| 1 | # -*-pyrex-*- |
| 2 | # |
| 3 | # $Id$ |
| 4 | # |
| 5 | # Universal hashing interface |
| 6 | # |
| 7 | # (c) 2005 Straylight/Edgeware |
| 8 | # |
| 9 | |
| 10 | #----- Licensing notice ----------------------------------------------------- |
| 11 | # |
| 12 | # This file is part of the Python interface to mLib. |
| 13 | # |
| 14 | # mLib/Python is free software; you can redistribute it and/or modify |
| 15 | # it under the terms of the GNU General Public License as published by |
| 16 | # the Free Software Foundation; either version 2 of the License, or |
| 17 | # (at your option) any later version. |
| 18 | # |
| 19 | # mLib/Python is distributed in the hope that it will be useful, |
| 20 | # but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 21 | # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 22 | # GNU General Public License for more details. |
| 23 | # |
| 24 | # You should have received a copy of the GNU General Public License |
| 25 | # along with mLib/Python; if not, write to the Free Software Foundation, |
| 26 | # Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 27 | |
| 28 | cdef extern from 'mLib/unihash.h': |
| 29 | ctypedef int uint32 |
| 30 | ctypedef struct unihash_info: |
| 31 | pass |
| 32 | void unihash_setkey(unihash_info *i, uint32 k) |
| 33 | uint32 UNIHASH_INIT(unihash_info *i) |
| 34 | uint32 unihash_hash(unihash_info *i, uint32 a, void *p, int sz) |
| 35 | unihash_info unihash_global |
| 36 | |
| 37 | cdef extern from 'limits.h': |
| 38 | enum: |
| 39 | LONG_MAX |
| 40 | |
| 41 | cdef extern from 'Python.h': |
| 42 | int PyObject_AsReadBuffer(obj, void **buf, int *len) except -1 |
| 43 | PyInt_FromLong(long i) |
| 44 | PyLong_FromUnsignedLong(unsigned long i) |
| 45 | |
| 46 | cdef _u32(uint32 x): |
| 47 | if x < LONG_MAX: |
| 48 | return PyInt_FromLong(x) |
| 49 | else: |
| 50 | return PyLong_FromUnsignedLong(x) |
| 51 | |
| 52 | def setglobalkey(uint32 k): |
| 53 | unihash_setkey(&unihash_global, k) |
| 54 | |
| 55 | cdef class Key: |
| 56 | cdef unihash_info _i |
| 57 | cdef uint32 _k |
| 58 | def __new__(me, uint32 k): |
| 59 | unihash_setkey(&me._i, k) |
| 60 | me._k = k |
| 61 | property k: |
| 62 | def __get__(me): |
| 63 | return _u32(me._k) |
| 64 | |
| 65 | cdef class Unihash: |
| 66 | cdef uint32 _a |
| 67 | cdef readonly Key key |
| 68 | cdef unihash_info *_i |
| 69 | def __new__(me, key = None): |
| 70 | cdef Key k |
| 71 | me.key = key |
| 72 | if key is None: |
| 73 | me._i = &unihash_global |
| 74 | else: |
| 75 | k = key |
| 76 | me._i = &k._i |
| 77 | me._a = UNIHASH_INIT(me._i) |
| 78 | def chunk(me, data): |
| 79 | cdef void *p |
| 80 | cdef int n |
| 81 | PyObject_AsReadBuffer(data, &p, &n) |
| 82 | me._a = unihash_hash(me._i, me._a, p, n) |
| 83 | def done(me): |
| 84 | return _u32(me._a) |
| 85 | |
| 86 | #----- That's all, folks ---------------------------------------------------- |