src/queue.h

   1 /*======================================================================*
   2  * Copyright (C) 2008 Light Weight Event System                         *
   3  * All rights reserved.                                                 *
   4  *                                                                      *
   5  * This program is free software; you can redistribute it and/or modify *
   6  * it under the terms of the GNU General Public License as published by *
   7  * the Free Software Foundation; either version 2 of the License, or    *
   8  * (at your option) any later version.                                  *
   9  *                                                                      *
  10  * This program is distributed in the hope that it will be useful,      *
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of       *
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the        *
  13  * GNU General Public License for more details.                         *
  14  *                                                                      *
  15  * You should have received a copy of the GNU General Public License    *
  16  * along with this program; if not, write to the Free Software          *
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor,                   *
  18  * Boston, MA 02110-1301 USA.                                           *
  19  *======================================================================*/
  20
  21 #ifndef QUEUE_DOT_H
  22 #define QUEUE_DOT_H
  23
  24 #include <stddef.h>
  25
  26 /* Queue methods:
  27  *
  28  * open() -- opens a queue, return 0 on success, -1 on error
  29  *
  30  * close() -- closes a queue, return 0 on success, -1 on error
  31  *
  32  * read() -- reads "count" bytes from a queue into "buf", return the
  33  * number of bytes read on success, -1 on error
  34  *
  35  * write() -- writes "count" bytes from "buf" to a queue, return the
  36  * number of bytes written on success, -1 on error
  37  *
  38  * alloc() -- return a buffer suitable for use with read and write
  39  *
  40  * dealloc() -- free a buffer returned by alloc().
  41  *
  42  */
  43
  44 struct queue;
  45
  46 struct queue_vtbl {
  47   void  (*destructor)   (struct queue* this_queue);
  48
  49   int   (*open)         (struct queue* this_queue, int flags);
  50   int   (*close)        (struct queue* this_queue);
  51
  52   int   (*read)         (struct queue* this_queue, void* buf, size_t count, int* pending);
  53   int   (*write)        (struct queue* this_queue, const void* buf, size_t count);
  54
  55   void* (*alloc)        (struct queue* this_queue, size_t* newcount);
  56   void  (*dealloc)      (struct queue* this_queue, void* buf);
  57 };
  58
  59 struct queue {
  60   struct queue_vtbl* vtbl;
  61   void*              priv;
  62 };
  63
  64 int queue_factory(struct queue* this_queue);
  65 typedef int (*lwes_journaller_queue_init_t)(struct queue*, const char*, size_t, size_t) ;
  66
  67 #endif /* QUEUE_DOT_H */