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complete javadoc, add comment, use Lists.reverse

This commit is contained in:
nishantmonu51 2014-04-15 22:55:40 +05:30
parent 3eb8160b51
commit 6217c67027
1 changed files with 7 additions and 5 deletions
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12
processing/src/main/java/io/druid/query/aggregation/AggregatorUtil.java
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@ -28,8 +28,11 @@ import java.util.Set;
public class AggregatorUtil
{
/** returns the list of dependent postAggregators that should be calculated in order to calculate given postAgg
* @param postAggregatorList List of postAggregator, there is a restriction that the postAgg should be in order that it can
/**
* returns the list of dependent postAggregators that should be calculated in order to calculate given postAgg
*
* @param postAggregatorList List of postAggregator, there is a restriction that the list should be in an order
* such that all the dependencies of any given aggregator should occur before that aggregator
* @param postAggName name of the postAgg on which dependency is to be calculated
*/
public static List<PostAggregator> pruneDependentPostAgg(List<PostAggregator> postAggregatorList, String postAggName)
@ -37,9 +40,8 @@ public class AggregatorUtil
LinkedList<PostAggregator> rv = Lists.newLinkedList();
Set<String> deps = new HashSet<>();
deps.add(postAggName);
// Iterate backwards to calculate deps
for (int i = postAggregatorList.size() - 1; i >= 0; i--) {
PostAggregator agg = postAggregatorList.get(i);
// Iterate backwards to find the last calculated aggregate and add dependent aggregator as we find dependencies in reverse order
for (PostAggregator agg : Lists.reverse(postAggregatorList)) {
if (deps.contains(agg.getName())) {
rv.addFirst(agg); // add to the beginning of List
deps.remove(agg.getName());