1 files changed, 91 insertions, 0 deletions
diff --git a/src/com/android/gallery3d/data/BytesBufferPool.java b/src/com/android/gallery3d/data/BytesBufferPool.java
new file mode 100644
index 000000000..d2da323fc
--- /dev/null
+++ b/src/com/android/gallery3d/data/BytesBufferPool.java
@@ -0,0 +1,91 @@
+/*
+ * Copyright (C) 2012 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;
+
+import com.android.gallery3d.util.ThreadPool.JobContext;
+
+import java.io.FileDescriptor;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.util.ArrayList;
+
+public class BytesBufferPool {
+
+    private static final int READ_STEP = 4096;
+
+    public static class BytesBuffer {
+        public byte[] data;
+        public int offset;
+        public int length;
+
+        private BytesBuffer(int capacity) {
+            this.data = new byte[capacity];
+        }
+
+        // an helper function to read content from FileDescriptor
+        public void readFrom(JobContext jc, FileDescriptor fd) throws IOException {
+            FileInputStream fis = new FileInputStream(fd);
+            length = 0;
+            try {
+                int capacity = data.length;
+                while (true) {
+                    int step = Math.min(READ_STEP, capacity - length);
+                    int rc = fis.read(data, length, step);
+                    if (rc < 0 || jc.isCancelled()) return;
+                    length += rc;
+
+                    if (length == capacity) {
+                        byte[] newData = new byte[data.length * 2];
+                        System.arraycopy(data, 0, newData, 0, data.length);
+                        data = newData;
+                        capacity = data.length;
+                    }
+                }
+            } finally {
+                fis.close();
+            }
+        }
+    }
+
+    private final int mPoolSize;
+    private final int mBufferSize;
+    private final ArrayList<BytesBuffer> mList;
+
+    public BytesBufferPool(int poolSize, int bufferSize) {
+        mList = new ArrayList<BytesBuffer>(poolSize);
+        mPoolSize = poolSize;
+        mBufferSize = bufferSize;
+    }
+
+    public synchronized BytesBuffer get() {
+        int n = mList.size();
+        return n > 0 ? mList.remove(n - 1) : new BytesBuffer(mBufferSize);
+    }
+
+    public synchronized void recycle(BytesBuffer buffer) {
+        if (buffer.data.length != mBufferSize) return;
+        if (mList.size() < mPoolSize) {
+            buffer.offset = 0;
+            buffer.length = 0;
+            mList.add(buffer);
+        }
+    }
+
+    public synchronized void clear() {
+        mList.clear();
+    }
+}