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Diffstat (limited to '')
-rw-r--r-- | lib/buffer.h | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/lib/buffer.h b/lib/buffer.h new file mode 100644 index 0000000..8b5a898 --- /dev/null +++ b/lib/buffer.h @@ -0,0 +1,110 @@ +/* + * Buffering to output and input. + * Copyright (C) 1998 Kunihiro Ishiguro + * + * This file is part of GNU Zebra. + * + * GNU Zebra is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published + * by the Free Software Foundation; either version 2, or (at your + * option) any later version. + * + * GNU Zebra is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; see the file COPYING; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#ifndef _ZEBRA_BUFFER_H +#define _ZEBRA_BUFFER_H + +#ifdef __cplusplus +extern "C" { +#endif + +/* Create a new buffer. Memory will be allocated in chunks of the given + size. If the argument is 0, the library will supply a reasonable + default size suitable for buffering socket I/O. */ +extern struct buffer *buffer_new(size_t); + +/* Free all data in the buffer. */ +extern void buffer_reset(struct buffer *); + +/* This function first calls buffer_reset to release all buffered data. + Then it frees the struct buffer itself. */ +extern void buffer_free(struct buffer *); + +/* Add the given data to the end of the buffer. */ +extern void buffer_put(struct buffer *, const void *, size_t); +/* Add a single character to the end of the buffer. */ +extern void buffer_putc(struct buffer *, uint8_t); +/* Add a NUL-terminated string to the end of the buffer. */ +extern void buffer_putstr(struct buffer *, const char *); +/* Add given data, inline-expanding \n to \r\n */ +extern void buffer_put_crlf(struct buffer *b, const void *p, size_t size); + +/* Combine all accumulated (and unflushed) data inside the buffer into a + single NUL-terminated string allocated using XMALLOC(MTYPE_TMP). Note + that this function does not alter the state of the buffer, so the data + is still inside waiting to be flushed. */ +char *buffer_getstr(struct buffer *); + +/* Returns 1 if there is no pending data in the buffer. Otherwise returns 0. */ +int buffer_empty(struct buffer *); + +typedef enum { + /* An I/O error occurred. The buffer should be destroyed and the + file descriptor should be closed. */ + BUFFER_ERROR = -1, + + /* The data was written successfully, and the buffer is now empty + (there is no pending data waiting to be flushed). */ + BUFFER_EMPTY = 0, + + /* There is pending data in the buffer waiting to be flushed. Please + try flushing the buffer when select indicates that the file + descriptor + is writeable. */ + BUFFER_PENDING = 1 +} buffer_status_t; + +/* Try to write this data to the file descriptor. Any data that cannot + be written immediately is added to the buffer queue. */ +extern buffer_status_t buffer_write(struct buffer *, int fd, const void *, + size_t); + +/* This function attempts to flush some (but perhaps not all) of + the queued data to the given file descriptor. */ +extern buffer_status_t buffer_flush_available(struct buffer *, int fd); + +/* The following 2 functions (buffer_flush_all and buffer_flush_window) + are for use in lib/vty.c only. They should not be used elsewhere. */ + +/* Call buffer_flush_available repeatedly until either all data has been + flushed, or an I/O error has been encountered, or the operation would + block. */ +extern buffer_status_t buffer_flush_all(struct buffer *, int fd); + +/* Attempt to write enough data to the given fd to fill a window of the + given width and height (and remove the data written from the buffer). + + If !no_more, then a message saying " --More-- " is appended. + If erase is true, then first overwrite the previous " --More-- " message + with spaces. + + Any write error (including EAGAIN or EINTR) will cause this function + to return -1 (because the logic for handling the erase and more features + is too complicated to retry the write later). +*/ +extern buffer_status_t buffer_flush_window(struct buffer *, int fd, int width, + int height, int erase, int no_more); + +#ifdef __cplusplus +} +#endif + +#endif /* _ZEBRA_BUFFER_H */ |