mirror of
https://github.com/asterisk/asterisk.git
synced 2025-09-20 03:59:01 +00:00
Add data buffer API to store packets.
Adds a data buffer with a configurable size that can store different kinds of packets (like RTP packets for retransmission). Given a number it will store a data packet at that position relative to the others. Given a number it will retrieve the given data packet if it is present. This is purposely a storage of arbitrary things so it can be used not just for RTP packets but also Asterisk frames in the future if needed. The API does not internally use a lock, so it will be up to the user of the API to properly protect the data buffer. For more information, refer to the wiki page: https://wiki.asterisk.org/wiki/display/AST/WebRTC+User+Experience+Improvements Change-Id: Iff13c5d4795d52356959fe2a57360cd57dfade07
This commit is contained in:
Ben Ford
committed by
Benjamin Keith Ford
Benjamin Keith Ford
parent
a4a5b8d562
commit
138e0eff4e
314
main/data_buffer.c
Normal file
314
main/data_buffer.c
Normal file
@@ -0,0 +1,314 @@
|
||||
/*
|
||||
* Asterisk -- An open source telephony toolkit.
|
||||
*
|
||||
* Copyright (C) 2018, Digium, Inc.
|
||||
*
|
||||
* Joshua Colp <jcolp@digium.com>
|
||||
* Ben Ford <bford@digium.com>
|
||||
*
|
||||
* See http://www.asterisk.org for more information about
|
||||
* the Asterisk project. Please do not directly contact
|
||||
* any of the maintainers of this project for assistance;
|
||||
* the project provides a web site, mailing lists and IRC
|
||||
* channels for your use.
|
||||
*
|
||||
* This program is free software, distributed under the terms of
|
||||
* the GNU General Public License Version 2. See the LICENSE file
|
||||
* at the top of the source tree.
|
||||
*/
|
||||
|
||||
/*! \file
|
||||
*
|
||||
* \brief Data Buffer API
|
||||
*
|
||||
* \author Joshua Colp <jcolp@digium.com>
|
||||
* \author Ben Ford <bford@digium.com>
|
||||
*/
|
||||
|
||||
/*** MODULEINFO
|
||||
<support_level>core</support_level>
|
||||
***/
|
||||
|
||||
#include "asterisk.h"
|
||||
|
||||
#include "asterisk/logger.h"
|
||||
#include "asterisk/strings.h"
|
||||
#include "asterisk/data_buffer.h"
|
||||
#include "asterisk/linkedlists.h"
|
||||
|
||||
/*!
|
||||
* \brief The number of payloads to increment the cache by
|
||||
*/
|
||||
#define CACHED_PAYLOAD_MAX 5
|
||||
|
||||
/*!
|
||||
* \brief Payload entry placed inside of the data buffer list
|
||||
*/
|
||||
struct data_buffer_payload_entry {
|
||||
/*! \brief The payload for this position */
|
||||
void *payload;
|
||||
/*! \brief The provided position for this */
|
||||
size_t pos;
|
||||
/*! \brief Linked list information */
|
||||
AST_LIST_ENTRY(data_buffer_payload_entry) list;
|
||||
};
|
||||
|
||||
/*!
|
||||
* \brief Data buffer containing fixed number of data payloads
|
||||
*/
|
||||
struct ast_data_buffer {
|
||||
/*! \brief Callback function to free a data payload */
|
||||
ast_data_buffer_free_callback free_fn;
|
||||
/*! \brief A linked list of data payloads */
|
||||
AST_LIST_HEAD_NOLOCK(, data_buffer_payload_entry) payloads;
|
||||
/*! \brief A linked list of unused cached data payloads */
|
||||
AST_LIST_HEAD_NOLOCK(, data_buffer_payload_entry) cached_payloads;
|
||||
/*! \brief The current number of data payloads in the buffer */
|
||||
size_t count;
|
||||
/*! \brief Maximum number of data payloads in the buffer */
|
||||
size_t max;
|
||||
/*! \brief The current number of data payloads in the cache */
|
||||
size_t cache_count;
|
||||
};
|
||||
|
||||
static void free_fn_do_nothing(void *data)
|
||||
{
|
||||
return;
|
||||
}
|
||||
|
||||
/*!
|
||||
* \brief Helper function to allocate a data payload
|
||||
*/
|
||||
static struct data_buffer_payload_entry *data_buffer_payload_alloc(void *payload, size_t pos)
|
||||
{
|
||||
struct data_buffer_payload_entry *data_payload;
|
||||
|
||||
data_payload = ast_calloc(1, sizeof(*data_payload));
|
||||
if (!data_payload) {
|
||||
return NULL;
|
||||
}
|
||||
|
||||
data_payload->payload = payload;
|
||||
data_payload->pos = pos;
|
||||
|
||||
return data_payload;
|
||||
}
|
||||
|
||||
/*!
