/*
* Copyright 2011 The Apache Software Foundation
*
* 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.hadoop.hbase.coprocessor;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.hbase.KeyValue;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.filter.FirstKeyOnlyFilter;
import org.apache.hadoop.hbase.ipc.ProtocolSignature;
import org.apache.hadoop.hbase.regionserver.InternalScanner;
import org.apache.hadoop.hbase.util.Pair;
/**
* A concrete AggregateProtocol implementation. Its system level coprocessor
* that computes the aggregate function at a region level.
*/
public class AggregateImplementation extends BaseEndpointCoprocessor implements
AggregateProtocol {
protected static Log log = LogFactory.getLog(AggregateImplementation.class);
@Override
public ProtocolSignature getProtocolSignature(
String protocol, long version, int clientMethodsHashCode)
throws IOException {
if (AggregateProtocol.class.getName().equals(protocol)) {
return new ProtocolSignature(AggregateProtocol.VERSION, null);
}
throw new IOException("Unknown protocol: " + protocol);
}
@Override
public <T, S> T getMax(ColumnInterpreter<T, S> ci, Scan scan)
throws IOException {
T temp;
T max = null;
InternalScanner scanner = ((RegionCoprocessorEnvironment) getEnvironment())
.getRegion().getScanner(scan);
List<KeyValue> results = new ArrayList<KeyValue>();
byte[] colFamily = scan.getFamilies()[0];
byte[] qualifier = scan.getFamilyMap().get(colFamily).pollFirst();
// qualifier can be null.
try {
boolean hasMoreRows = false;
do {
hasMoreRows = scanner.next(results);
for (KeyValue kv : results) {
temp = ci.getValue(colFamily, qualifier, kv);
max = (max == null || ci.compare(temp, max) > 0) ? temp : max;
}
results.clear();
} while (hasMoreRows);
} finally {
scanner.close();
}
log.info("Maximum from this region is "
+ ((RegionCoprocessorEnvironment) getEnvironment()).getRegion()
.getRegionNameAsString() + ": " + max);
return max;
}
@Override
public <T, S> T getMin(ColumnInterpreter<T, S> ci, Scan scan)
throws IOException {
T min = null;
T temp;
InternalScanner scanner = ((RegionCoprocessorEnvironment) getEnvironment())
.getRegion().getScanner(scan);
List<KeyValue> results = new ArrayList<KeyValue>();
byte[] colFamily = scan.getFamilies()[0];
byte[] qualifier = scan.getFamilyMap().get(colFamily).pollFirst();
try {
boolean hasMoreRows = false;
do {
hasMoreRows = scanner.next(results);
for (KeyValue kv : results) {
temp = ci.getValue(colFamily, qualifier, kv);
min = (min == null || ci.compare(temp, min) < 0) ? temp : min;
}
results.clear();
} while (hasMoreRows);
} finally {
scanner.close();
}
log.info("Minimum from this region is "
+ ((RegionCoprocessorEnvironment) getEnvironment()).getRegion()
.getRegionNameAsString() + ": " + min);
return min;
}
@Override
public <T, S> S getSum(ColumnInterpreter<T, S> ci, Scan scan)
throws IOException {
long sum = 0l;
S sumVal = null;
T temp;
InternalScanner scanner = ((RegionCoprocessorEnvironment) getEnvironment())
.getRegion().getScanner(scan);
byte[] colFamily = scan.getFamilies()[0];
byte[] qualifier = scan.getFamilyMap().get(colFamily).pollFirst();
List<KeyValue> results = new ArrayList<KeyValue>();
try {
boolean hasMoreRows = false;
do {
hasMoreRows = scanner.next(results);
for (KeyValue kv : results) {
temp = ci.getValue(colFamily, qualifier, kv);
if (temp != null)
sumVal = ci.add(sumVal, ci.castToReturnType(temp));
}
results.clear();
} while (hasMoreRows);
} finally {
scanner.close();
}
log.debug("Sum from this region is "
+ ((RegionCoprocessorEnvironment) getEnvironment()).getRegion()
.getRegionNameAsString() + ": " + sum);
return sumVal;
}
@Override
public <T, S> long getRowNum(ColumnInterpreter<T, S> ci, Scan scan)
throws IOException {
long counter = 0l;
List<KeyValue> results = new ArrayList<KeyValue>();
byte[] colFamily = scan.getFamilies()[0];
byte[] qualifier = scan.getFamilyMap().get(colFamily).pollFirst();
if (scan.getFilter() == null && qualifier == null)
scan.setFilter(new FirstKeyOnlyFilter());
InternalScanner scanner = ((RegionCoprocessorEnvironment) getEnvironment())
.getRegion().getScanner(scan);
try {
boolean hasMoreRows = false;
do {
hasMoreRows = scanner.next(results);
if (results.size() > 0) {
counter++;
}
results.clear();
} while (hasMoreRows);
} finally {
scanner.close();
}
log.info("Row counter from this region is "
+ ((RegionCoprocessorEnvironment) getEnvironment()).getRegion()
.getRegionNameAsString() + ": " + counter);
return counter;
}
@Override
public <T, S> Pair<S, Long> getAvg(ColumnInterpreter<T, S> ci, Scan scan)
throws IOException {
S sumVal = null;
Long rowCountVal = 0l;
InternalScanner scanner = ((RegionCoprocessorEnvironment) getEnvironment())
.getRegion().getScanner(scan);
byte[] colFamily = scan.getFamilies()[0];
byte[] qualifier = scan.getFamilyMap().get(colFamily).pollFirst();
List<KeyValue> results = new ArrayList<KeyValue>();
boolean hasMoreRows = false;
try {
do {
results.clear();
hasMoreRows = scanner.next(results);
for (KeyValue kv : results) {
sumVal = ci.add(sumVal, ci.castToReturnType(ci.getValue(colFamily,
qualifier, kv)));
}
rowCountVal++;
} while (hasMoreRows);
} finally {
scanner.close();
}
Pair<S, Long> pair = new Pair<S, Long>(sumVal, rowCountVal);
return pair;
}
@Override
public <T, S> Pair<List<S>, Long> getStd(ColumnInterpreter<T, S> ci, Scan scan)
throws IOException {
S sumVal = null, sumSqVal = null, tempVal = null;
long rowCountVal = 0l;
InternalScanner scanner = ((RegionCoprocessorEnvironment) getEnvironment())
.getRegion().getScanner(scan);
byte[] colFamily = scan.getFamilies()[0];
byte[] qualifier = scan.getFamilyMap().get(colFamily).pollFirst();
List<KeyValue> results = new ArrayList<KeyValue>();
boolean hasMoreRows = false;
try {
do {
tempVal = null;
hasMoreRows = scanner.next(results);
for (KeyValue kv : results) {
tempVal = ci.add(tempVal, ci.castToReturnType(ci.getValue(colFamily,
qualifier, kv)));
}
results.clear();
sumVal = ci.add(sumVal, tempVal);
sumSqVal = ci.add(sumSqVal, ci.multiply(tempVal, tempVal));
rowCountVal++;
} while (hasMoreRows);
} finally {
scanner.close();
}
List<S> l = new ArrayList<S>();
l.add(sumVal);
l.add(sumSqVal);
Pair<List<S>, Long> p = new Pair<List<S>, Long>(l, rowCountVal);
return p;
}
}