1 files changed, 105 insertions, 0 deletions
diff --git a/jimfs/src/main/java/com/google/common/jimfs/Feature.java b/jimfs/src/main/java/com/google/common/jimfs/Feature.java
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+++ b/jimfs/src/main/java/com/google/common/jimfs/Feature.java
@@ -0,0 +1,105 @@
+/*
+ * Copyright 2014 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 java.nio.channels.AsynchronousFileChannel;
+import java.nio.channels.FileChannel;
+import java.nio.channels.SeekableByteChannel;
+import java.nio.file.DirectoryStream;
+import java.nio.file.Files;
+import java.nio.file.OpenOption;
+import java.nio.file.Path;
+import java.nio.file.SecureDirectoryStream;
+import java.nio.file.attribute.FileAttribute;
+import java.util.Set;
+import java.util.concurrent.ExecutorService;
+
+/**
+ * Optional file system features that may be supported or unsupported by a Jimfs file system
+ * instance.
+ *
+ * @author Colin Decker
+ */
+public enum Feature {
+
+  /**
+   * Feature controlling support for hard links to regular files.
+   *
+   * <p>Affected method:
+   *
+   * <ul>
+   *   <li>{@link Files#createLink(Path, Path)}
+   * </ul>
+   *
+   * <p>If this feature is not enabled, this method will throw {@link
+   * UnsupportedOperationException}.
+   */
+  LINKS,
+
+  /**
+   * Feature controlling support for symbolic links.
+   *
+   * <p>Affected methods:
+   *
+   * <ul>
+   *   <li>{@link Files#createSymbolicLink(Path, Path, FileAttribute...)}
+   *   <li>{@link Files#readSymbolicLink(Path)}
+   * </ul>
+   *
+   * <p>If this feature is not enabled, these methods will throw {@link
+   * UnsupportedOperationException}.
+   */
+  SYMBOLIC_LINKS,
+
+  /**
+   * Feature controlling support for {@link SecureDirectoryStream}.
+   *
+   * <p>Affected methods:
+   *
+   * <ul>
+   *   <li>{@link Files#newDirectoryStream(Path)}
+   *   <li>{@link Files#newDirectoryStream(Path, DirectoryStream.Filter)}
+   *   <li>{@link Files#newDirectoryStream(Path, String)}
+   * </ul>
+   *
+   * <p>If this feature is enabled, the {@link DirectoryStream} instances returned by these methods
+   * will also implement {@link SecureDirectoryStream}.
+   */
+  SECURE_DIRECTORY_STREAM,
+
+  /**
+   * Feature controlling support for {@link FileChannel}.
+   *
+   * <p>Affected methods:
+   *
+   * <ul>
+   *   <li>{@link Files#newByteChannel(Path, OpenOption...)}
+   *   <li>{@link Files#newByteChannel(Path, Set, FileAttribute...)}
+   *   <li>{@link FileChannel#open(Path, OpenOption...)}
+   *   <li>{@link FileChannel#open(Path, Set, FileAttribute...)}
+   *   <li>{@link AsynchronousFileChannel#open(Path, OpenOption...)}
+   *   <li>{@link AsynchronousFileChannel#open(Path, Set, ExecutorService, FileAttribute...)}
+   * </ul>
+   *
+   * <p>If this feature is not enabled, the {@link SeekableByteChannel} instances returned by the
+   * {@code Files} methods will not be {@code FileChannel} instances and the {@code
+   * FileChannel.open} and {@code AsynchronousFileChannel.open} methods will throw {@link
+   * UnsupportedOperationException}.
+   */
+  // TODO(cgdecker): Should support for AsynchronousFileChannel be a separate feature?
+  FILE_CHANNEL
+}