static void ngx_http_push_publisher_body_handler(ngx_http_request_t * r) { ngx_str_t *channel_id; ngx_http_push_loc_conf_t *cf = ngx_http_get_module_loc_conf(r, ngx_http_push_module); ngx_uint_t method = r->method; if((channel_id = ngx_http_push_get_channel_id(r, cf))==NULL) { ngx_http_finalize_request(r, r->headers_out.status ? NGX_OK : NGX_HTTP_INTERNAL_SERVER_ERROR); return; } switch(method) { case NGX_HTTP_POST: case NGX_HTTP_PUT: ngx_http_push_store->publish(channel_id, r, &publish_callback); break; case NGX_HTTP_DELETE: ngx_http_finalize_request(r, ngx_http_push_response_channel_info(channel_id, r, NGX_HTTP_OK)); ngx_http_push_store->delete_channel(channel_id); break; case NGX_HTTP_GET: ngx_http_finalize_request(r, ngx_http_push_response_channel_info(channel_id, r, NGX_HTTP_OK)); break; case NGX_HTTP_OPTIONS: ngx_http_push_add_response_header(r, &NGX_HTTP_PUSH_HEADER_ACCESS_CONTROL_ALLOW_ORIGIN, &NGX_HTTP_PUSH_ANYSTRING); ngx_http_push_add_response_header(r, &NGX_HTTP_PUSH_HEADER_ACCESS_CONTROL_ALLOW_HEADERS, &NGX_HTTP_PUSH_ACCESS_CONTROL_ALLOWED_PUBLISHER_HEADERS); ngx_http_push_add_response_header(r, &NGX_HTTP_PUSH_HEADER_ACCESS_CONTROL_ALLOW_METHODS, &NGX_HTTP_PUSH_ALLOW_GET_POST_PUT_DELETE_OPTIONS); r->header_only = 1; r->headers_out.content_length_n = 0; r->headers_out.status=NGX_HTTP_OK; ngx_http_send_header(r); ngx_http_finalize_request(r, NGX_HTTP_OK); break; default: //some other weird request method ngx_http_push_add_response_header(r, &NGX_HTTP_PUSH_HEADER_ALLOW, &NGX_HTTP_PUSH_ALLOW_GET_POST_PUT_DELETE_OPTIONS); ngx_http_finalize_request(r, NGX_HTTP_NOT_ALLOWED); break; } }
ngx_int_t ngx_http_push_subscriber_handler(ngx_http_request_t *r) { ngx_http_push_loc_conf_t *cf = ngx_http_get_module_loc_conf(r, ngx_http_push_module); ngx_str_t *channel_id; ngx_http_push_msg_id_t msg_id; if((channel_id=ngx_http_push_get_channel_id(r, cf)) == NULL) { return r->headers_out.status ? NGX_OK : NGX_HTTP_INTERNAL_SERVER_ERROR; } switch(r->method) { case NGX_HTTP_GET: ngx_http_push_subscriber_get_msg_id(r, &msg_id); r->main->count++; //let it linger until callback switch(cf->subscriber_poll_mechanism) { ngx_int_t msg_search_outcome; //for NGX_HTTP_PUSH_MECHANISM_LONGPOLL case NGX_HTTP_PUSH_MECHANISM_INTERVALPOLL: ngx_http_push_store->get_message(channel_id, &msg_id, &msg_search_outcome, r, &subscribe_intervalpoll_callback); break; case NGX_HTTP_PUSH_MECHANISM_LONGPOLL: ngx_http_push_store->subscribe(channel_id, &msg_id, r, &subscribe_longpoll_callback); break; } return NGX_DONE; case NGX_HTTP_OPTIONS: ngx_http_push_add_response_header(r, &NGX_HTTP_PUSH_HEADER_ACCESS_CONTROL_ALLOW_ORIGIN, &NGX_HTTP_PUSH_ANYSTRING); ngx_http_push_add_response_header(r, &NGX_HTTP_PUSH_HEADER_ACCESS_CONTROL_ALLOW_HEADERS, &NGX_HTTP_PUSH_ACCESS_CONTROL_ALLOWED_SUBSCRIBER_HEADERS); ngx_http_push_add_response_header(r, &NGX_HTTP_PUSH_HEADER_ACCESS_CONTROL_ALLOW_METHODS, &NGX_HTTP_PUSH_ALLOW_GET_OPTIONS); r->headers_out.content_length_n = 0; r->header_only = 1; r->headers_out.status=NGX_HTTP_OK; ngx_http_send_header(r); return NGX_OK; default: ngx_http_push_add_response_header(r, &NGX_HTTP_PUSH_HEADER_ALLOW, &NGX_HTTP_PUSH_ALLOW_GET_OPTIONS); //valid HTTP for the win return NGX_HTTP_NOT_ALLOWED; } }
