yurmix commented on a change in pull request #6430: Contributing Moving-Average Query to open source. URL: https://github.com/apache/incubator-druid/pull/6430#discussion_r267088298
########## File path: extensions-contrib/moving-average-query/src/main/java/org/apache/druid/query/movingaverage/RowBucketIterable.java ########## @@ -0,0 +1,147 @@ +/* + * 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.druid.query.movingaverage; + +import org.apache.druid.data.input.Row; +import org.apache.druid.java.util.common.guava.Sequence; +import org.apache.druid.java.util.common.guava.Yielder; +import org.joda.time.DateTime; +import org.joda.time.Interval; +import org.joda.time.Period; + +import java.util.Collections; +import java.util.Iterator; +import java.util.List; +import java.util.NoSuchElementException; + +/** + * It is the iterable used to bucket data into days, + * doing appropriate lookahead to see if the next row is in the same day or a new day. + */ +public class RowBucketIterable implements Iterable<RowBucket> +{ + + public final Sequence<Row> seq; + private List<Interval> intervals; + private Period period; + + public RowBucketIterable(Sequence<Row> seq, List<Interval> intervals, Period period) + { + this.seq = seq; + this.period = period; + this.intervals = intervals; + } + + /* (non-Javadoc) + * @see java.lang.Iterable#iterator() + */ + @Override + public Iterator<RowBucket> iterator() + { + return new RowBucketIterator(seq, intervals, period); + } + + static class RowBucketIterator implements Iterator<RowBucket> + { + private Yielder<RowBucket> yielder; + private DateTime endTime; + private DateTime expectedBucket; + private Period period; + private int intervalIndex = 0; + private List<Interval> intervals; + private boolean processedLastRow = false; + private boolean processedExtraRow = false; + + public RowBucketIterator(Sequence<Row> rows, List<Interval> intervals, Period period) + { + this.period = period; + this.intervals = intervals; + expectedBucket = intervals.get(intervalIndex).getStart(); + endTime = intervals.get(intervals.size() - 1).getEnd(); + yielder = rows.toYielder(null, new BucketingAccumulator()); + } + + /* (non-Javadoc) + * @see java.util.Iterator#hasNext() + */ + @Override + public boolean hasNext() + { + return expectedBucket.compareTo(endTime) < 0; + } + + /* (non-Javadoc) + * @see java.util.Iterator#next() + */ + @Override + public RowBucket next() + { + RowBucket currentBucket = yielder.get(); + + if (expectedBucket.compareTo(intervals.get(intervalIndex).getEnd()) >= 0) { + intervalIndex++; + if (intervalIndex < intervals.size()) { + expectedBucket = intervals.get(intervalIndex).getStart(); + } + } + // currentBucket > expectedBucket + if (currentBucket != null && currentBucket.getDateTime().compareTo(expectedBucket) > 0) { + currentBucket = new RowBucket(expectedBucket, Collections.emptyList()); + expectedBucket = expectedBucket.plus(period); + return currentBucket; + } + + if (!yielder.isDone()) { + // standard case. return regular row + yielder = yielder.next(currentBucket); + expectedBucket = expectedBucket.plus(period); + return currentBucket; Review comment: `hasNext()` is correct since interval upper bound is open-ended. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@druid.apache.org For additional commands, e-mail: commits-h...@druid.apache.org
