1 files changed, 280 insertions, 0 deletions
diff --git a/jimfs/src/main/java/com/google/common/jimfs/File.java b/jimfs/src/main/java/com/google/common/jimfs/File.java
new file mode 100644
index 0000000..ce1cc00
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+++ b/jimfs/src/main/java/com/google/common/jimfs/File.java
@@ -0,0 +1,280 @@
+/*
+ * 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 com.google.common.annotations.VisibleForTesting;
+import com.google.common.base.MoreObjects;
+import com.google.common.collect.HashBasedTable;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Table;
+import java.io.IOException;
+import java.util.concurrent.locks.ReadWriteLock;
+import org.checkerframework.checker.nullness.compatqual.NullableDecl;
+
+/**
+ * A file object, containing both the file's metadata and content.
+ *
+ * @author Colin Decker
+ */
+public abstract class File {
+
+  private final int id;
+
+  private int links;
+
+  private long creationTime;
+  private long lastAccessTime;
+  private long lastModifiedTime;
+
+  @NullableDecl // null when only the basic view is used (default)
+  private Table<String, String, Object> attributes;
+
+  File(int id) {
+    this.id = id;
+
+    long now = System.currentTimeMillis(); // TODO(cgdecker): Use a Clock
+    this.creationTime = now;
+    this.lastAccessTime = now;
+    this.lastModifiedTime = now;
+  }
+
+  /** Returns the ID of this file. */
+  public int id() {
+    return id;
+  }
+
+  /**
+   * Returns the size, in bytes, of this file's content. Directories and symbolic links have a size
+   * of 0.
+   */
+  public long size() {
+    return 0;
+  }
+
+  /** Returns whether or not this file is a directory. */
+  public final boolean isDirectory() {
+    return this instanceof Directory;
+  }
+
+  /** Returns whether or not this file is a regular file. */
+  public final boolean isRegularFile() {
+    return this instanceof RegularFile;
+  }
+
+  /** Returns whether or not this file is a symbolic link. */
+  public final boolean isSymbolicLink() {
+    return this instanceof SymbolicLink;
+  }
+
+  /**
+   * Creates a new file of the same type as this file with the given ID. Does not copy the content
+   * of this file unless the cost of copying the content is minimal. This is because this method is
+   * called with a hold on the file system's lock.
+   */
+  abstract File copyWithoutContent(int id);
+
+  /**
+   * Copies the content of this file to the given file. The given file must be the same type of file
+   * as this file and should have no content.
+   *
+   * <p>This method is used for copying the content of a file after copying the file itself. Does
+   * nothing by default.
+   */
+  void copyContentTo(File file) throws IOException {}
+
+  /**
+   * Returns the read-write lock for this file's content, or {@code null} if there is no content
+   * lock.
+   */
+  @NullableDecl
+  ReadWriteLock contentLock() {
+    return null;
+  }
+
+  /** Called when a stream or channel to this file is opened. */
+  void opened() {}
+
+  /**
+   * Called when a stream or channel to this file is closed. If there are no more streams or
+   * channels open to the file and it has been deleted, its contents may be deleted.
+   */
+  void closed() {}
+
+  /**
+   * Called when (a single link to) this file is deleted. There may be links remaining. Does nothing
+   * by default.
+   */
+  void deleted() {}
+
+  /** Returns whether or not this file is a root directory of the file system. */
+  final boolean isRootDirectory() {
+    // only root directories have their parent link pointing to themselves
+    return isDirectory() && equals(((Directory) this).parent());
+  }
+
+  /** Returns the current count of links to this file. */
+  public final synchronized int links() {
+    return links;
+  }
+
+  /**
+   * Called when this file has been linked in a directory. The given entry is the new directory
+   * entry that links to this file.
