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/*
This file is part of GNUnet.
Copyright (C) 2001--2013 GNUnet e.V.
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., 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA.
*/
/**
* @file util/disk_iterator.c
* @brief asynchronous iteration over a directory
* @author Christian Grothoff
* @author Nils Durner
*/
#include "platform.h"
#include "gnunet_util_lib.h"
#include "disk.h"
#define LOG(kind,...) GNUNET_log_from (kind, "util", __VA_ARGS__)
#define LOG_STRERROR(kind,syscall) GNUNET_log_from_strerror (kind, "util", syscall)
#define LOG_STRERROR_FILE(kind,syscall,filename) GNUNET_log_from_strerror_file (kind, "util", syscall, filename)
/**
* 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 */
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