mdw@git.distorted.org.uk Git - python-cdb/blob - src/cdbmodule.c

   1 /**
   2 python-cdb 0.32
   3 Copyright 2001, 2002 Michael J. Pomraning <mjp@pilcrow.madison.wi.us>
   4
   5 This program is free software; you can redistribute it and/or modify
   6 it under the terms of the GNU General Public License as published by
   7 the Free Software Foundation; either version 2 of the License, or
   8 (at your option) any later version.
   9
  10 This program is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU General Public License for more details.
  14
  15 You should have received a copy of the GNU General Public License
  16 along with this program; if not, write to the Free Software
  17 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18
  19 **/
  20
  21 #include <Python.h>
  22 #include <unistd.h>
  23 #include <sys/types.h>
  24 #include <fcntl.h>
  25 #include "cdb.h"
  26 #include "cdb_make.h"
  27
  28 #define open_read(x)       (open((x),O_RDONLY|O_NDELAY))
  29 /* ala djb's open_foo */
  30
  31 #define VERSION     "0.32"
  32 #define CDBVERSION  "0.75"
  33
  34 /* ------------------- cdb object -------------------- */
  35
  36 static char cdbo_object_doc[] = "\
  37 This object represents a CDB database:  a reliable, constant\n\
  38 database mapping strings of bytes (\"keys\") to strings of bytes\n\
  39 (\"data\"), and designed for fast lookups.\n\
  40 \n\
  41 Unlike a conventional mapping, CDBs can meaningfully store multiple\n\
  42 records under one key (though this feature is not often used).\n\
  43 \n\
  44 A CDB object 'cdb_o' offers the following interesting attributes:\n\
  45 \n\
  46   Dict-like Lookup Methods:\n\
  47     cdb_o[key], get(key), getnext(), getall(key)\n\
  48 \n\
  49   Key-based Iteration Methods:\n\
  50     keys(), firstkey(), nextkey()\n\
  51     (Key-based iteration returns only distinct keys.)\n\
  52 \n\
  53   Raw Iteration Method:\n\
  54     each()\n\
  55     (\"Dumping\" may return the same key more than once.)\n\
  56 \n\
  57   __members__:\n\
  58     fd   - File descriptor of the underlying cdb.\n\
  59     name - Name of the cdb, or None if not known.\n\
  60     size - Size of the cdb, or None if not mmap()d.\n\
  61 \n\
  62   __length__:\n\
  63     len(cdb_o) returns the total number of items in a cdb,\n\
  64     which may or may not exceed the number of distinct keys.\n";
  65
  66
  67 typedef struct {
  68     PyObject_HEAD
  69     struct cdb c;
  70     PyObject * name_py;  /* 'filename' or Py_None */
  71     PyObject * getkey;   /* squirreled away for getnext() */
  72     uint32 eod;          /* as in cdbdump */
  73     uint32 iter_pos;
  74     uint32 each_pos;
  75     uint32 numrecords;
  76 } CdbObject;
  77
  78 staticforward PyTypeObject CdbType;
  79
  80 PyObject * CDBError;
  81 #define CDBerr PyErr_SetFromErrno(CDBError)
  82
  83 static PyObject *
  84 cdb_pyread(CdbObject *cdb_o, unsigned int len, uint32 pos) {
  85   struct cdb *c;
  86   PyObject *s = NULL;
  87
  88   c = &cdb_o->c;
  89
  90   if (c->map) {
  91     if ((pos > c->size) || (c->size - pos < len))
  92       goto FORMAT;
  93     s = PyString_FromStringAndSize(c->map + pos, len);
  94   } else {
  95     s = PyString_FromStringAndSize(NULL, len);
  96     if (s == NULL)
  97       return NULL;
  98     if (lseek(c->fd,pos,SEEK_SET) == -1) goto ERRNO;
  99     while (len > 0) {
 100       int r;
 101       char * buf = PyString_AsString(s);
 102
 103       do {
 104         Py_BEGIN_ALLOW_THREADS
 105         r = read(c->fd,buf,len);
 106         Py_END_ALLOW_THREADS
 107       }
