Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 1 | |
| 2 | /* Buffer object implementation */ |
| 3 | |
| 4 | #include "Python.h" |
| 5 | |
| 6 | |
| 7 | typedef struct { |
| 8 | PyObject_HEAD |
| 9 | PyObject *b_base; |
| 10 | void *b_ptr; |
| 11 | int b_size; |
| 12 | int b_readonly; |
| 13 | #ifdef CACHE_HASH |
| 14 | long b_hash; |
| 15 | #endif |
| 16 | } PyBufferObject; |
| 17 | |
| 18 | |
| 19 | static PyObject * |
Fred Drake | 7991247 | 2000-07-09 04:06:11 +0000 | [diff] [blame] | 20 | _PyBuffer_FromMemory(PyObject *base, void *ptr, int size, int readonly) |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 21 | { |
| 22 | PyBufferObject * b; |
| 23 | |
Guido van Rossum | 49ded3e | 1999-03-19 19:04:25 +0000 | [diff] [blame] | 24 | if ( size < 0 ) { |
| 25 | PyErr_SetString(PyExc_ValueError, |
| 26 | "size must be zero or positive"); |
| 27 | return NULL; |
| 28 | } |
| 29 | |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 30 | b = PyObject_NEW(PyBufferObject, &PyBuffer_Type); |
| 31 | if ( b == NULL ) |
| 32 | return NULL; |
| 33 | |
| 34 | Py_XINCREF(base); |
| 35 | b->b_base = base; |
| 36 | b->b_ptr = ptr; |
| 37 | b->b_size = size; |
| 38 | b->b_readonly = readonly; |
| 39 | #ifdef CACHE_HASH |
| 40 | b->b_hash = -1; |
| 41 | #endif |
| 42 | |
| 43 | return (PyObject *) b; |
| 44 | } |
| 45 | |
| 46 | static PyObject * |
Fred Drake | 7991247 | 2000-07-09 04:06:11 +0000 | [diff] [blame] | 47 | _PyBuffer_FromObject(PyObject *base, int offset, int size, |
| 48 | getreadbufferproc proc, int readonly) |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 49 | { |
| 50 | PyBufferProcs *pb = base->ob_type->tp_as_buffer; |
| 51 | void *p; |
| 52 | int count; |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 53 | |
Guido van Rossum | 49ded3e | 1999-03-19 19:04:25 +0000 | [diff] [blame] | 54 | if ( offset < 0 ) { |
| 55 | PyErr_SetString(PyExc_ValueError, |
| 56 | "offset must be zero or positive"); |
| 57 | return NULL; |
| 58 | } |
| 59 | |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 60 | if ( (*pb->bf_getsegcount)(base, NULL) != 1 ) |
| 61 | { |
Guido van Rossum | cd037e7 | 1999-03-24 19:05:31 +0000 | [diff] [blame] | 62 | PyErr_SetString(PyExc_TypeError, |
| 63 | "single-segment buffer object expected"); |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 64 | return NULL; |
| 65 | } |
| 66 | if ( (count = (*proc)(base, 0, &p)) < 0 ) |
| 67 | return NULL; |
| 68 | |
| 69 | /* apply constraints to the start/end */ |
Guido van Rossum | 49ded3e | 1999-03-19 19:04:25 +0000 | [diff] [blame] | 70 | if ( size == Py_END_OF_BUFFER || size < 0 ) |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 71 | size = count; |
| 72 | if ( offset > count ) |
| 73 | offset = count; |
| 74 | if ( offset + size > count ) |
| 75 | size = count - offset; |
| 76 | |
| 77 | /* if the base object is another buffer, then "deref" it */ |
| 78 | if ( PyBuffer_Check(base) ) |
| 79 | base = ((PyBufferObject *)base)->b_base; |
| 80 | |
| 81 | return _PyBuffer_FromMemory(base, (char *)p + offset, size, readonly); |
| 82 | } |
| 83 | |
| 84 | |
| 85 | PyObject * |
