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Commit | Line | Data |
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4710c53d | 1 | \r |
2 | /* Buffer object implementation */\r | |
3 | \r | |
4 | #include "Python.h"\r | |
5 | \r | |
6 | \r | |
7 | typedef struct {\r | |
8 | PyObject_HEAD\r | |
9 | PyObject *b_base;\r | |
10 | void *b_ptr;\r | |
11 | Py_ssize_t b_size;\r | |
12 | Py_ssize_t b_offset;\r | |
13 | int b_readonly;\r | |
14 | long b_hash;\r | |
15 | } PyBufferObject;\r | |
16 | \r | |
17 | \r | |
18 | enum buffer_t {\r | |
19 | READ_BUFFER,\r | |
20 | WRITE_BUFFER,\r | |
21 | CHAR_BUFFER,\r | |
22 | ANY_BUFFER\r | |
23 | };\r | |
24 | \r | |
25 | static int\r | |
26 | get_buf(PyBufferObject *self, void **ptr, Py_ssize_t *size,\r | |
27 | enum buffer_t buffer_type)\r | |
28 | {\r | |
29 | if (self->b_base == NULL) {\r | |
30 | assert (ptr != NULL);\r | |
31 | *ptr = self->b_ptr;\r | |
32 | *size = self->b_size;\r | |
33 | }\r | |
34 | else {\r | |
35 | Py_ssize_t count, offset;\r | |
36 | readbufferproc proc = 0;\r | |
37 | PyBufferProcs *bp = self->b_base->ob_type->tp_as_buffer;\r | |
38 | if ((*bp->bf_getsegcount)(self->b_base, NULL) != 1) {\r | |
39 | PyErr_SetString(PyExc_TypeError,\r | |
40 | "single-segment buffer object expected");\r | |
41 | return 0;\r | |
42 | }\r | |
43 | if ((buffer_type == READ_BUFFER) ||\r | |
44 | ((buffer_type == ANY_BUFFER) && self->b_readonly))\r | |
45 | proc = bp->bf_getreadbuffer;\r | |
46 | else if ((buffer_type == WRITE_BUFFER) ||\r | |
47 | (buffer_type == ANY_BUFFER))\r | |
48 | proc = (readbufferproc)bp->bf_getwritebuffer;\r | |
49 | else if (buffer_type == CHAR_BUFFER) {\r | |
50 | if (!PyType_HasFeature(self->ob_type,\r | |
51 | Py_TPFLAGS_HAVE_GETCHARBUFFER)) {\r | |
52 | PyErr_SetString(PyExc_TypeError,\r | |
53 | "Py_TPFLAGS_HAVE_GETCHARBUFFER needed");\r | |
54 | return 0;\r | |
55 | }\r | |
56 | proc = (readbufferproc)bp->bf_getcharbuffer;\r | |
57 | }\r | |
58 | if (!proc) {\r | |
59 | char *buffer_type_name;\r | |
60 | switch (buffer_type) {\r | |
61 | case READ_BUFFER:\r | |
62 | buffer_type_name = "read";\r | |
63 | break;\r | |
64 | case WRITE_BUFFER:\r | |
65 | buffer_type_name = "write";\r | |
66 | break;\r | |
67 | case CHAR_BUFFER:\r | |
68 | buffer_type_name = "char";\r | |
69 | break;\r | |
70 | default:\r | |
71 | buffer_type_name = "no";\r | |
72 | break;\r | |
73 | }\r | |
74 | PyErr_Format(PyExc_TypeError,\r | |
75 | "%s buffer type not available",\r | |
76 | buffer_type_name);\r | |
77 | return 0;\r | |
78 | }\r | |
79 | if ((count = (*proc)(self->b_base, 0, ptr)) < 0)\r | |
80 | return 0;\r | |
81 | /* apply constraints to the start/end */\r | |
82 | if (self->b_offset > count)\r | |
83 | offset = count;\r | |
84 | else\r | |
85 | offset = self->b_offset;\r | |
86 | *(char **)ptr = *(char **)ptr + offset;\r | |
87 | if (self->b_size == Py_END_OF_BUFFER)\r | |
88 | *size = count;\r | |
89 | else\r | |
90 | *size = self->b_size;\r | |
91 | if (offset + *size > count)\r | |
92 | *size = count - offset;\r | |
93 | }\r | |
94 | return 1;\r | |
95 | }\r | |
96 | \r | |
97 | \r | |
98 | static PyObject *\r | |
99 | buffer_from_memory(PyObject *base, Py_ssize_t size, Py_ssize_t offset, void *ptr,\r | |
100 | int readonly)\r | |
101 | {\r | |
102 | PyBufferObject * b;\r | |
103 | \r | |
104 | if (size < 0 && size != Py_END_OF_BUFFER) {\r | |
105 | PyErr_SetString(PyExc_ValueError,\r | |
106 | "size must be zero or positive");\r | |
107 | return NULL;\r | |
108 | }\r | |
109 | if (offset < 0) {\r | |
