1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936
|
/* GIO - GLib Input, Output and Streaming Library
*
* Copyright (C) 2006-2007 Red Hat, Inc.
*
* SPDX-License-Identifier: LGPL-2.1-or-later
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General
* Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
*
* Author: Alexander Larsson <alexl@redhat.com>
*/
#include "config.h"
#include "gfileenumerator.h"
#include "gfile.h"
#include "gioscheduler.h"
#include "gasyncresult.h"
#include "gasynchelper.h"
#include "gioerror.h"
#include "glibintl.h"
struct _GFileEnumeratorPrivate {
/* TODO: Should be public for subclasses? */
GFile *container;
guint closed : 1;
guint pending : 1;
GAsyncReadyCallback outstanding_callback;
GError *outstanding_error;
};
/**
* SECTION:gfileenumerator
* @short_description: Enumerated Files Routines
* @include: gio/gio.h
*
* #GFileEnumerator allows you to operate on a set of #GFiles,
* returning a #GFileInfo structure for each file enumerated (e.g.
* g_file_enumerate_children() will return a #GFileEnumerator for each
* of the children within a directory).
*
* To get the next file's information from a #GFileEnumerator, use
* g_file_enumerator_next_file() or its asynchronous version,
* g_file_enumerator_next_files_async(). Note that the asynchronous
* version will return a list of #GFileInfos, whereas the
* synchronous will only return the next file in the enumerator.
*
* The ordering of returned files is unspecified for non-Unix
* platforms; for more information, see g_dir_read_name(). On Unix,
* when operating on local files, returned files will be sorted by
* inode number. Effectively you can assume that the ordering of
* returned files will be stable between successive calls (and
* applications) assuming the directory is unchanged.
*
* If your application needs a specific ordering, such as by name or
* modification time, you will have to implement that in your
* application code.
*
* To close a #GFileEnumerator, use g_file_enumerator_close(), or
* its asynchronous version, g_file_enumerator_close_async(). Once
* a #GFileEnumerator is closed, no further actions may be performed
* on it, and it should be freed with g_object_unref().
*
**/
G_DEFINE_TYPE_WITH_PRIVATE (GFileEnumerator, g_file_enumerator, G_TYPE_OBJECT)
enum {
PROP_0,
PROP_CONTAINER
};
static void g_file_enumerator_real_next_files_async (GFileEnumerator *enumerator,
int num_files,
int io_priority,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer user_data);
static GList * g_file_enumerator_real_next_files_finish (GFileEnumerator *enumerator,
GAsyncResult *res,
GError **error);
static void g_file_enumerator_real_close_async (GFileEnumerator *enumerator,
int io_priority,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer user_data);
static gboolean g_file_enumerator_real_close_finish (GFileEnumerator *enumerator,
GAsyncResult *res,
GError **error);
static void
g_file_enumerator_set_property (GObject *object,
guint property_id,
const GValue *value,
GParamSpec *pspec)
{
GFileEnumerator *enumerator;
enumerator = G_FILE_ENUMERATOR (object);
switch (property_id) {
case PROP_CONTAINER:
enumerator->priv->container = g_value_dup_object (value);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
break;
}
}
static void
g_file_enumerator_dispose (GObject *object)
{
GFileEnumerator *enumerator;
enumerator = G_FILE_ENUMERATOR (object);
if (enumerator->priv->container) {
g_object_unref (enumerator->priv->container);
enumerator->priv->container = NULL;
}
G_OBJECT_CLASS (g_file_enumerator_parent_class)->dispose (object);
}
static void
g_file_enumerator_finalize (GObject *object)
{
GFileEnumerator *enumerator;
enumerator = G_FILE_ENUMERATOR (object);
if (!enumerator->priv->closed)
g_file_enumerator_close (enumerator, NULL, NULL);
G_OBJECT_CLASS (g_file_enumerator_parent_class)->finalize (object);
}
static void
g_file_enumerator_class_init (GFileEnumeratorClass *klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
gobject_class->set_property = g_file_enumerator_set_property;
gobject_class->dispose = g_file_enumerator_dispose;
gobject_class->finalize = g_file_enumerator_finalize;
klass->next_files_async = g_file_enumerator_real_next_files_async;
klass->next_files_finish = g_file_enumerator_real_next_files_finish;
klass->close_async = g_file_enumerator_real_close_async;
klass->close_finish = g_file_enumerator_real_close_finish;
g_object_class_install_property
(gobject_class, PROP_CONTAINER,
g_param_spec_object ("container", P_("Container"),
P_("The container that is being enumerated"),
G_TYPE_FILE,
G_PARAM_WRITABLE |
G_PARAM_CONSTRUCT_ONLY |
G_PARAM_STATIC_STRINGS));
}
static void
g_file_enumerator_init (GFileEnumerator *enumerator)
{
enumerator->priv = g_file_enumerator_get_instance_private (enumerator);
}
/**
* g_file_enumerator_next_file:
* @enumerator: a #GFileEnumerator.
