static void
ngx_http_push_stream_send_old_messages(ngx_http_request_t *r, ngx_http_push_stream_channel_t *channel, ngx_uint_t backtrack, time_t if_modified_since, ngx_int_t tag, time_t greater_message_time, ngx_int_t greater_message_tag, ngx_str_t *last_event_id)
{
ngx_http_push_stream_module_ctx_t *ctx = ngx_http_get_module_ctx(r, ngx_http_push_stream_module);
ngx_http_push_stream_msg_t *message;
ngx_queue_t *q;
if (ngx_http_push_stream_has_old_messages_to_send(channel, backtrack, if_modified_since, tag, greater_message_time, greater_message_tag, last_event_id)) {
if (backtrack > 0) {
ngx_uint_t qtd = (backtrack > channel->stored_messages) ? channel->stored_messages : backtrack;
ngx_uint_t start = channel->stored_messages - qtd;
ngx_shmtx_lock(channel->mutex);
// positioning at first message, and send the others
for (q = ngx_queue_head(&channel->message_queue); (qtd > 0) && q != ngx_queue_sentinel(&channel->message_queue); q = ngx_queue_next(q)) {
message = ngx_queue_data(q, ngx_http_push_stream_msg_t, queue);
if (message->deleted) {
break;
}
if (start == 0) {
qtd--;
ngx_http_push_stream_send_response_message(r, channel, message, 0, ctx->message_sent);
} else {
start--;
}
}
ngx_shmtx_unlock(channel->mutex);
} else if ((last_event_id != NULL) || (if_modified_since >= 0)) {
ngx_flag_t found = 0;
ngx_shmtx_lock(channel->mutex);
for (q = ngx_queue_head(&channel->message_queue); q != ngx_queue_sentinel(&channel->message_queue); q = ngx_queue_next(q)) {
message = ngx_queue_data(q, ngx_http_push_stream_msg_t, queue);
if (message->deleted) {
break;
}
if ((!found) && (last_event_id != NULL) && (message->event_id != NULL) && (ngx_memn2cmp(message->event_id->data, last_event_id->data, message->event_id->len, last_event_id->len) == 0)) {
found = 1;
continue;
}
if ((!found) && (if_modified_since >= 0) && ((message->time > if_modified_since) || ((message->time == if_modified_since) && (tag >= 0) && (message->tag >= tag)))) {
found = 1;
if ((message->time == if_modified_since) && (message->tag == tag)) {
continue;
}
}
if (found && (((greater_message_time == 0) && (greater_message_tag == -1)) || (greater_message_time > message->time) || ((greater_message_time == message->time) && (greater_message_tag >= message->tag)))) {
ngx_http_push_stream_send_response_message(r, channel, message, 0, ctx->message_sent);
}
}
ngx_shmtx_unlock(channel->mutex);
}
}
}
static void
ngx_http_push_stream_send_old_messages(ngx_http_request_t *r, ngx_http_push_stream_channel_t *channel, ngx_uint_t backtrack, time_t if_modified_since, ngx_int_t tag, time_t greater_message_time, ngx_int_t greater_message_tag, ngx_str_t *last_event_id)
{
ngx_http_push_stream_msg_t *message;
ngx_queue_t *cur;
if (ngx_http_push_stream_has_old_messages_to_send(channel, backtrack, if_modified_since, tag, greater_message_time, greater_message_tag, last_event_id)) {
cur = &channel->message_queue;
if (backtrack > 0) {
ngx_uint_t qtd = (backtrack > channel->stored_messages) ? channel->stored_messages : backtrack;
ngx_uint_t start = channel->stored_messages - qtd;
// positioning at first message, and send the others
while ((qtd > 0) && (cur = ngx_queue_next(cur)) && (cur != NULL) && (cur != &channel->message_queue)) {
message = (ngx_http_push_stream_msg_t *) ngx_queue_data(cur, ngx_http_push_stream_msg_t, queue);
if (message->deleted) {
break;
}
if (start == 0) {
ngx_http_push_stream_send_response_message(r, channel, message, 0, 1);
qtd--;
} else {
start--;
}
}
} else if ((last_event_id != NULL) || (if_modified_since >= 0)) {
ngx_flag_t found = 0;
while ((cur = ngx_queue_next(cur)) && (cur != NULL) && (cur != &channel->message_queue)) {
message = (ngx_http_push_stream_msg_t *) ngx_queue_data(cur, ngx_http_push_stream_msg_t, queue);