110 | PyErr_SetString(PyExc_ValueError,\r | |
111 | "offset must be zero or positive");\r | |
112 | return NULL;\r | |
113 | }\r | |
114 | \r | |
115 | b = PyObject_NEW(PyBufferObject, &PyBuffer_Type);\r | |
116 | if ( b == NULL )\r | |
117 | return NULL;\r | |
118 | \r | |
119 | Py_XINCREF(base);\r | |
120 | b->b_base = base;\r | |
121 | b->b_ptr = ptr;\r | |
122 | b->b_size = size;\r | |
123 | b->b_offset = offset;\r | |
124 | b->b_readonly = readonly;\r | |
125 | b->b_hash = -1;\r | |
126 | \r | |
127 | return (PyObject *) b;\r | |
128 | }\r | |
129 | \r | |
130 | static PyObject *\r | |
131 | buffer_from_object(PyObject *base, Py_ssize_t size, Py_ssize_t offset, int readonly)\r | |
132 | {\r | |
133 | if (offset < 0) {\r | |
134 | PyErr_SetString(PyExc_ValueError,\r | |
135 | "offset must be zero or positive");\r | |
136 | return NULL;\r | |
137 | }\r | |
138 | if ( PyBuffer_Check(base) && (((PyBufferObject *)base)->b_base) ) {\r | |
139 | /* another buffer, refer to the base object */\r | |
140 | PyBufferObject *b = (PyBufferObject *)base;\r | |
141 | if (b->b_size != Py_END_OF_BUFFER) {\r | |
142 | Py_ssize_t base_size = b->b_size - offset;\r | |
143 | if (base_size < 0)\r | |
144 | base_size = 0;\r | |
145 | if (size == Py_END_OF_BUFFER || size > base_size)\r | |
146 | size = base_size;\r | |
147 | }\r | |
148 | offset += b->b_offset;\r | |
149 | base = b->b_base;\r | |
150 | }\r | |
151 | return buffer_from_memory(base, size, offset, NULL, readonly);\r | |
152 | }\r | |
153 | \r | |
154 | \r | |
155 | PyObject *\r | |
156 | PyBuffer_FromObject(PyObject *base, Py_ssize_t offset, Py_ssize_t size)\r | |
157 | {\r | |
158 | PyBufferProcs *pb = base->ob_type->tp_as_buffer;\r | |
159 | \r | |
160 | if ( pb == NULL ||\r | |
161 | pb->bf_getreadbuffer == NULL ||\r | |
162 | pb->bf_getsegcount == NULL )\r | |
163 | {\r | |
164 | PyErr_SetString(PyExc_TypeError, "buffer object expected");\r | |
165 | return NULL;\r | |
166 | }\r | |
167 | \r | |
168 | return buffer_from_object(base, size, offset, 1);\r | |
169 | }\r | |
170 | \r | |
171 | PyObject *\r | |
172 | PyBuffer_FromReadWriteObject(PyObject *base, Py_ssize_t offset, Py_ssize_t size)\r | |
173 | {\r | |
174 | PyBufferProcs *pb = base->ob_type->tp_as_buffer;\r | |
175 | \r | |
176 | if ( pb == NULL ||\r | |
177 | pb->bf_getwritebuffer == NULL ||\r | |
178 | pb->bf_getsegcount == NULL )\r | |
179 | {\r | |
180 | PyErr_SetString(PyExc_TypeError, "buffer object expected");\r | |
181 | return NULL;\r | |
182 | }\r | |
183 | \r | |
184 | return buffer_from_object(base, size, offset, 0);\r | |
185 | }\r | |
186 | \r | |
187 | PyObject *\r | |
188 | PyBuffer_FromMemory(void *ptr, Py_ssize_t size)\r | |
189 | {\r | |
190 | return buffer_from_memory(NULL, size, 0, ptr, 1);\r | |
191 | }\r | |
192 | \r | |
193 | PyObject *\r | |
194 | PyBuffer_FromReadWriteMemory(void *ptr, Py_ssize_t size)\r | |
195 | {\r | |
196 | return buffer_from_memory(NULL, size, 0, ptr, 0);\r | |
197 | }\r | |
198 | \r | |
199 | PyObject *\r | |
200 | PyBuffer_New(Py_ssize_t size)\r | |
201 | {\r | |
202 | PyObject *o;\r | |
203 | PyBufferObject * b;\r | |
204 | \r | |
205 | if (size < 0) {\r | |
206 | PyErr_SetString(PyExc_ValueError,\r | |
207 | "size must be zero or positive");\r | |
208 | return NULL;\r | |
209 | }\r | |
210 | if (sizeof(*b) > PY_SSIZE_T_MAX - size) {\r | |
211 | /* unlikely */\r | |
212 | return PyErr_NoMemory();\r | |
213 | }\r | |
214 | /* Inline PyObject_New */\r | |
215 | o = (PyObject *)PyObject_MALLOC(sizeof(*b) + size);\r | |