* @cancellable: (nullable): optional #GCancellable object, %NULL to ignore.
* @error: location to store the error occurring, or %NULL to ignore
*
* Returns information for the next file in the enumerated object.
* Will block until the information is available. The #GFileInfo
* returned from this function will contain attributes that match the
* attribute string that was passed when the #GFileEnumerator was created.
*
* See the documentation of #GFileEnumerator for information about the
* order of returned files.
*
* On error, returns %NULL and sets @error to the error. If the
* enumerator is at the end, %NULL will be returned and @error will
* be unset.
*
* Returns: (nullable) (transfer full): A #GFileInfo or %NULL on error
* or end of enumerator. Free the returned object with
* g_object_unref() when no longer needed.
**/
GFileInfo *
g_file_enumerator_next_file (GFileEnumerator *enumerator,
GCancellable *cancellable,
GError **error)
{
GFileEnumeratorClass *class;
GFileInfo *info;
g_return_val_if_fail (G_IS_FILE_ENUMERATOR (enumerator), NULL);
g_return_val_if_fail (enumerator != NULL, NULL);
if (enumerator->priv->closed)
{
g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_CLOSED,
_("Enumerator is closed"));
return NULL;
}
if (enumerator->priv->pending)
{
g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_PENDING,
_("File enumerator has outstanding operation"));
return NULL;
}
if (enumerator->priv->outstanding_error)
{
g_propagate_error (error, enumerator->priv->outstanding_error);
enumerator->priv->outstanding_error = NULL;
return NULL;
}
class = G_FILE_ENUMERATOR_GET_CLASS (enumerator);
if (cancellable)
g_cancellable_push_current (cancellable);
enumerator->priv->pending = TRUE;
info = (* class->next_file) (enumerator, cancellable, error);
enumerator->priv->pending = FALSE;
if (cancellable)
g_cancellable_pop_current (cancellable);
return info;
}
/**
* g_file_enumerator_close:
* @enumerator: a #GFileEnumerator.
* @cancellable: (nullable): optional #GCancellable object, %NULL to ignore.
* @error: location to store the error occurring, or %NULL to ignore
*
* Releases all resources used by this enumerator, making the
* enumerator return %G_IO_ERROR_CLOSED on all calls.
*
* This will be automatically called when the last reference
* is dropped, but you might want to call this function to make
* sure resources are released as early as possible.
*
* Returns: #TRUE on success or #FALSE on error.
