1 files changed, 217 insertions, 0 deletions
diff --git a/jimfs/src/main/java/com/google/common/jimfs/JimfsSecureDirectoryStream.java b/jimfs/src/main/java/com/google/common/jimfs/JimfsSecureDirectoryStream.java
new file mode 100644
index 0000000..e3391b6
--- /dev/null
+++ b/jimfs/src/main/java/com/google/common/jimfs/JimfsSecureDirectoryStream.java
@@ -0,0 +1,217 @@
+/*
+ * 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.checkNotNull;
+import static com.google.common.base.Preconditions.checkState;
+
+import com.google.common.collect.AbstractIterator;
+import com.google.common.collect.ImmutableSet;
+import java.io.IOException;
+import java.nio.channels.SeekableByteChannel;
+import java.nio.file.ClosedDirectoryStreamException;
+import java.nio.file.CopyOption;
+import java.nio.file.DirectoryIteratorException;
+import java.nio.file.LinkOption;
+import java.nio.file.OpenOption;
+import java.nio.file.Path;
+import java.nio.file.ProviderMismatchException;
+import java.nio.file.SecureDirectoryStream;
+import java.nio.file.attribute.FileAttribute;
+import java.nio.file.attribute.FileAttributeView;
+import java.util.Iterator;
+import java.util.Set;
+import org.checkerframework.checker.nullness.compatqual.NullableDecl;
+
+/**
+ * Secure directory stream implementation that uses a {@link FileSystemView} with the stream's
+ * directory as its working directory.
+ *
+ * @author Colin Decker
+ */
+final class JimfsSecureDirectoryStream implements SecureDirectoryStream<Path> {
+
+  private final FileSystemView view;
+  private final Filter<? super Path> filter;
+  private final FileSystemState fileSystemState;
+
+  private boolean open = true;
+  private Iterator<Path> iterator = new DirectoryIterator();
+
+  public JimfsSecureDirectoryStream(
+      FileSystemView view, Filter<? super Path> filter, FileSystemState fileSystemState) {
+    this.view = checkNotNull(view);
+    this.filter = checkNotNull(filter);
+    this.fileSystemState = fileSystemState;
+    fileSystemState.register(this);
+  }
+
+  private JimfsPath path() {
+    return view.getWorkingDirectoryPath();
+  }
+
+  @Override
+  public synchronized Iterator<Path> iterator() {
+    checkOpen();
+    Iterator<Path> result = iterator;
+    checkState(result != null, "iterator() has already been called once");
+    iterator = null;
+    return result;
+  }
+
+  @Override
+  public synchronized void close() {
+    open = false;
+    fileSystemState.unregister(this);
+  }
+
+  protected synchronized void checkOpen() {
+    if (!open) {
+      throw new ClosedDirectoryStreamException();
+    }
+  }
+
+  private final class DirectoryIterator extends AbstractIterator<Path> {
+
+    @NullableDecl private Iterator<Name> fileNames;
+
+    @Override
+    protected synchronized Path computeNext() {
+      checkOpen();
+
+      try {
+        if (fileNames == null) {
+          fileNames = view.snapshotWorkingDirectoryEntries().iterator();
+        }
+
+        while (fileNames.hasNext()) {
+          Name name = fileNames.next();
+          Path path = view.getWorkingDirectoryPath().resolve(name);
+
+          if (filter.accept(path)) {
+            return path;
+          }
+        }
+
+        return endOfData();
+      } catch (IOException e) {
+        throw new DirectoryIteratorException(e);
+      }
+    }
+  }
+
+  /** A stream filter that always returns true. */
+  public static final Filter<Object> ALWAYS_TRUE_FILTER =
+      new Filter<Object>() {
+        @Override
+        public boolean accept(Object entry) throws IOException {
+          return true;
+        }
+      };
+
+  @Override
+  public SecureDirectoryStream<Path> newDirectoryStream(Path path, LinkOption... options)
+      throws IOException {
+    checkOpen();
+    JimfsPath checkedPath = checkPath(path);
+
+    // safe cast because a file system that supports SecureDirectoryStream always creates
+    // SecureDirectoryStreams
+    return (SecureDirectoryStream<Path>)
+        view.newDirectoryStream(
+            checkedPath,
+            ALWAYS_TRUE_FILTER,
+            Options.getLinkOptions(options),
+            path().resolve(checkedPath));
+  }
+
+  @Override
+  public SeekableByteChannel newByteChannel(
+      Path path, Set<? extends OpenOption> options, FileAttribute<?>... attrs) throws IOException {
+    checkOpen();
+    JimfsPath checkedPath = checkPath(path);
+    ImmutableSet<OpenOption> opts = Options.getOptionsForChannel(options);
+    return new JimfsFileChannel(
+        view.getOrCreateRegularFile(checkedPath, opts), opts, fileSystemState);
+  }
+
+  @Override
+  public void deleteFile(Path path) throws IOException {
+    checkOpen();
+    JimfsPath checkedPath = checkPath(path);
+    view.deleteFile(checkedPath, FileSystemView.DeleteMode.NON_DIRECTORY_ONLY);
+  }
+
+  @Override
+  public void deleteDirectory(Path path) throws IOException {
+    checkOpen();
+    JimfsPath checkedPath = checkPath(path);
+    view.deleteFile(checkedPath, FileSystemView.DeleteMode.DIRECTORY_ONLY);
+  }
+
+  @Override
+  public void move(Path srcPath, SecureDirectoryStream<Path> targetDir, Path targetPath)
+      throws IOException {
+    checkOpen();
+    JimfsPath checkedSrcPath = checkPath(srcPath);
+    JimfsPath checkedTargetPath = checkPath(targetPath);
+
+    if (!(targetDir instanceof JimfsSecureDirectoryStream)) {
+      throw new ProviderMismatchException(
+          "targetDir isn't a secure directory stream associated with this file system");
+    }
+
+    JimfsSecureDirectoryStream checkedTargetDir = (JimfsSecureDirectoryStream) targetDir;
+
+    view.copy(
+        checkedSrcPath,
+        checkedTargetDir.view,
+        checkedTargetPath,
+        ImmutableSet.<CopyOption>of(),
+        true);
+  }
+
+  @Override
+  public <V extends FileAttributeView> V getFileAttributeView(Class<V> type) {
+    return getFileAttributeView(path().getFileSystem().getPath("."), type);
+  }
+
+  @Override
+  public <V extends FileAttributeView> V getFileAttributeView(
+      Path path, Class<V> type, LinkOption... options) {
+    checkOpen();
+    final JimfsPath checkedPath = checkPath(path);
+    final ImmutableSet<LinkOption> optionsSet = Options.getLinkOptions(options);
+    return view.getFileAttributeView(
+        new FileLookup() {
+          @Override
+          public File lookup() throws IOException {
+            checkOpen(); // per the spec, must check that the stream is open for each view operation
+            return view.lookUpWithLock(checkedPath, optionsSet).requireExists(checkedPath).file();
+          }
+        },
+        type);
+  }
+
+  private static JimfsPath checkPath(Path path) {
+    if (path instanceof JimfsPath) {
+      return (JimfsPath) path;
+    }
+    throw new ProviderMismatchException(
+        "path " + path + " is not associated with a Jimfs file system");
+  }
+}