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Posted to commits@flink.apache.org by se...@apache.org on 2015/09/07 17:35:18 UTC
[3/5] flink git commit: [FLINK-2626] [core] Add an average accumulator
[FLINK-2626] [core] Add an average accumulator
This closes #1096
Project: http://git-wip-us.apache.org/repos/asf/flink/repo
Commit: http://git-wip-us.apache.org/repos/asf/flink/commit/2f8bcf53
Tree: http://git-wip-us.apache.org/repos/asf/flink/tree/2f8bcf53
Diff: http://git-wip-us.apache.org/repos/asf/flink/diff/2f8bcf53
Branch: refs/heads/master
Commit: 2f8bcf538e025a953ac70f4f6d13f277111ee2a1
Parents: 9910510
Author: HuangWHWHW <40...@qq.com>
Authored: Sun Sep 6 12:15:12 2015 +0800
Committer: Stephan Ewen <se...@apache.org>
Committed: Mon Sep 7 14:46:31 2015 +0200
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.../common/accumulators/AverageAccumulator.java | 88 ++++++++++++++
.../accumulators/AverageAccumulatorTest.java | 114 +++++++++++++++++++
2 files changed, 202 insertions(+)
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http://git-wip-us.apache.org/repos/asf/flink/blob/2f8bcf53/flink-core/src/main/java/org/apache/flink/api/common/accumulators/AverageAccumulator.java
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diff --git a/flink-core/src/main/java/org/apache/flink/api/common/accumulators/AverageAccumulator.java b/flink-core/src/main/java/org/apache/flink/api/common/accumulators/AverageAccumulator.java
new file mode 100644
index 0000000..8982928
--- /dev/null
+++ b/flink-core/src/main/java/org/apache/flink/api/common/accumulators/AverageAccumulator.java
@@ -0,0 +1,88 @@
+/*
+ * 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.flink.api.common.accumulators;
+
+/**
+ * An accumulator that get the average values.
+ * Input can be {@code long}, {@code integer}, {@code double} as the result is {@code double}.
+ */
+public class AverageAccumulator implements SimpleAccumulator <Double> {
+
+ private double localValue = 0;
+ private long count = 0;
+
+ @Override
+ public void add(Double value) {
+ this.count++;
+ this.localValue += value;
+ }
+
+ public void add(double value) {
+ this.count++;
+ this.localValue += value;
+ }
+
+ public void add(long value) {
+ this.count++;
+ this.localValue += value;
+ }
+
+ public void add(int value) {
+ this.count++;
+ this.localValue += value;
+ }
+
+ @Override
+ public Double getLocalValue() {
+ if (this.count == 0) {
+ return 0.0;
+ }
+ return this.localValue / (double)this.count;
+ }
+
+ @Override
+ public void resetLocal() {
+ this.count = 0;
+ this.localValue = 0;
+ }
+
+ @Override
+ public void merge(Accumulator<Double, Double> other) {
+ if (other instanceof AverageAccumulator) {
+ AverageAccumulator temp = (AverageAccumulator)other;
+ this.count += temp.count;
+ this.localValue += other.getLocalValue();
+ } else {
+ throw new RuntimeException("The merged accumulator must be AverageAccumulator.");
+ }
+ }
+
+ @Override
+ public AverageAccumulator clone() {
+ AverageAccumulator average = new AverageAccumulator();
+ average.localValue = this.localValue;
+ average.count = this.count;
+ return average;
+ }
+
+ @Override
+ public String toString() {
+ return "AverageAccumulator " + this.localValue + " count " + this.count;
+ }
+}
http://git-wip-us.apache.org/repos/asf/flink/blob/2f8bcf53/flink-core/src/test/java/org/apache/flink/api/common/accumulators/AverageAccumulatorTest.java
----------------------------------------------------------------------
diff --git a/flink-core/src/test/java/org/apache/flink/api/common/accumulators/AverageAccumulatorTest.java b/flink-core/src/test/java/org/apache/flink/api/common/accumulators/AverageAccumulatorTest.java
new file mode 100644
index 0000000..5cd2a64
--- /dev/null
+++ b/flink-core/src/test/java/org/apache/flink/api/common/accumulators/AverageAccumulatorTest.java
@@ -0,0 +1,114 @@
+/*
+ * 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.flink.api.common.accumulators;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
+public class AverageAccumulatorTest {
+
+ @Test
+ public void testGet() {
+ AverageAccumulator average = new AverageAccumulator();
+ assertEquals(Double.valueOf(0), average.getLocalValue());
+ }
+
+ @Test
+ public void testAdd() {
+ AverageAccumulator average = new AverageAccumulator();
+ int i1;
+ for (i1 = 0; i1 < 10; i1++) {
+ average.add(i1);
+ }
+ assertEquals(Double.valueOf(4.5), average.getLocalValue());
+ average.resetLocal();
+
+ Integer i2;
+ for (i2 = 0; i2 < 10; i2++) {
+ average.add(i2);
+ }
+ assertEquals(Double.valueOf(4.5), average.getLocalValue());
+ average.resetLocal();
+
+ long i3;
+ for (i3 = 0; i3 < 10; i3++) {
+ average.add(i3);
+ }
+ assertEquals(Double.valueOf(4.5), average.getLocalValue());
+ average.resetLocal();
+
+ Long i4;
+ for (i4 = 0L; i4 < 10; i4++) {
+ average.add(i4);
+ }
+ assertEquals(Double.valueOf(4.5), average.getLocalValue());
+ average.resetLocal();
+
+ double i5;
+ for (i5 = 0; i5 < 10; i5++) {
+ average.add(i5);
+ }
+ assertEquals(Double.valueOf(4.5), average.getLocalValue());
+ average.resetLocal();
+
+ Double i6;
+ for (i6 = 0.0; i6 < 10; i6++) {
+ average.add(i6);
+ }
+ assertEquals(Double.valueOf(4.5), average.getLocalValue());
+ average.resetLocal();
+
+ assertEquals(Double.valueOf(0), average.getLocalValue());
+ }
+
+ @Test
+ public void testMergeSuccess() {
+ AverageAccumulator average = new AverageAccumulator();
+ AverageAccumulator averageNew = new AverageAccumulator();
+ average.add(1);
+ averageNew.add(2);
+ average.merge(averageNew);
+ assertEquals(Double.valueOf(1.5), average.getLocalValue());
+ }
+
+ @Test
+ public void testMergeFailed() {
+ AverageAccumulator average = new AverageAccumulator();
+ Accumulator<Double, Double> averageNew = null;
+ average.add(1);
+ try {
+ average.merge(averageNew);
+ } catch (Exception e) {
+ assertTrue(e.toString().indexOf("The merged accumulator must be AverageAccumulator.") != -1);
+ return;
+ }
+ fail();
+ }
+
+ @Test
+ public void testClone() {
+ AverageAccumulator average = new AverageAccumulator();
+ average.add(1);
+ AverageAccumulator averageNew = average.clone();
+ assertEquals(Double.valueOf(1), averageNew.getLocalValue());
+ }
+}