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Diffstat (limited to 'node_modules/setimmediate/setImmediate.js')
| -rw-r--r-- | node_modules/setimmediate/setImmediate.js | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/node_modules/setimmediate/setImmediate.js b/node_modules/setimmediate/setImmediate.js new file mode 100644 index 0000000..3c1b06e --- /dev/null +++ b/node_modules/setimmediate/setImmediate.js @@ -0,0 +1,186 @@ +(function (global, undefined) { + "use strict"; + + if (global.setImmediate) { + return; + } + + var nextHandle = 1; // Spec says greater than zero + var tasksByHandle = {}; + var currentlyRunningATask = false; + var doc = global.document; + var registerImmediate; + + function setImmediate(callback) { + // Callback can either be a function or a string + if (typeof callback !== "function") { + callback = new Function("" + callback); + } + // Copy function arguments + var args = new Array(arguments.length - 1); + for (var i = 0; i < args.length; i++) { + args[i] = arguments[i + 1]; + } + // Store and register the task + var task = { callback: callback, args: args }; + tasksByHandle[nextHandle] = task; + registerImmediate(nextHandle); + return nextHandle++; + } + + function clearImmediate(handle) { + delete tasksByHandle[handle]; + } + + function run(task) { + var callback = task.callback; + var args = task.args; + switch (args.length) { + case 0: + callback(); + break; + case 1: + callback(args[0]); + break; + case 2: + callback(args[0], args[1]); + break; + case 3: + callback(args[0], args[1], args[2]); + break; + default: + callback.apply(undefined, args); + break; + } + } + + function runIfPresent(handle) { + // From the spec: "Wait until any invocations of this algorithm started before this one have completed." + // So if we're currently running a task, we'll need to delay this invocation. + if (currentlyRunningATask) { + // Delay by doing a setTimeout. setImmediate was tried instead, but in Firefox 7 it generated a + // "too much recursion" error. + setTimeout(runIfPresent, 0, handle); + } else { + var task = tasksByHandle[handle]; + if (task) { + currentlyRunningATask = true; + try { + run(task); + } finally { + clearImmediate(handle); + currentlyRunningATask = false; + } + } + } + } + + function installNextTickImplementation() { + registerImmediate = function(handle) { + process.nextTick(function () { runIfPresent(handle); }); + }; + } + + function canUsePostMessage() { + // The test against `importScripts` prevents this implementation from being installed inside a web worker, + // where `global.postMessage` means something completely different and can't be used for this purpose. + if (global.postMessage && !global.importScripts) { + var postMessageIsAsynchronous = true; + var oldOnMessage = global.onmessage; + global.onmessage = function() { + postMessageIsAsynchronous = false; + }; + global.postMessage("", "*"); + global.onmessage = oldOnMessage; + return postMessageIsAsynchronous; + } + } + + function installPostMessageImplementation() { + // Installs an event handler on `global` for the `message` event: see + // * https://developer.mozilla.org/en/DOM/window.postMessage + // * http://www.whatwg.org/specs/web-apps/current-work/multipage/comms.html#crossDocumentMessages + + var messagePrefix = "setImmediate$" + Math.random() + "$"; + var onGlobalMessage = function(event) { + if (event.source === global && + typeof event.data === "string" && + event.data.indexOf(messagePrefix) === 0) { + runIfPresent(+event.data.slice(messagePrefix.length)); + } + }; + + if (global.addEventListener) { + global.addEventListener("message", onGlobalMessage, false); + } else { + global.attachEvent("onmessage", onGlobalMessage); + } + + registerImmediate = function(handle) { + global.postMessage(messagePrefix + handle, "*"); + }; + } + + function installMessageChannelImplementation() { + var channel = new MessageChannel(); + channel.port1.onmessage = function(event) { + var handle = event.data; + runIfPresent(handle); + }; + + registerImmediate = function(handle) { + channel.port2.postMessage(handle); + }; + } + + function installReadyStateChangeImplementation() { + var html = doc.documentElement; + registerImmediate = function(handle) { + // Create a <script> element; its readystatechange event will be fired asynchronously once it is inserted + // into the document. Do so, thus queuing up the task. Remember to clean up once it's been called. + var script = doc.createElement("script"); + script.onreadystatechange = function () { + runIfPresent(handle); + script.onreadystatechange = null; + html.removeChild(script); + script = null; + }; + html.appendChild(script); + }; + } + + function installSetTimeoutImplementation() { + registerImmediate = function(handle) { + setTimeout(runIfPresent, 0, handle); + }; + } + + // If supported, we should attach to the prototype of global, since that is where setTimeout et al. live. + var attachTo = Object.getPrototypeOf && Object.getPrototypeOf(global); + attachTo = attachTo && attachTo.setTimeout ? attachTo : global; + + // Don't get fooled by e.g. browserify environments. + if ({}.toString.call(global.process) === "[object process]") { + // For Node.js before 0.9 + installNextTickImplementation(); + + } else if (canUsePostMessage()) { + // For non-IE10 modern browsers + installPostMessageImplementation(); + + } else if (global.MessageChannel) { + // For web workers, where supported + installMessageChannelImplementation(); + + } else if (doc && "onreadystatechange" in doc.createElement("script")) { + // For IE 6–8 + installReadyStateChangeImplementation(); + + } else { + // For older browsers + installSetTimeoutImplementation(); + } + + attachTo.setImmediate = setImmediate; + attachTo.clearImmediate = clearImmediate; +}(typeof self === "undefined" ? typeof global === "undefined" ? this : global : self)); |