com.alipay.sofa.ark.loader.data.RandomAccessData Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.alipay.sofa.ark.loader.data;
import java.io.IOException;
import java.io.InputStream;
/**
* Interface that provides read-only random access to some underlying data.
* Implementations must allow concurrent reads in a thread-safe manner.
*
* @author Phillip Webb
*/
public interface RandomAccessData {
/**
* Returns an {@link InputStream} that can be used to read the underlying data. The
* caller is responsible close the underlying stream.
* @param access hint indicating how the underlying data should be accessed
* @return a new input stream that can be used to read the underlying data.
* @throws IOException if the stream cannot be opened
*/
InputStream getInputStream(ResourceAccess access) throws IOException;
/**
* Returns a new {@link RandomAccessData} for a specific subsection of this data.
* @param offset the offset of the subsection
* @param length the length of the subsection
* @return the subsection data
*/
RandomAccessData getSubsection(long offset, long length);
/**
* Returns the size of the data.
* @return the size
*/
long getSize();
/**
* Lock modes for accessing the underlying resource.
*/
enum ResourceAccess {
/**
* Obtain access to the underlying resource once and keep it until the stream is
* closed.
*/
ONCE,
/**
* Obtain access to the underlying resource on each read, releasing it when done.
*/
PER_READ
}
}