216 | if ( o == NULL )\r | |
217 | return PyErr_NoMemory();\r | |
218 | b = (PyBufferObject *) PyObject_INIT(o, &PyBuffer_Type);\r | |
219 | \r | |
220 | b->b_base = NULL;\r | |
221 | b->b_ptr = (void *)(b + 1);\r | |
222 | b->b_size = size;\r | |
223 | b->b_offset = 0;\r | |
224 | b->b_readonly = 0;\r | |
225 | b->b_hash = -1;\r | |
226 | \r | |
227 | return o;\r | |
228 | }\r | |
229 | \r | |
230 | /* Methods */\r | |
231 | \r | |
232 | static PyObject *\r | |
233 | buffer_new(PyTypeObject *type, PyObject *args, PyObject *kw)\r | |
234 | {\r | |
235 | PyObject *ob;\r | |
236 | Py_ssize_t offset = 0;\r | |
237 | Py_ssize_t size = Py_END_OF_BUFFER;\r | |
238 | \r | |
239 | if (PyErr_WarnPy3k("buffer() not supported in 3.x", 1) < 0)\r | |
240 | return NULL;\r | |
241 | \r | |
242 | if (!_PyArg_NoKeywords("buffer()", kw))\r | |
243 | return NULL;\r | |
244 | \r | |
245 | if (!PyArg_ParseTuple(args, "O|nn:buffer", &ob, &offset, &size))\r | |
246 | return NULL;\r | |
247 | return PyBuffer_FromObject(ob, offset, size);\r | |
248 | }\r | |
249 | \r | |
250 | PyDoc_STRVAR(buffer_doc,\r | |
251 | "buffer(object [, offset[, size]])\n\\r | |
252 | \n\\r | |
253 | Create a new buffer object which references the given object.\n\\r | |
254 | The buffer will reference a slice of the target object from the\n\\r | |
255 | start of the object (or at the specified offset). The slice will\n\\r | |
256 | extend to the end of the target object (or with the specified size).");\r | |
257 | \r | |
258 | \r | |
259 | static void\r | |
260 | buffer_dealloc(PyBufferObject *self)\r | |
261 | {\r | |
262 | Py_XDECREF(self->b_base);\r | |
263 | PyObject_DEL(self);\r | |
264 | }\r | |
265 | \r | |
266 | static int\r | |
267 | buffer_compare(PyBufferObject *self, PyBufferObject *other)\r | |
268 | {\r | |
269 | void *p1, *p2;\r | |
270 | Py_ssize_t len_self, len_other, min_len;\r | |
271 | int cmp;\r | |
272 | \r | |
273 | if (!get_buf(self, &p1, &len_self, ANY_BUFFER))\r | |
274 | return -1;\r | |
275 | if (!get_buf(other, &p2, &len_other, ANY_BUFFER))\r | |
276 | return -1;\r | |
277 | min_len = (len_self < len_other) ? len_self : len_other;\r | |
278 | if (min_len > 0) {\r | |
279 | cmp = memcmp(p1, p2, min_len);\r | |
280 | if (cmp != 0)\r | |
281 | return cmp < 0 ? -1 : 1;\r | |
282 | }\r | |
283 | return (len_self < len_other) ? -1 : (len_self > len_other) ? 1 : 0;\r | |
284 | }\r | |
285 | \r | |
286 | static PyObject *\r | |
287 | buffer_repr(PyBufferObject *self)\r | |
288 | {\r | |
289 | const char *status = self->b_readonly ? "read-only" : "read-write";\r | |
290 | \r | |
291 | if ( self->b_base == NULL )\r | |
292 | return PyString_FromFormat("<%s buffer ptr %p, size %zd at %p>",\r | |
293 | status,\r | |
294 | self->b_ptr,\r | |
295 | self->b_size,\r | |
296 | self);\r | |
297 | else\r | |
298 | return PyString_FromFormat(\r | |
299 | "<%s buffer for %p, size %zd, offset %zd at %p>",\r | |
300 | status,\r | |
301 | self->b_base,\r | |
302 | self->b_size,\r | |
303 | self->b_offset,\r | |
304 | self);\r | |
305 | }\r | |
306 | \r | |
307 | static long\r | |
308 | buffer_hash(PyBufferObject *self)\r | |
309 | {\r | |
310 | void *ptr;\r | |
311 | Py_ssize_t size;\r | |
312 | register Py_ssize_t len;\r | |
313 | register unsigned char *p;\r | |
314 | register long x;\r | |
315 | \r | |
316 | if ( self->b_hash != -1 )\r | |
317 | return self->b_hash;\r | |
318 | \r | |
319 | /* XXX potential bugs here, a readonly buffer does not imply that the\r | |