static void ngx_http_push_publisher_body_handler(ngx_http_request_t * r) { ngx_str_t *id; ngx_http_push_loc_conf_t *cf = ngx_http_get_module_loc_conf(r, ngx_http_push_module); ngx_slab_pool_t *shpool = (ngx_slab_pool_t *) ngx_http_push_shm_zone->shm.addr; ngx_buf_t *buf = NULL, *buf_copy; ngx_http_push_channel_t *channel; ngx_uint_t method = r->method; time_t last_seen = 0; ngx_uint_t subscribers = 0; ngx_uint_t messages = 0; if((id = ngx_http_push_get_channel_id(r, cf))==NULL) { ngx_http_finalize_request(r, r->headers_out.status ? NGX_OK : NGX_HTTP_INTERNAL_SERVER_ERROR); return; } ngx_shmtx_lock(&shpool->mutex); //POST requests will need a channel created if it doesn't yet exist. if(method==NGX_HTTP_POST || method==NGX_HTTP_PUT) { channel = ngx_http_push_get_channel(id, &((ngx_http_push_shm_data_t *) ngx_http_push_shm_zone->data)->tree, shpool, r->connection->log); NGX_HTTP_PUSH_PUBLISHER_CHECK_LOCKED(channel, NULL, r, "push module: unable to allocate memory for new channel", shpool); } //no other request method needs that. else{ //just find the channel. if it's not there, NULL. channel = ngx_http_push_find_channel(id, &((ngx_http_push_shm_data_t *) ngx_http_push_shm_zone->data)->tree, shpool, r->connection->log); } if(channel!=NULL) { subscribers = channel->subscribers; last_seen = channel->last_seen; messages = channel->messages; } else { //404! ngx_shmtx_unlock(&shpool->mutex); r->headers_out.status=NGX_HTTP_NOT_FOUND; //just the headers, please. we don't care to describe the situation or //respond with an html page r->headers_out.content_length_n=0; r->header_only = 1; ngx_http_finalize_request(r, ngx_http_send_header(r)); return; } ngx_shmtx_unlock(&shpool->mutex); switch(method) { ngx_http_push_msg_t *msg, *previous_msg; size_t content_type_len; ngx_uint_t received; ngx_http_push_msg_t *sentinel; case NGX_HTTP_POST: //first off, we'll want to extract the body buffer //note: this works mostly because of r->request_body_in_single_buf = 1; //which, i suppose, makes this module a little slower than it could be. //this block is a little hacky. might be a thorn for forward-compatibility. if(r->headers_in.content_length_n == -1 || r->headers_in.content_length_n == 0) { buf = ngx_create_temp_buf(r->pool, 0); //this buffer will get copied to shared memory in a few lines, //so it does't matter what pool we make it in. } else if(r->request_body->temp_file==NULL) { //everything in the first buffer, please //no file buf=r->request_body->bufs->buf; } else { //(r->request_body->bufs->next!=NULL) //there's probably a file buf=r->request_body->bufs->next->buf; } NGX_HTTP_PUSH_PUBLISHER_CHECK(buf, NULL, r, "push module: can't find or allocate publisher request body buffer"); content_type_len = (r->headers_in.content_type!=NULL ? r->headers_in.content_type->value.len : 0); ngx_shmtx_lock(&shpool->mutex); //create a buffer copy in shared mem msg = ngx_slab_alloc_locked(shpool, sizeof(*msg) + content_type_len); NGX_HTTP_PUSH_PUBLISHER_CHECK_LOCKED(msg, NULL, r, "push module: unable to allocate message in shared memory", shpool); previous_msg=ngx_http_push_get_latest_message_locked(channel); //need this for entity-tags generation NGX_HTTP_PUSH_CREATE_BUF_COPY(buf, buf_copy, shpool, ngx_slab_alloc_locked); NGX_HTTP_PUSH_PUBLISHER_CHECK_LOCKED(buf_copy, NULL, r, "push module: unable to allocate buffer in shared memory", shpool); msg->buf=buf_copy; if(cf->store_messages) { ngx_queue_insert_tail(&channel->message_queue->queue, &msg->queue); channel->messages++; } //Stamp the new message with entity tags msg->message_time=ngx_time(); //ESSENTIAL TODO: make sure this ends up producing GMT time msg->message_tag=(previous_msg!