diff --git a/.gitignore b/.gitignore index ee93232c..3bdda58a 100644 --- a/.gitignore +++ b/.gitignore @@ -18,7 +18,7 @@ setuptools*.tar.gz setuptools*.egg cassandra/*.c -!cassandra/murmur3.c +!cassandra/cmurmur3.c # OSX .DS_Store diff --git a/cassandra/cmurmur3.c b/cassandra/cmurmur3.c new file mode 100644 index 00000000..0ffc3ad5 --- /dev/null +++ b/cassandra/cmurmur3.c @@ -0,0 +1,275 @@ +/* + * The majority of this code was taken from the python-smhasher library, + * which can be found here: https://github.com/phensley/python-smhasher + * + * That library is under the MIT license with the following copyright: + * + * Copyright (c) 2011 Austin Appleby (Murmur3 routine) + * Copyright (c) 2011 Patrick Hensley (Python wrapper, packaging) + * Copyright 2013 DataStax (Minor modifications to match Cassandra's MM3 hashes) + * + */ + +#define PY_SSIZE_T_CLEAN 1 +#include +#include + +#if PY_VERSION_HEX < 0x02050000 +typedef int Py_ssize_t; +#define PY_SSIZE_T_MAX INT_MAX +#define PY_SSIZE_T_MIN INT_MIN +#endif + +#ifdef PYPY_VERSION +#define COMPILING_IN_PYPY 1 +#define COMPILING_IN_CPYTHON 0 +#else +#define COMPILING_IN_PYPY 0 +#define COMPILING_IN_CPYTHON 1 +#endif +//----------------------------------------------------------------------------- +// Platform-specific functions and macros + +// Microsoft Visual Studio + +#if defined(_MSC_VER) + +typedef unsigned char uint8_t; +typedef unsigned long uint32_t; +typedef unsigned __int64 uint64_t; + +typedef char int8_t; +typedef long int32_t; +typedef __int64 int64_t; + +#define FORCE_INLINE __forceinline + +#include + +#define ROTL32(x,y) _rotl(x,y) +#define ROTL64(x,y) _rotl64(x,y) + +#define BIG_CONSTANT(x) (x) + +// Other compilers + +#else // defined(_MSC_VER) + +#include + +#define FORCE_INLINE inline __attribute__((always_inline)) + +inline uint32_t rotl32 ( int32_t x, int8_t r ) +{ + // cast to unsigned for logical right bitshift (to match C* MM3 implementation) + return (x << r) | ((int32_t) (((uint32_t) x) >> (32 - r))); +} + +inline int64_t rotl64 ( int64_t x, int8_t r ) +{ + // cast to unsigned for logical right bitshift (to match C* MM3 implementation) + return (x << r) | ((int64_t) (((uint64_t) x) >> (64 - r))); +} + +#define ROTL32(x,y) rotl32(x,y) +#define ROTL64(x,y) rotl64(x,y) + +#define BIG_CONSTANT(x) (x##LL) + +#endif // !defined(_MSC_VER) + +//----------------------------------------------------------------------------- +// Block read - if your platform needs to do endian-swapping or can only +// handle aligned reads, do the conversion here + +// TODO 32bit? + +FORCE_INLINE int64_t getblock ( const int64_t * p, int i ) +{ + return p[i]; +} + +//----------------------------------------------------------------------------- +// Finalization mix - force all bits of a hash block to avalanche + +FORCE_INLINE int64_t fmix ( int64_t k ) +{ + // cast to unsigned for logical right bitshift (to match C* MM3 implementation) + k ^= ((uint64_t) k) >> 33; + k *= BIG_CONSTANT(0xff51afd7ed558ccd); + k ^= ((uint64_t) k) >> 33; + k *= BIG_CONSTANT(0xc4ceb9fe1a85ec53); + k ^= ((uint64_t) k) >> 33; + + return k; +} + +int64_t MurmurHash3_x64_128 (const void * key, const int len, + const uint32_t seed) +{ + const int8_t * data = (const int8_t*)key; + const int nblocks = len / 16; + + int64_t h1 = seed; + int64_t h2 = seed; + + int64_t c1 = BIG_CONSTANT(0x87c37b91114253d5); + int64_t c2 = BIG_CONSTANT(0x4cf5ad432745937f); + int64_t k1 = 0; + int64_t k2 = 0; + + const int64_t * blocks = (const int64_t *)(data); + const int8_t * tail = (const int8_t*)(data + nblocks*16); + + //---------- + // body + + int i; + for(i = 0; i < nblocks; i++) + { + int64_t k1 = getblock(blocks,i*2+0); + int64_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 + switch(len & 15) + { + case 15: k2 ^= ((int64_t) (tail[14])) << 48; + case 14: k2 ^= ((int64_t) (tail[13])) << 40; + case 13: k2 ^= ((int64_t) (tail[12])) << 32; + case 12: k2 ^= ((int64_t) (tail[11])) << 24; + case 11: k2 ^= ((int64_t) (tail[10])) << 16; + case 10: k2 ^= ((int64_t) (tail[ 9])) << 8; + case 9: k2 ^= ((int64_t) (tail[ 8])) << 0; + k2 *= c2; k2 = ROTL64(k2,33); k2 *= c1; h2 ^= k2; + + case 8: k1 ^= ((int64_t) (tail[ 7])) << 56; + case 7: k1 ^= ((int64_t) (tail[ 6])) << 48; + case 6: k1 ^= ((int64_t) (tail[ 5])) << 40; + case 5: k1 ^= ((int64_t) (tail[ 4])) << 32; + case 4: k1 ^= ((int64_t) (tail[ 3])) << 24; + case 3: k1 ^= ((int64_t) (tail[ 2])) << 16; + case 2: k1 ^= ((int64_t) (tail[ 1])) << 8; + case 1: k1 ^= ((int64_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; + + return h1; +} + + +struct module_state { + PyObject *error; +}; + +// pypy3 doesn't have GetState yet. +#if COMPILING_IN_CPYTHON && PY_MAJOR_VERSION >= 3 +#define GETSTATE(m) ((struct module_state*)PyModule_GetState(m)) +#else +#define GETSTATE(m) (&_state) +static struct module_state _state; +#endif + +static PyObject * +murmur3(PyObject *self, PyObject *args) +{ + const char *key; + Py_ssize_t len; + uint32_t seed = 0; + int64_t result = 0; + + + if (!PyArg_ParseTuple(args, "s#|I", &key, &len, &seed)) { + return NULL; + } + + // TODO handle x86 version? + result = MurmurHash3_x64_128((void *)key, len, seed); + return (PyObject *) PyLong_FromLongLong(result); +} + +static PyMethodDef cmurmur3_methods[] = { + {"murmur3", murmur3, METH_VARARGS, "Make an x64 murmur3 64-bit hash value"}, + {NULL, NULL, 0, NULL} +}; + +#if PY_MAJOR_VERSION >= 3 + +static int cmurmur3_traverse(PyObject *m, visitproc visit, void *arg) { + Py_VISIT(GETSTATE(m)->error); + return 0; +} + +static int cmurmur3_clear(PyObject *m) { + Py_CLEAR(GETSTATE(m)->error); + return 0; +} + +static struct PyModuleDef moduledef = { + PyModuleDef_HEAD_INIT, + "cmurmur3", + NULL, + sizeof(struct module_state), + cmurmur3_methods, + NULL, + cmurmur3_traverse, + cmurmur3_clear, + NULL +}; + +#define INITERROR return NULL + +PyObject * +PyInit_cmurmur3(void) + +#else +#define INITERROR return + +void +initcmurmur3(void) +#endif +{ +#if PY_MAJOR_VERSION >= 3 + PyObject *module = PyModule_Create(&moduledef); +#else + PyObject *module = Py_InitModule("cmurmur3", cmurmur3_methods); +#endif + struct module_state *st = NULL; + + if (module == NULL) + INITERROR; + st = GETSTATE(module); + + st->error = PyErr_NewException("cmurmur3.Error", NULL, NULL); + if (st->error == NULL) { + Py_DECREF(module); + INITERROR; + } + +#if PY_MAJOR_VERSION >= 3 + return module; +#endif +}