node-postgres/lib/native/index.js
2014-09-14 01:23:02 -04:00

117 lines
2.9 KiB
JavaScript

var Native = require('pg-native');
var EventEmitter = require('events').EventEmitter;
var util = require('util');
var ConnectionParameters = require(__dirname + '/../connection-parameters');
var NativeQuery = require('./query');
var Client = module.exports = function(config) {
EventEmitter.call(this);
if(typeof config === 'string') {
this.connectionString = config;
}
this.native = new Native();
this._queryQueue = [];
this._connected = false;
//keep these on the object for legacy reasons
//for the time being. TODO: deprecate all this jazz
var cp = new ConnectionParameters(config);
this.user = cp.user;
this.password = cp.password;
this.database = cp.database;
this.host = cp.host;
this.port = cp.port;
};
util.inherits(Client, EventEmitter);
//connect to the backend
//pass an optional callback to be called once connected
//or with an error if there was a connection error
//if no callback is passed and there is a connection error
//the client will emit an error event.
Client.prototype.connect = function(cb) {
var self = this;
this.native.connect(this.connectionString, function(err) {
//error handling
if(err) {
if(cb) return cb(err);
return self.emit('error', err);
}
//set internal states to connected
self._connected = true;
self.emit('connect');
self._pulseQueryQueue(true);
//possibly call the optional callback
if(cb) cb();
});
};
Client.prototype.query = function(config, values, callback) {
var query = new NativeQuery(this.native);
//support query('text', ...) style calls
if(typeof config == 'string') {
query.text = config;
}
//support passing everything in via a config object
if(typeof config == 'object') {
query.text = config.text;
query.values = config.values;
query.name = config.name;
query.callback = config.callback;
}
//support query({...}, function() {}) style calls
//& support query(..., ['values'], ...) style calls
if(typeof values == 'function') {
query.callback = values;
}
else if(util.isArray(values)) {
query.values = values;
}
if(typeof callback == 'function') {
query.callback = callback;
}
this._queryQueue.push(query);
this._pulseQueryQueue();
return query;
};
Client.prototype.end = function(cb) {
var self = this;
this.native.end(function() {
self.emit('end');
if(cb) cb();
});
};
Client.prototype._pulseQueryQueue = function(initialConnection) {
if(!this._connected) {
return;
}
if(this._activeQuery) {
if(this._activeQuery.state != 'error' && this._activeQuery.state != 'end') {
return;
}
}
var query = this._queryQueue.shift();
if(!query) {
if(!initialConnection) {
this.emit('drain');
}
return;
}
this._activeQuery = query;
query.submit();
var self = this;
query.once('_done', function() {
self._pulseQueryQueue();
});
};