 108       while ((r == -1) && (errno == EINTR));
 109       if (r == -1) goto ERRNO;
 110       if (r == 0) goto FORMAT;
 111       buf += r;
 112       len -= r;
 113     }
 114   }
 115
 116   return s;
 117
 118   FORMAT:
 119   Py_XDECREF(s);
 120   PyErr_SetFromErrno(PyExc_RuntimeError);
 121   return NULL;
 122
 123   ERRNO:
 124   Py_XDECREF(s);
 125   return CDBerr;
 126
 127 }
 128
 129
 130 #define CDBO_CURDATA(x) (cdb_pyread(x, x->c.dlen, x->c.dpos))
 131
 132
 133 /* ------------------- CdbObject methods -------------------- */
 134
 135 static char cdbo_has_key_doc[] =
 136 "cdb_o.has_key(k) -> 1 (or 0)\n\
 137 \n\
 138 Returns true if the CDB contains key k.";
 139
 140 static PyObject *
 141 cdbo_has_key(CdbObject *self, PyObject *args) {
 142
 143   char * key;
 144   unsigned int klen;
 145   int r;
 146
 147   if (!PyArg_ParseTuple(args, "s#", &key, &klen))
 148     return NULL;
 149
 150   r = cdb_find(&self->c, key, klen);
 151   if (r == -1)
 152     return CDBerr;
 153
 154   return Py_BuildValue("i", r);
 155
 156 }
 157
 158 static char cdbo_get_doc[] =
 159 "cdb_o.get(k [, i]) -> data (or None)\n\
 160 \n\
 161 Fetches the record stored under key k, skipping past the first i\n\
 162 records under that key (default: 0).  Prepares the next call to\n\
 163 getnext().\n\
 164 \n\
 165 Assuming cdb_o.has_key(k) == 1, then all of the following return:\n\
 166 the first record stored under key k:\n\
 167 \n\
 168     cdb_o.get(k) == cdb_o[k] == cdb_o.getall(k)[0]\n";
 169
 170 static PyObject *
 171 cdbo_get(CdbObject *self, PyObject *args) {
 172
 173   char * key;
 174   unsigned int klen;
 175   int r;
 176   int i = 0;
 177
 178   if (!PyArg_ParseTuple(args, "s#|i:get", &key, &klen, &i))
 179     return NULL;
 180
 181   cdb_findstart(&self->c);
 182
 183   for (;;) {
 184     r = cdb_findnext(&self->c, key, klen);
 185     if (r == -1) return CDBerr;
 186     if (!r) return Py_BuildValue("");
 187     if (!i) break;
 188     --i;
 189   }
 190
 191   /* prep. possibly ensuing call to getnext() */
 192   Py_XDECREF(self->getkey);
 193   self->getkey = PyString_FromStringAndSize(key, klen);
 194   if (self->getkey == NULL)
 195     return NULL;
 196
 197   return CDBO_CURDATA(self);
 198 }
 199
 200 static char cdbo_getall_doc[] =
 201 "cdb_o.getall(k) -> ['data', ... ]\n\
 202 \n\
 203 Return a list of all records stored under key k.";
 204
 205 static PyObject *
 206 cdbo_getall(CdbObject *self, PyObject *args) {
 207
 208   PyObject * list, * data;
 209   char * key;
 210   unsigned int klen;
 211   int r, err;
 212
 213   if (!PyArg_ParseTuple(args, "s#:getall", &key, &klen))
 214     return NULL;
 215
 216   list = PyList_New(0);
 217
 218   if (list == NULL) return NULL;
 219
 220   cdb_findstart(&self->c);
 221
 222   while ((r = cdb_findnext(&self->c, key, klen))) {
 223     if (r == -1) {
 224       Py_DECREF(list);
 225       return CDBerr;
 226     }
 227     data = CDBO_CURDATA(self);
 228     if (data == NULL) {
 229       Py_DECREF(list);
 230       return NULL;
 231     }
 232     err = PyList_Append(list, data);
 233     Py_DECREF(data);
 234     if (err != 0) {
 235       Py_DECREF(list);
 236       return NULL;
 237     }
 238   }
 239
 240   return list;
 241
 242 }
 243
 244 static char cdbo_getnext_doc[] =
 245 "cdb_o.getnext() -> 'data' (or None)\n\
 246 \n\
 247 For iteration over the records stored under one key, avoiding loading\n\
 248 all items into memory).  The \"current key\" is determined by the most\n\
 249 recent call to get().\n\
 250 \n\
 251 The following loops through all items stored under key k:\n\
