| /* |
| * Copyright 2022 Google LLC |
| * |
| * 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.android.libraries.mobiledatadownload.file.openers; |
| |
| import com.google.android.libraries.mobiledatadownload.file.OpenContext; |
| import com.google.android.libraries.mobiledatadownload.file.Opener; |
| import com.google.common.io.Files; |
| import java.io.File; |
| import java.io.IOException; |
| import java.io.RandomAccessFile; |
| |
| /** Opener that returns a RandomAccessFile. */ |
| public final class RandomAccessFileOpener implements Opener<RandomAccessFile> { |
| |
| private final boolean writeSupport; |
| |
| /** |
| * If writeSupport is false, the RAF is read only. If writeSupport is enabled, the RAF is read and |
| * write, and the directory is created if necessary. |
| */ |
| private RandomAccessFileOpener(boolean writeSupport) { |
| this.writeSupport = writeSupport; |
| } |
| |
| public static RandomAccessFileOpener createForRead() { |
| return new RandomAccessFileOpener(/*writeSupport=*/ false); |
| } |
| |
| /** |
| * Create an opener that returns a RandomAccessFile opened for read and write. If the File or its |
| * parent directories do not exist, they will be created. |
| */ |
| public static RandomAccessFileOpener createForReadWrite() { |
| return new RandomAccessFileOpener(/*writeSupport=*/ true); |
| } |
| |
| @Override |
| public RandomAccessFile open(OpenContext openContext) throws IOException { |
| if (writeSupport) { |
| ReadFileOpener readFileOpener = ReadFileOpener.create().withShortCircuit(); |
| File file = readFileOpener.open(openContext); |
| Files.createParentDirs(file); |
| return new RandomAccessFile(file, "rw"); |
| } else /* if (!writeSupport) */ { |
| ReadFileOpener readFileOpener = ReadFileOpener.create(); |
| File file = readFileOpener.open(openContext); |
| return new RandomAccessFile(file, "r"); |
| } |
| } |
| } |