| /* |
| * Copyright 2009 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.gwt.dev.util; |
| |
| import java.io.IOException; |
| import java.io.OutputStream; |
| import java.util.HashSet; |
| import java.util.Set; |
| |
| /** |
| * An abstract set of files that a linker links into. |
| */ |
| public abstract class OutputFileSet { |
| |
| /** |
| * Indicates that the file should be overwritten. |
| */ |
| public static final int TIMESTAMP_UNAVAILABLE = -1; |
| |
| private final String pathDescription; |
| private final Set<String> pathsSeen = new HashSet<String>(); |
| |
| protected OutputFileSet(String pathDescription) { |
| this.pathDescription = pathDescription; |
| } |
| |
| /** |
| * No more output will be sent to this OutputFileSet. It is safe to call |
| * {@link #close()} on an already-closed instance. |
| * |
| * @throws IOException |
| */ |
| public abstract void close() throws IOException; |
| |
| /** |
| * Return a description of this output file set's path. The precise meaning is |
| * unspecified, except that it should be informative when used in log |
| * messages. |
| */ |
| public String getPathDescription() { |
| return pathDescription; |
| } |
| |
| /** |
| * Opens a file for write. If writing to a zip file and the file already exists, |
| * this has no effect. Otherwise, overwrites any existing file. |
| * @return the output stream to write to, possibly a NullOutputStream |
| */ |
| public final OutputStream openForWrite(String path) throws IOException { |
| return openForWrite(path, TIMESTAMP_UNAVAILABLE); |
| } |
| |
| /** |
| * Opens a file for write. If writing to a zip file and the file already exists, |
| * there will be no effect. If writing to a directory, the file exists, and the |
| * given timestamp is older than the current timestamp, there will be no effect. |
| * |
| * @param timeStampMillis last modified time in milliseconds, or |
| * TIMESTAMP_UNAVAILABLE to force an overwrite. |
| * @return the output stream to write to, possibly a NullOutputStream |
| */ |
| // TODO: revalidate whether any timestamp based overwrite prevention is needed. |
| public OutputStream openForWrite(String path, long timeStampMillis) throws IOException { |
| pathsSeen.add(path); |
| return createNewOutputStream(path, timeStampMillis); |
| } |
| |
| protected abstract OutputStream createNewOutputStream(String path, |
| long lastModifiedTime) throws IOException; |
| } |