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101 lines
3.1 KiB
JavaScript
101 lines
3.1 KiB
JavaScript
9 years ago
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'use strict';
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var inherits = require('util').inherits,
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EventEmitter = require('events').EventEmitter,
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debug = require('debug')('pool2');
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var _id = 0;
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// this has promisey semantics but can't really be replaced with a simple promise
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function ResourceRequest(timeout, callback) {
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if (typeof timeout === 'function') {
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callback = timeout;
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timeout = Infinity;
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}
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if (typeof callback !== 'function') {
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throw new Error('new ResourceRequest(): callback is required');
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}
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EventEmitter.call(this);
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this.id = _id++;
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this.ts = new Date();
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this.cb = callback;
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this.fulfilled = false;
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this.timer = null;
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debug('New ResourceRequest (id=%s, timeout=%s)', this.id, timeout);
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if (timeout !== Infinity) { this.setTimeout(timeout); }
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}
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inherits(ResourceRequest, EventEmitter);
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ResourceRequest.prototype.setTimeout = function (_duration) {
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if (_duration === Infinity) {
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debug('ResourceRequest: setTimeout called with Infinity: clearing timeout');
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this.clearTimeout();
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return;
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}
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var duration = parseInt(_duration, 10);
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if (isNaN(duration) || duration <= 0) {
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throw new Error('ResourceRequest.setTimeout(): invalid duration: ' + duration);
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}
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var now = new Date(),
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elapsed = now - this.ts;
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if (elapsed > duration) {
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setImmediate(this._rejectTimeout.bind(this));
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} else {
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this.timer = setTimeout(this._rejectTimeout.bind(this), duration - elapsed);
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}
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};
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ResourceRequest.prototype.clearTimeout = function () {
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debug('ResourceRequest: clearing timeout (id=%s)', this.id);
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clearTimeout(this.timer);
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this.timer = null;
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};
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ResourceRequest.prototype.resolve = function (res) {
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debug('ResourceRequest: resolve (id=%s)', this.id);
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this._fulfill(null, res);
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};
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ResourceRequest.prototype.reject = function (err) {
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debug('ResourceRequest: reject (id=%s)', this.id);
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this._fulfill(err);
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};
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ResourceRequest.prototype.abort = function (msg) {
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msg = msg || 'No reason given';
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debug('ResourceRequest: abort (id=%s)', this.id);
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this.reject(new Error('ResourceRequest aborted: ' + msg));
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};
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ResourceRequest.prototype._rejectTimeout = function () {
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debug('ResourceRequest: rejectTimeout (id=%s)', this.id);
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this.reject(new Error('ResourceRequest timed out'));
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};
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ResourceRequest.prototype._fulfill = function (err, res) {
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if (err !== null) {
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debug('ResourceRequest: fulfilling with error: %s (id=%s)', err.message, this.id);
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// ensure any error gets emitted
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this.emit('error', err);
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} else {
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debug('ResourceRequest: fulfilling with resource (id=%s)', this.id);
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}
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// if we've already fulfilled this request, don't try to do it again
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if (this.fulfilled) {
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debug('ResourceRequest: redundant fulfill, not calling callback (id=%s)', this.id);
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// but make sure somebody knows about it
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this.emit('error', new Error('ResourceRequest already fulfilled'));
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return;
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}
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this.fulfilled = true;
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this.clearTimeout();
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this.cb.apply(this, arguments);
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};
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module.exports = ResourceRequest;
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