Add thumb pool the cache Bitmap used for thumbnails.

Change-Id: Ib710f2a6fc1aa86fe4abdd18d1fa7ac71396a3b4

4 files changed, 100 insertions, 14 deletions

diff --git a/src/com/android/gallery3d/data/BitmapPool.java b/src/com/android/gallery3d/data/BitmapPool.java
index c52a57b0a..0fbd84ef5 100644
--- a/src/com/android/gallery3d/data/BitmapPool.java
+++ b/src/com/android/gallery3d/data/BitmapPool.java
@@ -1,4 +1,18 @@
-// Copyright 2012 Google Inc. All Rights Reserved.
+/*
+ * Copyright (C) 2011 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 com.android.gallery3d.data;
 
@@ -6,6 +20,7 @@ import android.graphics.Bitmap;
 import android.graphics.BitmapFactory;
 import android.graphics.BitmapFactory.Options;
 
+import com.android.gallery3d.common.Utils;
 import com.android.gallery3d.ui.Log;
 import com.android.gallery3d.util.ThreadPool.JobContext;
 
@@ -15,30 +30,63 @@ import java.util.ArrayList;
 public class BitmapPool {
     private static final String TAG = "BitmapPool";
 
-    private static final int POOL_SIZE = 16;
-    private final ArrayList<Bitmap> mPool = new ArrayList<Bitmap>(POOL_SIZE);
+    private final ArrayList<Bitmap> mPool;
+    private final int mPoolLimit;
 
-    private final int mWidth;
-    private final int mHeight;
+    // mOneSize is true if the pool can only cache Bitmap with one size.
+    private final boolean mOneSize;
+    private final int mWidth, mHeight;  // only used if mOneSize is true
 
-    public BitmapPool(int width, int height) {
+    // Construct a BitmapPool which caches bitmap with the specified size.
+    public BitmapPool(int width, int height, int poolLimit) {
         mWidth = width;
         mHeight = height;
+        mPoolLimit = poolLimit;
+        mPool = new ArrayList<Bitmap>(poolLimit);
+        mOneSize = true;
     }
 
+    // Construct a BitmapPool which caches bitmap with any size;
+    public BitmapPool(int poolLimit) {
+        mWidth = -1;
+        mHeight = -1;
+        mPoolLimit = poolLimit;
+        mPool = new ArrayList<Bitmap>(poolLimit);
+        mOneSize = false;
+    }
+
+    // Get a Bitmap from the pool.
     public synchronized Bitmap getBitmap() {
+        Utils.assertTrue(mOneSize);
         int size = mPool.size();
         return size > 0 ? mPool.remove(size - 1) : null;
     }
 
+    // Get a Bitmap from the pool with the specified size.
+    public synchronized Bitmap getBitmap(int width, int height) {
+        Utils.assertTrue(!mOneSize);
+        for (int i = mPool.size() - 1; i >= 0; i--) {
+            Bitmap b = mPool.get(i);
+            if (b.getWidth() == width && b.getHeight() == height) {
+                return mPool.remove(i);
+            }
+        }
+        return null;
+    }
+
+    // Put a Bitmap into the pool, if the Bitmap has a proper size. Otherwise
+    // the Bitmap will be recycled. If the pool is full, an old Bitmap will be
+    // recycled.
     public void recycle(Bitmap bitmap) {
         if (bitmap == null) return;
-        if ((bitmap.getWidth() != mWidth) || (bitmap.getHeight() != mHeight)) {
+        if (mOneSize && ((bitmap.getWidth() != mWidth) ||
+                (bitmap.getHeight() != mHeight))) {
             bitmap.recycle();
             return;
         }
         synchronized (this) {
-            if (mPool.size() < POOL_SIZE) mPool.add(bitmap);
+            if (mPool.size() >= mPoolLimit) mPool.remove(0);
+            mPool.add(bitmap);
         }
     }
 
