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 #ifdef PY2
  46   x->ob_sstate = SSTATE_NOT_INTERNED;
  47 #endif
  48   return ((PyObject *)x);
  49 }
  50
  51 static PyObject *dowrap(PyTypeObject *ty, const void *p, size_t n)
  52 {
  53   PyObject *x;
  54   int ch;
  55
  56   if (p && ty == bytestring_pytype) {
  57     if (!n) {
  58       if (!empty) empty = allocate(ty, 0);
  59       Py_INCREF(empty); return (empty);
  60     } else if (n == 1 && (ch = *(unsigned char *)p) < sizeof(bytev)) {
  61       if (!bytev[ch])
  62         { bytev[ch] = allocate(ty, 1); *BIN_PTR(bytev[ch]) = ch; }
  63       Py_INCREF(bytev[ch]); return (bytev[ch]);
  64     }
  65   }
  66
  67   x = allocate(ty, n);
  68   if (p) memcpy(BIN_PTR(x), p, n);
  69   return (x);
  70 }
  71
  72 PyObject *bytestring_pywrap(const void *p, size_t n)
  73   { return (dowrap(bytestring_pytype, p, n)); }
  74
  75 PyObject *bytestring_pywrapbuf(buf *b)
  76   { return (dowrap(bytestring_pytype, BCUR(b), BLEFT(b))); }
  77
  78 static PyObject *bytestring_pynew(PyTypeObject *ty,
  79                                   PyObject *arg, PyObject *kw)
  80 {
  81   struct bin in;
  82   static const char *const kwlist[] = { "data", 0 };
  83   if (!PyArg_ParseTupleAndKeywords(arg, kw, "O&:new", KWLIST, convbin, &in))
  84     return (0);
  85   return (dowrap(ty, in.p, in.sz));
  86 }
  87
  88 static PyObject *meth_ctstreq(PyObject *me, PyObject *arg)
  89 {
  90   struct bin s0, s1;
  91   if (!PyArg_ParseTuple(arg, "O&O&:ctstreq", convbin, &s0 , convbin, &s1))
  92     goto end;
  93   if (s0.sz == s1.sz && ct_memeq(s0.p, s1.p, s0.sz)) RETURN_TRUE;
  94   else RETURN_FALSE;
  95 end:
  96   return (0);
  97 }
  98
  99 static PyObject *bymeth_zero(PyObject *me, PyObject *arg)
 100 {
 101   size_t sz;
 102   PyObject *rc = 0;
 103   if (!PyArg_ParseTuple(arg, "O&:zero", convszt, &sz)) goto end;
 104   rc = bytestring_pywrap(0, sz);
 105   memset(BIN_PTR(rc), 0, sz);
 106 end:
 107   return (rc);
 108 }
 109
 110 static PyObject *bytestring_pyrichcompare(PyObject *me,
 111                                           PyObject *you, int op)
 112 {
 113   struct bin s0, s1;
 114   int b;
 115   Py_ssize_t minlen;
 116
 117   s0.p = BIN_PTR(me); s0.sz = BIN_LEN(me);
 118   if (!convbin(you, &s1)) { PyErr_Clear(); RETURN_NOTIMPL; }
 119
 120   switch (op) {
 121     case Py_EQ:
 122       b = s0.sz == s1.sz && ct_memeq(s0.p, s1.p, s1.sz);
 123       break;
 124     case Py_NE:
 125       b = s0.sz != s1.sz || !ct_memeq(s0.p, s1.p, s1.sz);
 126       break;
 127     default:
 128       minlen = s0.sz < s1.sz ? s0.sz : s1.sz;
 129       b = memcmp(s0.p, s1.p, minlen);
 130       if (!b) b = s0.sz < s1.sz ? -1 : s0.sz > s1.sz ? +1 : 0;
 131       switch (op) {
 132         case Py_LT: b = b <  0; break;
 133         case Py_LE: b = b <= 0; break;
 134         case Py_GE: b = b >= 0; break;
 135         case Py_GT: b = b >  0; break;
 136         default: abort();
 137       }
 138   }
 139   if (b) RETURN_TRUE;
 140   else RETURN_FALSE;
 141 }
 142
 143 static PyObject *bytestring_pyconcat(PyObject *x, PyObject *y)
 144 {
 145   struct bin xx, yy;
 146   PyObject *z = 0; char *zp; size_t zsz;
 147
 148   if (!convbin(x, &xx) || !convbin(y, &yy)) goto end;
 149   zsz = (size_t)xx.sz + (size_t)yy.sz;
 150   if (xx.sz < 0 || yy.sz < 0 || zsz < xx.sz) VALERR("too long");
 151   z = bytestring_pywrap(0, zsz); zp = BIN_PTR(z);
 152   memcpy(zp, xx.p, xx.sz); memcpy(zp + xx.sz, yy.p, yy.sz);
 153 end:
