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

2 files changed, 274 insertions, 0 deletions

diff --git a/src/com/android/photos/data/GalleryBitmapPool.java b/src/com/android/photos/data/GalleryBitmapPool.java
new file mode 100644
index 000000000..cddc160fd
--- /dev/null
+++ b/src/com/android/photos/data/GalleryBitmapPool.java
@@ -0,0 +1,128 @@
+/*
+ * Copyright (C) 2013 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.photos.data;
+
+import android.graphics.Bitmap;
+import android.graphics.Point;
+import android.util.Pools.Pool;
+import android.util.Pools.SimplePool;
+
+import com.android.photos.data.SparseArrayBitmapPool.Node;
+
+public class GalleryBitmapPool {
+
+    private static final int CAPACITY_BYTES = 20971520;
+    private static final int POOL_INDEX_NONE = -1;
+    private static final int POOL_INDEX_SQUARE = 0;
+    private static final int POOL_INDEX_PHOTO = 1;
+    private static final int POOL_INDEX_MISC = 2;
+
+    private static final Point[] COMMON_PHOTO_ASPECT_RATIOS =
+        { new Point(4, 3), new Point(3, 2), new Point(16, 9) };
+
+    private int mCapacityBytes;
+    private SparseArrayBitmapPool [] mPools;
+    private Pool<Node> mSharedNodePool = new SimplePool<Node>(128);
+
+    private GalleryBitmapPool(int capacityBytes) {
+        mPools = new SparseArrayBitmapPool[3];
+        mPools[POOL_INDEX_SQUARE] = new SparseArrayBitmapPool(capacityBytes / 3, mSharedNodePool);
+        mPools[POOL_INDEX_PHOTO] = new SparseArrayBitmapPool(capacityBytes / 3, mSharedNodePool);
+        mPools[POOL_INDEX_MISC] = new SparseArrayBitmapPool(capacityBytes / 3, mSharedNodePool);
+        mCapacityBytes = capacityBytes;
+    }
+
+    private static GalleryBitmapPool sInstance;
+    public static GalleryBitmapPool getInstance() {
+        if (sInstance == null) {
+            sInstance = new GalleryBitmapPool(CAPACITY_BYTES);
+        }
+        return sInstance;
+    }
+
+    private SparseArrayBitmapPool getPoolForDimensions(int width, int height) {
+        int index = getPoolIndexForDimensions(width, height);
+        if (index == POOL_INDEX_NONE) {
+            return null;
+        } else {
+            return mPools[index];
+        }
+    }
+
+    private int getPoolIndexForDimensions(int width, int height) {
+        if (width <= 0 || height <= 0) {
+            return POOL_INDEX_NONE;
+        }
+        if (width == height) {
+            return POOL_INDEX_SQUARE;
+        }
+        int min, max;
+        if (width > height) {
+            min = height;
+            max = width;
+        } else {
+            min = width;
+            max = height;
+        }
+        for (Point ar : COMMON_PHOTO_ASPECT_RATIOS) {
+            if (min * ar.x == max * ar.y) {
+                return POOL_INDEX_PHOTO;
+            }
+        }
+        return POOL_INDEX_MISC;
+    }
+
+    public synchronized int getCapacity() {
+        return mCapacityBytes;
+    }
+
+    public synchronized int getSize() {
+        int total = 0;
+        for (SparseArrayBitmapPool p : mPools) {
+            total += p.getSize();
+        }
+        return total;
+    }
+
+    public Bitmap get(int width, int height) {
+        SparseArrayBitmapPool pool = getPoolForDimensions(width, height);
+        if (pool == null) {
+            return null;
+        } else {
+            return pool.get(width, height);
+        }
+    }
+
+    public boolean put(Bitmap b) {
+        if (b == null) {
+            return false;
+        }
+        SparseArrayBitmapPool pool = getPoolForDimensions(b.getWidth(), b.getHeight());
+        if (pool == null) {
+            b.recycle();
+            return false;
+        } else {
+            return pool.put(b);
+        }
+    }
+
+    public void clear() {
+        for (SparseArrayBitmapPool p : mPools) {
+            p.clear();
+        }
+    }
+}
diff --git a/src/com/android/photos/data/SparseArrayBitmapPool.java b/src/com/android/photos/data/SparseArrayBitmapPool.java
new file mode 100644
index 000000000..851259056
--- /dev/null
