icomet/src/comet/subscriber.cpp at dev · cccssw/icomet · GitHub

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#include "subscriber.h"
#include "channel.h"
#include "server.h"
#include "util/log.h"
#include "server_config.h"

static std::string iframe_header = "<html><head><meta http-equiv='Content-Type' content='text/html; charset=utf-8'><meta http-equiv='Cache-Control' content='no-store'><meta http-equiv='Cache-Control' content='no-cache'><meta http-equiv='Pragma' content='no-cache'><meta http-equiv=' Expires' content='Thu, 1 Jan 1970 00:00:00 GMT'><script type='text/javascript'>window.onError = null;try{ document.domain = (window.location.hostname.match(/^(d{1,3}.){3}d{1,3}$/)) ? window.location.hostname : window.location.hostname.split('.').slice(-2).join('.');}catch(e){};</script></head><body>";
static std::string iframe_chunk_prefix = "<script>parent.icomet_cb(";
static std::string iframe_chunk_suffix = ");</script>";

static void on_sub_disconnect(struct evhttp_connection *evcon, void *arg){
	log_debug("subscriber disconnected");
	Subscriber *sub = (Subscriber *)arg;
	Server *serv = sub->serv;
	serv->sub_end(sub);
}

void Subscriber::start(){
	evhttp_add_header(req->output_headers, "Connection", "keep-alive");
	//evhttp_add_header(req->output_headers, "Cache-Control", "no-cache");
	//evhttp_add_header(req->output_headers, "Expires", "0");
	evhttp_add_header(req->output_headers, "Content-Type", "text/html; charset=utf-8");

	evhttp_send_reply_start(req, HTTP_OK, "OK");
	evhttp_connection_set_closecb(req->evcon, on_sub_disconnect, this);

	if(this->type == POLL){
		//
	}else if(this->type == IFRAME){
		struct evbuffer *buf = evbuffer_new();
		evbuffer_add_printf(buf, "%s\n", iframe_header.c_str());
		evhttp_send_reply_chunk(this->req, buf);
		evbuffer_free(buf);
	}

	// send buffered messages
	if(!channel->msg_list.empty() && channel->seq_next != this->seq_next){
		this->send_old_msgs();
	}
}

void Subscriber::send_old_msgs(){
	std::vector<std::string>::iterator it = channel->msg_list.end();
	int msg_seq_min = channel->seq_next - channel->msg_list.size();
	if(Channel::SEQ_GT(this->seq_next, channel->seq_next) || Channel::SEQ_LT(this->seq_next, msg_seq_min)){
		this->seq_next = msg_seq_min;
	}
	log_debug("send old msg: [%d, %d]", this->seq_next, channel->seq_next - 1);
	it -= (channel->seq_next - this->seq_next);

	struct evbuffer *buf = evbuffer_new();
	if(this->type == POLL){
		if(!this->callback.empty()){
			evbuffer_add_printf(buf, "%s(", this->callback.c_str());
		}
		evbuffer_add_printf(buf, "[");
		for(/**/; it != channel->msg_list.end(); it++, this->seq_next++){
			std::string &msg = *it;
			evbuffer_add_printf(buf,
				"{\"type\":\"data\",\"cname\":\"%s\",\"seq\":%d,\"content\":\"%s\"}",
				this->channel->name.c_str(),
				this->seq_next,
				msg.c_str());
			if(this->seq_next != channel->seq_next - 1){
				evbuffer_add(buf, ",", 1);
			}
		}
		evbuffer_add_printf(buf, "]");
		if(!this->callback.empty()){
			evbuffer_add_printf(buf, ");");
		}
		evbuffer_add_printf(buf, "\n");
		evhttp_send_reply_chunk(this->req, buf);
		this->close();
	}else if(this->type == IFRAME || this->type == STREAM){
		for(/**/; it != channel->msg_list.end(); it++, this->seq_next++){
			std::string &msg = *it;
			this->send_chunk(this->seq_next, "data", msg.c_str());
		}
	}
	evbuffer_free(buf);
}

void Subscriber::close(){
	evhttp_send_reply_end(this->req);
	evhttp_connection_set_closecb(this->req->evcon, NULL, NULL);
	this->serv->sub_end(this);
}

void Subscriber::noop(){
	this->send_chunk(this->seq_noop, "noop", "");
}

void Subscriber::send_chunk(int seq, const char *type, const char *content){
	struct evbuffer *buf = evbuffer_new();

	if(this->type == POLL){
		if(!this->callback.empty()){
			evbuffer_add_printf(buf, "%s(", this->callback.c_str());
		}
	}else if(this->type == IFRAME){
		evbuffer_add_printf(buf, "%s", iframe_chunk_prefix.c_str());
	}

	evbuffer_add_printf(buf,
		"{\"type\":\"%s\",\"cname\":\"%s\",\"seq\":%d,\"content\":\"%s\"}",
		type,
		this->channel->name.c_str(),
		seq,
		content);

	if(this->type == POLL){
		if(!this->callback.empty()){
			evbuffer_add_printf(buf, ");");
		}
	}else if(this->type == IFRAME){
		evbuffer_add_printf(buf, "%s", iframe_chunk_suffix.c_str());
	}

	evbuffer_add_printf(buf, "\n");
	evhttp_send_reply_chunk(this->req, buf);
	evbuffer_free(buf);

	this->idle = 0;
	if(this->type == POLL){
		this->close();
	}
}

void Subscriber::send_error_reply(int sub_type, struct evhttp_request *req, const char *cb, const char *type, const char *content){
	struct evbuffer *buf = evbuffer_new();

	if(sub_type == POLL){
		evbuffer_add_printf(buf, "%s(", cb);
	}else if(sub_type == IFRAME){
		evbuffer_add_printf(buf, "%s", iframe_chunk_prefix.c_str());
	}

	evbuffer_add_printf(buf,
		"{\"type\":\"%s\",\"cname\":\"%s\",\"seq\":%d,\"content\":\"%s\"}",
		type,
		"",
		0,
		content);

	if(sub_type == POLL){
		evbuffer_add_printf(buf, ");");
	}else if(sub_type == IFRAME){
		evbuffer_add_printf(buf, "%s", iframe_chunk_suffix.c_str());
	}

	evbuffer_add_printf(buf, "\n");
	evhttp_send_reply(req, HTTP_OK, "OK", buf);
	evbuffer_free(buf);
}