1 files changed, 112 insertions, 0 deletions
diff --git a/Source/WebInspectorUI/UserInterface/Base/LinkedList.js b/Source/WebInspectorUI/UserInterface/Base/LinkedList.js
new file mode 100644
index 000000000..f9978af42
--- /dev/null
+++ b/Source/WebInspectorUI/UserInterface/Base/LinkedList.js
@@ -0,0 +1,112 @@
+/*
+ * 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.
+ */
+
+class LinkedList
+{
+    constructor()
+    {
+        this.head = new LinkedListNode;
+        this.head.next = this.head.prev = this.head;
+        this.length = 0;
+    }
+
+    clear()
+    {
+        this.head.next = this.head.prev = this.head;
+        this.length = 0;
+    }
+
+    get last()
+    {
+        return this.head.prev;
+    }
+
+    push(item)
+    {
+        let newNode = new LinkedListNode(item);
+        let last = this.last;
+        let head = this.head;
+
+        last.next = newNode;
+        newNode.next = head;
+        head.prev = newNode;
+        newNode.prev = last;
+
+        this.length++;
+
+        return newNode;
+    }
+
+    remove(node)
+    {
+        if (!node)
+            return false;
+
+        node.prev.next = node.next;
+        node.next.prev = node.prev;
+
+        this.length--;
+        return true;
+    }
+
+    forEach(callback)
+    {
+        let node = this.head;
+        for (let i = 0, length = this.length; i < length; i++) {
+            node = node.next;
+            let returnValue = callback(node.value, i);
+            if (returnValue === false)
+                return;
+        }
+    }
+
+    toArray()
+    {
+        let node = this.head;
+        let i = this.length;
+        let result = new Array(i);
+        while (i--) {
+            node = node.prev;
+            result[i] = node.value;
+        }
+        return result;
+    }
+
+    toJSON()
+    {
+        return this.toArray();
+    }
+}
+
+
+class LinkedListNode
+{
+    constructor(value)
+    {
+        this.value = value;
+        this.prev = null;
+        this.next = null;
+    }
+}