Pomelo's push mechanism (channel) and Source code interpretation

Originally from: http://blog.csdn.net/xufeng0991/article/details/45499665

Respect the original, reproduced please indicate the source, thank you!

Pomelo is NetEase open source server architecture, the type of communication is divided into four kinds: request, response, notify, push.

The first two types are implemented using Pomelo.request, notify is implemented by Pomelo.notify, here only see how push is implemented.

A channelservicechannelservice is created by the Pomelo default loading component channel. You can use the following methods to obtain:

App.get (' Channelservice ');

The following common methods are available in Channelservice:
1 CreateChannel (name); Name:channel Name
Creates a channel with the specified name.

ChannelService.prototype.createChannel = function (name) {    if (This.channels[name]) {        return this.channels[ Name];    }    var c = new Channel (name, this);    This.channels[name] = C;    return c;};

2 Getchannel (name, create); Name:channel name
Create: If not present, creates
Gets a channel that specifies the user name, if Create is true, does not exist creates one.

ChannelService.prototype.getChannel = function (name, create) {    var channel = This.channels[name];    if (!channel &&!!) Create) {        channel = this.channels[name] = new Channel (name, this);    }    return channel;};

3 Destroychannel (name); Name:channel Name
Use name to destroy a specified channel.

ChannelService.prototype.destroyChannel = function (name) {    delete this.channels[name];};

4 Pushmessagebyuids (Route, MSG, UIDs, opts, CB); route: routing of the front-end message listener method
MSG: message content sent to the front end
UIDs: Message Recipient {
Uid:userid,
Sid:frontendserverid
}，
UID is session.bind (UID);
of the specified
OPTs: Optional Custom parameters
Cb:callback method
Pushes a message to the specified UID.

ChannelService.prototype.pushMessageByUids = function (route, MSG, UIDs, opts, CB) {    if (typeof Route!== ' string ') {
   CB = opts;        opts = UIDs;        UIDs = msg;        msg = route;        route = Msg.route;    }    if (!CB && typeof opts = = = ' function ') {        cb = opts;        opts = {};    }    if (!uids | | uids.length = = 0) {        utils.invokecallback (CB, New Error (' UIDs should not is empty '));        return;    }    var groups = {},        record;    for (var i = 0, L = uids.length; i < L; i++) {        record = uids[i];        Add (Record.uid, record.sid, groups);    }    Sendmessagebygroup (this, route, MSG, groups, opts, CB);};

5 Broadcast (Stype, Route, MSG, opts, CB) Stype: Front End server type
Route: Routing of the front-end message listener method
MSG: message content sent to the front end
OPTs: Optional Custom parameters
Cb:callback method
Pushes a message to all the linker on the specified server.

ChannelService.prototype.broadcast = function (stype, route, MSG, opts, CB) {var app = This.app;    var namespace = ' sys ';    var service = ' channelremote ';    var method = ' broadcast ';    var servers = App.getserversbytype (stype);        if (!servers | | servers.length = = = 0) {//server list is empty utils.invokecallback (CB);    Return    } var count = Servers.length;    var successflag = false; var latch = Countdownlatch.createcountdownlatch (count, function () {if (!successflag) {Utils.invokecall            Back (CB, New Error (' broadcast fails '));        Return    } utils.invokecallback (CB, NULL);    });  var GENCB = function () {return function (err) {if (err) {Logger.error (' [broadcast] fail                To push message, err: ' + err.stack);                Latch.done ();            Return            } Successflag = true;        Latch.done ();    };    };   opts = {type: ' broadcast ',     useroptions:opts | |    {}    };    For compatiblity opts.isbroadcast = true;        if (opts.useroptions) {opts.binded = opts.userOptions.binded;    Opts.filterparam = Opts.userOptions.filterParam;            } for (var i = 0, L = count; i < L; i++) {App.rpcinvoke (servers[i].id, {namespace:namespace,    Service:service, Method:method, args: [Route, MSG, opts]}, GENCB ()); }};

The second channel above is the Channelservice object provides some way to operate the channel, the following is the method of the channel object.
1 Add (UID, sid) UID: UID for front-end connection
SID: The server ID to which the front-end is connected
Adds the UID to the channel.

Channel.prototype.add = function (uid, sid) {    if (This.state > st_inited) {        return false;    } else {        var r ES = Add (uid, sid, This.groups);        if (res) {            This.records[uid] = {                Sid:sid,                uid:uid            };        }        return res;    }};

2 Leave (UID, sid) UID: UID of the user
SID: The server ID to which the front-end is connected
Removes the UID from the channel.

Channel.prototype.leave = function (uid, sid) {    if (!uid | |!sid) {        return false;    }    Delete This.records[uid];    var res = deletefrom (uid, sid, This.groups[sid]);    if (This.groups[sid] && this.groups[sid].length = = = 0) {        delete this.groups[sid];    }    return res;};

3 GetMembers () gets all the users in the current channel.

Channel.prototype.getMembers = function () {    var res = [],        groups = this.groups;    Var group, I, L;    for (var sid in groups) {        group = Groups[sid];        for (i = 0, L = group.length; i < L; i++) {            res.push (group[i]);        }    }    return res;};

4 GetMember (UID) UID: uid of the user
Gets the UID of the specified user.

Channel.prototype.getMember = function (UID) {    return this.records[uid];};

5 Destroy () Destroy channel.

Channel.prototype.destroy = function () {    this.state = st_destroyed;    This.__channelservice__.destroychannel (this.name);};

6 Pushmessage (Route, MSG, opts, CB) Route: The route of the front-end message listener method
MSG: message content sent to the front end
OPTs: Optional Custom parameters
Cb:callback method
Pushes messages to all users in the current channel.

Channel.prototype.pushMessage = function (route, MSG, opts, CB) {    if (this.state!== st_inited) {        Utils.invokecallback (New Error (' channel is not running now ');        return;    }    if (typeof Route!== ' string ') {        cb = opts;        opts = msg;        msg = route;        route = Msg.route;    }    if (!CB && typeof opts = = = ' function ') {        cb = opts;        opts = {};    }    Sendmessagebygroup (this.__channelservice__, Route, MSG, This.groups, opts, CB);};

Three summary from the methods provided above, it can be seen that there are two ways to achieve push:
1 Anonymous channel is no need to create channel, directly using Channelservice.pushmessagebyuids and channelservice.broadcast push;
Example:

var uidarray = new Array (); uidobject.uid = "Session uid"; uidobject.sid = "Connector-server-1"; Uidarray.push (Uidobject); Channelservice.pushmessagebyuids (' onmsg ', {    msg:msg}, Uidarray, function (err) {    if (err) {        Console.log ( ERR);        return;}    ); Channelservice.broadcast (' connector ', ' onmsg ', msg, {    binded:true}, function (err) {    if (err)        { Console.log (err);    }});

2 Explicit channel requires the use of Channel.createchannel or Channel.getchannel to obtain a channel first and then push with Chanel.pushmessage.
Example:

Create Channelvar channelname = ' Allpushchannel '; var channel = this.channelservice.getchannel//Add the user to the channel inside if (!!) Channel) {    channel.add (uid, sid);} Push message according to channel name var channelname = ' Allpushchannel '; var pushchannel = This.channelService.getChannel (ChannelName, False);p ushchannel.pushmessage (' onmsg ', {    msg:msg}, function (err) {    if (err) {        console.log (err);    } else {        Console.log (' push ok ');}    });

Reference
Official api:http://pomelo.netease.com/api.html
Cnodejs:https://cnodejs.org/topic/51b531bef78196a85c4f0c89

Pomelo's push mechanism (channel) and Source code interpretation