Fred Drake | 7991247 | 2000-07-09 04:06:11 +0000 | [diff] [blame] | 86 | PyBuffer_FromObject(PyObject *base, int offset, int size) |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 87 | { |
| 88 | PyBufferProcs *pb = base->ob_type->tp_as_buffer; |
| 89 | |
| 90 | if ( pb == NULL || |
| 91 | pb->bf_getreadbuffer == NULL || |
| 92 | pb->bf_getsegcount == NULL ) |
| 93 | { |
| 94 | PyErr_SetString(PyExc_TypeError, "buffer object expected"); |
| 95 | return NULL; |
| 96 | } |
| 97 | |
Guido van Rossum | cd037e7 | 1999-03-24 19:05:31 +0000 | [diff] [blame] | 98 | return _PyBuffer_FromObject(base, offset, size, |
| 99 | pb->bf_getreadbuffer, 1); |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 100 | } |
| 101 | |
| 102 | PyObject * |
Fred Drake | 7991247 | 2000-07-09 04:06:11 +0000 | [diff] [blame] | 103 | PyBuffer_FromReadWriteObject(PyObject *base, int offset, int size) |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 104 | { |
| 105 | PyBufferProcs *pb = base->ob_type->tp_as_buffer; |
| 106 | |
| 107 | if ( pb == NULL || |
| 108 | pb->bf_getwritebuffer == NULL || |
| 109 | pb->bf_getsegcount == NULL ) |
| 110 | { |
| 111 | PyErr_SetString(PyExc_TypeError, "buffer object expected"); |
| 112 | return NULL; |
| 113 | } |
| 114 | |
Guido van Rossum | cd037e7 | 1999-03-24 19:05:31 +0000 | [diff] [blame] | 115 | return _PyBuffer_FromObject(base, offset, size, |
| 116 | (getreadbufferproc)pb->bf_getwritebuffer, |
| 117 | 0); |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 118 | } |
| 119 | |
| 120 | PyObject * |
Fred Drake | 7991247 | 2000-07-09 04:06:11 +0000 | [diff] [blame] | 121 | PyBuffer_FromMemory(void *ptr, int size) |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 122 | { |
| 123 | return _PyBuffer_FromMemory(NULL, ptr, size, 1); |
| 124 | } |
| 125 | |
| 126 | PyObject * |
Fred Drake | 7991247 | 2000-07-09 04:06:11 +0000 | [diff] [blame] | 127 | PyBuffer_FromReadWriteMemory(void *ptr, int size) |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 128 | { |
| 129 | return _PyBuffer_FromMemory(NULL, ptr, size, 0); |
| 130 | } |
| 131 | |
| 132 | PyObject * |
Fred Drake | 7991247 | 2000-07-09 04:06:11 +0000 | [diff] [blame] | 133 | PyBuffer_New(int size) |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 134 | { |
Moshe Zadka | cf703f0 | 2000-08-04 15:36:13 +0000 | [diff] [blame] | 135 | PyObject *o; |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 136 | PyBufferObject * b; |
| 137 | |
Fred Drake | 4574f23 | 1999-08-04 13:08:19 +0000 | [diff] [blame] | 138 | if (size < 0) { |
| 139 | PyErr_SetString(PyExc_ValueError, |
| 140 | "size must be zero or positive"); |
| 141 | return NULL; |
| 142 | } |
Guido van Rossum | b18618d | 2000-05-03 23:44:39 +0000 | [diff] [blame] | 143 | /* PyObject_New is inlined */ |
Moshe Zadka | cf703f0 | 2000-08-04 15:36:13 +0000 | [diff] [blame] | 144 | o = PyObject_MALLOC(sizeof(*b) + size); |
| 145 | if ( o == NULL ) |
Fred Drake | 4574f23 | 1999-08-04 13:08:19 +0000 | [diff] [blame] | 146 | return PyErr_NoMemory(); |
Moshe Zadka | cf703f0 | 2000-08-04 15:36:13 +0000 | [diff] [blame] | 147 | b = (PyBufferObject *) PyObject_INIT(o, &PyBuffer_Type); |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 148 | |
