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 static PyTypeObject *bytestring_pytype;
  34
  35 static PyObject *empty, *bytev[256];
  36
  37 static PyObject *allocate(PyTypeObject *ty, size_t n)
  38 {
  39   BINOBJ *x;
  40   x = (BINOBJ *)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); *BIN_PTR(bytev[ch]) = ch; }
  61       Py_INCREF(bytev[ch]); return (bytev[ch]);
  62     }
  63   }
  64
  65   x = allocate(ty, n);
  66   if (p) memcpy(BIN_PTR(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   struct bin in;
  80   static const char *const kwlist[] = { "data", 0 };
  81   if (!PyArg_ParseTupleAndKeywords(arg, kw, "O&:new", KWLIST, convbin, &in))
  82     return (0);
  83   return (dowrap(ty, in.p, in.sz));
  84 }
  85
  86 static PyObject *meth_ctstreq(PyObject *me, PyObject *arg)
  87 {
  88   struct bin s0, s1;
  89   if (!PyArg_ParseTuple(arg, "O&O&:ctstreq", convbin, &s0 , convbin, &s1))
  90     goto end;
  91   if (s0.sz == s1.sz && ct_memeq(s0.p, s1.p, s0.sz)) RETURN_TRUE;
  92   else RETURN_FALSE;
  93 end:
  94   return (0);
  95 }
  96
  97 static PyObject *bymeth_zero(PyObject *me, PyObject *arg)
  98 {
  99   size_t sz;
 100   PyObject *rc = 0;
 101   if (!PyArg_ParseTuple(arg, "O&:zero", convszt, &sz)) goto end;
 102   rc = bytestring_pywrap(0, sz);
 103   memset(BIN_PTR(rc), 0, sz);
 104 end:
 105   return (rc);
 106 }
 107
 108 static PyObject *bytestring_pyrichcompare(PyObject *me,
 109                                           PyObject *you, int op)
 110 {
 111   struct bin s0, s1;
 112   int b;
 113   Py_ssize_t minlen;
 114
 115   s0.p = BIN_PTR(me); s0.sz = BIN_LEN(me);
 116   if (!convbin(you, &s1)) { PyErr_Clear(); RETURN_NOTIMPL; }
 117
 118   switch (op) {
 119     case Py_EQ:
 120       b = s0.sz == s1.sz && ct_memeq(s0.p, s1.p, s1.sz);
 121       break;
 122     case Py_NE:
 123       b = s0.sz != s1.sz || !ct_memeq(s0.p, s1.p, s1.sz);
 124       break;
 125     default:
 126       minlen = s0.sz < s1.sz ? s0.sz : s1.sz;
 127       b = memcmp(s0.p, s1.p, minlen);
 128       if (!b) b = s0.sz < s1.sz ? -1 : s0.sz > s1.sz ? +1 : 0;
 129       switch (op) {
 130         case Py_LT: b = b <  0; break;
 131         case Py_LE: b = b <= 0; break;
 132         case Py_GE: b = b >= 0; break;
 133         case Py_GT: b = b >  0; break;
 134         default: abort();
 135       }
 136   }
 137   if (b) RETURN_TRUE;
 138   else RETURN_FALSE;
 139 }
 140
 141 static PyObject *bytestring_pyconcat(PyObject *x, PyObject *y)
 142 {
 143   struct bin xx, yy;
 144   PyObject *z = 0; char *zp; size_t zsz;
 145
 146   if (!convbin(x, &xx) || !convbin(y, &yy)) goto end;
 147   zsz = (size_t)xx.sz + (size_t)yy.sz;
 148   if (xx.sz < 0 || yy.sz < 0 || zsz < xx.sz) VALERR("too long");
 149   z = bytestring_pywrap(0, zsz); zp = BIN_PTR(z);
 150   memcpy(zp, xx.p, xx.sz); memcpy(zp + xx.sz, yy.p, yy.sz);
 151 end:
 152   return (z);
 153 }
 154
 155 static PyObject *bytestring_pyrepeat(PyObject *me, Py_ssize_t n)
 156 {
 157   const unsigned char *xp; size_t xsz;
 158   PyObject *z = 0; char *zp; size_t zsz;
 159
 160   xp = (const unsigned char *)BIN_PTR(me);
 161   xsz = BIN_LEN(me);
 162   if (n < 0 || (n && xsz >= (size_t)-1/n)) VALERR("too long");
 163   zsz = n*xsz; z = bytestring_pywrap(0, zsz); zp = BIN_PTR(z);
 164   if (xsz == 1) memset(zp, *xp, zsz);
 165   else while (zsz) { memcpy(zp, xp, xsz); zp += xsz; zsz -= xsz; }
 166 end:
 167   return (z);
 168 }
 169
 170 static PyObject *bytestring_pyitem(PyObject *me, Py_ssize_t i)
 171 {
 172   PyObject *rc = 0;
 173
 174   if (i < 0 || i >= BIN_LEN(me)) IXERR("out of range");
 175   rc = bytestring_pywrap(BIN_PTR(me) + i, 1);
 176 end:
 177   return (rc);
 178 }
 179
 180 static PyObject *bytestring_pyslice(PyObject *me, Py_ssize_t i, Py_ssize_t j)
 181 {
 182   PyObject *rc = 0;
 183   size_t n = BIN_LEN(me);
 184
 185   if (i < 0) i = 0;
 186   if (j < 0) j = 0;
 187   else if (j > n) j = n;
 188   if (j < i) i = j = 0;
 189   if (i == 0 && j == n && Py_TYPE(me) == bytestring_pytype)
 190     { Py_INCREF(me); rc = me; goto end; }
 191   rc = bytestring_pywrap(BIN_PTR(me) + i, j - i);
 192 end:
 193   return (rc);
 194 }
 195
 196 static PyObject *bytestring_pysubscript(PyObject *me, PyObject *ix)
 197 {
 198   Py_ssize_t i, j, k, n;
 199   const unsigned char *p;
 200   unsigned char *q;
 201   PyObject *rc = 0;
 202
 203   if (PyIndex_Check(ix)) {
 204     i = PyNumber_AsSsize_t(ix, PyExc_IndexError);
