webkitgtk-2.16.5HEADwebkitgtk-2.16.5master

1 files changed, 156 insertions, 0 deletions

diff --git a/Source/WebInspectorUI/UserInterface/Base/YieldableTask.js b/Source/WebInspectorUI/UserInterface/Base/YieldableTask.js
new file mode 100644
index 000000000..e7ceb5119
--- /dev/null
+++ b/Source/WebInspectorUI/UserInterface/Base/YieldableTask.js
@@ -0,0 +1,156 @@
+/*
+ * Copyright (C) 2016 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+ * THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+WebInspector.YieldableTask = class YieldableTask extends WebInspector.Object
+{
+    constructor(delegate, items, options={})
+    {
+        super();
+
+        let {workInterval, idleInterval} = options;
+        console.assert(!workInterval || workInterval > 0, workInterval);
+        console.assert(!idleInterval || idleInterval > 0, idleInterval);
+
+        console.assert(delegate && typeof delegate.yieldableTaskWillProcessItem === "function", "Delegate provide an implementation of method 'yieldableTaskWillProcessItem'.");
+
+        console.assert(items instanceof Object && Symbol.iterator in items, "Argument `items` must subclass Object and be iterable.", items);
+
+        // Milliseconds to run before the task should yield.
+        this._workInterval = workInterval || 10;
+        // Milliseconds to idle before asynchronously resuming the task.
+        this._idleInterval = idleInterval || 0;
+
+        this._delegate = delegate;
+
+        this._items = items;
+        this._idleTimeoutIdentifier = undefined;
+        this._processing = false;
+        this._processing = false;
+        this._cancelled = false;
+    }
+
+    // Public
+
+    get processing() { return this._processing; }
+    get cancelled() { return this._cancelled; }
+
+    get idleInterval() { return this._idleInterval; }
+    get workInterval() { return this._workInterval; }
+
+    start()
+    {
+        console.assert(!this._processing);
+        if (this._processing)
+            return;
+
+        console.assert(!this._cancelled);
+        if (this._cancelled)
+            return;
+
+        function* createIteratorForProcessingItems()
+        {
+            let startTime = Date.now();
+            let processedItems = [];
+
+            for (let item of this._items) {
+                if (this._cancelled)
+                    break;
+
+                this._delegate.yieldableTaskWillProcessItem(this, item);
+                processedItems.push(item);
+
+                // Calling out to the delegate may cause the task to be cancelled.
+                if (this._cancelled)
+                    break;
+
+                let elapsedTime = Date.now() - startTime;
+                if (elapsedTime > this._workInterval) {
+                    let returnedItems = processedItems.slice();
+                    processedItems = [];
+                    this._willYield(returnedItems, elapsedTime);
+
+                    yield;
+
+                    startTime = Date.now();
+                }
+            }
+
+            // The task sends a fake yield notification to the delegate so that
+            // the delegate receives notification of all processed items before finishing.
+            if (processedItems.length)
+                this._willYield(processedItems, Date.now() - startTime);
+        }
+
+        this._processing = true;
+        this._pendingItemsIterator = createIteratorForProcessingItems.call(this);
+        this._processPendingItems();
+    }
+
+    cancel()
+    {
+        if (!this._processing)
+            return;
+
+        this._cancelled = true;
+    }
+
+    // Private
+
+    _processPendingItems()
+    {
+        console.assert(this._processing);
+
+        if (this._cancelled)
+            return;
+
+        if (!this._pendingItemsIterator.next().done) {
+            this._idleTimeoutIdentifier = setTimeout(() => { this._processPendingItems(); }, this._idleInterval);
+            return;
+        }
+
+        this._didFinish();
+    }
+
+    _willYield(processedItems, elapsedTime)
+    {
+        if (typeof this._delegate.yieldableTaskDidYield === "function")
+            this._delegate.yieldableTaskDidYield(this, processedItems, elapsedTime);
+    }
+
+    _didFinish()
+    {
+        this._processing = false;
+        this._pendingItemsIterator = null;
+
+        if (this._idleTimeoutIdentifier) {
+            clearTimeout(this._idleTimeoutIdentifier);
+            this._idleTimeoutIdentifier = undefined;
+        }
+
+        if (typeof this._delegate.yieldableTaskDidFinish === "function")
+            this._delegate.yieldableTaskDidFinish(this);
+    }
+};
+