 252 \n\
 253     ## cdb_o.getall(k) possibly too big for memory\n\
 254     rec = cdb_o.get(k)\n\
 255     while rec is not None:\n\
 256       do_something(rec)\n\
 257       rec = cdb_o.getnext()\n";
 258
 259 static PyObject *
 260 cdbo_getnext(CdbObject *self, PyObject *args) {
 261
 262   if (!PyArg_ParseTuple(args, ":getnext"))
 263     return NULL;
 264
 265   if (self->getkey == NULL) {
 266     PyErr_SetString(PyExc_TypeError,
 267                     "getnext() called without first calling get()");
 268     return NULL;
 269   }
 270
 271   switch(cdb_findnext(&self->c,
 272                       PyString_AsString(self->getkey),
 273                       PyString_Size(self->getkey))) {
 274     case -1:
 275       return CDBerr;
 276     case  0:
 277       Py_DECREF(self->getkey);
 278       self->getkey = NULL;
 279       return Py_BuildValue("");
 280     default:
 281       return CDBO_CURDATA(self);
 282   }
 283  /* not reached */
 284 }
 285
 286 uint32
 287 _cdbo_init_eod(CdbObject *self) {
 288
 289   char nonce[4];
 290
 291   if (cdb_read(&self->c, nonce, 4, 0) == -1)
 292     return 0;
 293
 294   uint32_unpack(nonce, &self->eod);
 295
 296   return self->eod;
 297
 298 }
 299
 300 /*
 301  * _cdbo_keyiter(cdb_o)
 302  *
 303  * Whiz-bang all-in-one:
 304  *   extract current record
 305  *   compare current pos to pos implied by cdb_find(current_key)
 306  *     (Different? adv. iter cursor, loop and try again)
 307  *   advance iteration cursor
 308  *   return key
 309  */
 310
 311 static PyObject *
 312 _cdbo_keyiter(CdbObject *self) {
 313
 314   PyObject *key;
 315   char buf[8];
 316   uint32 klen, dlen;
 317
 318   if (! self->eod)
 319     _cdbo_init_eod(self);
 320
 321   while (self->iter_pos < self->eod) {
 322     if (cdb_read(&self->c, buf, 8, self->iter_pos) == -1)
 323       return CDBerr;
 324
 325     uint32_unpack(buf, &klen);
 326     uint32_unpack(buf+4, &dlen);
 327
 328     key = cdb_pyread(self, klen, self->iter_pos + 8);
 329
 330     if (key == NULL)
 331       return NULL;
 332
 333     switch(cdb_find(&self->c,PyString_AsString(key),PyString_Size(key))) {
 334       case -1:
 335         Py_DECREF(key);
 336         key = NULL;
 337         return CDBerr;
 338       case 0:
 339         /* bizarre, impossible? PyExc_RuntimeError? */
 340         PyErr_SetString(PyExc_KeyError,
 341                         PyString_AS_STRING((PyStringObject *) key));
 342         Py_DECREF(key);
 343         key = NULL;
 344       default:
 345         if (key == NULL)  /* already raised error */
 346           return NULL;
 347
 348         if (cdb_datapos(&self->c) == self->iter_pos + klen + 8) {
 349           /** first occurrence of key in the cdb **/
 350           self->iter_pos += 8 + klen + dlen;
 351           return key;
 352         }
 353         Py_DECREF(key);   /* better luck next time around */
 354         self->iter_pos += 8 + klen + dlen;
 355     }
 356   }
 357
 358   return Py_BuildValue("");  /* iter_pos >= eod; we're done */
 359
 360 }
 361
 362 static char cdbo_keys_doc[] =
 363 "cdb_o.keys() -> ['k1', 'k2', ... ]\n\
 364 \n\
 365 Returns a list of all (distinct) keys in the database.";
 366
 367 static PyObject *
 368 cdbo_keys(CdbObject *self, PyObject *args) {
 369
 370   PyObject *r, *key;
 371   uint32 pos;
 372   int err;
 373
 374   if (! PyArg_ParseTuple(args, ""))
 375     return NULL;
 376
 377   r = PyList_New(0);
 378   if (r == NULL)
 379     return NULL;
 380
 381   pos = self->iter_pos;  /* don't interrupt a manual iteration */
 382