 154   return (z);
 155 }
 156
 157 static PyObject *bytestring_pyrepeat(PyObject *me, Py_ssize_t n)
 158 {
 159   const unsigned char *xp; size_t xsz;
 160   PyObject *z = 0; char *zp; size_t zsz;
 161
 162   xp = (const unsigned char *)BIN_PTR(me);
 163   xsz = BIN_LEN(me);
 164   if (n < 0 || (n && xsz >= (size_t)-1/n)) VALERR("too long");
 165   zsz = n*xsz; z = bytestring_pywrap(0, zsz); zp = BIN_PTR(z);
 166   if (xsz == 1) memset(zp, *xp, zsz);
 167   else while (zsz) { memcpy(zp, xp, xsz); zp += xsz; zsz -= xsz; }
 168 end:
 169   return (z);
 170 }
 171
 172 static PyObject *bytestring_pyitem(PyObject *me, Py_ssize_t i)
 173 {
 174   PyObject *rc = 0;
 175
 176   if (i < 0 || i >= BIN_LEN(me)) IXERR("out of range");
 177 #ifdef PY3
 178   rc = getulong(BIN_PTR(me)[i]&0xff);
 179 #else
 180   rc = bytestring_pywrap(BIN_PTR(me) + i, 1);
 181 #endif
 182 end:
 183   return (rc);
 184 }
 185
 186 static PyObject *bytestring_pyslice(PyObject *me, Py_ssize_t i, Py_ssize_t j)
 187 {
 188   PyObject *rc = 0;
 189   size_t n = BIN_LEN(me);
 190
 191   if (i < 0) i = 0;
 192   if (j < 0) j = 0;
 193   else if (j > n) j = n;
 194   if (j < i) i = j = 0;
 195   if (i == 0 && j == n && Py_TYPE(me) == bytestring_pytype)
 196     { Py_INCREF(me); rc = me; goto end; }
 197   rc = bytestring_pywrap(BIN_PTR(me) + i, j - i);
 198 end:
 199   return (rc);
 200 }
 201
 202 static PyObject *bytestring_pysubscript(PyObject *me, PyObject *ix)
 203 {
 204   Py_ssize_t i, j, k, n;
 205   const unsigned char *p;
 206   unsigned char *q;
 207   PyObject *rc = 0;
 208
 209   if (PyIndex_Check(ix)) {
 210     i = PyNumber_AsSsize_t(ix, PyExc_IndexError);
 211     if (i == -1 && PyErr_Occurred()) return (0);
 212     if (i < 0) i += BIN_LEN(me);
 213     rc = bytestring_pyitem(me, i);
 214   } else if (PySlice_Check(ix)) {
 215     if (PySlice_GetIndicesEx(PY23((PySliceObject *), NOTHING)ix,
 216                              BIN_LEN(me), &i, &j, &k, &n))
 217       return (0);
 218     if (k == 1) return bytestring_pyslice(me, i, j);
 219     rc = bytestring_pywrap(0, n);
 220     p = (unsigned char *)BIN_PTR(me) + i;
 221     q = (unsigned char *)BIN_PTR(rc);
 222     while (n--) { *q++ = *p; p += k; }
 223   } else
 224     TYERR("wanted integer or slice");
 225 end:
 226   return (rc);
 227 }
 228
 229 #define BINOP(name, op)                                                 \
 230   static PyObject *bytestring_py##name(PyObject *x, PyObject *y) {      \
 231     struct bin xx, yy;                                                  \
 232     const unsigned char *xp, *yp;                                       \
 233     unsigned char *zp;                                                  \
 234     int i;                                                              \
 235     PyObject *rc = 0;                                                   \
 236     if (!convbin(x, &xx) || !convbin(y, &yy)) goto end;                 \
 237     if (xx.sz != yy.sz) VALERR("length mismatch");                      \
 238     rc = bytestring_pywrap(0, xx.sz);                                   \
 239     xp = xx.p; yp = yy.p; zp = (unsigned char *)BIN_PTR(rc);            \
 240     for (i = xx.sz; i > 0; i--) *zp++ = *xp++ op *yp++;                 \
 241   end:                                                                  \
 242     return (rc);                                                        \
 243   }
 244 BINOP(and, &)
 245 BINOP(or, |)
 246 BINOP(xor, ^)
 247
 248 #define UNOP(name, op)                                                  \
