/*
** Copyright (C) 2006-2007 by Carnegie Mellon University.
**
** @OPENSOURCE_HEADER_START@
** 
** Use of the SILK system and related source code is subject to the terms 
** of the following licenses:
** 
** GNU Public License (GPL) Rights pursuant to Version 2, June 1991
** Government Purpose License Rights (GPLR) pursuant to DFARS 252.225-7013
** 
** NO WARRANTY
** 
** ANY INFORMATION, MATERIALS, SERVICES, INTELLECTUAL PROPERTY OR OTHER 
** PROPERTY OR RIGHTS GRANTED OR PROVIDED BY CARNEGIE MELLON UNIVERSITY 
** PURSUANT TO THIS LICENSE (HEREINAFTER THE "DELIVERABLES") ARE ON AN 
** "AS-IS" BASIS. CARNEGIE MELLON UNIVERSITY MAKES NO WARRANTIES OF ANY 
** KIND, EITHER EXPRESS OR IMPLIED AS TO ANY MATTER INCLUDING, BUT NOT 
** LIMITED TO, WARRANTY OF FITNESS FOR A PARTICULAR PURPOSE, 
** MERCHANTABILITY, INFORMATIONAL CONTENT, NONINFRINGEMENT, OR ERROR-FREE 
** OPERATION. CARNEGIE MELLON UNIVERSITY SHALL NOT BE LIABLE FOR INDIRECT, 
** SPECIAL OR CONSEQUENTIAL DAMAGES, SUCH AS LOSS OF PROFITS OR INABILITY 
** TO USE SAID INTELLECTUAL PROPERTY, UNDER THIS LICENSE, REGARDLESS OF 
** WHETHER SUCH PARTY WAS AWARE OF THE POSSIBILITY OF SUCH DAMAGES. 
** LICENSEE AGREES THAT IT WILL NOT MAKE ANY WARRANTY ON BEHALF OF 
** CARNEGIE MELLON UNIVERSITY, EXPRESS OR IMPLIED, TO ANY PERSON 
** CONCERNING THE APPLICATION OF OR THE RESULTS TO BE OBTAINED WITH THE 
** DELIVERABLES UNDER THIS LICENSE.
** 
** Licensee hereby agrees to defend, indemnify, and hold harmless Carnegie 
** Mellon University, its trustees, officers, employees, and agents from 
** all claims or demands made against them (and any related losses, 
** expenses, or attorney's fees) arising out of, or relating to Licensee's 
** and/or its sub licensees' negligent use or willful misuse of or 
** negligent conduct or willful misconduct regarding the Software, 
** facilities, or other rights or assistance granted by Carnegie Mellon 
** University under this License, including, but not limited to, any 
** claims of product liability, personal injury, death, damage to 
** property, or violation of any laws or regulations.
** 
** Carnegie Mellon University Software Engineering Institute authored 
** documents are sponsored by the U.S. Department of Defense under 
** Contract F19628-00-C-0003. Carnegie Mellon University retains 
** copyrights in all material produced under this contract. The U.S. 
** Government retains a non-exclusive, royalty-free license to publish or 
** reproduce these documents, or allow others to do so, for U.S. 
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*/
#ifndef _POLLDIR_H
#define _POLLDIR_H

#include "silk.h"

RCSIDENTVAR(rcsID_POLLDIR_H, "$SiLK: skpolldir.h 6513 2007-03-01 21:43:26Z mwd $");

/*
**  polldir.h
**
**  Library for polling directories for new files
**
*/

#include "skdeque.h"

/* Add additional #includes and your protypes/types/#defines here */

/* The type of directory polling objects. */
typedef struct sk_polldir_t *skPollDir_t;
typedef struct sk_polldir_queue_t *skPollDirQueue_t;

/* The type of polldir errors */
typedef enum { PDERR_NONE = 0, PDERR_MEMORY, PDERR_FILESYSTEM } skpdErr_t;

/* Create a directory polling queue. */
skPollDirQueue_t skPollDirQueueCreate(void);

/* Destroy a directory polling queue. */
void skPollDirQueueDestroy(skPollDirQueue_t queue);


/* Create a directory polling object.  
 *  
 *   Creates a polldir object for directory.  The poll_interval is the
 *   number of seconds between polls of the directory for new files.
 *   The queue argument is used to synchronize the return of files
 *   from multiple polldir objects; i.e., to allow one to monitor
 *   several directories simultaneously.
 */
skPollDir_t skPollDirCreate(
    const char      *directory, 
    uint32_t         poll_interval,
    skPollDirQueue_t queue);

/* Destroy a directory polling object. */
void skPollDirDestroy(skPollDir_t pd);

/* Get the next added filename entry to a directory.
 *
 *   This function blocks on the existance of a new file entry to the
 *   polldir directory.  The buffer 'path' will be filled with the
 *   full path to the file entry.  It is up to the caller to make sure
 *   that 'path' is at least PATH_MAX bytes in size.  If
 *   'filename_ptr' is non-NULL, it will set it to point to the
 *   position in 'path' where the filename begins.
 * 
 *   If the polldir object is destroyed, returns 1. If an error
 *   occurs, returns -1.  Otherwise returns 0.
 */
int skPollDirGetNextFile(
    skPollDirQueue_t queue, 
    char *path, 
    char **filename_ptr);


/* Get the error state of a polldir object. */
skpdErr_t skPollDirGetError(skPollDir_t pd);

/* Get the directory being polled by a polldir object. */
const char *skPollDirGetDir(skPollDir_t pd);

#endif /* _POLLDIR_H */