chiark - git - mdw - catacomb-python/blob - bytestring.c

   1 /* -*-c-*-
   2  *
   3  * Byte strings
   4  *
   5  * (c) 2004 Straylight/Edgeware
   6  */
   7
   8 /*----- Licensing notice --------------------------------------------------*
   9  *
  10  * This file is part of the Python interface to Catacomb.
  11  *
  12  * Catacomb/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  * Catacomb/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 Catacomb/Python; if not, write to the Free Software Foundation,
  24  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  25  */
  26
  27 /*----- Header files ------------------------------------------------------*/
  28
  29 #include "catacomb-python.h"
  30
  31 /*----- Main code ---------------------------------------------------------*/
  32
  33 PyTypeObject *bytestring_pytype;
  34
  35 static PyObject *empty, *bytev[256];
  36
  37 static PyObject *allocate(PyTypeObject *ty, size_t n)
  38 {
  39   PyStringObject *x;
  40   x = (PyStringObject *)ty->tp_alloc(ty, n);
  41   x->ob_sval[n] = 0;
  42 #if defined(CACHE_HASH) || PY_VERSION_HEX >= 0x02030000
  43   x->ob_shash = -1;
  44 #endif
  45   x->ob_sstate = SSTATE_NOT_INTERNED;
  46   return ((PyObject *)x);
  47 }
  48
  49 static PyObject *dowrap(PyTypeObject *ty, const void *p, size_t n)
  50 {
  51   PyObject *x;
  52   int ch;
  53
  54   if (p && ty == bytestring_pytype) {
  55     if (!n) {
  56       if (!empty) empty = allocate(ty, 0);
  57       Py_INCREF(empty); return (empty);
  58     } else if (n == 1 && (ch = *(unsigned char *)p) < sizeof(bytev)) {
  59       if (!bytev[ch])
  60         { bytev[ch] = allocate(ty, 1); *PyString_AS_STRING(bytev[ch]) = ch; }
  61       Py_INCREF(bytev[ch]); return (bytev[ch]);
  62     }
  63   }
  64
  65   x = allocate(ty, n);
  66   if (p) memcpy(PyString_AS_STRING(x), p, n);
  67   return (x);
  68 }
  69
  70 PyObject *bytestring_pywrap(const void *p, size_t n)
  71   { return (dowrap(bytestring_pytype, p, n)); }
  72
  73 PyObject *bytestring_pywrapbuf(buf *b)
  74   { return (dowrap(bytestring_pytype, BCUR(b), BLEFT(b))); }
  75
  76 static PyObject *bytestring_pynew(PyTypeObject *ty,
  77                                   PyObject *arg, PyObject *kw)
  78 {
  79   const char *p;
  80   Py_ssize_t n;
  81   static const char *const kwlist[] = { "data", 0 };
  82   if (!PyArg_ParseTupleAndKeywords(arg, kw, "s#:new", KWLIST, &p, &n))
  83     return (0);
  84   return (dowrap(ty, p, n));
  85 }
  86
  87 static PyObject *meth_ctstreq(PyObject *me, PyObject *arg)
  88 {
  89   char *p, *q;
  90   Py_ssize_t psz, qsz;
  91   if (!PyArg_ParseTuple(arg, "s#s#:ctstreq", &p, &psz, &q, &qsz))
  92     goto end;
  93   if (psz == qsz && ct_memeq(p, q, psz)) RETURN_TRUE;
  94   else RETURN_FALSE;
  95 end:
  96   return (0);
  97 }
  98
  99 static PyObject *meth__ByteString_zero(PyObject *me, PyObject *arg)
 100 {
 101   size_t sz;
 102   PyObject *rc = 0;
 103   if (!PyArg_ParseTuple(arg, "OO&:zero", &me, convszt, &sz)) goto end;
 104   rc = bytestring_pywrap(0, sz);
 105   memset(PyString_AS_STRING(rc), 0, sz);
 106 end:
 107   return (rc);
 108 }
 109
 110 static PyObject *bytestring_pyrichcompare(PyObject *me,
 111                                           PyObject *you, int op)
 112 {
 113   int b;
 114   void *mystr, *yourstr;
 115   Py_ssize_t mylen, yourlen, minlen;
 116
 117   if (!PyString_Check(me) || !PyString_Check(you)) RETURN_NOTIMPL;
 118   mystr = PyString_AS_STRING(me); mylen = PyString_GET_SIZE(me);
 119   yourstr = PyString_AS_STRING(you); yourlen = PyString_GET_SIZE(you);
 120
 121   switch (op) {
 122     case Py_EQ:
 123       b = mylen == yourlen && ct_memeq(mystr, yourstr, mylen);
 124       break;
 125     case Py_NE:
 126       b = mylen != yourlen || !ct_memeq(mystr, yourstr, mylen);
 127       break;
 128     default:
 129       minlen = mylen < yourlen ? mylen : yourlen;