if (message->deleted) {
break;
}
if ((!found) && (last_event_id != NULL) && (message->event_id != NULL) && (ngx_memn2cmp(message->event_id->data, last_event_id->data, message->event_id->len, last_event_id->len) == 0)) {
found = 1;
continue;
}
if ((!found) && (last_event_id == NULL) && (if_modified_since >= 0) && ((message->time > if_modified_since) || ((message->time == if_modified_since) && (tag >= 0) && (message->tag >= tag)))) {
found = 1;
if ((message->time == if_modified_since) && (message->tag == tag)) {
continue;
}
}
if (found && (((greater_message_time == 0) && (greater_message_tag == -1)) || (greater_message_time > message->time) || ((greater_message_time == message->time) && (greater_message_tag >= message->tag)))) {
ngx_http_push_stream_send_response_message(r, channel, message, 0, 1);
}
}
}
}
}
static void
ngx_http_push_stream_send_old_messages(ngx_http_request_t *r, ngx_http_push_stream_channel_t *channel, ngx_uint_t backtrack, time_t if_modified_since, ngx_int_t tag, time_t greater_message_time, ngx_int_t greater_message_tag, ngx_str_t *last_event_id, ngx_int_t *message_count_had_send)
{
ngx_http_push_stream_msg_t *message;
ngx_queue_t *cur;
time_t next_greater_message_time = greater_message_time;//add by xinlu
ngx_int_t next_greater_message_tag = greater_message_tag;//add by xinlu
if (ngx_http_push_stream_has_old_messages_to_send(channel, backtrack, if_modified_since, tag, greater_message_time, greater_message_tag, last_event_id, &next_greater_message_time, &next_greater_message_tag) >= 2)
{
cur = &channel->message_queue;
if ((last_event_id != NULL) || (if_modified_since >= 0)) {
ngx_flag_t found = 0;
while ((cur = ngx_queue_next(cur)) && (cur != NULL) && (cur != &channel->message_queue)) {
message = (ngx_http_push_stream_msg_t *) ngx_queue_data(cur, ngx_http_push_stream_msg_t, queue);
if (message->deleted) {
break;
}
if ((!found) && (last_event_id != NULL) && (message->event_id != NULL) && (ngx_memn2cmp(message->event_id->data, last_event_id->data, message->event_id->len, last_event_id->len) == 0)) {
found = 1;
continue;
}
if ((!found) && (last_event_id == NULL) && (if_modified_since >= 0) && ((message->time > if_modified_since) || ((message->time == if_modified_since) && (tag >= 0) && (message->tag >= tag)))) {
found = 1;
if ((message->time == if_modified_since) && (message->tag == tag)) {
continue;
}
}
//if (found && (((greater_message_time == 0) && (greater_message_tag == -1)) || (greater_message_time > message->time) || ((greater_message_time == message->time) && (greater_message_tag >= message->tag))))
if (found && (greater_message_time == message->time) && (greater_message_tag == message->tag))
{
ngx_http_push_stream_send_response_message(r, channel, message, 0, 1);
(*message_count_had_send)++;
return;
}
}
}
}
}
static ngx_int_t
ngx_http_push_stream_subscriber_polling_handler(ngx_http_request_t *r, ngx_http_push_stream_requested_channel_t *channels_ids, time_t if_modified_since, ngx_str_t *last_event_id, ngx_flag_t longpolling, ngx_pool_t *temp_pool)
{
ngx_http_push_stream_loc_conf_t *cf = ngx_http_get_module_loc_conf(r, ngx_http_push_stream_module);
ngx_slab_pool_t *shpool = (ngx_slab_pool_t *)ngx_http_push_stream_shm_zone->shm.addr;
ngx_http_push_stream_subscriber_ctx_t *ctx = ngx_http_get_module_ctx(r, ngx_http_push_stream_module);
ngx_http_push_stream_requested_channel_t *cur;
ngx_http_push_stream_subscriber_t *worker_subscriber;
ngx_http_push_stream_channel_t *channel;
ngx_http_push_stream_subscription_t *subscription;
ngx_str_t *etag = NULL, vv_etag = ngx_null_string;
ngx_int_t tag;
time_t greater_message_time;
ngx_int_t greater_message_tag;
ngx_flag_t has_message_to_send = 0;
ngx_str_t callback_function_name;