 205     if (i == -1 && PyErr_Occurred()) return (0);
 206     if (i < 0) i += BIN_LEN(me);
 207     rc = bytestring_pyitem(me, i);
 208   } else if (PySlice_Check(ix)) {
 209     if (PySlice_GetIndicesEx((PySliceObject *)ix, BIN_LEN(me),
 210                              &i, &j, &k, &n))
 211       return (0);
 212     if (k == 1) return bytestring_pyslice(me, i, j);
 213     rc = bytestring_pywrap(0, n);
 214     p = (unsigned char *)BIN_PTR(me) + i;
 215     q = (unsigned char *)BIN_PTR(rc);
 216     while (n--) { *q++ = *p; p += k; }
 217   } else
 218     TYERR("wanted integer or slice");
 219 end:
 220   return (rc);
 221 }
 222
 223 #define BINOP(name, op)                                                 \
 224   static PyObject *bytestring_py##name(PyObject *x, PyObject *y) {      \
 225     struct bin xx, yy;                                                  \
 226     const unsigned char *xp, *yp;                                       \
 227     unsigned char *zp;                                                  \
 228     int i;                                                              \
 229     PyObject *rc = 0;                                                   \
 230     if (!convbin(x, &xx) || !convbin(y, &yy)) goto end;                 \
 231     if (xx.sz != yy.sz) VALERR("length mismatch");                      \
 232     rc = bytestring_pywrap(0, xx.sz);                                   \
 233     xp = xx.p; yp = yy.p; zp = (unsigned char *)BIN_PTR(rc);            \
 234     for (i = xx.sz; i > 0; i--) *zp++ = *xp++ op *yp++;                 \
 235   end:                                                                  \
 236     return (rc);                                                        \
 237   }
 238 BINOP(and, &)
 239 BINOP(or, |)
 240 BINOP(xor, ^)
 241
 242 #define UNOP(name, op)                                                  \
 243   static PyObject *bytestring_py##name(PyObject *x) {                   \
 244     struct bin xx;                                                      \
 245     const unsigned char *xp;                                            \
 246     unsigned char *zp;                                                  \
 247     int i;                                                              \
 248     PyObject *rc = 0;                                                   \
 249     if (!convbin(x, &xx)) goto end;                                     \
 250     rc = bytestring_pywrap(0, xx.sz);                                   \
 251     xp = xx.p; zp = (unsigned char *)BIN_PTR(rc);                       \
 252     for (i = xx.sz; i > 0; i--) *zp++ = op *xp++;                       \
 253   end:                                                                  \
 254     return (rc);                                                        \
 255   }
 256 UNOP(not, ~)
 257
 258 static const PyMethodDef bytestring_pymethods[] = {
 259 #define METHNAME(name) bymeth_##name
 260   SMTH  (zero,          "zero(N) -> 0000...00")
 261 #undef METHNAME
 262   { 0 }
 263 };
 264
 265 static const PyNumberMethods bytestring_pynumber = {
 266   0,                                    /* @nb_add@ */
 267   0,                                    /* @nb_subtract@ */
 268   0,                                    /* @nb_multiply@ */
 269   0,                                    /* @nb_divide@ */
 270   0,                                    /* @nb_remainder@ */
 271   0,                                    /* @nb_divmod@ */
 272   0,                                    /* @nb_power@ */
 273   0,                                    /* @nb_negative@ */
 274   0,                                    /* @nb_positive@ */
 275   0,                                    /* @nb_absolute@ */
 276   0,                                    /* @nb_nonzero@ */
 277   bytestring_pynot,                     /* @nb_invert@ */
 278   0,                                    /* @nb_lshift@ */
 279   0,                                    /* @nb_rshift@ */
 280   bytestring_pyand,                     /* @nb_and@ */
 281   bytestring_pyxor,                     /* @nb_xor@ */
 282   bytestring_pyor,                      /* @nb_or@ */
 283   0,                                    /* @nb_coerce@ */
 284   0,                                    /* @nb_int@ */
 285   0,                                    /* @nb_long@ */
 286   0,                                    /* @nb_float@ */
