/*
* Copyright (C) 2016 The Android Open Source Project
*
* 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.android.apksig.util;
import com.android.apksig.internal.util.ByteBufferDataSource;
import com.android.apksig.internal.util.FileChannelDataSource;
import java.io.RandomAccessFile;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
/**
* Utility methods for working with {@link DataSource} abstraction.
*/
public abstract class DataSources {
private DataSources() {}
/**
* Returns a {@link DataSource} backed by the provided {@link ByteBuffer}. The data source
* represents the data contained between the position and limit of the buffer. Changes to the
* buffer's contents will be visible in the data source.
*/
public static DataSource asDataSource(ByteBuffer buffer) {
if (buffer == null) {
throw new NullPointerException();
}
return new ByteBufferDataSource(buffer);
}
/**
* Returns a {@link DataSource} backed by the provided {@link RandomAccessFile}. Changes to the
* file, including changes to size of file, will be visible in the data source.
*/
public static DataSource asDataSource(RandomAccessFile file) {
return asDataSource(file.getChannel());
}
/**
* Returns a {@link DataSource} backed by the provided region of the {@link RandomAccessFile}.
* Changes to the file will be visible in the data source.
*/
public static DataSource asDataSource(RandomAccessFile file, long offset, long size) {
return asDataSource(file.getChannel(), offset, size);
}
/**
* Returns a {@link DataSource} backed by the provided {@link FileChannel}. Changes to the
* file, including changes to size of file, will be visible in the data source.
*/
public static DataSource asDataSource(FileChannel channel) {
if (channel == null) {
throw new NullPointerException();
}
return new FileChannelDataSource(channel);
}
/**
* Returns a {@link DataSource} backed by the provided region of the {@link FileChannel}.
* Changes to the file will be visible in the data source.
*/
public static DataSource asDataSource(FileChannel channel, long offset, long size) {
if (channel == null) {
throw new NullPointerException();
}
return new FileChannelDataSource(channel, offset, size);
}
}