if (cf->last_received_message_tag != NULL) {
ngx_http_push_stream_complex_value(r, cf->last_received_message_tag, &vv_etag);
etag = vv_etag.len ? &vv_etag : NULL;
} else {
etag = ngx_http_push_stream_get_header(r, &NGX_HTTP_PUSH_STREAM_HEADER_IF_NONE_MATCH);
}
if (ngx_http_arg(r, NGX_HTTP_PUSH_STREAM_CALLBACK.data, NGX_HTTP_PUSH_STREAM_CALLBACK.len, &callback_function_name) == NGX_OK) {
ngx_http_push_stream_unescape_uri(&callback_function_name);
if ((ctx->callback = ngx_http_push_stream_get_formatted_chunk(callback_function_name.data, callback_function_name.len, r->pool)) == NULL) {
ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "push stream module: unable to allocate memory for callback function name");
return NGX_HTTP_INTERNAL_SERVER_ERROR;
}
}
tag = ((etag != NULL) && ((tag = ngx_atoi(etag->data, etag->len)) != NGX_ERROR)) ? ngx_abs(tag) : -1;
greater_message_tag = tag;
greater_message_time = if_modified_since = (if_modified_since < 0) ? 0 : if_modified_since;
ngx_shmtx_lock(&shpool->mutex);
// check if has any message to send
cur = channels_ids;
while ((cur = (ngx_http_push_stream_requested_channel_t *) ngx_queue_next(&cur->queue)) != channels_ids) {
channel = ngx_http_push_stream_find_channel(cur->id, r->connection->log);
if (channel == NULL) {
// channel not found
ngx_shmtx_unlock(&shpool->mutex);
ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "push stream module: unable to allocate shared memory for channel %s", cur->id->data);
return NGX_HTTP_INTERNAL_SERVER_ERROR;
}
if (ngx_http_push_stream_has_old_messages_to_send(channel, cur->backtrack_messages, if_modified_since, tag, greater_message_time, greater_message_tag, last_event_id)) {
has_message_to_send = 1;
if (channel->last_message_time > greater_message_time) {
greater_message_time = channel->last_message_time;
greater_message_tag = channel->last_message_tag;
} else {
if ((channel->last_message_time == greater_message_time) && (channel->last_message_tag > greater_message_tag) ) {
greater_message_tag = channel->last_message_tag;
}
}
}
}
if (longpolling && !has_message_to_send) {
// long polling mode without messages
if ((worker_subscriber = ngx_http_push_stream_subscriber_prepare_request_to_keep_connected(r)) == NULL) {
ngx_shmtx_unlock(&shpool->mutex);
return NGX_HTTP_INTERNAL_SERVER_ERROR;
}
worker_subscriber->longpolling = 1;
if (ngx_http_push_stream_registry_subscriber_locked(r, worker_subscriber) == NGX_ERROR) {
ngx_shmtx_unlock(&shpool->mutex);
return NGX_HTTP_INTERNAL_SERVER_ERROR;
}
// adding subscriber to channel(s)
cur = channels_ids;
while ((cur = (ngx_http_push_stream_requested_channel_t *) ngx_queue_next(&cur->queue)) != channels_ids) {
if ((channel = ngx_http_push_stream_find_channel(cur->id, r->connection->log)) == NULL) {
// channel not found
ngx_shmtx_unlock(&shpool->mutex);
ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "push stream module: unable to allocate shared memory for channel %s", cur->id->data);
return NGX_HTTP_INTERNAL_SERVER_ERROR;
}
if ((subscription = ngx_http_push_stream_create_channel_subscription(r, channel, worker_subscriber)) == NULL) {
ngx_shmtx_unlock(&shpool->mutex);
return NGX_HTTP_INTERNAL_SERVER_ERROR;
}
ngx_http_push_stream_assing_subscription_to_channel_locked(shpool, cur->id, subscription, &worker_subscriber->subscriptions_sentinel, r->connection->log);
}
ngx_shmtx_unlock(&shpool->mutex);
return NGX_DONE;
}
ngx_shmtx_unlock(&shpool->mutex);
// polling or long polling without messages to send
ngx_http_push_stream_add_polling_headers(r, greater_message_time, greater_message_tag, temp_pool);
if (!has_message_to_send) {
// polling subscriber requests get a 304 with their entity tags preserved if don't have new messages.