|
||||
* \brief Helper function that sets the cache to its maximum number of payloads
|
||||
*/
|
||||
static void ast_data_buffer_cache_adjust(struct ast_data_buffer *buffer)
|
||||
{
|
||||
int buffer_space;
|
||||
|
||||
ast_assert(buffer != NULL);
|
||||
|
||||
buffer_space = buffer->max - buffer->count;
|
||||
|
||||
if (buffer->cache_count == buffer_space) {
|
||||
return;
|
||||
}
|
||||
|
||||
if (buffer->cache_count < buffer_space) {
|
||||
/* Add payloads to the cache, if able */
|
||||
while (buffer->cache_count < CACHED_PAYLOAD_MAX && buffer->cache_count < buffer_space) {
|
||||
struct data_buffer_payload_entry *buffer_payload;
|
||||
|
||||
buffer_payload = data_buffer_payload_alloc(NULL, -1);
|
||||
if (buffer_payload) {
|
||||
AST_LIST_INSERT_TAIL(&buffer->cached_payloads, buffer_payload, list);
|
||||
buffer->cache_count++;
|
||||
continue;
|
||||
}
|
||||
|
||||
ast_log(LOG_ERROR, "Failed to allocate memory to the cache.");
|
||||
break;
|
||||
}
|
||||
} else if (buffer->cache_count > buffer_space) {
|
||||
/* Remove payloads from the cache */
|
||||
while (buffer->cache_count > buffer_space) {
|
||||
struct data_buffer_payload_entry *buffer_payload;
|
||||
|
||||
buffer_payload = AST_LIST_REMOVE_HEAD(&buffer->cached_payloads, list);
|
||||
if (buffer_payload) {
|
||||
ast_free(buffer_payload);
|
||||
buffer->cache_count--;
|
||||
continue;
|
||||
}
|
||||
|
||||
ast_log(LOG_ERROR, "Failed to remove memory from the cache.");
|
||||
break;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
struct ast_data_buffer *ast_data_buffer_alloc(ast_data_buffer_free_callback free_fn, size_t size)
|
||||
{
|
||||
struct ast_data_buffer *buffer;
|
||||
|
||||
ast_assert(size != 0);
|
||||
|
||||
buffer = ast_calloc(1, sizeof(*buffer));
|
||||
if (!buffer) {
|
||||
return NULL;
|
||||
}
|
||||
|
||||
AST_LIST_HEAD_INIT_NOLOCK(&buffer->payloads);
|
||||
AST_LIST_HEAD_INIT_NOLOCK(&buffer->cached_payloads);
|
||||
|
||||
/* If free_fn is NULL, just use free_fn_do_nothing as a default */
|
||||
buffer->free_fn = free_fn ? free_fn : free_fn_do_nothing;
|
||||
buffer->max = size;
|
||||
|
||||
ast_data_buffer_cache_adjust(buffer);
|
||||
|
||||
return buffer;
|
||||
}
|
||||
|
||||
void ast_data_buffer_resize(struct ast_data_buffer *buffer, size_t size)
|
||||
{
|
||||
struct data_buffer_payload_entry *existing_payload;
|
||||
|
||||
ast_assert(buffer != NULL);
|
||||
|
||||
/* The buffer must have at least a size of 1 */
|
||||
ast_assert(size > 0);
|
||||
|
||||
if (buffer->max == size) {
|
||||
return;
|
||||
}
|
||||
|
||||
/* If the size is decreasing, some payloads will need to be freed */
|
||||
if (buffer->max > size) {
|
||||
int remove = buffer->max - size;
|
||||
|
||||
AST_LIST_TRAVERSE_SAFE_BEGIN(&buffer->payloads, existing_payload, list) {
|
||||
if (remove) {
|
||||
AST_LIST_REMOVE_HEAD(&buffer->payloads, list);
|
||||
buffer->free_fn(existing_payload->payload);
|
||||
ast_free(existing_payload);
|
||||
buffer->count--;
|
||||
remove--;
|
||||
continue;
|
||||
}
|
||||
break;
|
||||
}
|
||||
AST_LIST_TRAVERSE_SAFE_END;
|
||||
}
|
||||
|
||||
buffer->max = size;
|
||||
ast_data_buffer_cache_adjust(buffer);
|
||||
}
|
||||
|
||||
int ast_data_buffer_put(struct ast_data_buffer *buffer, size_t pos, void *payload)
|
||||
{
|
||||
