91 lines
2.3 KiB
JavaScript
91 lines
2.3 KiB
JavaScript
var url = require('url');
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var events = require('events');
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var sys = require('sys');
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if(typeof events.EventEmitter.prototype.once !== 'function') {
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events.EventEmitter.prototype.once = function (type, listener) {
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var self = this;
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self.on(type, function g () {
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self.removeListener(type, g);
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listener.apply(this, arguments);
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});
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};
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}
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var Pool = function(maxSize, createFn) {
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events.EventEmitter.call(this);
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this.maxSize = maxSize;
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this.createFn = createFn;
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this.items = [];
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this.waits = [];
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}
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sys.inherits(Pool, events.EventEmitter);
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var p = Pool.prototype;
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p.checkOut = function(callback) {
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var len = 0;
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for(var i = 0, len = this.items.length; i < len; i++) {
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var item = this.items[i];
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if(item.checkedIn) {
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return this._pulse(item, callback);
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}
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}
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//check if we can create a new item
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if(this.items.length < this.maxSize && this.createFn) {
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var result = this.createFn();
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var item = result;
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//create function can return item conforming to interface
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//of stored items to allow for create function to create
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//checked out items
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if(typeof item.checkedIn == "undefined") {
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var item = {ref: result, checkedIn: true}
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}
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this.items.push(item);
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if(item.checkedIn) {
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return this._pulse(item, callback)
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}
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}
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this.waits.push(callback);
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return false; //did not execute sync
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}
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p.checkIn = function(item) {
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//scan current items
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for(var i = 0, len = this.items.length; i < len; i++) {
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var currentItem = this.items[i];
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if(currentItem.ref == item) {
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currentItem.checkedIn = true;
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this._pulse(currentItem);
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return true;
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}
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}
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//add new item
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var newItem = {ref: item, checkedIn: true};
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this.items.push(newItem);
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this._pulse(newItem);
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return false;
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}
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p._pulse = function(item, cb) {
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cb = cb || this.waits.shift()
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if(cb) {
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item.checkedIn = false;
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cb(null, item.ref)
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return true;
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}
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return false;
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}
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module.exports = {
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Pool: Pool,
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parseConnectionString: function(str) {
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var result = url.parse(str);
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result.host = result.hostname;
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result.database = result.pathname ? result.pathname.slice(1) : null
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var auth = (result.auth || ':').split(':');
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result.user = auth[0];
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result.password = auth[1];
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return result;
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}
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}
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