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/*
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* Buffering to output and input.
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* Copyright (C) 1998 Kunihiro Ishiguro
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*
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* This file is part of GNU Zebra.
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*
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* GNU Zebra is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published
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* by the Free Software Foundation; either version 2, or (at your
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* option) any later version.
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*
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* GNU Zebra is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with GNU Zebra; see the file COPYING. If not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 02111-1307, USA.
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*/
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#ifndef _ZEBRA_BUFFER_H
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#define _ZEBRA_BUFFER_H
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/* Create a new buffer. Memory will be allocated in chunks of the given
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size. If the argument is 0, the library will supply a reasonable
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default size suitable for buffering socket I/O. */
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struct buffer *buffer_new(size_t);
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/* Free all data in the buffer. */
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void buffer_reset(struct buffer *);
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/* This function first calls buffer_reset to release all buffered data.
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Then it frees the struct buffer itself. */
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void buffer_free(struct buffer *);
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/* Add the given data to the end of the buffer. */
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extern void buffer_put(struct buffer *, const void *, size_t);
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/* Add a single character to the end of the buffer. */
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extern void buffer_putc(struct buffer *, u_char);
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/* Add a NUL-terminated string to the end of the buffer. */
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extern void buffer_putstr(struct buffer *, const char *);
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/* Combine all accumulated (and unflushed) data inside the buffer into a
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single NUL-terminated string allocated using XMALLOC(MTYPE_TMP). Note
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that this function does not alter the state of the buffer, so the data
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is still inside waiting to be flushed. */
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char *buffer_getstr(struct buffer *);
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/* Returns 1 if there is no pending data in the buffer. Otherwise returns 0. */
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int buffer_empty(struct buffer *);
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typedef enum {
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/* An I/O error occurred. The buffer should be destroyed and the
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file descriptor should be closed. */
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BUFFER_ERROR = -1,
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/* The data was written successfully, and the buffer is now empty
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(there is no pending data waiting to be flushed). */
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BUFFER_EMPTY = 0,
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/* There is pending data in the buffer waiting to be flushed. Please
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try flushing the buffer when select indicates that the file descriptor
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is writeable. */
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BUFFER_PENDING = 1
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} buffer_status_t;
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/* Try to write this data to the file descriptor. Any data that cannot
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be written immediately is added to the buffer queue. */
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extern buffer_status_t buffer_write(struct buffer *, int fd,
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const void *, size_t);
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/* This function attempts to flush some (but perhaps not all) of
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the queued data to the given file descriptor. */
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extern buffer_status_t buffer_flush_available(struct buffer *, int fd);
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/* The following 2 functions (buffer_flush_all and buffer_flush_window)
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are for use in lib/vty.c only. They should not be used elsewhere. */
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/* Call buffer_flush_available repeatedly until either all data has been
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flushed, or an I/O error has been encountered, or the operation would
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block. */
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extern buffer_status_t buffer_flush_all(struct buffer *, int fd);
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/* Attempt to write enough data to the given fd to fill a window of the
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given width and height (and remove the data written from the buffer).
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If !no_more, then a message saying " --More-- " is appended.
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If erase is true, then first overwrite the previous " --More-- " message
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with spaces.
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Any write error (including EAGAIN or EINTR) will cause this function
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to return -1 (because the logic for handling the erase and more features
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is too complicated to retry the write later).
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*/
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extern buffer_status_t buffer_flush_window(struct buffer *, int fd, int width,
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int height, int erase, int no_more);
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#endif /* _ZEBRA_BUFFER_H */
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