lib/buffer.h

   1 /*
   2  * Buffering to output and input.
   3  * Copyright (C) 1998 Kunihiro Ishiguro
   4  *
   5  * This file is part of GNU Zebra.
   6  *
   7  * GNU Zebra is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published
   9  * by the Free Software Foundation; either version 2, or (at your
  10  * option) any later version.
  11  *
  12  * GNU Zebra is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with GNU Zebra; see the file COPYING.  If not, write to the
  19  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  20  * Boston, MA 02111-1307, USA.
  21  */
  22
  23 #ifndef _ZEBRA_BUFFER_H
  24 #define _ZEBRA_BUFFER_H
  25
  26 /* Buffer master. */
  27 struct buffer
  28 {
  29   /* Data list. */
  30   struct buffer_data *head;
  31   struct buffer_data *tail;
  32
  33   /* XXX: These unsigned longs should be size_t's */
  34   /* Current allocated data. */
  35   unsigned long alloc;
  36
  37   /* Size of each buffer_data chunk. */
  38   unsigned long size;
  39
  40   /* For allocation. */
  41   struct buffer_data *unused_head;
  42   struct buffer_data *unused_tail;
  43
  44   /* Current total length of this buffer. */
  45   unsigned long length;
  46 };
  47
  48 /* Data container. */
  49 struct buffer_data
  50 {
  51   struct buffer_data *next;
  52   struct buffer_data *prev;
  53
  54   /* Current pointer. */
  55   unsigned long cp;
  56
  57   /* Start pointer. */
  58   unsigned long sp;
  59
  60   /* Actual data stream (variable length). */
  61   unsigned char data[0];  /* real dimension is buffer->size */
  62 };
  63
  64 /* Buffer prototypes. */
  65 struct buffer *buffer_new (size_t);
  66 int buffer_write (struct buffer *, const void *, size_t);
  67 void buffer_free (struct buffer *);
  68 char *buffer_getstr (struct buffer *);
  69 int buffer_putc (struct buffer *, u_char);
  70 int buffer_putstr (struct buffer *, const char *);
  71 void buffer_reset (struct buffer *);
  72 int buffer_flush_all (struct buffer *, int);
  73 int buffer_flush_vty_all (struct buffer *, int, int, int);
  74 int buffer_flush_window (struct buffer *, int, int, int, int, int);
  75 int buffer_empty (struct buffer *);
  76
  77 /* buffer_flush_available attempts to flush the queued data to the given
  78    file descriptor.  It returns 0 if the buffers are now empty (after
  79    flushing), or 1 if more data remains on the buffer queue (must be flushed
  80    later).  This function (unlike the other buffer_flush* functions) is
  81    designed to work with non-blocking file descriptors. */
  82 int buffer_flush_available(struct buffer *, int fd);
  83
  84 #endif /* _ZEBRA_BUFFER_H */