Ensure that RandomAccessFile is not leaked.

This change ensures that RandomAccessFile is always closed. Also, it
changes the BufferIterator implementation to delegate to the byte buffer
directly instead of mainitaining the position itself.

Change-Id: I8f93e80c91a7c35e6a7fb015185b8b11e36b6286

2 files changed, 34 insertions, 38 deletions

diff --git a/tools/layoutlib/bridge/src/com/android/layoutlib/bridge/libcore/io/BridgeBufferIterator.java b/tools/layoutlib/bridge/src/com/android/layoutlib/bridge/libcore/io/BridgeBufferIterator.java
index 2075989e5919..7e361a11f387 100644
--- a/tools/layoutlib/bridge/src/com/android/layoutlib/bridge/libcore/io/BridgeBufferIterator.java
+++ b/tools/layoutlib/bridge/src/com/android/layoutlib/bridge/libcore/io/BridgeBufferIterator.java
@@ -16,74 +16,61 @@
 
 package com.android.layoutlib.bridge.libcore.io;
 
-import java.nio.MappedByteBuffer;
+import java.nio.ByteBuffer;
 
 import libcore.io.BufferIterator;
 
 /**
- * Provides an implementation of {@link BufferIterator} over a {@link MappedByteBuffer}.
+ * Provides an implementation of {@link BufferIterator} over a {@link ByteBuffer}.
  */
 public class BridgeBufferIterator extends BufferIterator {
 
-    private int mPosition;
     private final long mSize;
-    private final MappedByteBuffer mMappedByteBuffer;
+    private final ByteBuffer mByteBuffer;
 
-    public BridgeBufferIterator(long size, MappedByteBuffer buffer) {
+    public BridgeBufferIterator(long size, ByteBuffer buffer) {
         mSize = size;
-        mMappedByteBuffer = buffer;
+        mByteBuffer = buffer;
     }
 
     @Override
     public void seek(int offset) {
-        assert offset < mSize;
-       mPosition = offset;
+        assert offset <= mSize;
+        mByteBuffer.position(offset);
     }
 
     @Override
     public void skip(int byteCount) {
-        assert mPosition + byteCount <= mSize;
-        mPosition += byteCount;
+        int newPosition = mByteBuffer.position() + byteCount;
+        assert newPosition <= mSize;
+        mByteBuffer.position(newPosition);
     }
 
     @Override
     public void readByteArray(byte[] dst, int dstOffset, int byteCount) {
         assert dst.length >= dstOffset + byteCount;
-        mMappedByteBuffer.position(mPosition);
-        mMappedByteBuffer.get(dst, dstOffset, byteCount);
-        mPosition = mMappedByteBuffer.position();
+        mByteBuffer.get(dst, dstOffset, byteCount);
     }
 
     @Override
     public byte readByte() {
-        mMappedByteBuffer.position(mPosition);
-        byte b = mMappedByteBuffer.get();
-        mPosition = mMappedByteBuffer.position();
-        return b;
+        return mByteBuffer.get();
     }
 
     @Override
     public int readInt() {
-        mMappedByteBuffer.position(mPosition);
-        int i = mMappedByteBuffer.getInt();
-        mPosition = mMappedByteBuffer.position();
-        return i;
+        return mByteBuffer.getInt();
     }
 
     @Override
     public void readIntArray(int[] dst, int dstOffset, int intCount) {
-        mMappedByteBuffer.position(mPosition);
         while (--intCount >= 0) {
-            dst[dstOffset++] = mMappedByteBuffer.getInt();
+            dst[dstOffset++] = mByteBuffer.getInt();
         }
-        mPosition = mMappedByteBuffer.position();
     }
 
     @Override
     public short readShort() {
-        mMappedByteBuffer.position(mPosition);
-        short s = mMappedByteBuffer.getShort();
-        mPosition = mMappedByteBuffer.position();
-        return s;
+        return mByteBuffer.getShort();
     }
 }
diff --git a/tools/layoutlib/bridge/src/libcore/io/MemoryMappedFile_Delegate.java b/tools/layoutlib/bridge/src/libcore/io/MemoryMappedFile_Delegate.java
index 3c18bd3239d3..723d5c4b0d0c 100644
--- a/tools/layoutlib/bridge/src/libcore/io/MemoryMappedFile_Delegate.java
+++ b/tools/layoutlib/bridge/src/libcore/io/MemoryMappedFile_Delegate.java
@@ -25,6 +25,7 @@ import android.system.ErrnoException;
 import java.io.File;
 import java.io.IOException;
 import java.io.RandomAccessFile;
+import java.nio.ByteOrder;
 import java.nio.MappedByteBuffer;
 import java.nio.channels.FileChannel.MapMode;
 import java.util.HashMap;
@@ -59,15 +60,22 @@ public class MemoryMappedFile_Delegate {
         }
         path = path.substring(TARGET_PATH.length());
         try {
-            RandomAccessFile file = new RandomAccessFile(new File(sRootPath, path), "r");
-            long size = file.length();
-            MemoryMappedFile_Delegate newDelegate = new MemoryMappedFile_Delegate(file);
-            long filePointer = file.getFilePointer();
-            MemoryMappedFile mmFile = new MemoryMappedFile(filePointer, size);
-            long delegateIndex = sManager.addNewDelegate(newDelegate);
-            sMemoryMappedFileMap.put(mmFile, delegateIndex);
-            file.close();  // Also closes the channel opened by the delegate constructor.
-            return mmFile;
+            File f = new File(sRootPath, path);
+            if (!f.exists()) {
+                throw new ErrnoException("File not found: " + f.getPath(), 1);
+            }
+            RandomAccessFile file = new RandomAccessFile(f, "r");
+            try {
+                long size = file.length();
+                MemoryMappedFile_Delegate newDelegate = new MemoryMappedFile_Delegate(file);
+                long filePointer = file.getFilePointer();
+                MemoryMappedFile mmFile = new MemoryMappedFile(filePointer, size);
+                long delegateIndex = sManager.addNewDelegate(newDelegate);
+                sMemoryMappedFileMap.put(mmFile, delegateIndex);
+                return mmFile;
+            } finally {
+                file.close();
+            }
         } catch (IOException e) {
             throw new ErrnoException("mmapRO", 1, e);
         }
@@ -85,7 +93,7 @@ public class MemoryMappedFile_Delegate {
     @LayoutlibDelegate
     static BufferIterator bigEndianIterator(MemoryMappedFile file) {
         MemoryMappedFile_Delegate delegate = getDelegate(file);
-        return new BridgeBufferIterator(delegate.mSize, delegate.mMappedByteBuffer);
+        return new BridgeBufferIterator(delegate.mSize, delegate.mMappedByteBuffer.duplicate());
     }
 
     // TODO: implement littleEndianIterator()
@@ -95,6 +103,7 @@ public class MemoryMappedFile_Delegate {
         // It's weird that map() takes size as long, but returns MappedByteBuffer which uses an int
         // to store the marker to the position.
         mMappedByteBuffer = file.getChannel().map(MapMode.READ_ONLY, 0, mSize);
+        assert mMappedByteBuffer.order() == ByteOrder.BIG_ENDIAN;
     }
 
     public static void setDataDir(File path) {