 383   self->iter_pos = 2048;
 384
 385   key = _cdbo_keyiter(self);
 386   while (key != Py_None) {
 387     err = PyList_Append(r, key);
 388     Py_DECREF(key);
 389     if (err != 0) {
 390       Py_DECREF(r);
 391       self->iter_pos = pos;
 392       return NULL;
 393     }
 394     key = _cdbo_keyiter(self);
 395   }
 396   Py_DECREF(key);
 397
 398   self->iter_pos = pos;
 399
 400   return r;
 401
 402 }
 403
 404 static char cdbo_firstkey_doc[] =
 405 "cdb_o.firstkey() -> key (or None)\n\
 406 \n\
 407 Return the first key in the database, resetting the internal\n\
 408 iteration cursor.  firstkey() and nextkey() may be used to\n\
 409 traverse all distinct keys in the cdb. See each() for raw\n\
 410 iteration.";
 411
 412 static PyObject *
 413 cdbo_firstkey(CdbObject *self, PyObject *args) {
 414
 415   if (! PyArg_ParseTuple(args, ":firstkey"))
 416     return NULL;
 417
 418   self->iter_pos = 2048;
 419
 420   return _cdbo_keyiter(self);
 421
 422 }
 423
 424 static char cdbo_nextkey_doc[] =
 425 "cdb_o.nextkey() -> key (or None)\n\
 426 \n\
 427 Return the next distinct key in the cdb.\n\
 428 \n\
 429 The following code walks the CDB one key at a time:\n\
 430 \n\
 431     key = cdb_o.firstkey()\n\
 432     while key is not None:\n\
 433         print key\n\
 434         key = cdb_o.nextkey()\n";
 435
 436 static PyObject *
 437 cdbo_nextkey(CdbObject *self, PyObject *args) {
 438
 439   if (! PyArg_ParseTuple(args, ":nextkey"))
 440     return NULL;
 441
 442   return _cdbo_keyiter(self);
 443
 444 }
 445
 446 static char cdbo_each_doc[] =
 447 "cdb_o.each() -> (key, data) (or None)\n\
 448 \n\
 449 Fetch the next ('key', 'data') record from the underlying cdb file,\n\
 450 returning None and resetting the iteration cursor when all records\n\
 451 have been fetched.\n\
 452 \n\
 453 Keys appear with each item under them -- e.g., (key,foo), (key2,bar),\n\
 454 (key,baz) --  order of records is determined by actual position on\n\
 455 disk.  Both keys() and (for GDBM fanciers) firstkey()/nextkey()-style\n\
 456 iteration go to pains to present the user with only distinct keys.";
 457
 458 static PyObject *
 459 cdbo_each(CdbObject *self, PyObject *args) {
 460
 461   PyObject *tup, *key, *dat;
 462   char buf[8];
 463   uint32 klen, dlen;
 464
 465   if (! PyArg_ParseTuple(args, ":each"))
 466     return NULL;
 467
 468   tup = PyTuple_New(2);
 469   if (tup == NULL)
 470     return NULL;
 471
 472   if (! self->eod)
 473     (void) _cdbo_init_eod(self);
 474
 475   if (self->each_pos >= self->eod) { /* all done, reset cursor */
 476     self->each_pos = 2048;
 477     Py_INCREF(Py_None);
 478     return Py_None;
 479   }
 480
 481   if (cdb_read(&self->c, buf, 8, self->each_pos) == -1)
 482     return CDBerr;
 483
 484   uint32_unpack(buf, &klen);
 485   uint32_unpack(buf+4, &dlen);
 486
 487   key = cdb_pyread(self, klen, self->each_pos + 8);
 488   dat = cdb_pyread(self, dlen, self->each_pos + 8 + klen);
 489
 490   self->each_pos += klen + dlen + 8;
 491
 492   if (key == NULL || dat == NULL) {
 493     Py_XDECREF(key); Py_XDECREF(dat);
 494     Py_DECREF(tup);
 495     return NULL;
 496   }
 497
 498   if (PyTuple_SetItem(tup, 0, key) || PyTuple_SetItem(tup, 1, dat)) {
 499     Py_DECREF(key); Py_DECREF(dat); Py_DECREF(tup);
 500     return NULL;
 501   }
 502
 503   return tup;
 504 }
 505
 506 /*** cdb object as mapping ***/
 507
 508 static int
 509 cdbo_length(CdbObject *self) {
 510
 511   if (! self->numrecords) {
 512     char buf[8];
 513     uint32 pos, klen, dlen;
 514
 515     pos = 2048;
 516
 517     if (! self->eod)
