From 196351946ff26a917fa0e5bf07ceb9be16436d22 Mon Sep 17 00:00:00 2001
From: Luca Frosini <luca.frosini@isti.cnr.it>
Date: Fri, 10 Jul 2015 09:58:29 +0000
Subject: [PATCH] Fixed bug on calculation average duration

git-svn-id: https://svn.d4science.research-infrastructures.eu/gcube/trunk/accounting/accounting-lib@117147 82a268e6-3cf1-43bd-a215-b396298e98cf
---
 .../ServiceUsageRecordAggregationStrategy.java  | 10 +++++++++-
 ...rviceUsageRecordAggregationStrategyTest.java | 17 +++++++++++------
 2 files changed, 20 insertions(+), 7 deletions(-)

diff --git a/src/main/java/org/gcube/accounting/aggregation/strategy/ServiceUsageRecordAggregationStrategy.java b/src/main/java/org/gcube/accounting/aggregation/strategy/ServiceUsageRecordAggregationStrategy.java
index e013d1e..6e5c882 100644
--- a/src/main/java/org/gcube/accounting/aggregation/strategy/ServiceUsageRecordAggregationStrategy.java
+++ b/src/main/java/org/gcube/accounting/aggregation/strategy/ServiceUsageRecordAggregationStrategy.java
@@ -23,13 +23,21 @@ public class ServiceUsageRecordAggregationStrategy extends AggregationStrategy<S
 		this.aggregationField.add(ServiceUsageRecord.SERVICE_CLASS);
 		this.aggregationField.add(ServiceUsageRecord.SERVICE_NAME);
 	}
+	
+	protected long durationWeightedAverage(ServiceUsageRecord record){
+		long tDuration = t.getDuration() * t.getOperationCount();
+		long recordDuration = record.getDuration() * record.getOperationCount();
+		long totalOperationCount = t.getOperationCount() + record.getOperationCount();
+		return (tDuration + recordDuration) / totalOperationCount;
+	}
 
 	protected ServiceUsageRecord reallyAggregate(ServiceUsageRecord record)
 			throws NotAggregatableRecordsExceptions {
 		
 		try {
+			t.setDuration(durationWeightedAverage(record));
 			t.setOperationCount(t.getOperationCount() + record.getOperationCount());
-			t.setDuration((t.getDuration() + record.getDuration()) / 2);
+			
 			
 			long max = record.getMaxInvocationTime();
 			if(max > t.getMaxInvocationTime()){
diff --git a/src/test/java/org/gcube/accounting/aggregation/strategy/ServiceUsageRecordAggregationStrategyTest.java b/src/test/java/org/gcube/accounting/aggregation/strategy/ServiceUsageRecordAggregationStrategyTest.java
index 7db4f02..1cc0a63 100644
--- a/src/test/java/org/gcube/accounting/aggregation/strategy/ServiceUsageRecordAggregationStrategyTest.java
+++ b/src/test/java/org/gcube/accounting/aggregation/strategy/ServiceUsageRecordAggregationStrategyTest.java
@@ -106,6 +106,10 @@ public class ServiceUsageRecordAggregationStrategyTest {
 		Assert.assertFalse(aggregated.getResourceProperties().containsKey(TestUsageRecord.TEST_PROPERTY_NAME));
 	}
 	
+	protected long durationWeightedAverage(int numberA, long durationA, int numberB, long durationB){
+		return ((numberA * durationA) + (numberB * durationB)) / (numberA + numberB);
+	}
+	
 	@Test
 	public void aggregationStressTest() throws InvalidValueException, NotAggregatableRecordsExceptions {
 		
@@ -131,25 +135,26 @@ public class ServiceUsageRecordAggregationStrategyTest {
 			long minInvocationTime = aggregated.getMinInvocationTime();
 			long maxInvocationTime = aggregated.getMaxInvocationTime();
 			long oldDuration = aggregated.getDuration();
-			long newDuration = sur.getDuration();
+			long surDuration = sur.getDuration();
 			
 			suras.aggregate(sur);
 			logger.debug("Resulting Aggregated ServiceUsageRecord: {}", aggregated);
 			aggregated.validate();
 			
-			Assert.assertTrue(aggregated.getDuration() == ((oldDuration + newDuration)/2));
+			long avgDuration = durationWeightedAverage(i-1, oldDuration, 1, surDuration);
+			Assert.assertTrue(aggregated.getDuration() == (avgDuration));
 			Assert.assertTrue(aggregated.getOperationCount() == i);
 			
-			if(minInvocationTime >= newDuration){
-				Assert.assertTrue(aggregated.getMinInvocationTime() == newDuration);
+			if(minInvocationTime >= surDuration){
+				Assert.assertTrue(aggregated.getMinInvocationTime() == surDuration);
 			}else{
 				Assert.assertTrue(aggregated.getMinInvocationTime() == minInvocationTime);
 			}
 			
-			if(maxInvocationTime >= newDuration){
+			if(maxInvocationTime >= surDuration){
 				Assert.assertTrue(aggregated.getMaxInvocationTime() == maxInvocationTime);
 			}else{
-				Assert.assertTrue(aggregated.getMaxInvocationTime() == newDuration);
+				Assert.assertTrue(aggregated.getMaxInvocationTime() == surDuration);
 			}
 			
 			Assert.assertFalse(aggregated.getResourceProperties().containsKey(TestUsageRecord.TEST_PROPERTY_NAME));