 249   static PyObject *bytestring_py##name(PyObject *x) {                   \
 250     struct bin xx;                                                      \
 251     const unsigned char *xp;                                            \
 252     unsigned char *zp;                                                  \
 253     int i;                                                              \
 254     PyObject *rc = 0;                                                   \
 255     if (!convbin(x, &xx)) goto end;                                     \
 256     rc = bytestring_pywrap(0, xx.sz);                                   \
 257     xp = xx.p; zp = (unsigned char *)BIN_PTR(rc);                       \
 258     for (i = xx.sz; i > 0; i--) *zp++ = op *xp++;                       \
 259   end:                                                                  \
 260     return (rc);                                                        \
 261   }
 262 UNOP(not, ~)
 263
 264 static const PyMethodDef bytestring_pymethods[] = {
 265 #define METHNAME(name) bymeth_##name
 266   SMTH  (zero,          "zero(N) -> 0000...00")
 267 #undef METHNAME
 268   { 0 }
 269 };
 270
 271 static const PyNumberMethods bytestring_pynumber = {
 272   0,                                    /* @nb_add@ */
 273   0,                                    /* @nb_subtract@ */
 274   0,                                    /* @nb_multiply@ */
 275 #ifdef PY2
 276   0,                                    /* @nb_divide@ */
 277 #endif
 278   0,                                    /* @nb_remainder@ */
 279   0,                                    /* @nb_divmod@ */
 280   0,                                    /* @nb_power@ */
 281   0,                                    /* @nb_negative@ */
 282   0,                                    /* @nb_positive@ */
 283   0,                                    /* @nb_absolute@ */
 284   0,                                    /* @nb_nonzero@ */
 285   bytestring_pynot,                     /* @nb_invert@ */
 286   0,                                    /* @nb_lshift@ */
 287   0,                                    /* @nb_rshift@ */
 288   bytestring_pyand,                     /* @nb_and@ */
 289   bytestring_pyxor,                     /* @nb_xor@ */
 290   bytestring_pyor,                      /* @nb_or@ */
 291   0,                                    /* @nb_coerce@ */
 292   0,                                    /* @nb_int@ */
 293   0,                                    /* @nb_long@ */
 294   0,                                    /* @nb_float@ */
 295   0,                                    /* @nb_oct@ */
 296   0,                                    /* @nb_hex@ */
 297 };
 298
 299 static const PySequenceMethods bytestring_pysequence = {
 300   0,                                    /* @sq_length@ */
 301   bytestring_pyconcat,                  /* @sq_concat@ */
 302   bytestring_pyrepeat,                  /* @sq_repeat@ */
 303   bytestring_pyitem,                    /* @sq_item@ */
 304   bytestring_pyslice,                   /* @sq_slice@ */
 305   0,                                    /* @sq_ass_item@ */
 306   0,                                    /* @sq_ass_slice@ */
 307   0,                                    /* @sq_contains@ */
 308   0,                                    /* @sq_inplace_concat@ */
 309   0,                                    /* @sq_inplace_repeat@ */
 310 };
 311
 312 static const PyMappingMethods bytestring_pymapping = {
