borgbackup/src/borg/algorithms/checksums.pyx
2017-06-01 21:26:42 +02:00

106 lines
3.1 KiB
Cython

from ..helpers import bin_to_hex
from libc.stdint cimport uint32_t
from cpython.buffer cimport PyBUF_SIMPLE, PyObject_GetBuffer, PyBuffer_Release
from cpython.bytes cimport PyBytes_FromStringAndSize
cdef extern from "crc32_dispatch.c":
uint32_t _crc32_slice_by_8 "crc32_slice_by_8"(const void* data, size_t length, uint32_t initial_crc)
uint32_t _crc32_clmul "crc32_clmul"(const void* data, size_t length, uint32_t initial_crc)
int _have_clmul "have_clmul"()
cdef extern from "xxh64/xxhash.c":
ctypedef struct XXH64_canonical_t:
char digest[8]
ctypedef struct XXH64_state_t:
pass # opaque
ctypedef unsigned long long XXH64_hash_t
ctypedef enum XXH_errorcode:
XXH_OK,
XXH_ERROR
XXH64_hash_t XXH64(const void* input, size_t length, unsigned long long seed);
XXH_errorcode XXH64_reset(XXH64_state_t* statePtr, unsigned long long seed);
XXH_errorcode XXH64_update(XXH64_state_t* statePtr, const void* input, size_t length);
XXH64_hash_t XXH64_digest(const XXH64_state_t* statePtr);
void XXH64_canonicalFromHash(XXH64_canonical_t* dst, XXH64_hash_t hash);
XXH64_hash_t XXH64_hashFromCanonical(const XXH64_canonical_t* src);
cdef Py_buffer ro_buffer(object data) except *:
cdef Py_buffer view
PyObject_GetBuffer(data, &view, PyBUF_SIMPLE)
return view
def crc32_slice_by_8(data, value=0):
cdef Py_buffer data_buf = ro_buffer(data)
cdef uint32_t val = value
try:
return _crc32_slice_by_8(data_buf.buf, data_buf.len, val)
finally:
PyBuffer_Release(&data_buf)
def crc32_clmul(data, value=0):
cdef Py_buffer data_buf = ro_buffer(data)
cdef uint32_t val = value
try:
return _crc32_clmul(data_buf.buf, data_buf.len, val)
finally:
PyBuffer_Release(&data_buf)
have_clmul = _have_clmul()
if have_clmul:
crc32 = crc32_clmul
else:
crc32 = crc32_slice_by_8
def xxh64(data, seed=0):
cdef unsigned long long _seed = seed
cdef XXH64_hash_t hash
cdef XXH64_canonical_t digest
cdef Py_buffer data_buf = ro_buffer(data)
try:
hash = XXH64(data_buf.buf, data_buf.len, _seed)
finally:
PyBuffer_Release(&data_buf)
XXH64_canonicalFromHash(&digest, hash)
return PyBytes_FromStringAndSize(<const char*> digest.digest, 8)
cdef class StreamingXXH64:
cdef XXH64_state_t state
def __cinit__(self, seed=0):
cdef unsigned long long _seed = seed
if XXH64_reset(&self.state, _seed) != XXH_OK:
raise Exception('XXH64_reset failed')
def update(self, data):
cdef Py_buffer data_buf = ro_buffer(data)
try:
if XXH64_update(&self.state, data_buf.buf, data_buf.len) != XXH_OK:
raise Exception('XXH64_update failed')
finally:
PyBuffer_Release(&data_buf)
def digest(self):
cdef XXH64_hash_t hash
cdef XXH64_canonical_t digest
hash = XXH64_digest(&self.state)
XXH64_canonicalFromHash(&digest, hash)
return PyBytes_FromStringAndSize(<const char*> digest.digest, 8)
def hexdigest(self):
return bin_to_hex(self.digest())