=NULL && msg->message_time == previous_msg->message_time) ? (previous_msg->message_tag + 1) : 0; //store the content-type if(content_type_len>0) { msg->content_type.len=r->headers_in.content_type->value.len; msg->content_type.data=(u_char *) (msg+1); //we had reserved a contiguous chunk, myes? ngx_memcpy(msg->content_type.data, r->headers_in.content_type->value.data, msg->content_type.len); } else { msg->content_type.len=0; msg->content_type.data=NULL; } //set message expiration time time_t message_timeout = cf->buffer_timeout; msg->expires = (message_timeout==0 ? 0 : (ngx_time() + message_timeout)); //FMI (For My Information): shm is still locked. switch(ngx_http_push_broadcast_message_locked(channel, msg, r->connection->log, shpool)) { case NGX_HTTP_PUSH_MESSAGE_QUEUED: //message was queued successfully, but there were no //subscribers to receive it. r->headers_out.status = NGX_HTTP_ACCEPTED; r->headers_out.status_line.len =sizeof("202 Accepted")- 1; r->headers_out.status_line.data=(u_char *) "202 Accepted"; break; case NGX_HTTP_PUSH_MESSAGE_RECEIVED: //message was queued successfully, and it was already sent //to at least one subscriber r->headers_out.status = NGX_HTTP_CREATED; r->headers_out.status_line.len =sizeof("201 Created")- 1; r->headers_out.status_line.data=(u_char *) "201 Created"; //update the number of times the message was received. //in the interest of premature optimization, I assume all //current subscribers have received the message successfully. received = msg->received; //nasty overflow check msg->received = (received + subscribers < received) ? NGX_MAX_UINT32_VALUE : (received + subscribers); break; case NGX_ERROR: //WTF? ngx_shmtx_unlock(&shpool->mutex); ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "push module: error broadcasting message to workers"); ngx_http_finalize_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR); return; default: //for debugging, mostly. I don't expect this branch to be //hit during regular operation ngx_shmtx_unlock(&shpool->mutex); ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "push module: TOTALLY UNEXPECTED error broadcasting message to workers"); ngx_http_finalize_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR); return; } //shm is still locked I hope. if(buf->file!=NULL) { //future subscribers won't be able to use this file descriptor -- //it will be closed once the publisher request is finalized. //(That's about to happen a handful of lines below.) msg->buf->file->fd=NGX_INVALID_FILE; } //now see if the queue is too big if(channel->messages > (ngx_uint_t) cf->max_messages) { //exceeeds max queue size. force-delete oldest message ngx_http_push_force_delete_message_locked(channel, ngx_http_push_get_oldest_message_locked(channel), shpool); } if(channel->messages > (ngx_uint_t) cf->min_messages) { //exceeeds min queue size. maybe delete the oldest message ngx_http_push_msg_t *oldest_msg = ngx_http_push_get_oldest_message_locked(channel); NGX_HTTP_PUSH_PUBLISHER_CHECK_LOCKED(oldest_msg, NULL, r, "push module: oldest message not found", shpool); if(oldest_msg->received >= (ngx_uint_t) cf->min_message_recipients) { //received more than min_message_recipients times ngx_http_push_delete_message_locked(channel, oldest_msg, shpool); } } messages = channel->messages; ngx_shmtx_unlock(&shpool->mutex); ngx_http_finalize_request(r, ngx_http_push_channel_info(r, messages, subscribers, last_seen)); return; case NGX_HTTP_PUT: case NGX_HTTP_GET: r->headers_out.status = NGX_HTTP_OK; ngx_http_finalize_request(r, ngx_http_push_channel_info(r, messages, subscribers, last_seen)); return; case NGX_HTTP_DELETE: ngx_shmtx_lock(&shpool->mutex); sentinel = channel->message_queue; msg = sentinel; while((msg=(ngx_http_push_msg_t *)ngx_queue_next(&msg->queue))!