/*
 * 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.jena.tdb2.store.nodetable;

import java.util.Objects ;

import org.apache.jena.dboe.base.file.BinaryDataFile;
import org.apache.thrift.transport.TTransport ;

/** A file transport that supports random access read and
 *  buffered append write.
 *  <p>
 *  Adapter TTransport -&gt; BinaryDataFile
 */
public class TReadAppendFileTransport extends TTransport {
    private BinaryDataFile file ;
    private long readPosn = -1 ;
    
    public TReadAppendFileTransport(BinaryDataFile file) {
        Objects.requireNonNull(file) ;
        this.file = file ;
    }
    
    @Override
    public boolean isOpen() {
        return file.isOpen() ;
    }

    @Override
    public void open() {
        file.open() ; 
    }

    @Override
    public void close() {
        file.close() ; 
    }
    
    public void truncate(long posn) {
        file.truncate(posn); 
    }

    public BinaryDataFile getBinaryDataFile() { return file ; }

    public long readPosition() {
        return readPosn ;
    }

    public void readPosition(long posn) {
        readPosn = posn ;
    }
    
    @Override
    public int read(byte[] buf, int off, int len) {
        int x = file.read(readPosn, buf, off, len) ;
        readPosn += x ;
        return x ;
    }

    @Override
    public void write(byte[] buf, int off, int len) {
        file.write(buf, off, len) ;
    }
    
    @Override
    public void flush()  {
        file.sync(); 
    }
}

