2 * Buffering to output and input.
3 * Copyright (C) 1998 Kunihiro Ishiguro
5 * This file is part of GNU Zebra.
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.
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.
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.
23 #ifndef _ZEBRA_BUFFER_H
24 #define _ZEBRA_BUFFER_H
26 #include <sys/types.h>
28 /* Create a new buffer. Memory will be allocated in chunks of the given
29 size. If the argument is 0, the library will supply a reasonable
30 default size suitable for buffering socket I/O. */
31 struct buffer *buffer_new(void *ctx, size_t);
33 /* Free all data in the buffer. */
34 void buffer_reset(struct buffer *);
36 /* This function first calls buffer_reset to release all buffered data.
37 Then it frees the struct buffer itself. */
38 void buffer_free(struct buffer *);
40 /* Add the given data to the end of the buffer. */
41 extern void buffer_put(struct buffer *, const void *, size_t);
42 /* Add a single character to the end of the buffer. */
43 extern void buffer_putc(struct buffer *, u_char);
44 /* Add a NUL-terminated string to the end of the buffer. */
45 extern void buffer_putstr(struct buffer *, const char *);
47 /* Combine all accumulated (and unflushed) data inside the buffer into a
48 single NUL-terminated string allocated using XMALLOC(MTYPE_TMP). Note
49 that this function does not alter the state of the buffer, so the data
50 is still inside waiting to be flushed. */
51 char *buffer_getstr(struct buffer *);
53 /* Returns 1 if there is no pending data in the buffer. Otherwise returns 0. */
54 int buffer_empty(struct buffer *);
57 /* An I/O error occurred. The buffer should be destroyed and the
58 file descriptor should be closed. */
61 /* The data was written successfully, and the buffer is now empty
62 (there is no pending data waiting to be flushed). */
65 /* There is pending data in the buffer waiting to be flushed. Please
66 try flushing the buffer when select indicates that the file descriptor
71 /* Try to write this data to the file descriptor. Any data that cannot
72 be written immediately is added to the buffer queue. */
73 extern buffer_status_t buffer_write(struct buffer *, int fd,
74 const void *, size_t);
76 /* This function attempts to flush some (but perhaps not all) of
77 the queued data to the given file descriptor. */
78 extern buffer_status_t buffer_flush_available(struct buffer *, int fd);
80 /* The following 2 functions (buffer_flush_all and buffer_flush_window)
81 are for use in lib/vty.c only. They should not be used elsewhere. */
83 /* Call buffer_flush_available repeatedly until either all data has been
84 flushed, or an I/O error has been encountered, or the operation would
86 extern buffer_status_t buffer_flush_all(struct buffer *, int fd);
88 /* Attempt to write enough data to the given fd to fill a window of the
89 given width and height (and remove the data written from the buffer).
91 If !no_more, then a message saying " --More-- " is appended.
92 If erase is true, then first overwrite the previous " --More-- " message
95 Any write error (including EAGAIN or EINTR) will cause this function
96 to return -1 (because the logic for handling the erase and more features
97 is too complicated to retry the write later).
99 extern buffer_status_t buffer_flush_window(struct buffer *, int fd, int width,
100 int height, int erase, int no_more);
102 #endif /* _ZEBRA_BUFFER_H */