
+ uint64_t k2 = 0;
+
+ switch(len & 15)
+ {
+ case 15: k2 ^= static_cast<uint64_t>(tail[14]) << 48;
+ case 14: k2 ^= static_cast<uint64_t>(tail[13]) << 40;
+ case 13: k2 ^= static_cast<uint64_t>(tail[12]) << 32;
+ case 12: k2 ^= static_cast<uint64_t>(tail[11]) << 24;
+ case 11: k2 ^= static_cast<uint64_t>(tail[10]) << 16;
+ case 10: k2 ^= static_cast<uint64_t>(tail[ 9]) << 8;
+ case 9: k2 ^= static_cast<uint64_t>(tail[ 8]) << 0;
+ k2 *= c2; k2 = rotl64(k2,33); k2 *= c1; h2 ^= k2;
+
+ case 8: k1 ^= static_cast<uint64_t>(tail[ 7]) << 56;
+ case 7: k1 ^= static_cast<uint64_t>(tail[ 6]) << 48;
+ case 6: k1 ^= static_cast<uint64_t>(tail[ 5]) << 40;
+ case 5: k1 ^= static_cast<uint64_t>(tail[ 4]) << 32;
+ case 4: k1 ^= static_cast<uint64_t>(tail[ 3]) << 24;
+ case 3: k1 ^= static_cast<uint64_t>(tail[ 2]) << 16;
+ case 2: k1 ^= static_cast<uint64_t>(tail[ 1]) << 8;
+ case 1: k1 ^= static_cast<uint64_t>(tail[ 0]) << 0;
+ k1 *= c1; k1 = rotl64(k1,31); k1 *= c2; h1 ^= k1;
+ };
+
+ //----------
+ // finalization
+
+ h1 ^= len; h2 ^= len;
+
+ h1 += h2;
+ h2 += h1;
+
+ h1 = fmix(h1);
+ h2 = fmix(h2);
+
+ h1 += h2;
+ h2 += h1;
+
+ ((uint64_t*)out)[0] = h1;
+ ((uint64_t*)out)[1] = h2;
+ }
+ }// detail
+ }// hash
+}// boost