| 149 | b->b_base = NULL; |
| 150 | b->b_ptr = (void *)(b + 1); |
| 151 | b->b_size = size; |
| 152 | b->b_readonly = 0; |
| 153 | #ifdef CACHE_HASH |
| 154 | b->b_hash = -1; |
| 155 | #endif |
| 156 | |
Moshe Zadka | cf703f0 | 2000-08-04 15:36:13 +0000 | [diff] [blame] | 157 | return o; |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 158 | } |
| 159 | |
| 160 | /* Methods */ |
| 161 | |
| 162 | static void |
Fred Drake | 7991247 | 2000-07-09 04:06:11 +0000 | [diff] [blame] | 163 | buffer_dealloc(PyBufferObject *self) |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 164 | { |
| 165 | Py_XDECREF(self->b_base); |
Guido van Rossum | b18618d | 2000-05-03 23:44:39 +0000 | [diff] [blame] | 166 | PyObject_DEL(self); |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 167 | } |
| 168 | |
| 169 | static int |
Fred Drake | 7991247 | 2000-07-09 04:06:11 +0000 | [diff] [blame] | 170 | buffer_compare(PyBufferObject *self, PyBufferObject *other) |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 171 | { |
| 172 | int len_self = self->b_size; |
| 173 | int len_other = other->b_size; |
| 174 | int min_len = (len_self < len_other) ? len_self : len_other; |
| 175 | int cmp; |
| 176 | if (min_len > 0) { |
| 177 | cmp = memcmp(self->b_ptr, other->b_ptr, min_len); |
| 178 | if (cmp != 0) |
| 179 | return cmp; |
| 180 | } |
| 181 | return (len_self < len_other) ? -1 : (len_self > len_other) ? 1 : 0; |
| 182 | } |
| 183 | |
| 184 | static PyObject * |
Fred Drake | 7991247 | 2000-07-09 04:06:11 +0000 | [diff] [blame] | 185 | buffer_repr(PyBufferObject *self) |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 186 | { |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 187 | char *status = self->b_readonly ? "read-only" : "read-write"; |
| 188 | |
| 189 | if ( self->b_base == NULL ) |
Barry Warsaw | 7ce3694 | 2001-08-24 18:34:26 +0000 | [diff] [blame] | 190 | return PyString_FromFormat("<%s buffer ptr %p, size %d at %p>", |
| 191 | status, |
| 192 | self->b_ptr, |
| 193 | self->b_size, |
| 194 | self); |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 195 | else |
Barry Warsaw | 7ce3694 | 2001-08-24 18:34:26 +0000 | [diff] [blame] | 196 | return PyString_FromFormat( |
| 197 | "<%s buffer for %p, ptr %p, size %d at %p>", |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 198 | status, |
Fred Drake | a44d353 | 2000-06-30 15:01:00 +0000 | [diff] [blame] | 199 | self->b_base, |
| 200 | self->b_ptr, |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 201 | self->b_size, |
Fred Drake | a44d353 | 2000-06-30 15:01:00 +0000 | [diff] [blame] | 202 | self); |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 203 | } |
| 204 | |
| 205 | static long |
Fred Drake | 7991247 | 2000-07-09 04:06:11 +0000 | [diff] [blame] | 206 | buffer_hash(PyBufferObject *self) |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 207 | { |
| 208 | register int len; |
| 209 | register unsigned char *p; |
| 210 | register long x; |
| 211 | |
| 212 | #ifdef CACHE_HASH |
| 213 | if ( self->b_hash != -1 ) |
| 214 | return self->b_hash; |