 518       (void) _cdbo_init_eod(self);
 519
 520     while (pos < self->eod) {
 521       if (cdb_read(&self->c, buf, 8, pos) == -1)
 522         return -1;
 523       uint32_unpack(buf, &klen);
 524       uint32_unpack(buf + 4, &dlen);
 525       pos += 8 + klen + dlen;
 526       self->numrecords++;
 527     }
 528   }
 529   return (int) self->numrecords;
 530 }
 531
 532 static PyObject *
 533 cdbo_subscript(CdbObject *self, PyObject *k) {
 534   char * key;
 535   int klen;
 536
 537   if (! PyArg_Parse(k, "s#", &key, &klen))
 538     return NULL;
 539
 540   switch(cdb_find(&self->c, key, (unsigned int)klen)) {
 541     case -1:
 542       return CDBerr;
 543     case 0:
 544       PyErr_SetString(PyExc_KeyError,
 545                       PyString_AS_STRING((PyStringObject *) k));
 546       return NULL;
 547     default:
 548       return CDBO_CURDATA(self);
 549   }
 550   /* not reached */
 551 }
 552
 553 static PyMappingMethods cdbo_as_mapping = {
 554         (inquiry)cdbo_length,
 555         (binaryfunc)cdbo_subscript,
 556         (objobjargproc)0
 557 };
 558
 559 static PyMethodDef cdb_methods[] = {
 560
 561   {"get",      (PyCFunction)cdbo_get,      METH_VARARGS,
 562                cdbo_get_doc },
 563   {"getnext",  (PyCFunction)cdbo_getnext,  METH_VARARGS,
 564                cdbo_getnext_doc },
 565   {"getall",   (PyCFunction)cdbo_getall,   METH_VARARGS,
 566                cdbo_getall_doc },
 567   {"has_key",  (PyCFunction)cdbo_has_key,  METH_VARARGS,
 568                cdbo_has_key_doc },
 569   {"keys",     (PyCFunction)cdbo_keys,     METH_VARARGS,
 570                cdbo_keys_doc },
 571   {"firstkey", (PyCFunction)cdbo_firstkey, METH_VARARGS,
 572                cdbo_firstkey_doc },
 573   {"nextkey",  (PyCFunction)cdbo_nextkey,  METH_VARARGS,
 574                cdbo_nextkey_doc },
 575   {"each",     (PyCFunction)cdbo_each, METH_VARARGS,
 576                cdbo_each_doc },
 577   { NULL,    NULL }
 578 };
 579
 580 /* ------------------- cdb operations -------------------- */
 581
 582 static PyObject *
 583 _wrap_cdb_init(int fd) {  /* constructor implementation */
 584
 585   CdbObject *self;
 586
 587   self = PyObject_NEW(CdbObject, &CdbType);
 588   if (self == NULL) return NULL;
 589
 590   self->c.map = 0; /* break encapsulation -- cdb struct init'd to zero */
 591   cdb_init(&self->c, fd);
 592
 593   self->iter_pos   = 2048;
 594   self->each_pos   = 2048;
 595   self->numrecords = 0;
 596   self->eod        = 0;
 597   self->getkey     = NULL;
 598
 599   return (PyObject *) self;
 600 }
 601
 602
 603 static PyObject *
 604 cdbo_constructor(PyObject *ignore, PyObject *args) {
 605
 606   PyObject *self;
 607   PyObject *f;
 608   PyObject *name_attr = Py_None;
 609   int fd;
 610
 611   if (! PyArg_ParseTuple(args, "O:new", &f))
 612     return NULL;
 613
 614   if (PyString_Check(f)) {
 615
 616     if ((fd = open_read(PyString_AsString(f))) == -1)
 617       return CDBerr;
 618
 619     name_attr = f;
 620
 621   } else if (PyInt_Check(f)) {
 622
 623     fd = (int) PyInt_AsLong(f);
 624
 625   } else {
 626
 627     PyErr_SetString(PyExc_TypeError,
 628                     "expected filename or file descriptor");
 629     return NULL;
 630
 631   }
 632
 633   self = _wrap_cdb_init(fd);
 634   if (self == NULL) return NULL;
 635
 636   ((CdbObject *)self)->name_py = name_attr;
 637   Py_INCREF(name_attr);
 638
 639   return self;
 640 }
 641
 642 static void
 643 cdbo_dealloc(CdbObject *self) {  /* del(cdb_o) */
 644
 645   if (self->name_py != NULL) {
 646