320 | * underlying memory is immutable. b_readonly is a necessary but not\r | |
321 | * sufficient condition for a buffer to be hashable. Perhaps it would\r | |
322 | * be better to only allow hashing if the underlying object is known to\r | |
323 | * be immutable (e.g. PyString_Check() is true). Another idea would\r | |
324 | * be to call tp_hash on the underlying object and see if it raises\r | |
325 | * an error. */\r | |
326 | if ( !self->b_readonly )\r | |
327 | {\r | |
328 | PyErr_SetString(PyExc_TypeError,\r | |
329 | "writable buffers are not hashable");\r | |
330 | return -1;\r | |
331 | }\r | |
332 | \r | |
333 | if (!get_buf(self, &ptr, &size, ANY_BUFFER))\r | |
334 | return -1;\r | |
335 | p = (unsigned char *) ptr;\r | |
336 | len = size;\r | |
337 | x = *p << 7;\r | |
338 | while (--len >= 0)\r | |
339 | x = (1000003*x) ^ *p++;\r | |
340 | x ^= size;\r | |
341 | if (x == -1)\r | |
342 | x = -2;\r | |
343 | self->b_hash = x;\r | |
344 | return x;\r | |
345 | }\r | |
346 | \r | |
347 | static PyObject *\r | |
348 | buffer_str(PyBufferObject *self)\r | |
349 | {\r | |
350 | void *ptr;\r | |
351 | Py_ssize_t size;\r | |
352 | if (!get_buf(self, &ptr, &size, ANY_BUFFER))\r | |
353 | return NULL;\r | |
354 | return PyString_FromStringAndSize((const char *)ptr, size);\r | |
355 | }\r | |
356 | \r | |
357 | /* Sequence methods */\r | |
358 | \r | |
359 | static Py_ssize_t\r | |
360 | buffer_length(PyBufferObject *self)\r | |
361 | {\r | |
362 | void *ptr;\r | |
363 | Py_ssize_t size;\r | |
364 | if (!get_buf(self, &ptr, &size, ANY_BUFFER))\r | |
365 | return -1;\r | |
366 | return size;\r | |
367 | }\r | |
368 | \r | |
369 | static PyObject *\r | |
370 | buffer_concat(PyBufferObject *self, PyObject *other)\r | |
371 | {\r | |
372 | PyBufferProcs *pb = other->ob_type->tp_as_buffer;\r | |
373 | void *ptr1, *ptr2;\r | |
374 | char *p;\r | |
375 | PyObject *ob;\r | |
376 | Py_ssize_t size, count;\r | |
377 | \r | |
378 | if ( pb == NULL ||\r | |
379 | pb->bf_getreadbuffer == NULL ||\r | |
380 | pb->bf_getsegcount == NULL )\r | |
381 | {\r | |
382 | PyErr_BadArgument();\r | |
383 | return NULL;\r | |
384 | }\r | |
385 | if ( (*pb->bf_getsegcount)(other, NULL) != 1 )\r | |
386 | {\r | |
387 | /* ### use a different exception type/message? */\r | |
388 | PyErr_SetString(PyExc_TypeError,\r | |
389 | "single-segment buffer object expected");\r | |
390 | return NULL;\r | |
391 | }\r | |
392 | \r | |
393 | if (!get_buf(self, &ptr1, &size, ANY_BUFFER))\r | |
394 | return NULL;\r | |
395 | \r | |
396 | /* optimize special case */\r | |
397 | if ( size == 0 )\r | |
398 | {\r | |
399 | Py_INCREF(other);\r | |
400 | return other;\r | |
401 | }\r | |
402 | \r | |
403 | if ( (count = (*pb->bf_getreadbuffer)(other, 0, &ptr2)) < 0 )\r | |
404 | return NULL;\r | |
405 | \r | |
406 | assert(count <= PY_SIZE_MAX - size);\r | |
407 | \r | |
408 | ob = PyString_FromStringAndSize(NULL, size + count);\r | |
409 | if ( ob == NULL )\r | |
410 | return NULL;\r | |
411 | p = PyString_AS_STRING(ob);\r | |
412 | memcpy(p, ptr1, size);\r | |
413 | memcpy(p + size, ptr2, count);\r | |
414 | \r | |
415 | /* there is an extra byte in the string object, so this is safe */\r | |
416 | p[size + count] = '\0';\r | |
417 | \r | |
418 | return ob;\r | |
419 | }\r | |
420 | \r | |
421 | static PyObject *\r | |
422 | buffer_repeat(PyBufferObject *self, Py_ssize_t count)\r | |
423 | {\r | |
424 | PyObject *ob;\r | |
425 | register char *p;\r | |
426 | void *ptr;\r | |
427 | Py_ssize_t size;\r | |
428 | \r | |
429 | if ( count < 0 )\r | |