 130       b = memcmp(mystr, yourstr, minlen);
 131       if (!b) b = mylen < yourlen ? -1 : mylen > yourlen ? +1 : 0;
 132       switch (op) {
 133         case Py_LT: b = b <  0; break;
 134         case Py_LE: b = b <= 0; break;
 135         case Py_GE: b = b >= 0; break;
 136         case Py_GT: b = b >  0; break;
 137         default: abort();
 138       }
 139   }
 140   if (b) RETURN_TRUE;
 141   else RETURN_FALSE;
 142 }
 143
 144 #define BINOP(name, op)                                                 \
 145   static PyObject *bytestring_py##name(PyObject *x, PyObject *y) {      \
 146     const void *xv, *yv;                                                \
 147     const unsigned char *xp, *yp;                                       \
 148     unsigned char *zp;                                                  \
 149     Py_ssize_t xsz, ysz;                                                \
 150     int i;                                                              \
 151     PyObject *rc = 0;                                                   \
 152     if (PyObject_AsReadBuffer(x, &xv, &xsz) ||                          \
 153         PyObject_AsReadBuffer(y, &yv, &ysz))                            \
 154       goto end;                                                         \
 155     if (xsz != ysz) VALERR("length mismatch");                          \
 156     rc = bytestring_pywrap(0, xsz);                                     \
 157     xp = xv; yp = yv; zp = (unsigned char *)PyString_AS_STRING(rc);     \
 158     for (i = xsz; i > 0; i--) *zp++ = *xp++ op *yp++;                   \
 159   end:                                                                  \
 160     return (rc);                                                        \
 161   }
 162 BINOP(and, &)
 163 BINOP(or, |)
 164 BINOP(xor, ^)
 165
 166 #define UNOP(name, op)                                                  \
 167   static PyObject *bytestring_py##name(PyObject *x) {                   \
 168     const void *xv;                                                     \
 169     const unsigned char *xp;                                            \
 170     unsigned char *zp;                                                  \
 171     Py_ssize_t xsz;                                                     \
 172     int i;                                                              \
 173     PyObject *rc = 0;                                                   \
 174     if (PyObject_AsReadBuffer(x, &xv, &xsz)) goto end;                  \
 175     rc = bytestring_pywrap(0, xsz);                                     \
 176     xp = xv; zp = (unsigned char *)PyString_AS_STRING(rc);              \
 177     for (i = xsz; i > 0; i--) *zp++ = op *xp++;                         \
 178   end:                                                                  \
 179     return (rc);                                                        \
 180   }
 181 UNOP(not, ~)
 182
 183 static PyNumberMethods bytestring_pynumber = {
 184   0,                                    /* @nb_add@ */
 185   0,                                    /* @nb_subtract@ */
 186   0,                                    /* @nb_multiply@ */
 187   0,                                    /* @nb_divide@ */
 188   0,                                    /* @nb_remainder@ */
 189   0,                                    /* @nb_divmod@ */
 190   0,                                    /* @nb_power@ */
 191   0,                                    /* @nb_negative@ */
 192   0,                                    /* @nb_positive@ */
 193   0,                                    /* @nb_absolute@ */
 194   0,                                    /* @nb_nonzero@ */
 195   bytestring_pynot,                     /* @nb_invert@ */
 196   0,                                    /* @nb_lshift@ */
 197   0,                                    /* @nb_rshift@ */
 198   bytestring_pyand,                     /* @nb_and@ */
