Harald Welte | 3fb0b6f | 2010-05-19 19:02:52 +0200 | [diff] [blame^] | 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 | #include <sys/types.h> |
| 27 | |
| 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); |
| 32 | |
| 33 | /* Free all data in the buffer. */ |
| 34 | void buffer_reset(struct buffer *); |
| 35 | |
| 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 *); |
| 39 | |
| 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 *); |
| 46 | |
| 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 *); |
| 52 | |
| 53 | /* Returns 1 if there is no pending data in the buffer. Otherwise returns 0. */ |
| 54 | int buffer_empty(struct buffer *); |
| 55 | |
| 56 | typedef enum { |
| 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. */ |
| 73 | extern 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. */ |
| 78 | extern 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. */ |
| 86 | extern 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 | */ |
| 99 | extern 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 */ |