src/org/apache/pig/builtin/BinStorage.java

/*
 * 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.pig.builtin;

import java.io.BufferedOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Iterator;

import org.apache.pig.ReversibleLoadStoreFunc;
import org.apache.pig.data.Tuple;
import org.apache.pig.impl.io.BufferedPositionedInputStream;

public class BinStorage implements ReversibleLoadStoreFunc {
    Iterator<Tuple>     i              = null;
    protected BufferedPositionedInputStream in = null;
    private DataInputStream inData = null;
    protected long                end            = Long.MAX_VALUE;
    
    /**
     * Simple binary nested reader format
     */
    public BinStorage() {
    }

    public Tuple getNext() throws IOException {
        
        byte b = 0;
//      skip to next record
        while (true) {
            if (in == null || in.getPosition() >=end) {
                return null;
            }
            b = (byte) in.read();
            if(b != Tuple.RECORD_1 && b != -1) {
                continue;
            }
            if(b == -1) return null;
            b = (byte) in.read();
            if(b != Tuple.RECORD_2 && b != -1) {
                continue;
            }
            if(b == -1) return null;
            b = (byte) in.read();
            if(b != Tuple.RECORD_3 && b != -1) {
                continue;
            }
            if(b == -1) return null;
            break;
        }
        Tuple t = new Tuple();
        t.readFields(inData);
        return t;
    }

    public void bindTo(String fileName, BufferedPositionedInputStream in, long offset, long end) throws IOException {
        this.in = in;
        inData = new DataInputStream(in);
        this.end = end;
    }


    DataOutputStream         out     = null;
  
    public void bindTo(OutputStream os) throws IOException {
        this.out = new DataOutputStream(new BufferedOutputStream(os));
    }

    public void finish() throws IOException {
        out.flush();
    }

    public void putNext(Tuple t) throws IOException {
        out.write(Tuple.RECORD_1);
        out.write(Tuple.RECORD_2);
        out.write(Tuple.RECORD_3);
        t.write(out);
    }

    public boolean equals(Object obj) {
        return true;
    }
}