@@ -46,12 +94,27 @@ public class BitmapPool {
         mPool.clear();
     }
 
+    private Bitmap findCachedBitmap(JobContext jc,
+            byte[] data, int offset, int length, Options options) {
+        if (mOneSize) return getBitmap();
+        DecodeUtils.decodeBounds(jc, data, offset, length, options);
+        return getBitmap(options.outWidth, options.outHeight);
+    }
+
+    private Bitmap findCachedBitmap(JobContext jc,
+            FileDescriptor fileDescriptor, Options options) {
+        if (mOneSize) return getBitmap();
+        DecodeUtils.decodeBounds(jc, fileDescriptor, options);
+        return getBitmap(options.outWidth, options.outHeight);
+    }
+
     public Bitmap decode(JobContext jc,
             byte[] data, int offset, int length, BitmapFactory.Options options) {
         if (options == null) options = new BitmapFactory.Options();
         if (options.inSampleSize < 1) options.inSampleSize = 1;
         options.inPreferredConfig = Bitmap.Config.ARGB_8888;
-        options.inBitmap = (options.inSampleSize == 1) ? getBitmap() : null;
+        options.inBitmap = (options.inSampleSize == 1)
+                ? findCachedBitmap(jc, data, offset, length, options) : null;
         try {
             Bitmap bitmap = DecodeUtils.decode(jc, data, offset, length, options);
             if (options.inBitmap != null && options.inBitmap != bitmap) {
@@ -76,7 +139,8 @@ public class BitmapPool {
         if (options == null) options = new BitmapFactory.Options();
         if (options.inSampleSize < 1) options.inSampleSize = 1;
         options.inPreferredConfig = Bitmap.Config.ARGB_8888;
-        options.inBitmap = (options.inSampleSize == 1) ? getBitmap() : null;
+        options.inBitmap = (options.inSampleSize == 1)
+                ? findCachedBitmap(jc, fileDescriptor, options) : null;
         try {
             Bitmap bitmap = DecodeUtils.decode(jc, fileDescriptor, options);
             if (options.inBitmap != null&& options.inBitmap != bitmap) {
diff --git a/src/com/android/gallery3d/data/DecodeUtils.java b/src/com/android/gallery3d/data/DecodeUtils.java
index 319458a14..e51dc3fa9 100644
--- a/src/com/android/gallery3d/data/DecodeUtils.java
+++ b/src/com/android/gallery3d/data/DecodeUtils.java
@@ -55,6 +55,15 @@ public class DecodeUtils {
                 BitmapFactory.decodeFileDescriptor(fd, null, options));
     }
 
+    public static void decodeBounds(JobContext jc, FileDescriptor fd,
+            Options options) {
+        Utils.assertTrue(options != null);
+        options.inJustDecodeBounds = true;
+        jc.setCancelListener(new DecodeCanceller(options));
+        BitmapFactory.decodeFileDescriptor(fd, null, options);
+        options.inJustDecodeBounds = false;
+    }
+
     public static Bitmap decode(JobContext jc, byte[] bytes, Options options) {
         return decode(jc, bytes, 0, bytes.length, options);
     }
@@ -67,6 +76,15 @@ public class DecodeUtils {
                 BitmapFactory.decodeByteArray(bytes, offset, length, options));
     }
 
+    public static void decodeBounds(JobContext jc, byte[] bytes, int offset,
+            int length, Options options) {
+        Utils.assertTrue(options != null);
+        options.inJustDecodeBounds = true;
+        jc.setCancelListener(new DecodeCanceller(options));
+        BitmapFactory.decodeByteArray(bytes, offset, length, options);
+        options.inJustDecodeBounds = false;
+    }
+
     public static Bitmap decodeThumbnail(
             JobContext jc, String filePath, Options options, int targetSize, int type) {
         FileInputStream fis = null;
diff --git a/src/com/android/gallery3d/data/ImageCacheRequest.java b/src/com/android/gallery3d/data/ImageCacheRequest.java
index c10158bcd..81660c915 100644
--- a/src/com/android/gallery3d/data/ImageCacheRequest.java
+++ b/src/com/android/gallery3d/data/ImageCacheRequest.java
@@ -60,7 +60,7 @@ abstract class ImageCacheRequest implements Job<Bitmap> {
                     bitmap = MediaItem.getMicroThumbPool().decode(jc,
                             buffer.data, buffer.offset, buffer.length, options);
                 } else {
-                    bitmap = DecodeUtils.decode(jc,
+                    bitmap = MediaItem.getThumbPool().decode(jc,
                             buffer.data, buffer.offset, buffer.length, options);
                 }
                 if (bitmap == null && !jc.isCancelled()) {
diff --git a/src/com/android/gallery3d/data/MediaItem.java b/src/com/android/gallery3d/data/MediaItem.java
index 3de70d954..f0f1af434 100644
--- a/src/com/android/gallery3d/data/MediaItem.java
+++ b/src/com/android/gallery3d/data/MediaItem.java
@@ -42,9 +42,9 @@ public abstract class MediaItem extends MediaObject {
     private static final int BYTESBUFFE_POOL_SIZE = 4;
     private static final int BYTESBUFFER_SIZE = 200 * 1024;
 
-    private static final BitmapPool sMicroThumbPool =
-            new BitmapPool(MICROTHUMBNAIL_TARGET_SIZE, MICROTHUMBNAIL_TARGET_SIZE);
-
+    private static final BitmapPool sMicroThumbPool = new BitmapPool(
+            MICROTHUMBNAIL_TARGET_SIZE, MICROTHUMBNAIL_TARGET_SIZE, 16);
+    private static final BitmapPool sThumbPool = new BitmapPool(4);
     private static final BytesBufferPool sMicroThumbBufferPool =
             new BytesBufferPool(BYTESBUFFE_POOL_SIZE, BYTESBUFFER_SIZE);
 
@@ -122,6 +122,10 @@ public abstract class MediaItem extends MediaObject {
         return sMicroThumbPool;
     }
 
+    public static BitmapPool getThumbPool() {
+        return sThumbPool;
+    }
+
     public static BytesBufferPool getBytesBufferPool() {
         return sMicroThumbBufferPool;
     }