**/
gboolean
g_file_enumerator_close (GFileEnumerator *enumerator,
GCancellable *cancellable,
GError **error)
{
GFileEnumeratorClass *class;
g_return_val_if_fail (G_IS_FILE_ENUMERATOR (enumerator), FALSE);
g_return_val_if_fail (enumerator != NULL, FALSE);
class = G_FILE_ENUMERATOR_GET_CLASS (enumerator);
if (enumerator->priv->closed)
return TRUE;
if (enumerator->priv->pending)
{
g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_PENDING,
_("File enumerator has outstanding operation"));
return FALSE;
}
if (cancellable)
g_cancellable_push_current (cancellable);
enumerator->priv->pending = TRUE;
(* class->close_fn) (enumerator, cancellable, error);
enumerator->priv->pending = FALSE;
enumerator->priv->closed = TRUE;
if (cancellable)
g_cancellable_pop_current (cancellable);
return TRUE;
}
static void
next_async_callback_wrapper (GObject *source_object,
GAsyncResult *res,
gpointer user_data)
{
GFileEnumerator *enumerator = G_FILE_ENUMERATOR (source_object);
enumerator->priv->pending = FALSE;
if (enumerator->priv->outstanding_callback)
(*enumerator->priv->outstanding_callback) (source_object, res, user_data);
g_object_unref (enumerator);
}
/**
* g_file_enumerator_next_files_async:
* @enumerator: a #GFileEnumerator.
* @num_files: the number of file info objects to request
* @io_priority: the [I/O priority][io-priority] of the request
* @cancellable: (nullable): optional #GCancellable object, %NULL to ignore.
* @callback: (scope async) (closure user_data): a #GAsyncReadyCallback
* to call when the request is satisfied
* @user_data: the data to pass to callback function
*
* Request information for a number of files from the enumerator asynchronously.
* When all I/O for the operation is finished the @callback will be called with
* the requested information.
*
* See the documentation of #GFileEnumerator for information about the
* order of returned files.
*
* Once the end of the enumerator is reached, or if an error occurs, the
* @callback will be called with an empty list. In this case, the previous call
* to g_file_enumerator_next_files_async() will typically have returned fewer
* than @num_files items.
*
* If a request is cancelled the callback will be called with
* %G_IO_ERROR_CANCELLED.
*
* This leads to the following pseudo-code usage:
* |[
* g_autoptr(GFile) dir = get_directory ();
* g_autoptr(GFileEnumerator) enumerator = NULL;
* g_autolist(GFileInfo) files = NULL;
* g_autoptr(GError) local_error = NULL;
*
* enumerator = yield g_file_enumerate_children_async (dir,
* G_FILE_ATTRIBUTE_STANDARD_NAME ","
* G_FILE_ATTRIBUTE_STANDARD_TYPE,
* G_FILE_QUERY_INFO_NONE,
* G_PRIORITY_DEFAULT,
* cancellable,
* …,
* &local_error);
* if (enumerator == NULL)
* g_error ("Error enumerating: %s", local_error->message);
*
* // Loop until no files are returned, either because the end of the enumerator
* // has been reached, or an error was returned.
* do
* {
* files = yield g_file_enumerator_next_files_async (enumerator,
* 5, // number of files to request
* G_PRIORITY_DEFAULT,
* cancellable,
* …,
* &local_error);
*
* // Process the returned files, but don’t assume that exactly 5 were returned.
* for (GList *l = files; l != NULL; l = l->next)
* {
* GFileInfo *info = l->data;
* handle_file_info (info);
* }
* }
* while (files != NULL);
*
* if (local_error != NULL &&
* !g_error_matches (local_error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
* g_error ("Error while enumerating: %s", local_error->message);
* ]|
*
* During an async request no other sync and async calls are allowed, and will
* result in %G_IO_ERROR_PENDING errors.
*
* Any outstanding I/O request with higher priority (lower numerical value) will
* be executed before an outstanding request with lower priority. Default
* priority is %G_PRIORITY_DEFAULT.