=sentinel) { //force-delete all the messages ngx_http_push_force_delete_message_locked(NULL, msg, shpool); } channel->messages=0; //410 gone NGX_HTTP_PUSH_PUBLISHER_CHECK_LOCKED(ngx_http_push_broadcast_status_locked(channel, NGX_HTTP_GONE, &NGX_HTTP_PUSH_HTTP_STATUS_410, r->connection->log, shpool), NGX_ERROR, r, "push module: unable to send current subscribers a 410 Gone response", shpool); ngx_http_push_delete_node_locked(&((ngx_http_push_shm_data_t *) ngx_http_push_shm_zone->data)->tree, (ngx_rbtree_node_t *) channel, shpool); ngx_shmtx_unlock(&shpool->mutex); //done. r->headers_out.status=NGX_HTTP_OK; ngx_http_finalize_request(r, ngx_http_push_channel_info(r, messages, subscribers, last_seen)); return; default: //some other weird request method ngx_http_push_add_response_header(r, &NGX_HTTP_PUSH_HEADER_ALLOW, &NGX_HTTP_PUSH_ALLOW_GET_POST_PUT_DELETE); ngx_http_finalize_request(r, NGX_HTTP_NOT_ALLOWED); return; } }
static ngx_int_t ngx_http_push_subscriber_handler(ngx_http_request_t *r) { ngx_http_push_loc_conf_t *cf = ngx_http_get_module_loc_conf(r, ngx_http_push_module); ngx_slab_pool_t *shpool = (ngx_slab_pool_t *)ngx_http_push_shm_zone->shm.addr; ngx_str_t *id; ngx_http_push_channel_t *channel; ngx_http_push_msg_t *msg; ngx_int_t msg_search_outcome; ngx_str_t *content_type=NULL; ngx_str_t *etag; if (r->method != NGX_HTTP_GET) { ngx_http_push_add_response_header(r, &NGX_HTTP_PUSH_HEADER_ALLOW, &NGX_HTTP_PUSH_ALLOW_GET); //valid HTTP for teh win return NGX_HTTP_NOT_ALLOWED; } if((id=ngx_http_push_get_channel_id(r, cf)) == NULL) { return r->headers_out.status ? NGX_OK : NGX_HTTP_INTERNAL_SERVER_ERROR; } //get the channel and check channel authorization while we're at it. ngx_shmtx_lock(&shpool->mutex); channel = (cf->authorize_channel==1 ? ngx_http_push_find_channel : ngx_http_push_get_channel)(id, &((ngx_http_push_shm_data_t *) ngx_http_push_shm_zone->data)->tree, shpool, r->connection->log); if (channel==NULL) { //unable to allocate channel OR channel not found ngx_shmtx_unlock(&shpool->mutex); if(cf->authorize_channel) { return NGX_HTTP_FORBIDDEN; } else { ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "push module: unable to allocate shared memory for channel"); return NGX_HTTP_INTERNAL_SERVER_ERROR; } } msg = ngx_http_push_find_message_locked(channel, r, &msg_search_outcome); channel->last_seen = ngx_time(); ngx_shmtx_unlock(&shpool->mutex); switch(ngx_http_push_handle_subscriber_concurrency_setting(cf->subscriber_concurrency, channel, r, shpool)) { case NGX_DECLINED: //this request was declined for some reason. //status codes and whatnot should have already been written. just get out of here quickly. return NGX_OK; case NGX_ERROR: ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "push module: error handling subscriber concurrency setting"); return NGX_ERROR; } switch(msg_search_outcome) { //for message-found: ngx_chain_t *chain; time_t last_modified; size_t content_type_len; ngx_http_postponed_request_t *pr, *p; case NGX_HTTP_PUSH_MESSAGE_EXPECTED: // ♫ It's gonna be the future soon ♫ switch(cf->subscriber_poll_mechanism) { //for NGX_HTTP_PUSH_MECHANISM_LONGPOLL ngx_http_push_pid_queue_t *sentinel, *cur, *found; ngx_http_push_subscriber_t *subscriber; ngx_http_push_subscriber_t *subscriber_sentinel; case NGX_HTTP_PUSH_MECHANISM_LONGPOLL: //long-polling subscriber. wait for a message. //subscribers are queued up in a local pool. Queue sentinels are separate and also local, but not in the pool. ngx_shmtx_lock(&shpool->mutex); sentinel = &channel->workers_with_subscribers; cur = (ngx_http_push_pid_queue_t *)ngx_queue_head(&sentinel->queue); found = NULL; ngx_http_push_subscriber_cleanup_t *clndata; ngx_pool_cleanup_t *cln; while(cur!