spdylay/lib/spdylay_buffer.h

/*
 * Spdylay - SPDY Library
 *
 * Copyright (c) 2012 Tatsuhiro Tsujikawa
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
#ifndef SPDYLAY_BUFFER_H
#define SPDYLAY_BUFFER_H

#ifdef HAVE_CONFIG_H
#  include <config.h>
#endif /* HAVE_CONFIG_H */

#include <spdylay/spdylay.h>
#include "spdylay_queue.h"

/*
 * Fixed sized buffers backed by queue.
 */
typedef struct {
  /* Capacity of each chunk buffer */
  size_t capacity;
  /* Queue of chunk buffers */
  spdylay_queue q;
  /* Total length of this buffer */
  size_t len;
  /* Offset of last chunk buffer */
  size_t last_offset;
} spdylay_buffer;

/*
 * Initializes buffer with fixed chunk size chunk_capacity.
 */
void spdylay_buffer_init(spdylay_buffer *buffer, size_t chunk_capacity);
/* Releases allocated memory for buffer */
void spdylay_buffer_free(spdylay_buffer *buffer);
/* Returns buffer pointer */
uint8_t* spdylay_buffer_get(spdylay_buffer *buffer);
/* Returns available buffer length */
size_t spdylay_buffer_avail(spdylay_buffer *buffer);
/* Advances buffer pointer by amount. This reduces available buffer
   length. */
void spdylay_buffer_advance(spdylay_buffer *buffer, size_t amount);
/* Allocate new chunk buffer. This will increase total length of
   buffer (returned by spdylay_buffer_length) by capacity-last_offset.
   It means untouched buffer is assumued to be written. */
int spdylay_buffer_alloc(spdylay_buffer *buffer);

/* Returns total length of buffer */
size_t spdylay_buffer_length(spdylay_buffer *buffer);
/* Returns first chunk buffer length. If the chunk buffer is the last
   one, last_offset will be returned. */
size_t spdylay_buffer_front_length(spdylay_buffer *buffer);
/* Returns first chunk buffer pointer */
uint8_t* spdylay_buffer_front_data(spdylay_buffer *buffer);
/* Pops first chunk buffer and decreases total length of buffer by the
   size of poped chunk buffer. */
void spdylay_buffer_pop(spdylay_buffer *buffer);

/* Returns capacity of each fixed chunk buffer */
size_t spdylay_buffer_capacity(spdylay_buffer *buffer);

/* Stores the contents of buffer into buf. buf must be at least
   spdylay_buffer_length(buffer) bytes long. */
void spdylay_buffer_serialize(spdylay_buffer *buffer, uint8_t *buf);

#endif /* SPDYLAY_BUFFER_H */