430 | count = 0;\r | |
431 | if (!get_buf(self, &ptr, &size, ANY_BUFFER))\r | |
432 | return NULL;\r | |
433 | if (count > PY_SSIZE_T_MAX / size) {\r | |
434 | PyErr_SetString(PyExc_MemoryError, "result too large");\r | |
435 | return NULL;\r | |
436 | }\r | |
437 | ob = PyString_FromStringAndSize(NULL, size * count);\r | |
438 | if ( ob == NULL )\r | |
439 | return NULL;\r | |
440 | \r | |
441 | p = PyString_AS_STRING(ob);\r | |
442 | while ( count-- )\r | |
443 | {\r | |
444 | memcpy(p, ptr, size);\r | |
445 | p += size;\r | |
446 | }\r | |
447 | \r | |
448 | /* there is an extra byte in the string object, so this is safe */\r | |
449 | *p = '\0';\r | |
450 | \r | |
451 | return ob;\r | |
452 | }\r | |
453 | \r | |
454 | static PyObject *\r | |
455 | buffer_item(PyBufferObject *self, Py_ssize_t idx)\r | |
456 | {\r | |
457 | void *ptr;\r | |
458 | Py_ssize_t size;\r | |
459 | if (!get_buf(self, &ptr, &size, ANY_BUFFER))\r | |
460 | return NULL;\r | |
461 | if ( idx < 0 || idx >= size ) {\r | |
462 | PyErr_SetString(PyExc_IndexError, "buffer index out of range");\r | |
463 | return NULL;\r | |
464 | }\r | |
465 | return PyString_FromStringAndSize((char *)ptr + idx, 1);\r | |
466 | }\r | |
467 | \r | |
468 | static PyObject *\r | |
469 | buffer_slice(PyBufferObject *self, Py_ssize_t left, Py_ssize_t right)\r | |
470 | {\r | |
471 | void *ptr;\r | |
472 | Py_ssize_t size;\r | |
473 | if (!get_buf(self, &ptr, &size, ANY_BUFFER))\r | |
474 | return NULL;\r | |
475 | if ( left < 0 )\r | |
476 | left = 0;\r | |
477 | if ( right < 0 )\r | |
478 | right = 0;\r | |
479 | if ( right > size )\r | |
480 | right = size;\r | |
481 | if ( right < left )\r | |
482 | right = left;\r | |
483 | return PyString_FromStringAndSize((char *)ptr + left,\r | |
484 | right - left);\r | |
485 | }\r | |
486 | \r | |
487 | static PyObject *\r | |
488 | buffer_subscript(PyBufferObject *self, PyObject *item)\r | |
489 | {\r | |
490 | void *p;\r | |
491 | Py_ssize_t size;\r | |
492 | \r | |
493 | if (!get_buf(self, &p, &size, ANY_BUFFER))\r | |
494 | return NULL;\r | |
495 | if (PyIndex_Check(item)) {\r | |
496 | Py_ssize_t i = PyNumber_AsSsize_t(item, PyExc_IndexError);\r | |
497 | if (i == -1 && PyErr_Occurred())\r | |
498 | return NULL;\r | |
499 | if (i < 0)\r | |
500 | i += size;\r | |
501 | return buffer_item(self, i);\r | |
502 | }\r | |
503 | else if (PySlice_Check(item)) {\r | |
504 | Py_ssize_t start, stop, step, slicelength, cur, i;\r | |
505 | \r | |
506 | if (PySlice_GetIndicesEx((PySliceObject*)item, size,\r | |
507 | &start, &stop, &step, &slicelength) < 0) {\r | |
508 | return NULL;\r | |
509 | }\r | |
510 | \r | |
511 | if (slicelength <= 0)\r | |
512 | return PyString_FromStringAndSize("", 0);\r | |
513 | else if (step == 1)\r | |
514 | return PyString_FromStringAndSize((char *)p + start,\r | |
515 | stop - start);\r | |
516 | else {\r | |
517 | PyObject *result;\r | |
518 | char *source_buf = (char *)p;\r | |
519 | char *result_buf = (char *)PyMem_Malloc(slicelength);\r | |
520 | \r | |
521 | if (result_buf == NULL)\r | |
522 | return PyErr_NoMemory();\r | |
523 | \r | |
524 | for (cur = start, i = 0; i < slicelength;\r | |
525 | cur += step, i++) {\r | |
526 | result_buf[i] = source_buf[cur];\r | |
527 | }\r | |
528 | \r | |
529 | result = PyString_FromStringAndSize(result_buf,\r | |
530 | slicelength);\r | |
531 | PyMem_Free(result_buf);\r | |
532 | return result;\r | |
533 | }\r | |
534 | }\r | |
535 | else {\r | |
536 | PyErr_SetString(PyExc_TypeError,\r | |
537 | "sequence index must be integer");\r | |
