api: floaty

common/src/main/java/com/stardust/concurrent/ConcurrentArrayList.java

@@ -0,0 +1,62 @@
+package com.stardust.concurrent;
+
+import java.lang.reflect.Array;
+import java.util.concurrent.atomic.AtomicInteger;
+
+/**
+ * Created by Stardust on 2017/12/30.
+ */
+
+public class ConcurrentArrayList<T> {
+
+    private final Class<T> mTClass;
+    private volatile T[] mArray;
+    private final AtomicInteger mSize = new AtomicInteger();
+    private final Object mArrayResizeLock = mSize;
+
+    public ConcurrentArrayList(Class<T> tClass) {
+        mTClass = tClass;
+        mArray = newArray(10);
+    }
+
+    public void add(T element) {
+        int index = mSize.getAndIncrement();
+        ensureCapacity(index);
+        mArray[index] = element;
+    }
+
+    @SuppressWarnings("unchecked")
+    public T get(int i) {
+        int size = mSize.get();
+        if (i >= size) {
+            throw new IndexOutOfBoundsException("i = " + i + ", size = " + size);
+        }
+        return mArray[i];
+    }
+
+    public int size() {
+        return mSize.get();
+    }
+
+    public Object getArrayResizeLock() {
+        return mArrayResizeLock;
+    }
+
+    @SuppressWarnings("unchecked")
+    private T[] newArray(int size) {
+        return (T[]) Array.newInstance(mTClass, size);
+    }
+
+    private void ensureCapacity(int index) {
+        if (index < mArray.length)
+            return;
+        synchronized (mArrayResizeLock) {
+            if (index < mArray.length)
+                return;
+            T[] newArray = newArray(mArray.length * 2);
+            System.arraycopy(mArray, 0, newArray, 0, mArray.length);
+            mArray = newArray;
+        }
+    }
+
+}