| 215 | #endif |
| 216 | |
| 217 | if ( !self->b_readonly ) |
| 218 | { |
| 219 | /* ### use different wording, since this is conditional? */ |
| 220 | PyErr_SetString(PyExc_TypeError, "unhashable type"); |
| 221 | return -1; |
| 222 | } |
| 223 | |
| 224 | len = self->b_size; |
| 225 | p = (unsigned char *) self->b_ptr; |
| 226 | x = *p << 7; |
| 227 | while (--len >= 0) |
| 228 | x = (1000003*x) ^ *p++; |
| 229 | x ^= self->b_size; |
| 230 | if (x == -1) |
| 231 | x = -2; |
| 232 | #ifdef CACHE_HASH |
| 233 | self->b_hash = x; |
| 234 | #endif |
| 235 | return x; |
| 236 | } |
| 237 | |
| 238 | static PyObject * |
Fred Drake | 7991247 | 2000-07-09 04:06:11 +0000 | [diff] [blame] | 239 | buffer_str(PyBufferObject *self) |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 240 | { |
| 241 | return PyString_FromStringAndSize(self->b_ptr, self->b_size); |
| 242 | } |
| 243 | |
| 244 | /* Sequence methods */ |
| 245 | |
| 246 | static int |
Fred Drake | 7991247 | 2000-07-09 04:06:11 +0000 | [diff] [blame] | 247 | buffer_length(PyBufferObject *self) |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 248 | { |
| 249 | return self->b_size; |
| 250 | } |
| 251 | |
| 252 | static PyObject * |
Fred Drake | 7991247 | 2000-07-09 04:06:11 +0000 | [diff] [blame] | 253 | buffer_concat(PyBufferObject *self, PyObject *other) |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 254 | { |
| 255 | PyBufferProcs *pb = other->ob_type->tp_as_buffer; |
| 256 | char *p1; |
| 257 | void *p2; |
| 258 | PyObject *ob; |
| 259 | int count; |
| 260 | |
| 261 | if ( pb == NULL || |
| 262 | pb->bf_getreadbuffer == NULL || |
| 263 | pb->bf_getsegcount == NULL ) |
| 264 | { |
| 265 | PyErr_BadArgument(); |
| 266 | return NULL; |
| 267 | } |
| 268 | if ( (*pb->bf_getsegcount)(other, NULL) != 1 ) |
| 269 | { |
| 270 | /* ### use a different exception type/message? */ |
Guido van Rossum | cd037e7 | 1999-03-24 19:05:31 +0000 | [diff] [blame] | 271 | PyErr_SetString(PyExc_TypeError, |
| 272 | "single-segment buffer object expected"); |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 273 | return NULL; |
| 274 | } |
| 275 | |
| 276 | /* optimize special case */ |
| 277 | if ( self->b_size == 0 ) |
| 278 | { |
| 279 | Py_INCREF(other); |
| 280 | return other; |
| 281 | } |
| 282 | |
| 283 | if ( (count = (*pb->bf_getreadbuffer)(other, 0, &p2)) < 0 ) |
| 284 | return NULL; |
| 285 | |
| 286 | /* optimize special case */ |
| 287 | if ( count == 0 ) |
| 288 | { |
| 289 | Py_INCREF(self); |
| 290 | return (PyObject *)self; |
| 291 | } |
| 292 | |
| 293 | ob = PyString_FromStringAndSize(NULL, self->b_size + count); |
| 294 | p1 = PyString_AS_STRING(ob); |
| 295 | memcpy(p1, self->b_ptr, self->b_size); |
| 296 | memcpy(p1 + self->b_size, p2, count); |
| 297 | |
| 298 | /* there is an extra byte in the string object, so this is safe */ |
| 299 | p1[self->b_size + count] = '\0'; |
| 300 | |
| 301 | return ob; |
| 302 | } |
| 303 | |
| 304 | static PyObject * |
Fred Drake | 7991247 | 2000-07-09 04:06:11 +0000 | [diff] [blame] | 305 | buffer_repeat(PyBufferObject *self, int count) |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 306 | { |