return ngx_http_push_stream_send_only_header_response(r, NGX_HTTP_NOT_MODIFIED, NULL);
}
// polling with messages or long polling without messages to send
r->headers_out.status = NGX_HTTP_OK;
r->headers_out.content_length_n = -1;
ngx_http_push_stream_add_response_header(r, &NGX_HTTP_PUSH_STREAM_HEADER_TRANSFER_ENCODING, &NGX_HTTP_PUSH_STREAM_HEADER_CHUNCKED);
ngx_http_send_header(r);
// sending response content header
if (ngx_http_push_stream_send_response_content_header(r, cf) == NGX_ERROR) {
ngx_log_error(NGX_LOG_ERR, (r)->connection->log, 0, "push stream module: could not send content header to subscriber");
return NGX_HTTP_INTERNAL_SERVER_ERROR;
}
if (ctx->callback != NULL) {
ngx_http_push_stream_send_response_text(r, ctx->callback->data, ctx->callback->len, 0);
ngx_http_push_stream_send_response_text(r, NGX_HTTP_PUSH_STREAM_CALLBACK_INIT_CHUNK.data, NGX_HTTP_PUSH_STREAM_CALLBACK_INIT_CHUNK.len, 0);
}
cur = channels_ids;
while ((cur = (ngx_http_push_stream_requested_channel_t *) ngx_queue_next(&cur->queue)) != channels_ids) {
channel = ngx_http_push_stream_find_channel(cur->id, r->connection->log);
if (channel == NULL) {
// channel not found
ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "push stream module: unable to allocate shared memory for channel %s", cur->id->data);
return NGX_HTTP_INTERNAL_SERVER_ERROR;
}
ngx_http_push_stream_send_old_messages(r, channel, cur->backtrack_messages, if_modified_since, tag, greater_message_time, greater_message_tag, last_event_id);
}
if (ctx->callback != NULL) {
ngx_http_push_stream_send_response_text(r, NGX_HTTP_PUSH_STREAM_CALLBACK_END_CHUNK.data, NGX_HTTP_PUSH_STREAM_CALLBACK_END_CHUNK.len, 0);
}
if (cf->footer_template.len > 0) {
ngx_http_push_stream_send_response_text(r, cf->footer_template.data, cf->footer_template.len, 0);
}
ngx_http_push_stream_send_response_text(r, NGX_HTTP_PUSH_STREAM_LAST_CHUNK.data, NGX_HTTP_PUSH_STREAM_LAST_CHUNK.len, 1);
return NGX_OK;
}
static ngx_int_t
ngx_http_push_stream_subscriber_polling_handler(ngx_http_request_t *r, ngx_http_push_stream_requested_channel_t *requested_channels, time_t if_modified_since, ngx_int_t tag, ngx_str_t *last_event_id, ngx_flag_t longpolling, ngx_pool_t *temp_pool)
{
ngx_http_push_stream_main_conf_t *mcf = ngx_http_get_module_main_conf(r, ngx_http_push_stream_module);
ngx_http_push_stream_loc_conf_t *cf = ngx_http_get_module_loc_conf(r, ngx_http_push_stream_module);
ngx_slab_pool_t *shpool = mcf->shpool;
ngx_http_push_stream_module_ctx_t *ctx = ngx_http_get_module_ctx(r, ngx_http_push_stream_module);
ngx_http_push_stream_requested_channel_t *requested_channel;
ngx_queue_t *q;
ngx_http_push_stream_subscriber_t *worker_subscriber;
ngx_http_push_stream_subscription_t *subscription;
time_t greater_message_time;
ngx_int_t greater_message_tag;
ngx_flag_t has_message_to_send = 0;
ngx_str_t callback_function_name;
if (ngx_http_arg(r, NGX_HTTP_PUSH_STREAM_CALLBACK.data, NGX_HTTP_PUSH_STREAM_CALLBACK.len, &callback_function_name) == NGX_OK) {
ngx_http_push_stream_unescape_uri(&callback_function_name);
if ((ctx->callback = ngx_pcalloc(r->pool, sizeof(ngx_str_t))) == NULL) {
ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "push stream module: unable to allocate memory for callback function name");
return NGX_HTTP_INTERNAL_SERVER_ERROR;
}
ctx->callback->data = callback_function_name.data;
ctx->callback->len = callback_function_name.len;
}
greater_message_tag = tag;
greater_message_time = (if_modified_since < 0) ? 0 : if_modified_since;
// check if has any message to send
for (q = ngx_queue_head(&requested_channels->queue); q != ngx_queue_sentinel(&requested_channels->queue); q = ngx_queue_next(q)) {