**/
void
g_file_enumerator_next_files_async (GFileEnumerator *enumerator,
int num_files,
int io_priority,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer user_data)
{
GFileEnumeratorClass *class;
g_return_if_fail (G_IS_FILE_ENUMERATOR (enumerator));
g_return_if_fail (enumerator != NULL);
g_return_if_fail (num_files >= 0);
if (num_files == 0)
{
GTask *task;
task = g_task_new (enumerator, cancellable, callback, user_data);
g_task_set_source_tag (task, g_file_enumerator_next_files_async);
g_task_return_pointer (task, NULL, NULL);
g_object_unref (task);
return;
}
if (enumerator->priv->closed)
{
g_task_report_new_error (enumerator, callback, user_data,
g_file_enumerator_next_files_async,
G_IO_ERROR, G_IO_ERROR_CLOSED,
_("File enumerator is already closed"));
return;
}
if (enumerator->priv->pending)
{
g_task_report_new_error (enumerator, callback, user_data,
g_file_enumerator_next_files_async,
G_IO_ERROR, G_IO_ERROR_PENDING,
_("File enumerator has outstanding operation"));
return;
}
class = G_FILE_ENUMERATOR_GET_CLASS (enumerator);
enumerator->priv->pending = TRUE;
enumerator->priv->outstanding_callback = callback;
g_object_ref (enumerator);
(* class->next_files_async) (enumerator, num_files, io_priority, cancellable,
next_async_callback_wrapper, user_data);
}
/**
* g_file_enumerator_next_files_finish:
* @enumerator: a #GFileEnumerator.
* @result: a #GAsyncResult.
* @error: a #GError location to store the error occurring, or %NULL to
* ignore.
*
* Finishes the asynchronous operation started with g_file_enumerator_next_files_async().
*
* Returns: (transfer full) (element-type Gio.FileInfo): a #GList of #GFileInfos. You must free the list with
* g_list_free() and unref the infos with g_object_unref() when you're
* done with them.
**/
GList *
g_file_enumerator_next_files_finish (GFileEnumerator *enumerator,
GAsyncResult *result,
GError **error)
{
GFileEnumeratorClass *class;
g_return_val_if_fail (G_IS_FILE_ENUMERATOR (enumerator), NULL);
g_return_val_if_fail (G_IS_ASYNC_RESULT (result), NULL);
if (g_async_result_legacy_propagate_error (result, error))
return NULL;
else if (g_async_result_is_tagged (result, g_file_enumerator_next_files_async))
return g_task_propagate_pointer (G_TASK (result), error);
class = G_FILE_ENUMERATOR_GET_CLASS (enumerator);
return class->next_files_finish (enumerator, result, error);
}
static void
close_async_callback_wrapper (GObject *source_object,
GAsyncResult *res,
gpointer user_data)
{
GFileEnumerator *enumerator = G_FILE_ENUMERATOR (source_object);
enumerator->priv->pending = FALSE;
enumerator->priv->closed = TRUE;
if (enumerator->priv->outstanding_callback)
(*enumerator->priv->outstanding_callback) (source_object, res, user_data);
g_object_unref (enumerator);
}
/**
* g_file_enumerator_close_async:
* @enumerator: a #GFileEnumerator.
* @io_priority: the [I/O priority][io-priority] of the request
* @cancellable: (nullable): optional #GCancellable object, %NULL to ignore.
* @callback: (scope async) (closure user_data): a #GAsyncReadyCallback
* to call when the request is satisfied
* @user_data: the data to pass to callback function
*
* Asynchronously closes the file enumerator.
*
* If @cancellable is not %NULL, then the operation can be cancelled by
* triggering the cancellable object from another thread. If the operation
* was cancelled, the error %G_IO_ERROR_CANCELLED will be returned in
* g_file_enumerator_close_finish().
**/
void
g_file_enumerator_close_async (GFileEnumerator *enumerator,
int io_priority,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer user_data)
{
GFileEnumeratorClass *class;
g_return_if_fail (G_IS_FILE_ENUMERATOR (enumerator));
if (enumerator->priv->closed)
{
g_task_report_new_error (enumerator, callback, user_data,
g_file_enumerator_close_async,
G_IO_ERROR, G_IO_ERROR_CLOSED,
_("File enumerator is already closed"));
return;
}
if (enumerator->priv->pending)
{
g_task_report_new_error (enumerator, callback, user_data,
g_file_enumerator_close_async,
G_IO_ERROR, G_IO_ERROR_PENDING,
_("File enumerator has outstanding operation"));
return;
}
class = G_FILE_ENUMERATOR_GET_CLASS (enumerator);
enumerator->priv->pending = TRUE;
enumerator->priv->outstanding_callback = callback;
g_object_ref (enumerator);
(* class->close_async) (enumerator, io_priority, cancellable,
close_async_callback_wrapper, user_data);
}
/**
* g_file_enumerator_close_finish:
* @enumerator: a #GFileEnumerator.
