/*
* 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 org.apache.cassandra.io.util;
import java.nio.ByteBuffer;
import org.apache.cassandra.io.compress.BufferType;
/**
* RandomFileReader component that reads data from a file into a provided buffer and may have requirements over the
* size and alignment of reads.
* A caching or buffer-managing rebufferer will reference one of these to do the actual reading.
* Note: Implementations of this interface must be thread-safe!
*/
public interface ChunkReader extends RebuffererFactory
{
/**
* Read the chunk at the given position, attempting to fill the capacity of the given buffer.
* The filled buffer must be positioned at 0, with limit set at the size of the available data.
* The source may have requirements for the positioning and/or size of the buffer (e.g. chunk-aligned and
* chunk-sized). These must be satisfied by the caller.
*/
void readChunk(long position, ByteBuffer buffer);
/**
* Buffer size required for this rebufferer. Must be power of 2 if alignment is required.
*/
int chunkSize();
/**
* Specifies type of buffer the caller should attempt to give.
* This is not guaranteed to be fulfilled.
*/
BufferType preferredBufferType();
}