Moved PooledClass and improved js1 upgrade react

Reviewed By: gaearon

Differential Revision: D6136816

fbshipit-source-id: fca775786cf4f1717509d9bfeb0f789cc6a99e4e

Libraries/Components/Touchable/PooledClass.js

@@ -0,0 +1,121 @@
+/**
+ * Copyright (c) 2013-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @providesModule PooledClass
+ * @flow
+ */
+
+'use strict';
+
+var invariant = require('fbjs/lib/invariant');
+
+/**
+ * Static poolers. Several custom versions for each potential number of
+ * arguments. A completely generic pooler is easy to implement, but would
+ * require accessing the `arguments` object. In each of these, `this` refers to
+ * the Class itself, not an instance. If any others are needed, simply add them
+ * here, or in their own files.
+ */
+var oneArgumentPooler = function(copyFieldsFrom) {
+  var Klass = this;
+  if (Klass.instancePool.length) {
+    var instance = Klass.instancePool.pop();
+    Klass.call(instance, copyFieldsFrom);
+    return instance;
+  } else {
+    return new Klass(copyFieldsFrom);
+  }
+};
+
+var twoArgumentPooler = function(a1, a2) {
+  var Klass = this;
+  if (Klass.instancePool.length) {
+    var instance = Klass.instancePool.pop();
+    Klass.call(instance, a1, a2);
+    return instance;
+  } else {
+    return new Klass(a1, a2);
+  }
+};
+
+var threeArgumentPooler = function(a1, a2, a3) {
+  var Klass = this;
+  if (Klass.instancePool.length) {
+    var instance = Klass.instancePool.pop();
+    Klass.call(instance, a1, a2, a3);
+    return instance;
+  } else {
+    return new Klass(a1, a2, a3);
+  }
+};
+
+var fourArgumentPooler = function(a1, a2, a3, a4) {
+  var Klass = this;
+  if (Klass.instancePool.length) {
+    var instance = Klass.instancePool.pop();
+    Klass.call(instance, a1, a2, a3, a4);
+    return instance;
+  } else {
+    return new Klass(a1, a2, a3, a4);
+  }
+};
+
+var standardReleaser = function(instance) {
+  var Klass = this;
+  invariant(
+    instance instanceof Klass,
+    'Trying to release an instance into a pool of a different type.',
+  );
+  instance.destructor();
+  if (Klass.instancePool.length < Klass.poolSize) {
+    Klass.instancePool.push(instance);
+  }
+};
+
+var DEFAULT_POOL_SIZE = 10;
+var DEFAULT_POOLER = oneArgumentPooler;
+
+type Pooler = any;
+
+/**
+ * Augments `CopyConstructor` to be a poolable class, augmenting only the class
+ * itself (statically) not adding any prototypical fields. Any CopyConstructor
+ * you give this may have a `poolSize` property, and will look for a
+ * prototypical `destructor` on instances.
+ *
+ * @param {Function} CopyConstructor Constructor that can be used to reset.
+ * @param {Function} pooler Customizable pooler.
+ */
+var addPoolingTo = function<T>(
+  CopyConstructor: Class<T>,
+  pooler: Pooler,
+): Class<T> & {
+  getPooled(
+    ...args: $ReadOnlyArray<mixed>
+  ): /* arguments of the constructor */ T,
+  release(instance: mixed): void,
+} {
+  // Casting as any so that flow ignores the actual implementation and trusts
+  // it to match the type we declared
+  var NewKlass = (CopyConstructor: any);
+  NewKlass.instancePool = [];
+  NewKlass.getPooled = pooler || DEFAULT_POOLER;
+  if (!NewKlass.poolSize) {
+    NewKlass.poolSize = DEFAULT_POOL_SIZE;
+  }
+  NewKlass.release = standardReleaser;
+  return NewKlass;
+};
+
+var PooledClass = {
+  addPoolingTo: addPoolingTo,
+  oneArgumentPooler: (oneArgumentPooler: Pooler),
+  twoArgumentPooler: (twoArgumentPooler: Pooler),
+  threeArgumentPooler: (threeArgumentPooler: Pooler),
+  fourArgumentPooler: (fourArgumentPooler: Pooler),
+};
+
+module.exports = PooledClass;