+   */
+  void linked(DirectoryEntry entry) {
+    checkNotNull(entry);
+  }
+
+  /** Called when this file has been unlinked from a directory, either for a move or delete. */
+  void unlinked() {}
+
+  /** Increments the link count for this file. */
+  final synchronized void incrementLinkCount() {
+    links++;
+  }
+
+  /** Decrements the link count for this file. */
+  final synchronized void decrementLinkCount() {
+    links--;
+  }
+
+  /** Gets the creation time of the file. */
+  @SuppressWarnings("GoodTime") // should return a java.time.Instant
+  public final synchronized long getCreationTime() {
+    return creationTime;
+  }
+
+  /** Gets the last access time of the file. */
+  @SuppressWarnings("GoodTime") // should return a java.time.Instant
+  public final synchronized long getLastAccessTime() {
+    return lastAccessTime;
+  }
+
+  /** Gets the last modified time of the file. */
+  @SuppressWarnings("GoodTime") // should return a java.time.Instant
+  public final synchronized long getLastModifiedTime() {
+    return lastModifiedTime;
+  }
+
+  /** Sets the creation time of the file. */
+  final synchronized void setCreationTime(long creationTime) {
+    this.creationTime = creationTime;
+  }
+
+  /** Sets the last access time of the file. */
+  final synchronized void setLastAccessTime(long lastAccessTime) {
+    this.lastAccessTime = lastAccessTime;
+  }
+
+  /** Sets the last modified time of the file. */
+  final synchronized void setLastModifiedTime(long lastModifiedTime) {
+    this.lastModifiedTime = lastModifiedTime;
+  }
+
+  /** Sets the last access time of the file to the current time. */
+  final void updateAccessTime() {
+    setLastAccessTime(System.currentTimeMillis());
+  }
+
+  /** Sets the last modified time of the file to the current time. */
+  final void updateModifiedTime() {
+    setLastModifiedTime(System.currentTimeMillis());
+  }
+
+  /**
+   * Returns the names of the attributes contained in the given attribute view in the file's
+   * attributes table.
+   */
+  public final synchronized ImmutableSet<String> getAttributeNames(String view) {
+    if (attributes == null) {
+      return ImmutableSet.of();
+    }
+    return ImmutableSet.copyOf(attributes.row(view).keySet());
+  }
+
+  /** Returns the attribute keys contained in the attributes map for the file. */
+  @VisibleForTesting
+  final synchronized ImmutableSet<String> getAttributeKeys() {
+    if (attributes == null) {
+      return ImmutableSet.of();
+    }
+
+    ImmutableSet.Builder<String> builder = ImmutableSet.builder();
+    for (Table.Cell<String, String, Object> cell : attributes.cellSet()) {
+      builder.add(cell.getRowKey() + ':' + cell.getColumnKey());
+    }
+    return builder.build();
+  }
+
+  /** Gets the value of the given attribute in the given view. */
+  @NullableDecl
+  public final synchronized Object getAttribute(String view, String attribute) {
+    if (attributes == null) {
+      return null;
+    }
+    return attributes.get(view, attribute);
+  }
+
+  /** Sets the given attribute in the given view to the given value. */
+  public final synchronized void setAttribute(String view, String attribute, Object value) {
+    if (attributes == null) {
+      attributes = HashBasedTable.create();
+    }
+    attributes.put(view, attribute, value);
+  }
+
+  /** Deletes the given attribute from the given view. */
+  public final synchronized void deleteAttribute(String view, String attribute) {
+    if (attributes != null) {
+      attributes.remove(view, attribute);
+    }
+  }
+
+  /** Copies basic attributes (file times) from this file to the given file. */
+  final synchronized void copyBasicAttributes(File target) {
+    target.setFileTimes(creationTime, lastModifiedTime, lastAccessTime);
+  }
+
+  private synchronized void setFileTimes(
+      long creationTime, long lastModifiedTime, long lastAccessTime) {
+    this.creationTime = creationTime;
+    this.lastModifiedTime = lastModifiedTime;
+    this.lastAccessTime = lastAccessTime;
+  }
+
+  /** Copies the attributes from this file to the given file. */
+  final synchronized void copyAttributes(File target) {
+    copyBasicAttributes(target);
+    target.putAll(attributes);
+  }
+
+  private synchronized void putAll(@NullableDecl Table<String, String, Object> attributes) {
+    if (attributes != null && this.attributes != attributes) {
+      if (this.attributes == null) {
+        this.attributes = HashBasedTable.create();
+      }
+      this.attributes.putAll(attributes);
+    }
+  }
+
+  @Override
+  public final String toString() {
+    return MoreObjects.toStringHelper(this).add("id", id()).toString();
+  }
+}