| 307 | PyObject *ob; |
| 308 | register char *p; |
| 309 | void *ptr = self->b_ptr; |
| 310 | int size = self->b_size; |
| 311 | |
| 312 | if ( count < 0 ) |
| 313 | count = 0; |
| 314 | ob = PyString_FromStringAndSize(NULL, size * count); |
| 315 | if ( ob == NULL ) |
| 316 | return NULL; |
| 317 | |
| 318 | p = PyString_AS_STRING(ob); |
| 319 | while ( count-- ) |
| 320 | { |
| 321 | memcpy(p, ptr, size); |
| 322 | p += size; |
| 323 | } |
| 324 | |
| 325 | /* there is an extra byte in the string object, so this is safe */ |
| 326 | *p = '\0'; |
| 327 | |
| 328 | return ob; |
| 329 | } |
| 330 | |
| 331 | static PyObject * |
Fred Drake | 7991247 | 2000-07-09 04:06:11 +0000 | [diff] [blame] | 332 | buffer_item(PyBufferObject *self, int idx) |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 333 | { |
| 334 | if ( idx < 0 || idx >= self->b_size ) |
| 335 | { |
| 336 | PyErr_SetString(PyExc_IndexError, "buffer index out of range"); |
| 337 | return NULL; |
| 338 | } |
| 339 | return PyString_FromStringAndSize((char *)self->b_ptr + idx, 1); |
| 340 | } |
| 341 | |
| 342 | static PyObject * |
Fred Drake | 7991247 | 2000-07-09 04:06:11 +0000 | [diff] [blame] | 343 | buffer_slice(PyBufferObject *self, int left, int right) |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 344 | { |
| 345 | if ( left < 0 ) |
| 346 | left = 0; |
| 347 | if ( right < 0 ) |
| 348 | right = 0; |
| 349 | if ( right > self->b_size ) |
| 350 | right = self->b_size; |
| 351 | if ( left == 0 && right == self->b_size ) |
| 352 | { |
| 353 | /* same as self */ |
| 354 | Py_INCREF(self); |
| 355 | return (PyObject *)self; |
| 356 | } |
| 357 | if ( right < left ) |
| 358 | right = left; |
Guido van Rossum | cd037e7 | 1999-03-24 19:05:31 +0000 | [diff] [blame] | 359 | return PyString_FromStringAndSize((char *)self->b_ptr + left, |
| 360 | right - left); |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 361 | } |
| 362 | |
| 363 | static int |
Fred Drake | 7991247 | 2000-07-09 04:06:11 +0000 | [diff] [blame] | 364 | buffer_ass_item(PyBufferObject *self, int idx, PyObject *other) |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 365 | { |
| 366 | PyBufferProcs *pb; |
| 367 | void *p; |
| 368 | int count; |
| 369 | |
| 370 | if ( self->b_readonly ) { |
| 371 | PyErr_SetString(PyExc_TypeError, |
| 372 | "buffer is read-only"); |
| 373 | return -1; |
| 374 | } |
| 375 | |
| 376 | if (idx < 0 || idx >= self->b_size) { |
| 377 | PyErr_SetString(PyExc_IndexError, |
| 378 | "buffer assignment index out of range"); |
| 379 | return -1; |
| 380 | } |
| 381 | |
| 382 | pb = other ? other->ob_type->tp_as_buffer : NULL; |
| 383 | if ( pb == NULL || |
| 384 | pb->bf_getreadbuffer == NULL || |
| 385 | pb->bf_getsegcount == NULL ) |
| 386 | { |
| 387 | PyErr_BadArgument(); |
| 388 | return -1; |
| 389 | } |
| 390 | if ( (*pb->bf_getsegcount)(other, NULL) != 1 ) |
| 391 | { |
| 392 | /* ### use a different exception type/message? */ |
Guido van Rossum | cd037e7 | 1999-03-24 19:05:31 +0000 | [diff] [blame] | 393 | PyErr_SetString(PyExc_TypeError, |
