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author | Bobby Georgescu <georgescu@google.com> | 2013-02-19 15:49:14 -0800 |
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committer | Bobby Georgescu <georgescu@google.com> | 2013-02-22 12:56:23 -0800 |
commit | 11cfeeddedd61d3c4aa40945fef0bc2d87c7559d (patch) | |
tree | ab09906b8fe29d40768210bbeb5fc16be4a87625 /src/android/util/Pools.java | |
parent | 0718d480a144ba0a44c07c48f90e85cf4ec669c6 (diff) | |
download | android_packages_apps_Snap-11cfeeddedd61d3c4aa40945fef0bc2d87c7559d.tar.gz android_packages_apps_Snap-11cfeeddedd61d3c4aa40945fef0bc2d87c7559d.tar.bz2 android_packages_apps_Snap-11cfeeddedd61d3c4aa40945fef0bc2d87c7559d.zip |
Replace various BitmapPools with a smarter unified pool
Make all of gallery use a single shared pool, and pave the
way for making the pool more adaptive based on the current
workload.
Change-Id: Ia32561ad50b1b9716ebe2fd32a7bf02737685dac
Diffstat (limited to 'src/android/util/Pools.java')
-rw-r--r-- | src/android/util/Pools.java | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/src/android/util/Pools.java b/src/android/util/Pools.java new file mode 100644 index 000000000..40bab1eae --- /dev/null +++ b/src/android/util/Pools.java @@ -0,0 +1,165 @@ +/* + * Copyright (C) 2009 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package android.util; + +/** + * Helper class for crating pools of objects. An example use looks like this: + * <pre> + * public class MyPooledClass { + * + * private static final SynchronizedPool<MyPooledClass> sPool = + * new SynchronizedPool<MyPooledClass>(10); + * + * public static MyPooledClass obtain() { + * MyPooledClass instance = sPool.acquire(); + * return (instance != null) ? instance : new MyPooledClass(); + * } + * + * public void recycle() { + * // Clear state if needed. + * sPool.release(this); + * } + * + * . . . + * } + * </pre> + * + * @hide + */ +public final class Pools { + + /** + * Interface for managing a pool of objects. + * + * @param <T> The pooled type. + */ + public static interface Pool<T> { + + /** + * @return An instance from the pool if such, null otherwise. + */ + public T acquire(); + + /** + * Release an instance to the pool. + * + * @param instance The instance to release. + * @return Whether the instance was put in the pool. + * + * @throws IllegalStateException If the instance is already in the pool. + */ + public boolean release(T instance); + } + + private Pools() { + /* do nothing - hiding constructor */ + } + + /** + * Simple (non-synchronized) pool of objects. + * + * @param <T> The pooled type. + */ + public static class SimplePool<T> implements Pool<T> { + private final Object[] mPool; + + private int mPoolSize; + + /** + * Creates a new instance. + * + * @param maxPoolSize The max pool size. + * + * @throws IllegalArgumentException If the max pool size is less than zero. + */ + public SimplePool(int maxPoolSize) { + if (maxPoolSize <= 0) { + throw new IllegalArgumentException("The max pool size must be > 0"); + } + mPool = new Object[maxPoolSize]; + } + + @Override + @SuppressWarnings("unchecked") + public T acquire() { + if (mPoolSize > 0) { + final int lastPooledIndex = mPoolSize - 1; + T instance = (T) mPool[lastPooledIndex]; + mPool[lastPooledIndex] = null; + mPoolSize--; + return instance; + } + return null; + } + + @Override + public boolean release(T instance) { + if (isInPool(instance)) { + throw new IllegalStateException("Already in the pool!"); + } + if (mPoolSize < mPool.length) { + mPool[mPoolSize] = instance; + mPoolSize++; + return true; + } + return false; + } + + private boolean isInPool(T instance) { + for (int i = 0; i < mPoolSize; i++) { + if (mPool[i] == instance) { + return true; + } + } + return false; + } + } + + /** + * Synchronized) pool of objects. + * + * @param <T> The pooled type. + */ + public static class SynchronizedPool<T> extends SimplePool<T> { + private final Object mLock = new Object(); + + /** + * Creates a new instance. + * + * @param maxPoolSize The max pool size. + * + * @throws IllegalArgumentException If the max pool size is less than zero. + */ + public SynchronizedPool(int maxPoolSize) { + super(maxPoolSize); + } + + @Override + public T acquire() { + synchronized (mLock) { + return super.acquire(); + } + } + + @Override + public boolean release(T element) { + synchronized (mLock) { + return super.release(element); + } + } + } +}
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