 647     /* if cdb_o.name is not None:  we open()d it ourselves, so close it */
 648     if (PyString_Check(self->name_py))
 649       close(self->c.fd);
 650
 651     Py_DECREF(self->name_py);
 652   }
 653
 654   Py_XDECREF(self->getkey);
 655
 656   cdb_free(&self->c);
 657
 658   PyObject_Del((PyObject *)self);
 659 }
 660
 661 static PyObject *
 662 cdbo_getattr(CdbObject *self, char *name) {
 663
 664   PyObject * r;
 665
 666   r = Py_FindMethod(cdb_methods, (PyObject *) self, name);
 667
 668   if (r != NULL)
 669     return r;
 670
 671   PyErr_Clear();
 672
 673   if (!strcmp(name,"__members__"))
 674     return Py_BuildValue("[sss]", "fd", "name", "size");
 675
 676   if (!strcmp(name,"fd")) {
 677     return Py_BuildValue("i", self->c.fd);  /* cdb_o.fd */
 678   }
 679
 680   if (!strcmp(name,"name")) {
 681     Py_INCREF(self->name_py);
 682     return self->name_py;                   /* cdb_o.name */
 683   }
 684
 685   if (!strcmp(name,"size")) {               /* cdb_o.size */
 686     return self->c.map ?  /** mmap()d ? stat.st_size : None **/
 687            Py_BuildValue("l", (long) self->c.size) :
 688            Py_BuildValue("");
 689   }
 690
 691   PyErr_SetString(PyExc_AttributeError, name);
 692   return NULL;
 693 }
 694
 695
 696 /* ----------------- cdbmake object ------------------ */
 697
 698 static char cdbmake_object_doc[] =
 699 "cdbmake objects resemble the struct cdb_make interface:\n\
 700 \n\
 701   CDB Construction Methods:\n\
 702     add(k, v), finish()\n\
 703 \n\
 704   __members__:\n\
 705     fd         - fd of underlying CDB, or -1 if finish()ed\n\
 706     fn, fntmp  - as from the cdb package's cdbmake utility\n\
 707     numentries - current number of records add()ed\n";
 708
 709 typedef struct {
 710     PyObject_HEAD
 711     struct cdb_make cm;
 712     PyObject * fn;
 713     PyObject * fntmp;
 714 } cdbmakeobject;
 715
 716 staticforward PyTypeObject CdbMakeType;
 717
 718 #define CDBMAKEerr PyErr_SetFromErrno(PyExc_IOError)
 719
 720
 721 /* ----------------- CdbMake methods ------------------ */
 722
 723 static PyObject *
 724 CdbMake_add(cdbmakeobject *self, PyObject *args) {
 725
 726   char * key, * dat;
 727   unsigned int klen, dlen;
 728
 729   if (!PyArg_ParseTuple(args,"s#s#:add",&key,&klen,&dat,&dlen))
 730     return NULL;
 731
 732   if (cdb_make_add(&self->cm, key, klen, dat, dlen) == -1)
 733     return CDBMAKEerr;
 734
 735   return Py_BuildValue("");
 736
 737 }
 738
 739 static PyObject *
 740 CdbMake_finish(cdbmakeobject *self, PyObject *args) {
 741
 742   if (!PyArg_ParseTuple(args, ":finish"))
 743     return NULL;
 744
 745   if (cdb_make_finish(&self->cm) == -1)
 746     return CDBMAKEerr;
 747
 748   /* cleanup as in cdb dist's cdbmake */
 749
 750   if (fsync(fileno(self->cm.fp)) == -1)
 751     return CDBMAKEerr;
 752
 753   if (fclose(self->cm.fp) != 0)
 754     return CDBMAKEerr;
 755
 756   self->cm.fp = NULL;
 757
 758   if (rename(PyString_AsString(self->fntmp),
 759              PyString_AsString(self->fn))    == -1)
 760     return CDBMAKEerr;
 761
 762   return Py_BuildValue("");
 763 }
 764
 765 static PyMethodDef cdbmake_methods[] = {
 766   {"add",    (PyCFunction)CdbMake_add,    METH_VARARGS,
 767 "cm.add(key, data) -> None\n\
 768 \n\
 769 Add 'key' -> 'data' pair to the underlying CDB." },
 770   {"finish", (PyCFunction)CdbMake_finish, METH_VARARGS,
 771 "cm.finish() -> None\n\
 772 \n\
 773 Finish safely composing a new CDB, renaming cm.fntmp to\n\
 774 cm.fn." },
 775   { NULL,    NULL }
 776 };
 777
 778 /* ----------------- cdbmake operations ------------------ */
 779
