mdw@git.distorted.org.uk Git - mLib-python/blob - codec.pyx

   1 ### -*-pyrex-*-
   2 ###
   3 ### Generic encoder/decoder
   4 ###
   5 ### (c) 2005 Straylight/Edgeware
   6 ###
   7
   8 ###----- Licensing notice ---------------------------------------------------
   9 ###
  10 ### This file is part of the Python interface to mLib.
  11 ###
  12 ### mLib/Python is free software; you can redistribute it and/or modify
  13 ### it under the terms of the GNU General Public License as published by
  14 ### the Free Software Foundation; either version 2 of the License, or
  15 ### (at your option) any later version.
  16 ###
  17 ### mLib/Python is distributed in the hope that it will be useful,
  18 ### but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ### MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ### GNU General Public License for more details.
  21 ###
  22 ### You should have received a copy of the GNU General Public License
  23 ### along with mLib/Python; if not, write to the Free Software Foundation,
  24 ### Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  25
  26 ###--------------------------------------------------------------------------
  27 ### Base classes.
  28
  29 cdef extern from 'mLib/codec.h':
  30
  31   ctypedef struct codec
  32
  33   ctypedef struct codec_class:
  34     char *name
  35     codec *(*encoder)(unsigned f, char *ind, unsigned max)
  36     codec *(*decoder)(unsigned f)
  37
  38   ctypedef struct codec_ops:
  39     codec_class *c
  40     int (*code)(codec *c, void *p, size_t, dstr *d)
  41     void (*destroy)(codec *c)
  42   ctypedef struct codec:
  43     codec_ops *ops
  44
  45   enum:
  46     CDCF_LOWERC
  47     CDCF_IGNCASE
  48     CDCF_NOEQPAD
  49     CDCF_IGNEQPAD
  50     CDCF_IGNEQMID
  51     CDCF_IGNZPAD
  52     CDCF_IGNNEWL
  53     CDCF_IGNINVCH
  54     CDCF_IGNJUNK
  55
  56   enum:
  57     CDCERR_OK
  58     CDCERR_INVCH
  59     CDCERR_INVEQPAD
  60     CDCERR_INVZPAD
  61
  62   char *_codec_strerror "codec_strerror"(int err)
  63
  64 class CDCF:
  65   LOWERC = CDCF_LOWERC
  66   IGNCASE = CDCF_IGNCASE
  67   NOEQPAD = CDCF_NOEQPAD
  68   IGNEQPAD = CDCF_IGNEQPAD
  69   IGNEQMID = CDCF_IGNEQMID
  70   IGNZPAD = CDCF_IGNZPAD
  71   IGNNEWL = CDCF_IGNNEWL
  72   IGNINVCH = CDCF_IGNINVCH
  73   IGNJUNK = CDCF_IGNJUNK
  74
  75 class CDCERR:
  76   OK = CDCERR_OK
  77   INVCH = CDCERR_INVCH
  78   INVEQPAD = CDCERR_INVEQPAD
  79   INVZPAD = CDCERR_INVZPAD
  80
  81 class CodecError (Exception):
  82   def __init__(me, err):
  83     me.err = err
  84     me.msg = _codec_strerror(err)
  85   def __str__(me):
  86     return me.msg
  87
  88 def codec_strerror(err):
  89   return _codec_strerror(err)
  90
  91 cdef int code(codec *c, void *p, size_t len, dstr *d) except -1:
  92   cdef int err
  93   err = c.ops.code(c, p, len, d)
  94   if err:
  95     raise CodecError(err)
  96   return 0
  97
  98 cdef class _BaseCodec:
  99   cdef codec *c
 100   def __cinit__(me, *hunoz, **hukairz):
 101     me.c = NULL
 102   def __init__(me, *hunoz, **hukairz):
 103     raise TypeError, 'abstract class'
 104   def __dealloc__(me):
 105     if me.c is not NULL:
 106       me.c.ops.destroy(me.c)
 107   cdef code(me, text, int finishp):
 108     cdef void *p
 109     cdef int len
 110     cdef dstr d
 111     cdef int err
 112     if me.c is NULL:
 113       raise ValueError, 'Encoding finished'
 114     DCREATE(&d)
 115     try:
 116       PyObject_AsReadBuffer(text, &p, &len)
 117       code(me.c, p, len, &d)
 118       if finishp:
 119         code(me.c, NULL, 0, &d)
 120         me.c.ops.destroy(me.c)
 121         me.c = NULL
 122       return PyString_FromStringAndSize(d.buf, d.len)
 123     finally:
 124       dstr_destroy(&d)
 125   def done(me):
 126     me.code('', True)
 127
 128 cdef class _BaseEncoder (_BaseCodec):
 129   def encode(me, text, finishp = False):
 130     return me.code(text, finishp)
 131
 132 cdef class _BaseDecoder (_BaseCodec):
 133   def decode(me, text, finishp = False):
 134     return me.code(text, finishp)
 135
 136 ###--------------------------------------------------------------------------
 137 ### Base64.