requested_channel = ngx_queue_data(q, ngx_http_push_stream_requested_channel_t, queue);
if (ngx_http_push_stream_has_old_messages_to_send(requested_channel->channel, requested_channel->backtrack_messages, if_modified_since, tag, greater_message_time, greater_message_tag, last_event_id)) {
has_message_to_send = 1;
if (requested_channel->channel->last_message_time > greater_message_time) {
greater_message_time = requested_channel->channel->last_message_time;
greater_message_tag = requested_channel->channel->last_message_tag;
} else {
if ((requested_channel->channel->last_message_time == greater_message_time) && (requested_channel->channel->last_message_tag > greater_message_tag) ) {
greater_message_tag = requested_channel->channel->last_message_tag;
}
}
}
}
if (longpolling && !has_message_to_send) {
// long polling mode without messages
if ((worker_subscriber = ngx_http_push_stream_subscriber_prepare_request_to_keep_connected(r)) == NULL) {
return NGX_HTTP_INTERNAL_SERVER_ERROR;
}
worker_subscriber->longpolling = 1;
if (ngx_http_push_stream_registry_subscriber(r, worker_subscriber) == NGX_ERROR) {
return NGX_HTTP_INTERNAL_SERVER_ERROR;
}
// adding subscriber to channel(s)
for (q = ngx_queue_head(&requested_channels->queue); q != ngx_queue_sentinel(&requested_channels->queue); q = ngx_queue_next(q)) {
requested_channel = ngx_queue_data(q, ngx_http_push_stream_requested_channel_t, queue);
if ((subscription = ngx_http_push_stream_create_channel_subscription(r, requested_channel->channel, worker_subscriber)) == NULL) {
return NGX_HTTP_INTERNAL_SERVER_ERROR;
}
ngx_http_push_stream_assing_subscription_to_channel(shpool, requested_channel->channel, subscription, &worker_subscriber->subscriptions, r->connection->log);
}
return NGX_DONE;
}
// polling or long polling with messages to send
ngx_http_push_stream_add_polling_headers(r, greater_message_time, greater_message_tag, temp_pool);
if (!has_message_to_send) {
// polling subscriber requests get a 304 with their entity tags preserved if don't have new messages.
return ngx_http_push_stream_send_only_header_response(r, NGX_HTTP_NOT_MODIFIED, NULL);
}
// polling with messages or long polling without messages to send
r->headers_out.status = NGX_HTTP_OK;
r->headers_out.content_length_n = -1;
ngx_http_send_header(r);
// sending response content header
if (ngx_http_push_stream_send_response_content_header(r, cf) == NGX_ERROR) {
ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "push stream module: could not send content header to subscriber");
return NGX_HTTP_INTERNAL_SERVER_ERROR;
}
if (ctx->callback != NULL) {
ngx_http_push_stream_send_response_text(r, ctx->callback->data, ctx->callback->len, 0);
ngx_http_push_stream_send_response_text(r, NGX_HTTP_PUSH_STREAM_CALLBACK_INIT_CHUNK.data, NGX_HTTP_PUSH_STREAM_CALLBACK_INIT_CHUNK.len, 0);
}
for (q = ngx_queue_head(&requested_channels->queue); q != ngx_queue_sentinel(&requested_channels->queue); q = ngx_queue_next(q)) {
requested_channel = ngx_queue_data(q, ngx_http_push_stream_requested_channel_t, queue);
ngx_http_push_stream_send_old_messages(r, requested_channel->channel, requested_channel->backtrack_messages, if_modified_since, tag, greater_message_time, greater_message_tag, last_event_id);
}
if (ctx->callback != NULL) {
ngx_http_push_stream_send_response_text(r, NGX_HTTP_PUSH_STREAM_CALLBACK_END_CHUNK.data, NGX_HTTP_PUSH_STREAM_CALLBACK_END_CHUNK.len, 0);
}
if (cf->footer_template.len > 0) {
ngx_http_push_stream_send_response_text(r, cf->footer_template.data, cf->footer_template.len, 0);
}
ngx_http_send_special(r, NGX_HTTP_LAST | NGX_HTTP_FLUSH);
return NGX_OK;
}