=sentinel) { if(cur->pid==ngx_pid) { found = cur; break; } cur = (ngx_http_push_pid_queue_t *)ngx_queue_next(&cur->queue); } if(found==NULL) { //found nothing if((found=ngx_slab_alloc_locked(shpool, sizeof(*found)))==NULL) { ngx_shmtx_unlock(&shpool->mutex); ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "push module: unable to allocate worker subscriber queue marker in shared memory"); return NGX_HTTP_INTERNAL_SERVER_ERROR; } //initialize ngx_queue_insert_tail(&sentinel->queue, &found->queue); found->pid=ngx_pid; found->slot=ngx_process_slot; found->subscriber_sentinel=NULL; } ngx_shmtx_unlock(&shpool->mutex); if((subscriber = ngx_palloc(ngx_http_push_pool, sizeof(*subscriber)))==NULL) { //unable to allocate request queue element return NGX_ERROR; } //postpone the request. this seems to be magical. pr = ngx_palloc(r->pool, sizeof(ngx_http_postponed_request_t)); if (pr == NULL) { return NGX_ERROR; } pr->request = r; //really? pr->out = NULL; pr->next = NULL; if (r->postponed) { for (p = r->postponed; p->next; p = p->next) { /* void */ } p->next = pr; } else { r->postponed = pr; } //attach a cleaner to remove the request from the channel. if ((cln=ngx_pool_cleanup_add(r->pool, sizeof(*clndata))) == NULL) { //make sure we can. return NGX_ERROR; } cln->handler = (ngx_pool_cleanup_pt) ngx_http_push_subscriber_cleanup; clndata = (ngx_http_push_subscriber_cleanup_t *) cln->data; clndata->channel=channel; clndata->subscriber=subscriber; subscriber->request = r; subscriber->clndata=clndata; ngx_shmtx_lock(&shpool->mutex); channel->subscribers++; // do this only when we know everything went okay. //figure out the subscriber sentinel subscriber_sentinel = ((ngx_http_push_pid_queue_t *)found)->subscriber_sentinel; if(subscriber_sentinel==NULL) { if((subscriber_sentinel=ngx_palloc(ngx_http_push_pool, sizeof(*subscriber_sentinel)))==NULL) { ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "push module: unable to allocate channel subscriber sentinel"); return NGX_HTTP_INTERNAL_SERVER_ERROR; } ngx_queue_init(&subscriber_sentinel->queue); ((ngx_http_push_pid_queue_t *)found)->subscriber_sentinel=subscriber_sentinel; } ngx_shmtx_unlock(&shpool->mutex); ngx_queue_insert_tail(&subscriber_sentinel->queue, &subscriber->queue); #if defined(nginx_version) && nginx_version >= 7000 return NGX_OK; //do recall that the request was postponed #else return NGX_DONE; //oldschool #endif case NGX_HTTP_PUSH_MECHANISM_INTERVALPOLL: //interval-polling subscriber requests get a 304 with their entity tags preserved. if (r->headers_in.if_modified_since != NULL) { r->headers_out.last_modified_time=ngx_http_parse_time(r->headers_in.if_modified_since->value.data, r->headers_in.if_modified_since->value.len); } if ((etag=ngx_http_push_subscriber_get_etag(r)) != NULL) { r->headers_out.etag=ngx_http_push_add_response_header(r, &NGX_HTTP_PUSH_HEADER_ETAG, etag); } return NGX_HTTP_NOT_MODIFIED; default: //if this ever happens, there's a bug somewhere else. probably config stuff. return NGX_HTTP_INTERNAL_SERVER_ERROR; } case NGX_HTTP_PUSH_MESSAGE_EXPIRED: //subscriber wants an expired message //TODO: maybe respond with entity-identifiers for oldest available message? return NGX_HTTP_NO_CONTENT; case NGX_HTTP_PUSH_MESSAGE_FOUND: //found the message ngx_shmtx_lock(&shpool->mutex); msg->refcount++; // this probably isn't necessary, but i'm not thinking too straight at the moment. so just in case. if((msg->received)!