| // Copyright 2014 The Bazel Authors. All rights reserved. |
| // |
| // 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.devtools.build.lib.vfs.inmemoryfs; |
| |
| import com.google.common.base.Preconditions; |
| import com.google.devtools.build.lib.clock.Clock; |
| import com.google.devtools.build.lib.concurrent.ThreadSafety.ThreadSafe; |
| import java.io.ByteArrayOutputStream; |
| import java.io.IOException; |
| import java.io.OutputStream; |
| |
| /** |
| * InMemoryFileInfo manages file contents by storing them entirely in memory. |
| */ |
| @ThreadSafe |
| public class InMemoryFileInfo extends FileInfo { |
| |
| /** |
| * Updates to the content must atomically update the lastModifiedTime. So all |
| * accesses to this field must be synchronized. |
| */ |
| protected byte[] content; |
| |
| protected InMemoryFileInfo(Clock clock) { |
| super(clock); |
| content = new byte[0]; // New files start out empty. |
| } |
| |
| @Override |
| public synchronized long getSize() { |
| return content.length; |
| } |
| |
| @Override |
| public synchronized byte[] readContent() { |
| return content.clone(); |
| } |
| |
| private synchronized void setContent(byte[] newContent) { |
| content = newContent; |
| markModificationTime(); |
| } |
| |
| @Override |
| protected synchronized OutputStream getOutputStream(boolean append) |
| throws IOException { |
| OutputStream out = new ByteArrayOutputStream() { |
| private boolean closed = false; |
| |
| @Override |
| public void write(byte[] data) throws IOException { |
| Preconditions.checkState(!closed); |
| super.write(data); |
| } |
| |
| @Override |
| public synchronized void write(int dataByte) { |
| Preconditions.checkState(!closed); |
| super.write(dataByte); |
| } |
| |
| @Override |
| public synchronized void write(byte[] data, int offset, int length) { |
| Preconditions.checkState(!closed); |
| super.write(data, offset, length); |
| } |
| |
| @Override |
| public void close() { |
| flush(); |
| closed = true; |
| } |
| |
| @Override |
| public void flush() { |
| setContent(toByteArray().clone()); |
| } |
| }; |
| |
| if (append) { |
| out.write(readContent()); |
| } |
| return out; |
| } |
| } |