* @result: a #GAsyncResult.
* @error: a #GError location to store the error occurring, or %NULL to
* ignore.
*
* Finishes closing a file enumerator, started from g_file_enumerator_close_async().
*
* If the file enumerator was already closed when g_file_enumerator_close_async()
* was called, then this function will report %G_IO_ERROR_CLOSED in @error, and
* return %FALSE. If the file enumerator had pending operation when the close
* operation was started, then this function will report %G_IO_ERROR_PENDING, and
* return %FALSE. If @cancellable was not %NULL, then the operation may have been
* cancelled by triggering the cancellable object from another thread. If the operation
* was cancelled, the error %G_IO_ERROR_CANCELLED will be set, and %FALSE will be
* returned.
*
* Returns: %TRUE if the close operation has finished successfully.
**/
gboolean
g_file_enumerator_close_finish (GFileEnumerator *enumerator,
GAsyncResult *result,
GError **error)
{
GFileEnumeratorClass *class;
g_return_val_if_fail (G_IS_FILE_ENUMERATOR (enumerator), FALSE);
g_return_val_if_fail (G_IS_ASYNC_RESULT (result), FALSE);
if (g_async_result_legacy_propagate_error (result, error))
return FALSE;
else if (g_async_result_is_tagged (result, g_file_enumerator_close_async))
return g_task_propagate_boolean (G_TASK (result), error);
class = G_FILE_ENUMERATOR_GET_CLASS (enumerator);
return class->close_finish (enumerator, result, error);
}
/**
* g_file_enumerator_is_closed:
* @enumerator: a #GFileEnumerator.
*
* Checks if the file enumerator has been closed.
*
* Returns: %TRUE if the @enumerator is closed.
**/
gboolean
g_file_enumerator_is_closed (GFileEnumerator *enumerator)
{
g_return_val_if_fail (G_IS_FILE_ENUMERATOR (enumerator), TRUE);
return enumerator->priv->closed;
}
/**
* g_file_enumerator_has_pending:
* @enumerator: a #GFileEnumerator.
*
* Checks if the file enumerator has pending operations.
*
* Returns: %TRUE if the @enumerator has pending operations.
**/
gboolean
g_file_enumerator_has_pending (GFileEnumerator *enumerator)
{
g_return_val_if_fail (G_IS_FILE_ENUMERATOR (enumerator), TRUE);
return enumerator->priv->pending;
}
/**
* g_file_enumerator_set_pending:
* @enumerator: a #GFileEnumerator.
* @pending: a boolean value.
*
* Sets the file enumerator as having pending operations.
**/
void
g_file_enumerator_set_pending (GFileEnumerator *enumerator,
gboolean pending)
{
g_return_if_fail (G_IS_FILE_ENUMERATOR (enumerator));
enumerator->priv->pending = pending;
}
/**
* g_file_enumerator_iterate:
* @direnum: an open #GFileEnumerator
* @out_info: (out) (transfer none) (optional): Output location for the next #GFileInfo, or %NULL
* @out_child: (out) (transfer none) (optional): Output location for the next #GFile, or %NULL
* @cancellable: a #GCancellable
* @error: a #GError
*
* This is a version of g_file_enumerator_next_file() that's easier to
* use correctly from C programs. With g_file_enumerator_next_file(),
* the gboolean return value signifies "end of iteration or error", which
* requires allocation of a temporary #GError.
*
* In contrast, with this function, a %FALSE return from
* g_file_enumerator_iterate() *always* means
* "error". End of iteration is signaled by @out_info or @out_child being %NULL.