=(ngx_uint_t) NGX_MAX_UINT32_VALUE){ //overflow check? msg->received++; } NGX_HTTP_PUSH_MAKE_ETAG(msg->message_tag, etag, ngx_palloc, r->pool); if(etag==NULL) { //oh, nevermind... ngx_shmtx_unlock(&shpool->mutex); ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "push module: unable to allocate memory for Etag header"); return NGX_ERROR; } content_type_len = msg->content_type.len; if(content_type_len>0) { NGX_HTTP_PUSH_MAKE_CONTENT_TYPE(content_type, content_type_len, msg, r->pool); if(content_type==NULL) { ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "push module: unable to allocate memory for content-type header while responding to subscriber request"); ngx_shmtx_unlock(&shpool->mutex); return NGX_ERROR; } } //preallocate output chain. yes, same one for every waiting subscriber if((chain = ngx_http_push_create_output_chain_locked(msg->buf, r->pool, r->connection->log, shpool))==NULL) { ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "push module: unable to allocate buffer chain while responding to subscriber request"); ngx_shmtx_unlock(&shpool->mutex); return NGX_ERROR; } last_modified = msg->message_time; if(msg->received!=NGX_MAX_UINT32_VALUE) { msg->received++; } //is the message still needed? if(msg!=NULL && (--msg->refcount)==0 && msg->queue.next==NULL) { //message was dequeued, and nobody needs it anymore ngx_http_push_free_message_locked(msg, shpool); } ngx_shmtx_unlock(&shpool->mutex); if(chain->buf->file!=NULL) { //close file when we're done with it ngx_pool_cleanup_t *cln; ngx_pool_cleanup_file_t *clnf; if((cln = ngx_pool_cleanup_add(r->pool, sizeof(ngx_pool_cleanup_file_t)))==NULL) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } cln->handler = ngx_pool_cleanup_file; clnf = cln->data; clnf->fd = chain->buf->file->fd; clnf->name = chain->buf->file->name.data; clnf->log = r->pool->log; } return ngx_http_push_prepare_response_to_subscriber_request(r, chain, content_type, etag, last_modified); default: //we shouldn't be here. return NGX_HTTP_INTERNAL_SERVER_ERROR; } }
static ngx_int_t ngx_http_push_subscriber_handler(ngx_http_request_t *r) { ngx_http_push_loc_conf_t *cf = ngx_http_get_module_loc_conf(r, ngx_http_push_module); ngx_slab_pool_t *shpool = (ngx_slab_pool_t *)ngx_http_push_shm_zone->shm.addr; ngx_str_t *id; ngx_http_push_channel_t *channel; ngx_http_push_msg_t *msg; ngx_int_t msg_search_outcome; ngx_str_t *content_type=NULL; ngx_str_t *etag; if (r->method == NGX_HTTP_OPTIONS) { ngx_buf_t *buf = ngx_create_temp_buf(r->pool, sizeof(NGX_HTTP_PUSH_OPTIONS_OK_MESSAGE)); ngx_chain_t *chain; buf->pos=(u_char *)NGX_HTTP_PUSH_OPTIONS_OK_MESSAGE; buf->last=buf->pos + sizeof(NGX_HTTP_PUSH_OPTIONS_OK_MESSAGE)-1; chain = ngx_http_push_create_output_chain(buf, r->pool, r->connection->log); buf->last_buf=1; r->headers_out.content_length_n=ngx_buf_size(buf); r->headers_out.status=NGX_HTTP_OK; ngx_http_send_header(r); ngx_http_output_filter(r, chain); return NGX_OK; } if (r->method != NGX_HTTP_GET) { ngx_http_push_add_response_header(r, &NGX_HTTP_PUSH_HEADER_ALLOW, &NGX_HTTP_PUSH_ALLOW_GET); //valid HTTP for the win return NGX_HTTP_NOT_ALLOWED; } if((id=ngx_http_push_get_channel_id(r, cf)) == NULL) { return r->headers_out.status ? NGX_OK : NGX_HTTP_INTERNAL_SERVER_ERROR; } //get the channel and check channel authorization while we're at it. ngx_shmtx_lock(&shpool->mutex); if (cf->authorize_channel==1) { channel = ngx_http_push_find_channel(id, r->connection->log); }else{ channel = ngx_http_push_get_channel(id, r->connection->log, cf->channel_timeout); } if (channel==NULL) { //unable to allocate channel OR channel not found ngx_shmtx_unlock(&shpool->mutex); if(cf->authorize_channel) { return NGX_HTTP_FORBIDDEN; } else { ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "push module: unable to allocate shared memory for channel"); return NGX_HTTP_INTERNAL_SERVER_ERROR; } } msg = ngx_http_push_find_message_locked(channel, r, &msg_search_outcome); channel->last_seen = ngx_time(); channel->expires = ngx_time() + cf->channel_timeout; ngx_shmtx_unlock(&shpool->mutex); if (cf->ignore_queue_on_no_cache && !ngx_http_push_allow_caching(r)) { msg_search_outcome = NGX_HTTP_PUSH_MESSAGE_EXPECTED; msg = NULL; } switch(ngx_http_push_handle_subscriber_concurrency(r, channel, cf)) { case NGX_DECLINED: //this request was declined for some reason. //status codes and whatnot should have already been written. just get out of here quickly. return NGX_OK; case NGX_ERROR: ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "push module: error handling subscriber concurrency setting"); return NGX_ERROR; } switch(msg_search_outcome) { //for message-found: ngx_chain_t *chain; time_t last_modified; size_t content_type_len; case NGX_HTTP_PUSH_MESSAGE_EXPECTED: // ♫ It's gonna be the future soon ♫ switch(cf->subscriber_poll_mechanism) { //for NGX_HTTP_PUSH_MECHANISM_LONGPOLL ngx_http_push_pid_queue_t *sentinel, *cur, *found; ngx_http_push_subscriber_t *subscriber; ngx_http_push_subscriber_t *subscriber_sentinel; case NGX_HTTP_PUSH_MECHANISM_LONGPOLL: //long-polling subscriber. wait for a message. //subscribers are queued up in a local pool. Queue sentinels are separate and also local, but not in the pool. ngx_shmtx_lock(&shpool->mutex); sentinel = &channel->workers_with_subscribers; cur = (ngx_http_push_pid_queue_t *)ngx_queue_head(&sentinel->queue); found = NULL; ngx_http_push_subscriber_cleanup_t *clndata; ngx_pool_cleanup_t *cln; while(cur!=sentinel) { if(cur->pid==ngx_pid) { found = cur; break; } cur = (ngx_http_push_pid_queue_t *)ngx_queue_next(&cur->queue); } if(found == NULL) { //found nothing if((found=ngx_http_push_slab_alloc_locked(sizeof(*found)))==NULL) { ngx_shmtx_unlock(&shpool->mutex); ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "push module: unable to allocate worker subscriber queue marker in shared memory"); return NGX_HTTP_INTERNAL_SERVER_ERROR; } //initialize ngx_queue_insert_tail(&sentinel->queue, &found->queue); found->pid=ngx_pid; found->slot=ngx_process_slot; found->subscriber_sentinel=NULL; } ngx_shmtx_unlock(&shpool->mutex); if((subscriber = ngx_palloc(ngx_http_push_pool, sizeof(*subscriber)))==NULL) { //unable to allocate request queue element return NGX_ERROR; } //attach a cleaner to remove the request from the channel. if ((cln=ngx_pool_cleanup_add(r->pool, sizeof(*clndata))) == NULL) { //make sure we can. return NGX_ERROR; } cln->handler = (ngx_pool_cleanup_pt) ngx_http_push_subscriber_cleanup; clndata = (ngx_http_push_subscriber_cleanup_t *) cln->data; clndata->channel=channel; clndata->subscriber=subscriber; subscriber->request = r; subscriber->clndata=clndata; ngx_shmtx_lock(&shpool->mutex); channel->subscribers++; // do this only when we know everything went okay. //figure out the subscriber sentinel subscriber_sentinel = ((ngx_http_push_pid_queue_t *)found)->subscriber_sentinel; if(subscriber_sentinel==NULL) { //it's perfectly nornal for the sentinel to be NULL. if((subscriber_sentinel=ngx_palloc(ngx_http_push_pool, sizeof(*subscriber_sentinel)))==NULL) { ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "push