1 files changed, 166 insertions, 0 deletions

diff --git a/src/util/disk_iterator.c b/src/util/disk_iterator.c
new file mode 100644
index 000000000..118823df6
--- /dev/null
+++ b/src/util/disk_iterator.c
@@ -0,0 +1,166 @@
+/*
+     This file is part of GNUnet.
+     Copyright (C) 2001--2013 Christian Grothoff (and other contributing authors)
+
+     GNUnet is free software; you can redistribute it and/or modify
+     it under the terms of the GNU General Public License as published
+     by the Free Software Foundation; either version 3, or (at your
+     option) any later version.
+
+     GNUnet 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
+     General Public License for more details.
+
+     You should have received a copy of the GNU General Public License
+     along with GNUnet; see the file COPYING.  If not, write to the
+     Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+     Boston, MA 02111-1307, USA.
+*/
+/**
+ * @file util/disk_iterator.c
+ * @brief asynchronous iteration over a directory
+ * @author Christian Grothoff
+ * @author Nils Durner
+ */
+
+
+/**
+ * Opaque handle used for iterating over a directory.
+ */
+struct GNUNET_DISK_DirectoryIterator
+{
+
+  /**
+   * Function to call on directory entries.
+   */
+  GNUNET_DISK_DirectoryIteratorCallback callback;
+
+  /**
+   * Closure for @e callback.
+   */
+  void *callback_cls;
+
+  /**
+   * Reference to directory.
+   */
+  DIR *directory;
+
+  /**
+   * Directory name.
+   */
+  char *dirname;
+
+  /**
+   * Next filename to process.
+   */
+  char *next_name;
+
+  /**
+   * Our priority.
+   */
+  enum GNUNET_SCHEDULER_Priority priority;
+
+};
+
+
+/**
+ * Task used by the directory iterator.
+ */
+static void
+directory_iterator_task (void *cls,
+                         const struct GNUNET_SCHEDULER_TaskContext *tc)
+{
+  struct GNUNET_DISK_DirectoryIterator *iter = cls;
+  char *name;
+
+  name = iter->next_name;
+  GNUNET_assert (name != NULL);
+  iter->next_name = NULL;
+  iter->callback (iter->callback_cls, iter, name, iter->dirname);
+  GNUNET_free (name);
+}
+
+
+/**
+ * This function must be called during the DiskIteratorCallback
+ * (exactly once) to schedule the task to process the next
+ * filename in the directory (if there is one).
+ *
+ * @param iter opaque handle for the iterator
+ * @param can set to #GNUNET_YES to terminate the iteration early
+ * @return #GNUNET_YES if iteration will continue,
+ *         #GNUNET_NO if this was the last entry (and iteration is complete),
+ *         #GNUNET_SYSERR if abort was YES
+ */
+int
+GNUNET_DISK_directory_iterator_next (struct GNUNET_DISK_DirectoryIterator *iter,
+                                     int can)
+{
+  struct dirent *finfo;
+
+  GNUNET_assert (iter->next_name == NULL);
+  if (can == GNUNET_YES)
+  {
+    CLOSEDIR (iter->directory);
+    GNUNET_free (iter->dirname);
+    GNUNET_free (iter);
+    return GNUNET_SYSERR;
+  }
+  while (NULL != (finfo = READDIR (iter->directory)))
+  {
+    if ((0 == strcmp (finfo->d_name, ".")) ||
+        (0 == strcmp (finfo->d_name, "..")))
+      continue;
+    GNUNET_asprintf (&iter->next_name, "%s%s%s", iter->dirname,
+                     DIR_SEPARATOR_STR, finfo->d_name);
+    break;
+  }
+  if (finfo == NULL)
+  {
+    GNUNET_DISK_directory_iterator_next (iter, GNUNET_YES);
+    return GNUNET_NO;
+  }
+  GNUNET_SCHEDULER_add_with_priority (iter->priority, &directory_iterator_task,
+                                      iter);
+  return GNUNET_YES;
+}
+
+
+/**
+ * Scan a directory for files using the scheduler to run a task for
+ * each entry.  The name of the directory must be expanded first (!).
+ * If a scheduler does not need to be used, GNUNET_DISK_directory_scan
+ * may provide a simpler API.
+ *
+ * @param prio priority to use
+ * @param dir_name the name of the directory
+ * @param callback the method to call for each file
+ * @param callback_cls closure for @a callback
+ * @return #GNUNET_YES if directory is not empty and @a callback
+ *         will be called later, #GNUNET_NO otherwise, #GNUNET_SYSERR on error.
+ */
+int
+GNUNET_DISK_directory_iterator_start (enum GNUNET_SCHEDULER_Priority prio,
+                                      const char *dir_name,
+                                      GNUNET_DISK_DirectoryIteratorCallback
+                                      callback, void *callback_cls)
+{
+  struct GNUNET_DISK_DirectoryIterator *di;
+
+  di = GNUNET_new (struct GNUNET_DISK_DirectoryIterator);
+  di->callback = callback;
+  di->callback_cls = callback_cls;
+  di->directory = OPENDIR (dir_name);
+  if (di->directory == NULL)
+  {
+    GNUNET_free (di);
+    callback (callback_cls, NULL, NULL, NULL);
+    return GNUNET_SYSERR;
+  }
+  di->dirname = GNUNET_strdup (dir_name);
+  di->priority = prio;
+  return GNUNET_DISK_directory_iterator_next (di, GNUNET_NO);
+}
+
+/* end of disk_iterator */