struct data_buffer_payload_entry *buffer_payload = NULL;
|
||||
struct data_buffer_payload_entry *existing_payload;
|
||||
int inserted = 0;
|
||||
|
||||
ast_assert(buffer != NULL);
|
||||
ast_assert(payload != NULL);
|
||||
|
||||
/* If the data buffer has reached its maximum size then the head goes away and
|
||||
* we will reuse its buffer payload
|
||||
*/
|
||||
if (buffer->count == buffer->max) {
|
||||
buffer_payload = AST_LIST_REMOVE_HEAD(&buffer->payloads, list);
|
||||
buffer->free_fn(buffer_payload->payload);
|
||||
buffer->count--;
|
||||
|
||||
/* Update this buffer payload with its new information */
|
||||
buffer_payload->payload = payload;
|
||||
buffer_payload->pos = pos;
|
||||
}
|
||||
if (!buffer_payload) {
|
||||
if (!buffer->cache_count) {
|
||||
ast_data_buffer_cache_adjust(buffer);
|
||||
}
|
||||
buffer_payload = AST_LIST_REMOVE_HEAD(&buffer->cached_payloads, list);
|
||||
buffer->cache_count--;
|
||||
|
||||
/* Update the payload from the cache with its new information */
|
||||
buffer_payload->payload = payload;
|
||||
buffer_payload->pos = pos;
|
||||
}
|
||||
if (!buffer_payload) {
|
||||
return -1;
|
||||
}
|
||||
|
||||
/* Given the position find its ideal spot within the buffer */
|
||||
AST_LIST_TRAVERSE_SAFE_BEGIN(&buffer->payloads, existing_payload, list) {
|
||||
/* If it's already in the buffer, drop it */
|
||||
if (existing_payload->pos == pos) {
|
||||
ast_debug(3, "Packet with position %zu is already in buffer. Not inserting.\n", pos);
|
||||
inserted = -1;
|
||||
break;
|
||||
}
|
||||
|
||||
if (existing_payload->pos > pos) {
|
||||
AST_LIST_INSERT_BEFORE_CURRENT(buffer_payload, list);
|
||||
inserted = 1;
|
||||
break;
|
||||
}
|
||||
}
|
||||
AST_LIST_TRAVERSE_SAFE_END;
|
||||
|
||||
if (inserted == -1) {
|
||||
return 0;
|
||||
}
|
||||
|
||||
if (!inserted) {
|
||||
AST_LIST_INSERT_TAIL(&buffer->payloads, buffer_payload, list);
|
||||
}
|
||||
|
||||
buffer->count++;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
void *ast_data_buffer_get(const struct ast_data_buffer *buffer, size_t pos)
|
||||
{
|
||||
struct data_buffer_payload_entry *buffer_payload;
|
||||
|
||||
ast_assert(buffer != NULL);
|
||||
|
||||
AST_LIST_TRAVERSE(&buffer->payloads, buffer_payload, list) {
|
||||
if (buffer_payload->pos == pos) {
|
||||
return buffer_payload->payload;
|
||||
}
|
||||
}
|
||||
|
||||
return NULL;
|
||||
}
|
||||
|
||||
void ast_data_buffer_free(struct ast_data_buffer *buffer)
|
||||
{
|
||||
struct data_buffer_payload_entry *buffer_payload;
|
||||
|
||||
ast_assert(buffer != NULL);
|
||||
|
||||
while ((buffer_payload = AST_LIST_REMOVE_HEAD(&buffer->payloads, list))) {
|
||||
buffer->free_fn(buffer_payload->payload);
|
||||
ast_free(buffer_payload);
|
||||
}
|
||||
|
||||
while ((buffer_payload = AST_LIST_REMOVE_HEAD(&buffer->cached_payloads, list))) {
|
||||
ast_free(buffer_payload);
|
||||
}
|
||||
|
||||
ast_free(buffer);
|
||||
}
|
||||
|
||||
size_t ast_data_buffer_count(const struct ast_data_buffer *buffer)
|
||||
{
|
||||
ast_assert(buffer != NULL);
|
||||
|
||||
return buffer->count;
|
||||
}
|
||||
|
||||
size_t ast_data_buffer_max(const struct ast_data_buffer *buffer)
|
||||
{
|
||||
ast_assert(buffer != NULL);
|
||||
|
||||
return buffer->max;
|
||||
}
|
||||
Reference in New Issue
Block a user