module: unable to allocate channel subscriber sentinel"); return NGX_HTTP_INTERNAL_SERVER_ERROR; } ngx_queue_init(&subscriber_sentinel->queue); ((ngx_http_push_pid_queue_t *)found)->subscriber_sentinel=subscriber_sentinel; } ngx_shmtx_unlock(&shpool->mutex); ngx_queue_insert_tail(&subscriber_sentinel->queue, &subscriber->queue); ngx_memzero(&subscriber->event, sizeof(subscriber->event)); if (cf->subscriber_timeout > 0) { subscriber->event.handler = ngx_http_push_clean_timeouted_subscriber; subscriber->event.data = subscriber; subscriber->event.log = r->connection->log; ngx_add_timer(&subscriber->event, cf->subscriber_timeout * 1000); } //r->read_event_handler = ngx_http_test_reading; //r->write_event_handler = ngx_http_request_empty_handler; r->discard_body = 1; //r->keepalive = 1; //stayin' alive!! return NGX_DONE; case NGX_HTTP_PUSH_MECHANISM_INTERVALPOLL: //interval-polling subscriber requests get a 304 with their entity tags preserved. if (r->headers_in.if_modified_since != NULL) { r->headers_out.last_modified_time=ngx_http_parse_time(r->headers_in.if_modified_since->value.data, r->headers_in.if_modified_since->value.len); } if ((etag=ngx_http_push_subscriber_get_etag(r)) != NULL) { r->headers_out.etag=ngx_http_push_add_response_header(r, &NGX_HTTP_PUSH_HEADER_ETAG, etag); } return NGX_HTTP_NOT_MODIFIED; default: //if this ever happens, there's a bug somewhere else. probably config stuff. return NGX_HTTP_INTERNAL_SERVER_ERROR; } case NGX_HTTP_PUSH_MESSAGE_EXPIRED: //subscriber wants an expired message //TODO: maybe respond with entity-identifiers for oldest available message? return NGX_HTTP_NO_CONTENT; case NGX_HTTP_PUSH_MESSAGE_FOUND: //found the message ngx_shmtx_lock(&shpool->mutex); ngx_http_push_reserve_message_locked(channel, msg); NGX_HTTP_PUSH_MAKE_ETAG(msg->message_tag, etag, ngx_palloc, r->pool); if(etag==NULL) { //oh, nevermind... ngx_shmtx_unlock(&shpool->mutex); ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "push module: unable to allocate memory for Etag header"); return NGX_ERROR; } content_type_len = msg->content_type.len; if(content_type_len>0) { NGX_HTTP_PUSH_MAKE_CONTENT_TYPE(content_type, content_type_len, msg, r->pool); if(content_type==NULL) { ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "push module: unable to allocate memory for content-type header while responding to subscriber request"); ngx_shmtx_unlock(&shpool->mutex); return NGX_ERROR; } } //preallocate output chain. yes, same one for every waiting subscriber if((chain = ngx_http_push_create_output_chain_locked(msg->buf, r->pool, r->connection->log, shpool))==NULL) { ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "push module: unable to allocate buffer chain while responding to subscriber request"); ngx_shmtx_unlock(&shpool->mutex); return NGX_ERROR; } last_modified = msg->message_time; //is the message still needed? ngx_http_push_release_message_locked(channel, msg); ngx_shmtx_unlock(&shpool->mutex); if(chain->buf->file!=NULL) { //close file when we're done with it ngx_pool_cleanup_t *cln; ngx_pool_cleanup_file_t *clnf; if((cln = ngx_pool_cleanup_add(r->pool, sizeof(ngx_pool_cleanup_file_t)))==NULL) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } cln->handler = ngx_pool_cleanup_file; clnf = cln->data; clnf->fd = chain->buf->file->fd; clnf->name = chain->buf->file->name.data; clnf->log = r->pool->log; } return ngx_http_push_prepare_response_to_subscriber_request(r, chain, content_type, etag, last_modified); default: //we shouldn't be here. return NGX_HTTP_INTERNAL_SERVER_ERROR; } }