 138
 139 cdef extern from 'mLib/base64.h':
 140   codec_class base64_class
 141   codec_class file64_class
 142   codec_class base64url_class
 143
 144 cdef class Base64Encoder (_BaseEncoder):
 145   def __init__(me, indent = '\n', maxline = 72, flags = CDCF_IGNJUNK):
 146     me.c = base64_class.encoder(flags, indent, maxline)
 147
 148 cdef class Base64Decoder (_BaseDecoder):
 149   def __init__(me, flags = CDCF_IGNJUNK):
 150     me.c = base64_class.decoder(flags)
 151
 152 cdef class File64Encoder (_BaseEncoder):
 153   def __init__(me, indent = '\n', maxline = 72, flags = CDCF_IGNJUNK):
 154     me.c = file64_class.encoder(flags, indent, maxline)
 155
 156 cdef class File64Decoder (_BaseDecoder):
 157   def __init__(me, flags = CDCF_IGNJUNK):
 158     me.c = file64_class.decoder(flags)
 159
 160 cdef class Base64URLEncoder (_BaseEncoder):
 161   def __init__(me, indent = '\n', maxline = 72, flags = CDCF_IGNJUNK):
 162     me.c = base64url_class.encoder(flags, indent, maxline)
 163
 164 cdef class Base64URLDecoder (_BaseDecoder):
 165   def __init__(me, flags = CDCF_IGNJUNK):
 166     me.c = base64url_class.decoder(flags)
 167
 168 ###--------------------------------------------------------------------------
 169 ### Base32.
 170
 171 cdef extern from 'mLib/base32.h':
 172   codec_class base32_class
 173   codec_class base32hex_class
 174
 175 cdef class Base32Encoder (_BaseEncoder):
 176   def __init__(me, indent = '\n', maxline = 72, flags = CDCF_IGNJUNK):
 177     me.c = base32_class.encoder(flags, indent, maxline)
 178
 179 cdef class Base32Decoder (_BaseDecoder):
 180   def __init__(me, flags = CDCF_IGNJUNK):
 181     me.c = base32_class.decoder(flags)
 182
 183 cdef class Base32HexEncoder (_BaseEncoder):
 184   def __init__(me, indent = '\n', maxline = 72, flags = CDCF_IGNJUNK):
 185     me.c = base32hex_class.encoder(flags, indent, maxline)
 186
 187 cdef class Base32HexDecoder (_BaseDecoder):
 188   def __init__(me, flags = CDCF_IGNJUNK):
 189     me.c = base32hex_class.decoder(flags)
 190
 191 ###--------------------------------------------------------------------------
 192 ### Hex.
 193
 194 cdef extern from 'mLib/hex.h':
 195   codec_class hex_class
 196
 197 cdef class HexEncoder (_BaseEncoder):
 198   def __init__(me, indent = '\n', maxline = 72,
 199                flags = CDCF_IGNJUNK | CDCF_LOWERC):
 200     me.c = hex_class.encoder(flags, indent, maxline)
 201
 202 cdef class HexDecoder (_BaseDecoder):
 203   def __init__(me, flags = CDCF_IGNJUNK | CDCF_LOWERC):
 204     me.c = hex_class.decoder(flags)
 205
 206 ###----- That's all, folks --------------------------------------------------