 780 static PyObject *
 781 new_cdbmake(PyObject *ignore, PyObject *args) {
 782
 783   cdbmakeobject *self;
 784   PyObject *fn, *fntmp;
 785   FILE * f;
 786
 787   if (! PyArg_ParseTuple(args, "SS|i", &fn, &fntmp))
 788     return NULL;
 789
 790   f = fopen(PyString_AsString(fntmp), "w+b");
 791   if (f == NULL) {
 792     return CDBMAKEerr;
 793   }
 794
 795   self = PyObject_NEW(cdbmakeobject, &CdbMakeType);
 796   if (self == NULL) return NULL;
 797
 798   self->fn = fn;
 799   Py_INCREF(self->fn);
 800
 801   self->fntmp = fntmp;
 802   Py_INCREF(fntmp);
 803
 804   if (cdb_make_start(&self->cm, f) == -1) {
 805     Py_DECREF(self);
 806     CDBMAKEerr;
 807     return NULL;
 808   }
 809
 810   return (PyObject *) self;
 811 }
 812
 813 static void
 814 cdbmake_dealloc(cdbmakeobject *self) {
 815
 816   Py_XDECREF(self->fn);
 817
 818   if (self->fntmp != NULL) {
 819     if (self->cm.fp != NULL) {
 820       fclose(self->cm.fp);
 821       unlink(PyString_AsString(self->fntmp));
 822     }
 823     Py_DECREF(self->fntmp);
 824   }
 825
 826   PyObject_Del((PyObject *)self);
 827 }
 828
 829 static PyObject *
 830 cdbmake_getattr(cdbmakeobject *self, char *name) {
 831
 832   if (!strcmp(name,"__members__"))
 833     return Py_BuildValue("[ssss]", "fd", "fn", "fntmp", "numentries");
 834
 835   if (!strcmp(name,"fd"))
 836     return Py_BuildValue("i", fileno(self->cm.fp));  /* self.fd */
 837
 838   if (!strcmp(name,"fn")) {
 839     Py_INCREF(self->fn);
 840     return self->fn;                         /* self.fn */
 841   }
 842
 843   if (!strcmp(name,"fntmp")) {
 844     Py_INCREF(self->fntmp);
 845     return self->fntmp;                      /* self.fntmp */
 846   }
 847
 848   if (!strcmp(name,"numentries"))
 849     return Py_BuildValue("l", self->cm.numentries); /* self.numentries */
 850
 851   return Py_FindMethod(cdbmake_methods, (PyObject *) self, name);
 852 }
 853
 854 /* ---------------- Type delineation -------------------- */
 855
 856 statichere PyTypeObject CdbType = {
 857         /* The ob_type field must be initialized in the module init function
 858          * to be portable to Windows without using C++. */
 859         PyObject_HEAD_INIT(NULL)
 860         0,                      /*ob_size*/
 861         "cdb",              /*tp_name*/
 862         sizeof(CdbObject),  /*tp_basicsize*/
 863         0,                      /*tp_itemsize*/
 864         /* methods */
 865         (destructor)cdbo_dealloc, /*tp_dealloc*/
 866         0,                      /*tp_print*/
 867         (getattrfunc)cdbo_getattr, /*tp_getattr*/
 868         0,                      /*tp_setattr*/
 869         0,                      /*tp_compare*/
 870         0,                      /*tp_repr*/
 871         0,                      /*tp_as_number*/
 872         0,                      /*tp_as_sequence*/
 873         &cdbo_as_mapping,       /*tp_as_mapping*/
 874         0,                      /*tp_hash*/
 875         0,                      /*tp_call*/
 876         0,                      /*tp_str*/
 877         0,                      /*tp_getattro*/
 878         0,                      /*tp_setattro*/
 879         0,                      /*tp_as_buffer*/
 880         0,                      /*tp_xxx4*/
 881         cdbo_object_doc,        /*tp_doc*/
 882 };
 883
 884 statichere PyTypeObject CdbMakeType = {
 885         /* The ob_type field must be initialized in the module init function
 886          * to be portable to Windows without using C++. */
 887         PyObject_HEAD_INIT(NULL)
 888         0,                      /*ob_size*/