538 | return NULL;\r | |
539 | }\r | |
540 | }\r | |
541 | \r | |
542 | static int\r | |
543 | buffer_ass_item(PyBufferObject *self, Py_ssize_t idx, PyObject *other)\r | |
544 | {\r | |
545 | PyBufferProcs *pb;\r | |
546 | void *ptr1, *ptr2;\r | |
547 | Py_ssize_t size;\r | |
548 | Py_ssize_t count;\r | |
549 | \r | |
550 | if ( self->b_readonly ) {\r | |
551 | PyErr_SetString(PyExc_TypeError,\r | |
552 | "buffer is read-only");\r | |
553 | return -1;\r | |
554 | }\r | |
555 | \r | |
556 | if (!get_buf(self, &ptr1, &size, ANY_BUFFER))\r | |
557 | return -1;\r | |
558 | \r | |
559 | if (idx < 0 || idx >= size) {\r | |
560 | PyErr_SetString(PyExc_IndexError,\r | |
561 | "buffer assignment index out of range");\r | |
562 | return -1;\r | |
563 | }\r | |
564 | \r | |
565 | pb = other ? other->ob_type->tp_as_buffer : NULL;\r | |
566 | if ( pb == NULL ||\r | |
567 | pb->bf_getreadbuffer == NULL ||\r | |
568 | pb->bf_getsegcount == NULL )\r | |
569 | {\r | |
570 | PyErr_BadArgument();\r | |
571 | return -1;\r | |
572 | }\r | |
573 | if ( (*pb->bf_getsegcount)(other, NULL) != 1 )\r | |
574 | {\r | |
575 | /* ### use a different exception type/message? */\r | |
576 | PyErr_SetString(PyExc_TypeError,\r | |
577 | "single-segment buffer object expected");\r | |
578 | return -1;\r | |
579 | }\r | |
580 | \r | |
581 | if ( (count = (*pb->bf_getreadbuffer)(other, 0, &ptr2)) < 0 )\r | |
582 | return -1;\r | |
583 | if ( count != 1 ) {\r | |
584 | PyErr_SetString(PyExc_TypeError,\r | |
585 | "right operand must be a single byte");\r | |
586 | return -1;\r | |
587 | }\r | |
588 | \r | |
589 | ((char *)ptr1)[idx] = *(char *)ptr2;\r | |
590 | return 0;\r | |
591 | }\r | |
592 | \r | |
593 | static int\r | |
594 | buffer_ass_slice(PyBufferObject *self, Py_ssize_t left, Py_ssize_t right, PyObject *other)\r | |
595 | {\r | |
596 | PyBufferProcs *pb;\r | |
597 | void *ptr1, *ptr2;\r | |
598 | Py_ssize_t size;\r | |
599 | Py_ssize_t slice_len;\r | |
600 | Py_ssize_t count;\r | |
601 | \r | |
602 | if ( self->b_readonly ) {\r | |
603 | PyErr_SetString(PyExc_TypeError,\r | |
604 | "buffer is read-only");\r | |
605 | return -1;\r | |
606 | }\r | |
607 | \r | |
608 | pb = other ? other->ob_type->tp_as_buffer : NULL;\r | |
609 | if ( pb == NULL ||\r | |
610 | pb->bf_getreadbuffer == NULL ||\r | |
611 | pb->bf_getsegcount == NULL )\r | |
612 | {\r | |
613 | PyErr_BadArgument();\r | |
614 | return -1;\r | |
615 | }\r | |
616 | if ( (*pb->bf_getsegcount)(other, NULL) != 1 )\r | |
617 | {\r | |
618 | /* ### use a different exception type/message? */\r | |
619 | PyErr_SetString(PyExc_TypeError,\r | |
620 | "single-segment buffer object expected");\r | |
621 | return -1;\r | |
622 | }\r | |
623 | if (!get_buf(self, &ptr1, &size, ANY_BUFFER))\r | |
624 | return -1;\r | |
625 | if ( (count = (*pb->bf_getreadbuffer)(other, 0, &ptr2)) < 0 )\r | |
626 | return -1;\r | |
627 | \r | |
628 | if ( left < 0 )\r | |
629 | left = 0;\r | |
630 | else if ( left > size )\r | |
631 | left = size;\r | |
632 | if ( right < left )\r | |
633 | right = left;\r | |
634 | else if ( right > size )\r | |
635 | right = size;\r | |
636 | slice_len = right - left;\r | |
637 | \r | |
638 | if ( count != slice_len ) {\r | |
639 | PyErr_SetString(\r | |
640 | PyExc_TypeError,\r | |
641 | "right operand length must match slice length");\r | |
642 | return -1;\r | |
643 | }\r | |
644 | \r | |
645 | if ( slice_len )\r | |
646 | memcpy((char *)ptr1 + left, ptr2, slice_len);\r | |
647 | \r | |
648 | return 0;\r | |
649 | }\r | |