 313   0,                                    /* @mp_length@ */
 314   bytestring_pysubscript,               /* @mp_subscript@ */
 315   0,                                    /* @mp_ass_subscript@ */
 316 };
 317
 318 static const PyTypeObject bytestring_pytype_skel = {
 319   PyVarObject_HEAD_INIT(0, 0)           /* Header */
 320   "ByteString",                         /* @tp_name@ */
 321   0,                                    /* @tp_basicsize@ */
 322   0,                                    /* @tp_itemsize@ */
 323
 324   0,                                    /* @tp_dealloc@ */
 325   0,                                    /* @tp_print@ */
 326   0,                                    /* @tp_getattr@ */
 327   0,                                    /* @tp_setattr@ */
 328   0,                                    /* @tp_compare@ */
 329   0,                                    /* @tp_repr@ */
 330   PYNUMBER(bytestring),                 /* @tp_as_number@ */
 331   PYSEQUENCE(bytestring),               /* @tp_as_sequence@ */
 332   PYMAPPING(bytestring),                /* @tp_as_mapping@ */
 333   0,                                    /* @tp_hash@ */
 334   0,                                    /* @tp_call@ */
 335   0,                                    /* @tp_str@ */
 336   0,                                    /* @tp_getattro@ */
 337   0,                                    /* @tp_setattro@ */
 338   0,                                    /* @tp_as_buffer@ */
 339   Py_TPFLAGS_DEFAULT |                  /* @tp_flags@ */
 340     Py_TPFLAGS_CHECKTYPES |
 341     Py_TPFLAGS_BASETYPE,
 342
 343   /* @tp_doc@ */
 344   "ByteString(STR): byte string class.",
 345
 346   0,                                    /* @tp_traverse@ */
 347   0,                                    /* @tp_clear@ */
 348   bytestring_pyrichcompare,             /* @tp_richcompare@ */
 349   0,                                    /* @tp_weaklistoffset@ */
 350   0,                                    /* @tp_iter@ */
 351   0,                                    /* @tp_iternext@ */
 352   PYMETHODS(bytestring),                /* @tp_methods@ */
 353   0,                                    /* @tp_members@ */
 354   0,                                    /* @tp_getset@ */
 355   0,                                    /* @tp_base@ */
 356   0,                                    /* @tp_dict@ */
 357   0,                                    /* @tp_descr_get@ */
 358   0,                                    /* @tp_descr_set@ */
 359   0,                                    /* @tp_dictoffset@ */
 360   0,                                    /* @tp_init@ */
 361   PyType_GenericAlloc,                  /* @tp_alloc@ */
 362   bytestring_pynew,                     /* @tp_new@ */
 363   0,                                    /* @tp_free@ */
 364   0                                     /* @tp_is_gc@ */
 365 };
 366
 367 /*----- Initialization ----------------------------------------------------*/
 368
 369 static const PyMethodDef methods[] = {
 370 #define METHNAME(func) meth_##func
 371   METH  (ctstreq,       "ctstreq(S, T) -> BOOL")
 372 #undef METHNAME
 373   { 0 }
 374 };
 375
 376 #define string_pytype &BIN_TYPE
 377 void bytestring_pyinit(void)
 378 {
 379   INITTYPE(bytestring, string);
 380   addmethods(methods);
 381 }
 382
 383 void bytestring_pyinsert(PyObject *mod)
 384 {
 385   INSERT("ByteString", bytestring_pytype);
 386 }
 387
 388 /*----- That's all, folks -------------------------------------------------*/