 287   0,                                    /* @nb_oct@ */
 288   0,                                    /* @nb_hex@ */
 289 };
 290
 291 static const PySequenceMethods bytestring_pysequence = {
 292   0,                                    /* @sq_length@ */
 293   bytestring_pyconcat,                  /* @sq_concat@ */
 294   bytestring_pyrepeat,                  /* @sq_repeat@ */
 295   bytestring_pyitem,                    /* @sq_item@ */
 296   bytestring_pyslice,                   /* @sq_slice@ */
 297   0,                                    /* @sq_ass_item@ */
 298   0,                                    /* @sq_ass_slice@ */
 299   0,                                    /* @sq_contains@ */
 300   0,                                    /* @sq_inplace_concat@ */
 301   0,                                    /* @sq_inplace_repeat@ */
 302 };
 303
 304 static const PyMappingMethods bytestring_pymapping = {
 305   0,                                    /* @mp_length@ */
 306   bytestring_pysubscript,               /* @mp_subscript@ */
 307   0,                                    /* @mp_ass_subscript@ */
 308 };
 309
 310 static const PyTypeObject bytestring_pytype_skel = {
 311   PyVarObject_HEAD_INIT(0, 0)           /* Header */
 312   "ByteString",                         /* @tp_name@ */
 313   0,                                    /* @tp_basicsize@ */
 314   0,                                    /* @tp_itemsize@ */
 315
 316   0,                                    /* @tp_dealloc@ */
 317   0,                                    /* @tp_print@ */
 318   0,                                    /* @tp_getattr@ */
 319   0,                                    /* @tp_setattr@ */
 320   0,                                    /* @tp_compare@ */
 321   0,                                    /* @tp_repr@ */
 322   PYNUMBER(bytestring),                 /* @tp_as_number@ */
 323   PYSEQUENCE(bytestring),               /* @tp_as_sequence@ */
 324   PYMAPPING(bytestring),                /* @tp_as_mapping@ */
 325   0,                                    /* @tp_hash@ */
 326   0,                                    /* @tp_call@ */
 327   0,                                    /* @tp_str@ */
 328   0,                                    /* @tp_getattro@ */
 329   0,                                    /* @tp_setattro@ */
 330   0,                                    /* @tp_as_buffer@ */
 331   Py_TPFLAGS_DEFAULT |                  /* @tp_flags@ */
 332     Py_TPFLAGS_CHECKTYPES |
 333     Py_TPFLAGS_BASETYPE,
 334
 335   /* @tp_doc@ */
 336   "ByteString(STR): byte string class.",
 337
 338   0,                                    /* @tp_traverse@ */
 339   0,                                    /* @tp_clear@ */
 340   bytestring_pyrichcompare,             /* @tp_richcompare@ */
 341   0,                                    /* @tp_weaklistoffset@ */
 342   0,                                    /* @tp_iter@ */
 343   0,                                    /* @tp_iternext@ */
 344   PYMETHODS(bytestring),                /* @tp_methods@ */
 345   0,                                    /* @tp_members@ */
 346   0,                                    /* @tp_getset@ */
 347   0,                                    /* @tp_base@ */
 348   0,                                    /* @tp_dict@ */
 349   0,                                    /* @tp_descr_get@ */
 350   0,                                    /* @tp_descr_set@ */
 351   0,                                    /* @tp_dictoffset@ */
 352   0,                                    /* @tp_init@ */
 353   PyType_GenericAlloc,                  /* @tp_alloc@ */
 354   bytestring_pynew,                     /* @tp_new@ */
 355   0,                                    /* @tp_free@ */
 356   0                                     /* @tp_is_gc@ */
 357 };
 358
 359 /*----- Initialization ----------------------------------------------------*/
 360
 361 static const PyMethodDef methods[] = {
 362 #define METHNAME(func) meth_##func
 363   METH  (ctstreq,       "ctstreq(S, T) -> BOOL")
 364 #undef METHNAME
 365   { 0 }
 366 };
 367
 368 #define string_pytype &BIN_TYPE
 369 void bytestring_pyinit(void)
 370 {
 371   INITTYPE(bytestring, string);
 372   addmethods(methods);
 373 }
 374
 375 void bytestring_pyinsert(PyObject *mod)
 376 {
 377   INSERT("ByteString", bytestring_pytype);
 378 }
 379
 380 /*----- That's all, folks -------------------------------------------------*/