 199   bytestring_pyxor,                     /* @nb_xor@ */
 200   bytestring_pyor,                      /* @nb_or@ */
 201   0,                                    /* @nb_coerce@ */
 202   0,                                    /* @nb_int@ */
 203   0,                                    /* @nb_long@ */
 204   0,                                    /* @nb_float@ */
 205   0,                                    /* @nb_oct@ */
 206   0,                                    /* @nb_hex@ */
 207 };
 208
 209 static PyBufferProcs bytestring_pybuffer;
 210
 211 static PyTypeObject bytestring_pytype_skel = {
 212   PyObject_HEAD_INIT(0) 0,              /* Header */
 213   "ByteString",                         /* @tp_name@ */
 214   0,                                    /* @tp_basicsize@ */
 215   0,                                    /* @tp_itemsize@ */
 216
 217   0,                                    /* @tp_dealloc@ */
 218   0,                                    /* @tp_print@ */
 219   0,                                    /* @tp_getattr@ */
 220   0,                                    /* @tp_setattr@ */
 221   0,                                    /* @tp_compare@ */
 222   0,                                    /* @tp_repr@ */
 223   &bytestring_pynumber,                 /* @tp_as_number@ */
 224   0,                                    /* @tp_as_sequence@ */
 225   0,                                    /* @tp_as_mapping@ */
 226   0,                                    /* @tp_hash@ */
 227   0,                                    /* @tp_call@ */
 228   0,                                    /* @tp_str@ */
 229   0,                                    /* @tp_getattro@ */
 230   0,                                    /* @tp_setattro@ */
 231   &bytestring_pybuffer,                 /* @tp_as_buffer@ */
 232   Py_TPFLAGS_DEFAULT |                  /* @tp_flags@ */
 233     Py_TPFLAGS_CHECKTYPES |
 234     Py_TPFLAGS_BASETYPE,
 235
 236   /* @tp_doc@ */
 237 "ByteString(STR): byte string class.",
 238
 239   0,                                    /* @tp_traverse@ */
 240   0,                                    /* @tp_clear@ */
 241   bytestring_pyrichcompare,             /* @tp_richcompare@ */
 242   0,                                    /* @tp_weaklistoffset@ */
 243   0,                                    /* @tp_iter@ */
 244   0,                                    /* @tp_iternext@ */
 245   0,                                    /* @tp_methods@ */
 246   0,                                    /* @tp_members@ */
 247   0,                                    /* @tp_getset@ */
 248   0,                                    /* @tp_base@ */
 249   0,                                    /* @tp_dict@ */
 250   0,                                    /* @tp_descr_get@ */
 251   0,                                    /* @tp_descr_set@ */
 252   0,                                    /* @tp_dictoffset@ */
 253   0,                                    /* @tp_init@ */
 254   PyType_GenericAlloc,                  /* @tp_alloc@ */
 255   bytestring_pynew,                     /* @tp_new@ */
 256   0,                                    /* @tp_free@ */
 257   0                                     /* @tp_is_gc@ */
 258 };
 259
 260 /*----- Initialization ----------------------------------------------------*/
 261
 262 static PyMethodDef methods[] = {
 263 #define METHNAME(func) meth_##func
 264   METH  (ctstreq,               "ctstreq(S, T) -> BOOL")
 265   METH  (_ByteString_zero,      "zero(N) -> 0000...00")
 266 #undef METHNAME
 267   { 0 }
 268 };
 269
 270 #define string_pytype &PyString_Type
 271 void bytestring_pyinit(void)
 272 {
 273   INITTYPE(bytestring, string);
 274   addmethods(methods);
 275 }
 276
 277 void bytestring_pyinsert(PyObject *mod)
 278 {
 279   INSERT("ByteString", bytestring_pytype);
 280 }
 281
 282 /*----- That's all, folks -------------------------------------------------*/