*
* Another crucial difference is that the references for @out_info and
* @out_child are owned by @direnum (they are cached as hidden
* properties). You must not unref them in your own code. This makes
* memory management significantly easier for C code in combination
* with loops.
*
* Finally, this function optionally allows retrieving a #GFile as
* well.
*
* You must specify at least one of @out_info or @out_child.
*
* The code pattern for correctly using g_file_enumerator_iterate() from C
* is:
*
* |[
* direnum = g_file_enumerate_children (file, ...);
* while (TRUE)
* {
* GFileInfo *info;
* if (!g_file_enumerator_iterate (direnum, &info, NULL, cancellable, error))
* goto out;
* if (!info)
* break;
* ... do stuff with "info"; do not unref it! ...
* }
*
* out:
* g_object_unref (direnum); // Note: frees the last @info
* ]|
*
*
* Since: 2.44
*/
gboolean
g_file_enumerator_iterate (GFileEnumerator *direnum,
GFileInfo **out_info,
GFile **out_child,
GCancellable *cancellable,
GError **error)
{
gboolean ret = FALSE;
GError *temp_error = NULL;
GFileInfo *ret_info = NULL;
static GQuark cached_info_quark;
static GQuark cached_child_quark;
static gsize quarks_initialized;
g_return_val_if_fail (direnum != NULL, FALSE);
g_return_val_if_fail (out_info != NULL || out_child != NULL, FALSE);
if (g_once_init_enter (&quarks_initialized))
{
cached_info_quark = g_quark_from_static_string ("g-cached-info");
cached_child_quark = g_quark_from_static_string ("g-cached-child");
g_once_init_leave (&quarks_initialized, 1);
}
ret_info = g_file_enumerator_next_file (direnum, cancellable, &temp_error);
if (temp_error != NULL)
{
g_propagate_error (error, temp_error);
goto out;
}
if (ret_info)
{
if (out_child != NULL)
{
const char *name = g_file_info_get_name (ret_info);
if (G_UNLIKELY (name == NULL))
{
g_critical ("g_file_enumerator_iterate() created without standard::name");
g_return_val_if_reached (FALSE);
}
else
{
*out_child = g_file_get_child (g_file_enumerator_get_container (direnum), name);
g_object_set_qdata_full ((GObject*)direnum, cached_child_quark, *out_child, (GDestroyNotify)g_object_unref);
}
}
if (out_info != NULL)
{
g_object_set_qdata_full ((GObject*)direnum, cached_info_quark, ret_info, (GDestroyNotify)g_object_unref);
*out_info = ret_info;
}
else
g_object_unref (ret_info);
}
else
{
if (out_info)
*out_info = NULL;
if (out_child)
*out_child = NULL;
}
ret = TRUE;
out:
return ret;
}
/**
* g_file_enumerator_get_container:
* @enumerator: a #GFileEnumerator
*
* Get the #GFile container which is being enumerated.
*
* Returns: (transfer none): the #GFile which is being enumerated.
*
* Since: 2.18
*/
GFile *
g_file_enumerator_get_container (GFileEnumerator *enumerator)
{
g_return_val_if_fail (G_IS_FILE_ENUMERATOR (enumerator), NULL);
return enumerator->priv->container;
}
/**
* g_file_enumerator_get_child:
* @enumerator: a #GFileEnumerator
* @info: a #GFileInfo gotten from g_file_enumerator_next_file()
* or the async equivalents.
*
* Return a new #GFile which refers to the file named by @info in the source
* directory of @enumerator. This function is primarily intended to be used
* inside loops with g_file_enumerator_next_file().
*
* To use this, %G_FILE_ATTRIBUTE_STANDARD_NAME must have been listed in the
* attributes list used when creating the #GFileEnumerator.
*
* This is a convenience method that's equivalent to:
* |[<!-- language="C" -->
* gchar *name = g_file_info_get_name (info);
* GFile *child = g_file_get_child (g_file_enumerator_get_container (enumr),
* name);
* ]|
*
* Returns: (transfer full): a #GFile for the #GFileInfo passed it.