650 | \r | |
651 | static int\r | |
652 | buffer_ass_subscript(PyBufferObject *self, PyObject *item, PyObject *value)\r | |
653 | {\r | |
654 | PyBufferProcs *pb;\r | |
655 | void *ptr1, *ptr2;\r | |
656 | Py_ssize_t selfsize;\r | |
657 | Py_ssize_t othersize;\r | |
658 | \r | |
659 | if ( self->b_readonly ) {\r | |
660 | PyErr_SetString(PyExc_TypeError,\r | |
661 | "buffer is read-only");\r | |
662 | return -1;\r | |
663 | }\r | |
664 | \r | |
665 | pb = value ? value->ob_type->tp_as_buffer : NULL;\r | |
666 | if ( pb == NULL ||\r | |
667 | pb->bf_getreadbuffer == NULL ||\r | |
668 | pb->bf_getsegcount == NULL )\r | |
669 | {\r | |
670 | PyErr_BadArgument();\r | |
671 | return -1;\r | |
672 | }\r | |
673 | if ( (*pb->bf_getsegcount)(value, NULL) != 1 )\r | |
674 | {\r | |
675 | /* ### use a different exception type/message? */\r | |
676 | PyErr_SetString(PyExc_TypeError,\r | |
677 | "single-segment buffer object expected");\r | |
678 | return -1;\r | |
679 | }\r | |
680 | if (!get_buf(self, &ptr1, &selfsize, ANY_BUFFER))\r | |
681 | return -1;\r | |
682 | if (PyIndex_Check(item)) {\r | |
683 | Py_ssize_t i = PyNumber_AsSsize_t(item, PyExc_IndexError);\r | |
684 | if (i == -1 && PyErr_Occurred())\r | |
685 | return -1;\r | |
686 | if (i < 0)\r | |
687 | i += selfsize;\r | |
688 | return buffer_ass_item(self, i, value);\r | |
689 | }\r | |
690 | else if (PySlice_Check(item)) {\r | |
691 | Py_ssize_t start, stop, step, slicelength;\r | |
692 | \r | |
693 | if (PySlice_GetIndicesEx((PySliceObject *)item, selfsize,\r | |
694 | &start, &stop, &step, &slicelength) < 0)\r | |
695 | return -1;\r | |
696 | \r | |
697 | if ((othersize = (*pb->bf_getreadbuffer)(value, 0, &ptr2)) < 0)\r | |
698 | return -1;\r | |
699 | \r | |
700 | if (othersize != slicelength) {\r | |
701 | PyErr_SetString(\r | |
702 | PyExc_TypeError,\r | |
703 | "right operand length must match slice length");\r | |
704 | return -1;\r | |
705 | }\r | |
706 | \r | |
707 | if (slicelength == 0)\r | |
708 | return 0;\r | |
709 | else if (step == 1) {\r | |
710 | memcpy((char *)ptr1 + start, ptr2, slicelength);\r | |
711 | return 0;\r | |
712 | }\r | |
713 | else {\r | |
714 | Py_ssize_t cur, i;\r | |
715 | \r | |
716 | for (cur = start, i = 0; i < slicelength;\r | |
717 | cur += step, i++) {\r | |
718 | ((char *)ptr1)[cur] = ((char *)ptr2)[i];\r | |
719 | }\r | |
720 | \r | |
721 | return 0;\r | |
722 | }\r | |
723 | } else {\r | |
724 | PyErr_SetString(PyExc_TypeError,\r | |
725 | "buffer indices must be integers");\r | |
726 | return -1;\r | |
727 | }\r | |
728 | }\r | |
729 | \r | |
730 | /* Buffer methods */\r | |
731 | \r | |
732 | static Py_ssize_t\r | |
733 | buffer_getreadbuf(PyBufferObject *self, Py_ssize_t idx, void **pp)\r | |
734 | {\r | |
735 | Py_ssize_t size;\r | |
736 | if ( idx != 0 ) {\r | |
737 | PyErr_SetString(PyExc_SystemError,\r | |
738 | "accessing non-existent buffer segment");\r | |
739 | return -1;\r | |
740 | }\r | |
741 | if (!get_buf(self, pp, &size, READ_BUFFER))\r | |
742 | return -1;\r | |
743 | return size;\r | |
744 | }\r | |
745 | \r | |
746 | static Py_ssize_t\r | |
747 | buffer_getwritebuf(PyBufferObject *self, Py_ssize_t idx, void **pp)\r | |
748 | {\r | |
749 | Py_ssize_t size;\r | |
750 | \r | |
751 | if ( self->b_readonly )\r | |
752 | {\r | |
753 | PyErr_SetString(PyExc_TypeError, "buffer is read-only");\r | |
754 | return -1;\r | |
755 | }\r | |
756 | \r | |
757 | if ( idx != 0 ) {\r | |
758 | PyErr_SetString(PyExc_SystemError,\r | |
759 | "accessing non-existent buffer segment");\r | |
