001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase.client.coprocessor;
019
020import java.io.IOException;
021import org.apache.hadoop.hbase.Cell;
022import org.apache.hadoop.hbase.HBaseInterfaceAudience;
023import org.apache.hadoop.hbase.PrivateCellUtil;
024import org.apache.hadoop.hbase.coprocessor.ColumnInterpreter;
025import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.EmptyMsg;
026import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.LongMsg;
027import org.apache.hadoop.hbase.util.Bytes;
028import org.apache.yetus.audience.InterfaceAudience;
029import org.apache.yetus.audience.InterfaceStability;
030
031/**
032 * a concrete column interpreter implementation. The cell value is a Long value and its promoted
033 * data type is also a Long value. For computing aggregation function, this class is used to find
034 * the datatype of the cell value. Client is supposed to instantiate it and passed along as a
035 * parameter. See TestAggregateProtocol methods for its sample usage. Its methods handle null
036 * arguments gracefully.
037 */
038@InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.COPROC)
039@InterfaceStability.Evolving
040public class LongColumnInterpreter
041  extends ColumnInterpreter<Long, Long, EmptyMsg, LongMsg, LongMsg> {
042
043  @Override
044  public Long getValue(byte[] colFamily, byte[] colQualifier, Cell kv) throws IOException {
045    if (kv == null || kv.getValueLength() != Bytes.SIZEOF_LONG) return null;
046    return PrivateCellUtil.getValueAsLong(kv);
047  }
048
049  @Override
050  public Long add(Long l1, Long l2) {
051    if (l1 == null ^ l2 == null) {
052      return (l1 == null) ? l2 : l1; // either of one is null.
053    } else if (l1 == null) // both are null
054      return null;
055    return l1 + l2;
056  }
057
058  @Override
059  public int compare(final Long l1, final Long l2) {
060    if (l1 == null ^ l2 == null) {
061      return l1 == null ? -1 : 1; // either of one is null.
062    } else if (l1 == null) return 0; // both are null
063    return l1.compareTo(l2); // natural ordering.
064  }
065
066  @Override
067  public Long getMaxValue() {
068    return Long.MAX_VALUE;
069  }
070
071  @Override
072  public Long increment(Long o) {
073    return o == null ? null : (o + 1l);
074  }
075
076  @Override
077  public Long multiply(Long l1, Long l2) {
078    return (l1 == null || l2 == null) ? null : l1 * l2;
079  }
080
081  @Override
082  public Long getMinValue() {
083    return Long.MIN_VALUE;
084  }
085
086  @Override
087  public double divideForAvg(Long l1, Long l2) {
088    return (l2 == null || l1 == null) ? Double.NaN : (l1.doubleValue() / l2.doubleValue());
089  }
090
091  @Override
092  public Long castToReturnType(Long o) {
093    return o;
094  }
095
096  @Override
097  public Long castToCellType(Long l) {
098    return l;
099  }
100
101  @Override
102  public EmptyMsg getRequestData() {
103    return EmptyMsg.getDefaultInstance();
104  }
105
106  @Override
107  public void initialize(EmptyMsg msg) {
108    // nothing
109  }
110
111  @Override
112  public LongMsg getProtoForCellType(Long t) {
113    LongMsg.Builder builder = LongMsg.newBuilder();
114    return builder.setLongMsg(t).build();
115  }
116
117  @Override
118  public LongMsg getProtoForPromotedType(Long s) {
119    LongMsg.Builder builder = LongMsg.newBuilder();
120    return builder.setLongMsg(s).build();
121  }
122
123  @Override
124  public Long getPromotedValueFromProto(LongMsg r) {
125    return r.getLongMsg();
126  }
127
128  @Override
129  public Long getCellValueFromProto(LongMsg q) {
130    return q.getLongMsg();
131  }
132}