+++ b/src/com/android/photos/data/SparseArrayBitmapPool.java
@@ -0,0 +1,146 @@
+/*
+ * Copyright (C) 2013 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.photos.data;
+
+import android.graphics.Bitmap;
+import android.util.SparseArray;
+
+import android.util.Pools.Pool;
+
+public class SparseArrayBitmapPool {
+
+    private static final int BITMAPS_TO_KEEP_AFTER_UNNEEDED_HINT = 4;
+    private int mCapacityBytes;
+    private SparseArray<Node> mStore = new SparseArray<Node>();
+    private int mSizeBytes = 0;
+
+    private Pool<Node> mNodePool;
+    private Node mPoolNodesHead = null;
+    private Node mPoolNodesTail = null;
+
+    protected static class Node {
+        Bitmap bitmap;
+        Node prevInBucket;
+        Node nextInBucket;
+        Node nextInPool;
+        Node prevInPool;
+    }
+
+    public SparseArrayBitmapPool(int capacityBytes, Pool<Node> nodePool) {
+        mCapacityBytes = capacityBytes;
+        mNodePool = nodePool;
+    }
+
+    public synchronized void setCapacity(int capacityBytes) {
+        mCapacityBytes = capacityBytes;
+        freeUpCapacity(0);
+    }
+
+    private void freeUpCapacity(int bytesNeeded) {
+        int targetSize = mCapacityBytes - bytesNeeded;
+        while (mPoolNodesTail != null && mSizeBytes > targetSize) {
+            unlinkAndRecycleNode(mPoolNodesTail, true);
+        }
+    }
+
+    private void unlinkAndRecycleNode(Node n, boolean recycleBitmap) {
+        // Remove the node from its spot in its bucket
+        if (n.prevInBucket != null) {
+            n.prevInBucket.nextInBucket = n.nextInBucket;
+        } else {
+            mStore.put(n.bitmap.getWidth(), n.nextInBucket);
+        }
+        if (n.nextInBucket != null) {
+            n.nextInBucket.prevInBucket = n.prevInBucket;
+        }
+
+        // Remove the node from its spot in the list of pool nodes
+        if (n.prevInPool != null) {
+            n.prevInPool.nextInPool = n.nextInPool;
+        } else {
+            mPoolNodesHead = n.nextInPool;
+        }
+        if (n.nextInPool != null) {
+            n.nextInPool.prevInPool = n.prevInPool;
+        } else {
+            mPoolNodesTail = n.prevInPool;
+        }
+
+        // Recycle the node
+        n.nextInBucket = null;
+        n.nextInPool = null;
+        n.prevInBucket = null;
+        n.prevInPool = null;
+        mSizeBytes -= n.bitmap.getByteCount();
+        if (recycleBitmap) n.bitmap.recycle();
+        n.bitmap = null;
+        mNodePool.release(n);
+    }
+
+    public synchronized int getCapacity() {
+        return mCapacityBytes;
+    }
+
+    public synchronized int getSize() {
+        return mSizeBytes;
+    }
+
+    public synchronized Bitmap get(int width, int height) {
+        Node cur = mStore.get(width);
+        while (cur != null) {
+            if (cur.bitmap.getHeight() == height) {
+                Bitmap b = cur.bitmap;
+                unlinkAndRecycleNode(cur, false);
+                return b;
+            }
+            cur = cur.nextInBucket;
+        }
+        return null;
+    }
+
+    public synchronized boolean put(Bitmap b) {
+        if (b == null) {
+            return false;
+        }
+        int bytes = b.getByteCount();
+        freeUpCapacity(bytes);
+        Node newNode = mNodePool.acquire();
+        if (newNode == null) {
+            newNode = new Node();
+        }
+        newNode.bitmap = b;
+        newNode.prevInBucket = null;
+        newNode.prevInPool = null;
+        newNode.nextInPool = mPoolNodesHead;
+        mPoolNodesHead = newNode;
+        int key = b.getWidth();
+        newNode.nextInBucket = mStore.get(key);
+        if (newNode.nextInBucket != null) {
+            newNode.nextInBucket.prevInBucket = newNode;
+        }
+        mStore.put(key, newNode);
+        if (newNode.nextInPool == null) {
+            mPoolNodesTail = newNode;
+        }
+        mSizeBytes += bytes;
+        return true;
+    }
+
+    public synchronized void clear() {
+        freeUpCapacity(mCapacityBytes);
+    }
+}