Modify PackateQueue to let auth request go first and other request go last

[XadillaX]

See code below:

const client = ...;

client.addAuthInfo(...);
client.getData(...);

client.connect();

getData's command will be at the first position of the queue array and auth command will be the second.

Because getData will push to queue immediately but addAuthInfo will push after connected.

ConnectionManager.prototype.addAuthInfo = function(scheme, auth) {
    // ...
    switch(this.state) {
    // ...
    case STATES.DISCONNECTED:
        return;
    }
};

ConnectionManager.prototype.onSocketConnected = function() {
    if(this. credentials.length > 0) {
        // ...
        this.queue.push(...);
    }
};

Client.prototype.getData = function(path, watcher, callback) {
    // ...
    self.connectionManager.queue(...);
};

So I modify PacketQueue.prototype.push to let auth request go the first.

[XadillaX]

Anyone to review this?

[alexguan]

I will take a look this weekend

[XadillaX]

So how's the result?

[alexguan]

In what scenario you will call getData before the connection is established?

[XadillaX]

@alexguan Sorry but I forgot the reason because it takes a long time. Maybe reconnecting?

[subashcs]

This PR looks good. This is a much-needed PR for situations when there are multiple watchers receiving data and suddenly authentication fails due to any reason. To reinitiate the authentication zookeeper initiates another auth request. Since the auth request is not prioritized in the queue, the other requests initiated by the watchers fail until the authentication request passes.

[alexguan]

Sorry for the long delay, can someone bump up the version and changelog like this PR and I will merge it.

[subashcs]

@alexguan Are we supposed to create a new PR for the version bump?