*
* Since: 2.36
*/
GFile *
g_file_enumerator_get_child (GFileEnumerator *enumerator,
GFileInfo *info)
{
const gchar *name;
g_return_val_if_fail (G_IS_FILE_ENUMERATOR (enumerator), NULL);
g_return_val_if_fail (G_IS_FILE_INFO (info), NULL);
name = g_file_info_get_name (info);
if (G_UNLIKELY (name == NULL))
{
g_critical ("GFileEnumerator created without standard::name");
g_return_val_if_reached (NULL);
}
return g_file_get_child (enumerator->priv->container, name);
}
static void
next_async_op_free (GList *files)
{
g_list_free_full (files, g_object_unref);
}
static void
next_files_thread (GTask *task,
gpointer source_object,
gpointer task_data,
GCancellable *cancellable)
{
GFileEnumerator *enumerator = source_object;
int num_files = GPOINTER_TO_INT (task_data);
GFileEnumeratorClass *class;
GList *files = NULL;
GError *error = NULL;
GFileInfo *info;
int i;
class = G_FILE_ENUMERATOR_GET_CLASS (enumerator);
for (i = 0; i < num_files; i++)
{
if (g_cancellable_set_error_if_cancelled (cancellable, &error))
info = NULL;
else
info = class->next_file (enumerator, cancellable, &error);
if (info == NULL)
{
/* If we get an error after first file, return that on next operation */
if (error != NULL && i > 0)
{
if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
g_error_free (error); /* Never propagate cancel errors to other call */
else
enumerator->priv->outstanding_error = error;
error = NULL;
}
break;
}
else
files = g_list_prepend (files, info);
}
if (error)
{
g_list_free_full (files, g_object_unref);
g_task_return_error (task, error);
}
else
g_task_return_pointer (task, files, (GDestroyNotify)next_async_op_free);
}
static void
g_file_enumerator_real_next_files_async (GFileEnumerator *enumerator,
int num_files,
int io_priority,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer user_data)
{
GTask *task;
task = g_task_new (enumerator, cancellable, callback, user_data);
g_task_set_source_tag (task, g_file_enumerator_real_next_files_async);
g_task_set_task_data (task, GINT_TO_POINTER (num_files), NULL);
g_task_set_priority (task, io_priority);
g_task_run_in_thread (task, next_files_thread);
g_object_unref (task);
}
static GList *
g_file_enumerator_real_next_files_finish (GFileEnumerator *enumerator,
GAsyncResult *result,
GError **error)
{
g_return_val_if_fail (g_task_is_valid (result, enumerator), NULL);
return g_task_propagate_pointer (G_TASK (result), error);
}
static void
close_async_thread (GTask *task,
gpointer source_object,
gpointer task_data,
GCancellable *cancellable)
{
GFileEnumerator *enumerator = source_object;
GFileEnumeratorClass *class;
GError *error = NULL;
gboolean result;
class = G_FILE_ENUMERATOR_GET_CLASS (enumerator);
result = class->close_fn (enumerator, cancellable, &error);
if (result)
g_task_return_boolean (task, TRUE);
else
g_task_return_error (task, error);
}
static void
g_file_enumerator_real_close_async (GFileEnumerator *enumerator,
int io_priority,
GCancellable *cancellable,
GAsyncReadyCallback callback,
gpointer user_data)
{
GTask *task;
task = g_task_new (enumerator, cancellable, callback, user_data);
g_task_set_source_tag (task, g_file_enumerator_real_close_async);
g_task_set_priority (task, io_priority);
g_task_run_in_thread (task, close_async_thread);
g_object_unref (task);
}
static gboolean
g_file_enumerator_real_close_finish (GFileEnumerator *enumerator,
GAsyncResult *result,
GError **error)
{
g_return_val_if_fail (g_task_is_valid (result, enumerator), FALSE);
return g_task_propagate_boolean (G_TASK (result), error);
}
|