| 394 | "single-segment buffer object expected"); |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 395 | return -1; |
| 396 | } |
| 397 | |
| 398 | if ( (count = (*pb->bf_getreadbuffer)(other, 0, &p)) < 0 ) |
| 399 | return -1; |
| 400 | if ( count != 1 ) { |
| 401 | PyErr_SetString(PyExc_TypeError, |
| 402 | "right operand must be a single byte"); |
| 403 | return -1; |
| 404 | } |
| 405 | |
| 406 | ((char *)self->b_ptr)[idx] = *(char *)p; |
| 407 | return 0; |
| 408 | } |
| 409 | |
| 410 | static int |
Fred Drake | 7991247 | 2000-07-09 04:06:11 +0000 | [diff] [blame] | 411 | buffer_ass_slice(PyBufferObject *self, int left, int right, PyObject *other) |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 412 | { |
| 413 | PyBufferProcs *pb; |
| 414 | void *p; |
| 415 | int slice_len; |
| 416 | int count; |
| 417 | |
| 418 | if ( self->b_readonly ) { |
| 419 | PyErr_SetString(PyExc_TypeError, |
| 420 | "buffer is read-only"); |
| 421 | return -1; |
| 422 | } |
| 423 | |
| 424 | pb = other ? other->ob_type->tp_as_buffer : NULL; |
| 425 | if ( pb == NULL || |
| 426 | pb->bf_getreadbuffer == NULL || |
| 427 | pb->bf_getsegcount == NULL ) |
| 428 | { |
| 429 | PyErr_BadArgument(); |
| 430 | return -1; |
| 431 | } |
| 432 | if ( (*pb->bf_getsegcount)(other, NULL) != 1 ) |
| 433 | { |
| 434 | /* ### use a different exception type/message? */ |
Guido van Rossum | cd037e7 | 1999-03-24 19:05:31 +0000 | [diff] [blame] | 435 | PyErr_SetString(PyExc_TypeError, |
| 436 | "single-segment buffer object expected"); |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 437 | return -1; |
| 438 | } |
| 439 | if ( (count = (*pb->bf_getreadbuffer)(other, 0, &p)) < 0 ) |
| 440 | return -1; |
| 441 | |
| 442 | if ( left < 0 ) |
| 443 | left = 0; |
| 444 | else if ( left > self->b_size ) |
| 445 | left = self->b_size; |
| 446 | if ( right < left ) |
| 447 | right = left; |
| 448 | else if ( right > self->b_size ) |
| 449 | right = self->b_size; |
| 450 | slice_len = right - left; |
| 451 | |
| 452 | if ( count != slice_len ) { |
Guido van Rossum | cd037e7 | 1999-03-24 19:05:31 +0000 | [diff] [blame] | 453 | PyErr_SetString( |
| 454 | PyExc_TypeError, |
| 455 | "right operand length must match slice length"); |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 456 | return -1; |
| 457 | } |
| 458 | |
| 459 | if ( slice_len ) |
| 460 | memcpy((char *)self->b_ptr + left, p, slice_len); |
| 461 | |
| 462 | return 0; |
| 463 | } |
| 464 | |
| 465 | /* Buffer methods */ |
| 466 | |
| 467 | static int |
Fred Drake | 7991247 | 2000-07-09 04:06:11 +0000 | [diff] [blame] | 468 | buffer_getreadbuf(PyBufferObject *self, int idx, void **pp) |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 469 | { |
| 470 | if ( idx != 0 ) { |
| 471 | PyErr_SetString(PyExc_SystemError, |
Guido van Rossum | 1db7070 | 1998-10-08 02:18:52 +0000 | [diff] [blame] | 472 | "accessing non-existent buffer segment"); |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 473 | return -1; |
| 474 | } |
| 475 | *pp = self->b_ptr; |
| 476 | return self->b_size; |
| 477 | } |
| 478 | |
| 479 | static int |