 889         "cdbmake",              /*tp_name*/
 890         sizeof(cdbmakeobject),  /*tp_basicsize*/
 891         0,                      /*tp_itemsize*/
 892         /* methods */
 893         (destructor)cdbmake_dealloc, /*tp_dealloc*/
 894         0,                      /*tp_print*/
 895         (getattrfunc)cdbmake_getattr, /*tp_getattr*/
 896         0,                      /*tp_setattr*/
 897         0,                      /*tp_compare*/
 898         0,                      /*tp_repr*/
 899         0,                      /*tp_as_number*/
 900         0,                      /*tp_as_sequence*/
 901         0,                      /*tp_as_mapping*/
 902         0,                      /*tp_hash*/
 903         0,                      /*tp_call*/
 904         0,                      /*tp_str*/
 905         0,                      /*tp_getattro*/
 906         0,                      /*tp_setattro*/
 907         0,                      /*tp_as_buffer*/
 908         0,                      /*tp_xxx4*/
 909         cdbmake_object_doc,     /*tp_doc*/
 910 };
 911
 912 /* ---------------- exported functions ------------------ */
 913 static PyObject *
 914 _wrap_cdb_hash(PyObject *ignore, PyObject *args) {
 915
 916   char *s;
 917   int sz;
 918
 919   if (! PyArg_ParseTuple(args, "s#:hash", &s, &sz))
 920     return NULL;
 921
 922   return Py_BuildValue("l", cdb_hash(s, (unsigned int) sz));
 923
 924 }
 925
 926 /* ---------------- cdb Module -------------------- */
 927
 928 static PyMethodDef module_functions[] = {
 929   {"init",    cdbo_constructor, METH_VARARGS,
 930 "cdb.init(f) -> cdb_object\n\
 931 \n\
 932 Open a CDB specified by f and return a cdb object.\n\
 933 f may be a filename or an integral file descriptor\n\
 934 (e.g., init( sys.stdin.fileno() )...)."},
 935   {"cdbmake", new_cdbmake,     METH_VARARGS,
 936 "cdb.cdbmake(cdb, tmp) -> cdbmake_object\n\
 937 \n\
 938 Interface to the creation of a new CDB file \"cdb\".\n\
 939 \n\
 940 The cdbmake object first writes records to the temporary file\n\
 941 \"tmp\" (records are inserted via the object's add() method).\n\
 942 The finish() method then atomically renames \"tmp\" to \"cdb\",\n\
 943 ensuring that readers of \"cdb\" need never wait for updates to\n\
 944 complete."
 945 },
 946   {"hash",    _wrap_cdb_hash,  METH_VARARGS,
 947 "hash(s) -> hashval\n\
 948 \n\
 949 Compute the 32-bit hash value of some sequence of bytes s."},
 950   {NULL,  NULL}
 951 };
 952
 953 static char module_doc[] =
 954 "Python adaptation of D. J. Bernstein's constant database (CDB)\n\
 955 package.  See <http://cr.yp.to/cdb.html>\n\
 956 \n\
 957 CDB objects, created by init(), provide read-only, dict-like\n\
 958 access to cdb files, as well as iterative methods.\n\
 959 \n\
 960 CDBMake objects, created by cdbmake(), allow for creation and\n\
 961 atomic replacement of CDBs.\n\
 962 \n\
 963 This module defines a new Exception \"error\".";
 964
 965 DL_EXPORT(void)
 966 initcdb() {
 967   PyObject *m, *d, *v;
 968
 969   CdbType.ob_type = &PyType_Type;
 970   CdbMakeType.ob_type = &PyType_Type;
 971
 972   m = Py_InitModule3("cdb", module_functions, module_doc);
 973
 974   d = PyModule_GetDict(m);
 975
 976   CDBError = PyErr_NewException("cdb.error", NULL, NULL);
 977   PyDict_SetItemString(d, "error", CDBError);
 978
 979   PyDict_SetItemString(d, "__version__",
 980                        v = PyString_FromString(VERSION));
 981   PyDict_SetItemString(d, "__cdb_version__",
 982                        v = PyString_FromString(CDBVERSION));
 983   Py_XDECREF(v);
 984
 985 }