Java tutorial
/* * 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.kylin.engine.mr.steps; import java.io.IOException; import java.nio.BufferOverflowException; import java.nio.ByteBuffer; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.kylin.common.util.ImmutableBitSet; import org.apache.kylin.cube.CubeSegment; import org.apache.kylin.cube.cuboid.Cuboid; import org.apache.kylin.cube.inmemcubing.ICuboidWriter; import org.apache.kylin.cube.kv.AbstractRowKeyEncoder; import org.apache.kylin.cube.model.CubeDesc; import org.apache.kylin.engine.mr.ByteArrayWritable; import org.apache.kylin.gridtable.GTRecord; import org.apache.kylin.measure.BufferedMeasureEncoder; /** */ public abstract class KVGTRecordWriter implements ICuboidWriter { private static final Log logger = LogFactory.getLog(KVGTRecordWriter.class); private Long lastCuboidId; protected CubeSegment cubeSegment; protected CubeDesc cubeDesc; private AbstractRowKeyEncoder rowKeyEncoder; private int dimensions; private int measureCount; private byte[] keyBuf; private ImmutableBitSet measureColumns; private ByteBuffer valueBuf = ByteBuffer.allocate(BufferedMeasureEncoder.DEFAULT_BUFFER_SIZE); private ByteArrayWritable outputKey = new ByteArrayWritable(); private ByteArrayWritable outputValue = new ByteArrayWritable(); private long cuboidRowCount = 0; //for shard public KVGTRecordWriter(CubeDesc cubeDesc, CubeSegment cubeSegment) { this.cubeDesc = cubeDesc; this.cubeSegment = cubeSegment; this.measureCount = cubeDesc.getMeasures().size(); } @Override public void write(long cuboidId, GTRecord record) throws IOException { if (lastCuboidId == null || !lastCuboidId.equals(cuboidId)) { if (lastCuboidId != null) { logger.info("Cuboid " + lastCuboidId + " has " + cuboidRowCount + " rows"); cuboidRowCount = 0; } // output another cuboid initVariables(cuboidId); lastCuboidId = cuboidId; } cuboidRowCount++; rowKeyEncoder.encode(record, record.getInfo().getPrimaryKey(), keyBuf); //output measures valueBuf.clear(); try { record.exportColumns(measureColumns, valueBuf); } catch (BufferOverflowException boe) { valueBuf = ByteBuffer.allocate((int) (record.sizeOf(measureColumns) * 1.5)); record.exportColumns(measureColumns, valueBuf); } outputKey.set(keyBuf, 0, keyBuf.length); outputValue.set(valueBuf.array(), 0, valueBuf.position()); writeAsKeyValue(outputKey, outputValue); } protected abstract void writeAsKeyValue(ByteArrayWritable key, ByteArrayWritable value) throws IOException; private void initVariables(Long cuboidId) { rowKeyEncoder = AbstractRowKeyEncoder.createInstance(cubeSegment, Cuboid.findById(cubeDesc, cuboidId)); keyBuf = rowKeyEncoder.createBuf(); dimensions = Long.bitCount(cuboidId); measureColumns = new ImmutableBitSet(dimensions, dimensions + measureCount); } }