1 files changed, 231 insertions, 0 deletions
diff --git a/jimfs/src/main/java/com/google/common/jimfs/JimfsAsynchronousFileChannel.java b/jimfs/src/main/java/com/google/common/jimfs/JimfsAsynchronousFileChannel.java
new file mode 100644
index 0000000..c59522c
--- /dev/null
+++ b/jimfs/src/main/java/com/google/common/jimfs/JimfsAsynchronousFileChannel.java
@@ -0,0 +1,231 @@
+/*
+ * Copyright 2013 Google Inc.
+ *
+ * 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.google.common.jimfs;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import com.google.common.util.concurrent.ListenableFuture;
+import com.google.common.util.concurrent.ListeningExecutorService;
+import com.google.common.util.concurrent.MoreExecutors;
+import com.google.common.util.concurrent.SettableFuture;
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.nio.channels.AsynchronousFileChannel;
+import java.nio.channels.ClosedChannelException;
+import java.nio.channels.CompletionHandler;
+import java.nio.channels.FileLock;
+import java.util.concurrent.Callable;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.ExecutorService;
+import org.checkerframework.checker.nullness.compatqual.NullableDecl;
+
+/**
+ * {@link AsynchronousFileChannel} implementation that delegates to a {@link JimfsFileChannel}.
+ *
+ * @author Colin Decker
+ */
+final class JimfsAsynchronousFileChannel extends AsynchronousFileChannel {
+
+  private final JimfsFileChannel channel;
+  private final ListeningExecutorService executor;
+
+  public JimfsAsynchronousFileChannel(JimfsFileChannel channel, ExecutorService executor) {
+    this.channel = checkNotNull(channel);
+    this.executor = MoreExecutors.listeningDecorator(executor);
+  }
+
+  @Override
+  public long size() throws IOException {
+    return channel.size();
+  }
+
+  private <R, A> void addCallback(
+      ListenableFuture<R> future,
+      CompletionHandler<R, ? super A> handler,
+      @NullableDecl A attachment) {
+    future.addListener(new CompletionHandlerCallback<>(future, handler, attachment), executor);
+  }
+
+  @Override
+  public AsynchronousFileChannel truncate(long size) throws IOException {
+    channel.truncate(size);
+    return this;
+  }
+
+  @Override
+  public void force(boolean metaData) throws IOException {
+    channel.force(metaData);
+  }
+
+  @Override
+  public <A> void lock(
+      long position,
+      long size,
+      boolean shared,
+      @NullableDecl A attachment,
+      CompletionHandler<FileLock, ? super A> handler) {
+    checkNotNull(handler);
+    addCallback(lock(position, size, shared), handler, attachment);
+  }
+
+  @Override
+  public ListenableFuture<FileLock> lock(
+      final long position, final long size, final boolean shared) {
+    Util.checkNotNegative(position, "position");
+    Util.checkNotNegative(size, "size");
+    if (!isOpen()) {
+      return closedChannelFuture();
+    }
+    if (shared) {
+      channel.checkReadable();
+    } else {
+      channel.checkWritable();
+    }
+    return executor.submit(
+        new Callable<FileLock>() {
+          @Override
+          public FileLock call() throws IOException {
+            return tryLock(position, size, shared);
+          }
+        });
+  }
+
+  @Override
+  public FileLock tryLock(long position, long size, boolean shared) throws IOException {
+    Util.checkNotNegative(position, "position");
+    Util.checkNotNegative(size, "size");
+    channel.checkOpen();
+    if (shared) {
+      channel.checkReadable();
+    } else {
+      channel.checkWritable();
+    }
+    return new JimfsFileChannel.FakeFileLock(this, position, size, shared);
+  }
+
+  @Override
+  public <A> void read(
+      ByteBuffer dst,
+      long position,
+      @NullableDecl A attachment,
+      CompletionHandler<Integer, ? super A> handler) {
+    addCallback(read(dst, position), handler, attachment);
+  }
+
+  @Override
+  public ListenableFuture<Integer> read(final ByteBuffer dst, final long position) {
+    checkArgument(!dst.isReadOnly(), "dst may not be read-only");
+    Util.checkNotNegative(position, "position");
+    if (!isOpen()) {
+      return closedChannelFuture();
+    }
+    channel.checkReadable();
+    return executor.submit(
+        new Callable<Integer>() {
+          @Override
+          public Integer call() throws IOException {
+            return channel.read(dst, position);
+          }
+        });
+  }
+
+  @Override
+  public <A> void write(
+      ByteBuffer src,
+      long position,
+      @NullableDecl A attachment,
+      CompletionHandler<Integer, ? super A> handler) {
+    addCallback(write(src, position), handler, attachment);
+  }
+
+  @Override
+  public ListenableFuture<Integer> write(final ByteBuffer src, final long position) {
+    Util.checkNotNegative(position, "position");
+    if (!isOpen()) {
+      return closedChannelFuture();
+    }
+    channel.checkWritable();
+    return executor.submit(
+        new Callable<Integer>() {
+          @Override
+          public Integer call() throws IOException {
+            return channel.write(src, position);
+          }
+        });
+  }
+
+  @Override
+  public boolean isOpen() {
+    return channel.isOpen();
+  }
+
+  @Override
+  public void close() throws IOException {
+    channel.close();
+  }
+
+  /** Immediate future indicating that the channel is closed. */
+  private static <V> ListenableFuture<V> closedChannelFuture() {
+    SettableFuture<V> future = SettableFuture.create();
+    future.setException(new ClosedChannelException());
+    return future;
+  }
+
+  /** Runnable callback that wraps a {@link CompletionHandler} and an attachment. */
+  private static final class CompletionHandlerCallback<R, A> implements Runnable {
+
+    private final ListenableFuture<R> future;
+    private final CompletionHandler<R, ? super A> completionHandler;
+    @NullableDecl private final A attachment;
+
+    private CompletionHandlerCallback(
+        ListenableFuture<R> future,
+        CompletionHandler<R, ? super A> completionHandler,
+        @NullableDecl A attachment) {
+      this.future = checkNotNull(future);
+      this.completionHandler = checkNotNull(completionHandler);
+      this.attachment = attachment;
+    }
+
+    @Override
+    public void run() {
+      R result;
+      try {
+        result = future.get();
+      } catch (ExecutionException e) {
+        onFailure(e.getCause());
+        return;
+      } catch (InterruptedException | RuntimeException | Error e) {
+        // get() shouldn't be interrupted since this should only be called when the result is
+        // ready, but just handle it anyway to be sure and to satisfy the compiler
+        onFailure(e);
+        return;
+      }
+
+      onSuccess(result);
+    }
+
+    private void onSuccess(R result) {
+      completionHandler.completed(result, attachment);
+    }
+
+    private void onFailure(Throwable t) {
+      completionHandler.failed(t, attachment);
+    }
+  }
+}