760 | return -1;\r | |
761 | }\r | |
762 | if (!get_buf(self, pp, &size, WRITE_BUFFER))\r | |
763 | return -1;\r | |
764 | return size;\r | |
765 | }\r | |
766 | \r | |
767 | static Py_ssize_t\r | |
768 | buffer_getsegcount(PyBufferObject *self, Py_ssize_t *lenp)\r | |
769 | {\r | |
770 | void *ptr;\r | |
771 | Py_ssize_t size;\r | |
772 | if (!get_buf(self, &ptr, &size, ANY_BUFFER))\r | |
773 | return -1;\r | |
774 | if (lenp)\r | |
775 | *lenp = size;\r | |
776 | return 1;\r | |
777 | }\r | |
778 | \r | |
779 | static Py_ssize_t\r | |
780 | buffer_getcharbuf(PyBufferObject *self, Py_ssize_t idx, const char **pp)\r | |
781 | {\r | |
782 | void *ptr;\r | |
783 | Py_ssize_t size;\r | |
784 | if ( idx != 0 ) {\r | |
785 | PyErr_SetString(PyExc_SystemError,\r | |
786 | "accessing non-existent buffer segment");\r | |
787 | return -1;\r | |
788 | }\r | |
789 | if (!get_buf(self, &ptr, &size, CHAR_BUFFER))\r | |
790 | return -1;\r | |
791 | *pp = (const char *)ptr;\r | |
792 | return size;\r | |
793 | }\r | |
794 | \r | |
795 | static PySequenceMethods buffer_as_sequence = {\r | |
796 | (lenfunc)buffer_length, /*sq_length*/\r | |
797 | (binaryfunc)buffer_concat, /*sq_concat*/\r | |
798 | (ssizeargfunc)buffer_repeat, /*sq_repeat*/\r | |
799 | (ssizeargfunc)buffer_item, /*sq_item*/\r | |
800 | (ssizessizeargfunc)buffer_slice, /*sq_slice*/\r | |
801 | (ssizeobjargproc)buffer_ass_item, /*sq_ass_item*/\r | |
802 | (ssizessizeobjargproc)buffer_ass_slice, /*sq_ass_slice*/\r | |
803 | };\r | |
804 | \r | |
805 | static PyMappingMethods buffer_as_mapping = {\r | |
806 | (lenfunc)buffer_length,\r | |
807 | (binaryfunc)buffer_subscript,\r | |
808 | (objobjargproc)buffer_ass_subscript,\r | |
809 | };\r | |
810 | \r | |
811 | static PyBufferProcs buffer_as_buffer = {\r | |
812 | (readbufferproc)buffer_getreadbuf,\r | |
813 | (writebufferproc)buffer_getwritebuf,\r | |
814 | (segcountproc)buffer_getsegcount,\r | |
815 | (charbufferproc)buffer_getcharbuf,\r | |
816 | };\r | |
817 | \r | |
818 | PyTypeObject PyBuffer_Type = {\r | |
819 | PyVarObject_HEAD_INIT(&PyType_Type, 0)\r | |
820 | "buffer",\r | |
821 | sizeof(PyBufferObject),\r | |
822 | 0,\r | |
823 | (destructor)buffer_dealloc, /* tp_dealloc */\r | |
824 | 0, /* tp_print */\r | |
825 | 0, /* tp_getattr */\r | |
826 | 0, /* tp_setattr */\r | |
827 | (cmpfunc)buffer_compare, /* tp_compare */\r | |
828 | (reprfunc)buffer_repr, /* tp_repr */\r | |
829 | 0, /* tp_as_number */\r | |
830 | &buffer_as_sequence, /* tp_as_sequence */\r | |
831 | &buffer_as_mapping, /* tp_as_mapping */\r | |
832 | (hashfunc)buffer_hash, /* tp_hash */\r | |
833 | 0, /* tp_call */\r | |
834 | (reprfunc)buffer_str, /* tp_str */\r | |
835 | PyObject_GenericGetAttr, /* tp_getattro */\r | |
836 | 0, /* tp_setattro */\r | |
837 | &buffer_as_buffer, /* tp_as_buffer */\r | |
838 | Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GETCHARBUFFER, /* tp_flags */\r | |
839 | buffer_doc, /* tp_doc */\r | |
840 | 0, /* tp_traverse */\r | |
841 | 0, /* tp_clear */\r | |
842 | 0, /* tp_richcompare */\r | |
843 | 0, /* tp_weaklistoffset */\r | |
844 | 0, /* tp_iter */\r | |
845 | 0, /* tp_iternext */\r | |
846 | 0, /* tp_methods */\r | |
847 | 0, /* tp_members */\r | |
848 | 0, /* tp_getset */\r | |
849 | 0, /* tp_base */\r | |
850 | 0, /* tp_dict */\r | |
851 | 0, /* tp_descr_get */\r | |
852 | 0, /* tp_descr_set */\r | |
853 | 0, /* tp_dictoffset */\r | |
854 | 0, /* tp_init */\r | |
855 | 0, /* tp_alloc */\r | |
856 | buffer_new, /* tp_new */\r | |
857 | };\r |