org.zuinnote.hadoop.bitcoin.format.BitcoinRawBlockRecordReader.java Source code

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Here is the source code for org.zuinnote.hadoop.bitcoin.format.BitcoinRawBlockRecordReader.java

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/**
* Copyright 2016 ZuInnoTe (Jrn Franke) <zuinnote@gmail.com>
*
* 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 org.zuinnote.hadoop.bitcoin.format;

import org.zuinnote.hadoop.bitcoin.format.exception.HadoopCryptoLedgerConfigurationException;
import org.zuinnote.hadoop.bitcoin.format.exception.BitcoinBlockReadException;

import java.io.IOException;
import java.io.InputStream;

import java.nio.ByteBuffer;

import org.apache.hadoop.io.BytesWritable;

import org.apache.hadoop.mapred.FileSplit;
import org.apache.hadoop.mapred.JobConf;
import org.apache.hadoop.mapred.Reporter;

import org.apache.commons.logging.LogFactory;
import org.apache.commons.logging.Log;

public class BitcoinRawBlockRecordReader extends AbstractBitcoinRecordReader<BytesWritable, BytesWritable> {
    private static final Log LOG = LogFactory.getLog(BitcoinRawBlockRecordReader.class.getName());

    public BitcoinRawBlockRecordReader(FileSplit split, JobConf job, Reporter reporter)
            throws IOException, HadoopCryptoLedgerConfigurationException, BitcoinBlockReadException {
        super(split, job, reporter);
    }

    /**
    *
    * Create an empty key
    *
    * @return key
    */
    public BytesWritable createKey() {
        return new BytesWritable();
    }

    /**
    *
    * Create an empty value
    *
    * @return value
    */
    public BytesWritable createValue() {
        return new BytesWritable();
    }

    /**
    *
    * Read a next block. 
    *
    * @param key is a 64 byte array (hashMerkleRoot and prevHashBlock)
    * @param value is a deserialized Java object of class BitcoinBlock
    *
    * @return true if next block is available, false if not
    */
    public boolean next(BytesWritable key, BytesWritable value) throws IOException {
        // read all the blocks, if necessary a block overlapping a split
        while (getFilePosition() <= getEnd()) { // did we already went beyond the split (remote) or do we have no further data left?
            ByteBuffer dataBlock = null;
            try {
                dataBlock = getBbr().readRawBlock();
            } catch (BitcoinBlockReadException e) {
                // log
                LOG.error(e);
            }
            if (dataBlock == null)
                return false;
            byte newKey[] = getBbr().getKeyFromRawBlock(dataBlock);
            key.set(newKey, 0, newKey.length);
            byte[] dataBlockArray = null;
            if (dataBlock.hasArray() == true) {
                dataBlockArray = dataBlock.array();
            } else {
                dataBlockArray = new byte[dataBlock.capacity()];
                dataBlock.get(dataBlockArray);
            }
            value.set(dataBlockArray, 0, dataBlockArray.length);
            return true;
        }
        return false;
    }

}