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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 ---------------------------------------------------- |