Fred Drake | 7991247 | 2000-07-09 04:06:11 +0000 | [diff] [blame] | 480 | buffer_getwritebuf(PyBufferObject *self, int idx, void **pp) |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 481 | { |
| 482 | if ( self->b_readonly ) |
| 483 | { |
| 484 | PyErr_SetString(PyExc_TypeError, "buffer is read-only"); |
| 485 | return -1; |
| 486 | } |
| 487 | return buffer_getreadbuf(self, idx, pp); |
| 488 | } |
| 489 | |
| 490 | static int |
Fred Drake | 7991247 | 2000-07-09 04:06:11 +0000 | [diff] [blame] | 491 | buffer_getsegcount(PyBufferObject *self, int *lenp) |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 492 | { |
| 493 | if ( lenp ) |
| 494 | *lenp = self->b_size; |
| 495 | return 1; |
| 496 | } |
| 497 | |
Guido van Rossum | 1db7070 | 1998-10-08 02:18:52 +0000 | [diff] [blame] | 498 | static int |
Fred Drake | 7991247 | 2000-07-09 04:06:11 +0000 | [diff] [blame] | 499 | buffer_getcharbuf(PyBufferObject *self, int idx, const char **pp) |
Guido van Rossum | 1db7070 | 1998-10-08 02:18:52 +0000 | [diff] [blame] | 500 | { |
| 501 | if ( idx != 0 ) { |
| 502 | PyErr_SetString(PyExc_SystemError, |
| 503 | "accessing non-existent buffer segment"); |
| 504 | return -1; |
| 505 | } |
| 506 | *pp = (const char *)self->b_ptr; |
| 507 | return self->b_size; |
| 508 | } |
| 509 | |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 510 | |
| 511 | static PySequenceMethods buffer_as_sequence = { |
| 512 | (inquiry)buffer_length, /*sq_length*/ |
| 513 | (binaryfunc)buffer_concat, /*sq_concat*/ |
| 514 | (intargfunc)buffer_repeat, /*sq_repeat*/ |
| 515 | (intargfunc)buffer_item, /*sq_item*/ |
| 516 | (intintargfunc)buffer_slice, /*sq_slice*/ |
| 517 | (intobjargproc)buffer_ass_item, /*sq_ass_item*/ |
| 518 | (intintobjargproc)buffer_ass_slice, /*sq_ass_slice*/ |
| 519 | }; |
| 520 | |
| 521 | static PyBufferProcs buffer_as_buffer = { |
| 522 | (getreadbufferproc)buffer_getreadbuf, |
| 523 | (getwritebufferproc)buffer_getwritebuf, |
| 524 | (getsegcountproc)buffer_getsegcount, |
Guido van Rossum | 1db7070 | 1998-10-08 02:18:52 +0000 | [diff] [blame] | 525 | (getcharbufferproc)buffer_getcharbuf, |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 526 | }; |
| 527 | |
| 528 | PyTypeObject PyBuffer_Type = { |
| 529 | PyObject_HEAD_INIT(&PyType_Type) |
| 530 | 0, |
| 531 | "buffer", |
| 532 | sizeof(PyBufferObject), |
| 533 | 0, |
Tim Peters | 6d6c1a3 | 2001-08-02 04:15:00 +0000 | [diff] [blame] | 534 | (destructor)buffer_dealloc, /* tp_dealloc */ |
| 535 | 0, /* tp_print */ |
| 536 | 0, /* tp_getattr */ |
| 537 | 0, /* tp_setattr */ |
| 538 | (cmpfunc)buffer_compare, /* tp_compare */ |
| 539 | (reprfunc)buffer_repr, /* tp_repr */ |
| 540 | 0, /* tp_as_number */ |
| 541 | &buffer_as_sequence, /* tp_as_sequence */ |
| 542 | 0, /* tp_as_mapping */ |
| 543 | (hashfunc)buffer_hash, /* tp_hash */ |
| 544 | 0, /* tp_call */ |
| 545 | (reprfunc)buffer_str, /* tp_str */ |
| 546 | PyObject_GenericGetAttr, /* tp_getattro */ |
| 547 | 0, /* tp_setattro */ |
| 548 | &buffer_as_buffer, /* tp_as_buffer */ |
| 549 | Py_TPFLAGS_DEFAULT, /* tp_flags */ |
| 550 | 0, /* tp_doc */ |
Guido van Rossum | 2e19bd7 | 1998-10-07 14:36:10 +0000 | [diff] [blame] | 551 | }; |