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 27/* Create a new buffer. Memory will be allocated in chunks of the given 28 size. If the argument is 0, the library will supply a reasonable 29 default size suitable for buffering socket I/O. */ 30extern struct buffer *buffer_new (size_t); 31 32/* Free all data in the buffer. */ 33extern void buffer_reset (struct buffer *); 34 35/* This function first calls buffer_reset to release all buffered data. 36 Then it frees the struct buffer itself. */ 37extern void buffer_free (struct buffer *); 38 39/* Add the given data to the end of the buffer. */ 40extern void buffer_put (struct buffer *, const void *, size_t); 41/* Add a single character to the end of the buffer. */ 42extern void buffer_putc (struct buffer *, u_char); 43/* Add a NUL-terminated string to the end of the buffer. */ 44extern void buffer_putstr (struct buffer *, const char *); 45 46/* Combine all accumulated (and unflushed) data inside the buffer into a 47 single NUL-terminated string allocated using XMALLOC(MTYPE_TMP). Note 48 that this function does not alter the state of the buffer, so the data 49 is still inside waiting to be flushed. */ 50char *buffer_getstr (struct buffer *); 51 52/* Returns 1 if there is no pending data in the buffer. Otherwise returns 0. */ 53int buffer_empty (struct buffer *); 54 55typedef enum 56 { 57 /* An I/O error occurred. The buffer should be destroyed and the 58 file descriptor should be closed. */ 59 BUFFER_ERROR = -1, 60 61 /* The data was written successfully, and the buffer is now empty 62 (there is no pending data waiting to be flushed). */ 63 BUFFER_EMPTY = 0, 64 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 67 is writeable. */ 68 BUFFER_PENDING = 1 69 } buffer_status_t; 70 71/* Try to write this data to the file descriptor. Any data that cannot 72 be written immediately is added to the buffer queue. */ 73extern buffer_status_t buffer_write(struct buffer *, int fd, 74 const void *, size_t); 75 76/* This function attempts to flush some (but perhaps not all) of 77 the queued data to the given file descriptor. */ 78extern buffer_status_t buffer_flush_available(struct buffer *, int fd); 79 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. */ 82 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 85 block. */ 86extern buffer_status_t buffer_flush_all (struct buffer *, int fd); 87 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). 90 91 If !no_more, then a message saying " --More-- " is appended. 92 If erase is true, then first overwrite the previous " --More-- " message 93 with spaces. 94 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). 98*/ 99extern buffer_status_t buffer_flush_window (struct buffer *, int fd, int width, 100 int height, int erase, int no_more); 101 102#endif /* _ZEBRA_BUFFER_H */ 103