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authorMatt Corallo <git@bluematt.me>2013-01-10 13:16:00 -0500
committerMatt Corallo <git@bluematt.me>2013-01-16 12:48:01 -0500
commit7ab026f4493b145f2255d816864cb1a3486e0788 (patch)
tree72a9b123331434c3ac8f2cf837692f6ec3413793 /src
parent68feac96b67b80a4fe59c4f349b58af9c77e2709 (diff)
Add MurmurHash3 implementation to hash.h/add hash.cpp.
Diffstat (limited to 'src')
-rw-r--r--src/hash.cpp58
-rw-r--r--src/hash.h3
-rw-r--r--src/makefile.linux-mingw1
-rw-r--r--src/makefile.mingw1
-rw-r--r--src/makefile.osx1
-rw-r--r--src/makefile.unix1
6 files changed, 65 insertions, 0 deletions
diff --git a/src/hash.cpp b/src/hash.cpp
new file mode 100644
index 0000000000..bddd8abf38
--- /dev/null
+++ b/src/hash.cpp
@@ -0,0 +1,58 @@
+#include "hash.h"
+
+inline uint32_t ROTL32 ( uint32_t x, int8_t r )
+{
+ return (x << r) | (x >> (32 - r));
+}
+
+unsigned int MurmurHash3(unsigned int nHashSeed, const std::vector<unsigned char>& vDataToHash)
+{
+ // The following is MurmurHash3 (x86_32), see http://code.google.com/p/smhasher/source/browse/trunk/MurmurHash3.cpp
+ uint32_t h1 = nHashSeed;
+ const uint32_t c1 = 0xcc9e2d51;
+ const uint32_t c2 = 0x1b873593;
+
+ const int nblocks = vDataToHash.size() / 4;
+
+ //----------
+ // body
+ const uint32_t * blocks = (const uint32_t *)(&vDataToHash[0] + nblocks*4);
+
+ for(int i = -nblocks; i; i++)
+ {
+ uint32_t k1 = blocks[i];
+
+ k1 *= c1;
+ k1 = ROTL32(k1,15);
+ k1 *= c2;
+
+ h1 ^= k1;
+ h1 = ROTL32(h1,13);
+ h1 = h1*5+0xe6546b64;
+ }
+
+ //----------
+ // tail
+ const uint8_t * tail = (const uint8_t*)(&vDataToHash[0] + nblocks*4);
+
+ uint32_t k1 = 0;
+
+ switch(vDataToHash.size() & 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 ^= vDataToHash.size();
+ h1 ^= h1 >> 16;
+ h1 *= 0x85ebca6b;
+ h1 ^= h1 >> 13;
+ h1 *= 0xc2b2ae35;
+ h1 ^= h1 >> 16;
+
+ return h1;
+}
diff --git a/src/hash.h b/src/hash.h
index bc013139bb..eaa1780c04 100644
--- a/src/hash.h
+++ b/src/hash.h
@@ -10,6 +10,7 @@
#include <openssl/sha.h>
#include <openssl/ripemd.h>
+#include <vector>
template<typename T1>
inline uint256 Hash(const T1 pbegin, const T1 pend)
@@ -113,4 +114,6 @@ inline uint160 Hash160(const std::vector<unsigned char>& vch)
return hash2;
}
+unsigned int MurmurHash3(unsigned int nHashSeed, const std::vector<unsigned char>& vDataToHash);
+
#endif
diff --git a/src/makefile.linux-mingw b/src/makefile.linux-mingw
index 47dc7c5c40..95e7e83cd0 100644
--- a/src/makefile.linux-mingw
+++ b/src/makefile.linux-mingw
@@ -83,6 +83,7 @@ OBJS= \
obj/wallet.o \
obj/walletdb.o \
obj/noui.o \
+ obj/hash.o \
obj/leveldb.o \
obj/txdb.o
diff --git a/src/makefile.mingw b/src/makefile.mingw
index 22d65d6703..2abc34478d 100644
--- a/src/makefile.mingw
+++ b/src/makefile.mingw
@@ -78,6 +78,7 @@ OBJS= \
obj/util.o \
obj/wallet.o \
obj/walletdb.o \
+ obj/hash.o \
obj/noui.o \
obj/leveldb.o \
obj/txdb.o
diff --git a/src/makefile.osx b/src/makefile.osx
index 25164c8679..474f17b735 100644
--- a/src/makefile.osx
+++ b/src/makefile.osx
@@ -96,6 +96,7 @@ OBJS= \
obj/util.o \
obj/wallet.o \
obj/walletdb.o \
+ obj/hash.o \
obj/noui.o \
obj/leveldb.o \
obj/txdb.o
diff --git a/src/makefile.unix b/src/makefile.unix
index 9e17e8ace2..979a4a6520 100644
--- a/src/makefile.unix
+++ b/src/makefile.unix
@@ -127,6 +127,7 @@ OBJS= \
obj/util.o \
obj/wallet.o \
obj/walletdb.o \
+ obj/hash.o \
obj/noui.o \
obj/leveldb.o \
obj/txdb.o