min and max star tree aggregators

Signed-off-by: Sarthak Aggarwal <sarthagg@amazon.com>

server/src/main/java/org/opensearch/index/compositeindex/datacube/startree/aggregators/MaxValueAggregator.java

@@ -0,0 +1,75 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+package org.opensearch.index.compositeindex.datacube.startree.aggregators;
+
+import org.apache.lucene.util.NumericUtils;
+import org.opensearch.index.compositeindex.datacube.MetricStat;
+import org.opensearch.index.compositeindex.datacube.startree.aggregators.numerictype.StarTreeNumericType;
+
+/**
+ * Max value aggregator for star tree
+ *
+ * @opensearch.experimental
+ */
+public class MaxValueAggregator implements ValueAggregator<Double> {
+
+    public static final StarTreeNumericType VALUE_AGGREGATOR_TYPE = StarTreeNumericType.DOUBLE;
+
+    @Override
+    public MetricStat getAggregationType() {
+        return MetricStat.MAX;
+    }
+
+    @Override
+    public StarTreeNumericType getAggregatedValueType() {
+        return VALUE_AGGREGATOR_TYPE;
+    }
+
+    @Override
+    public Double getInitialAggregatedValueForSegmentDocValue(Long segmentDocValue, StarTreeNumericType starTreeNumericType) {
+        return starTreeNumericType.getDoubleValue(segmentDocValue);
+    }
+
+    @Override
+    public Double mergeAggregatedValueAndSegmentValue(Double value, Long segmentDocValue, StarTreeNumericType starTreeNumericType) {
+        return Math.max(value, starTreeNumericType.getDoubleValue(segmentDocValue));
+    }
+
+    @Override
+    public Double mergeAggregatedValues(Double value, Double aggregatedValue) {
+        return Math.max(value, aggregatedValue);
+    }
+
+    @Override
+    public Double getInitialAggregatedValue(Double value) {
+        return value;
+    }
+
+    @Override
+    public int getMaxAggregatedValueByteSize() {
+        return Double.BYTES;
+    }
+
+    @Override
+    public Long toLongValue(Double value) {
+        try {
+            return NumericUtils.doubleToSortableLong(value);
+        } catch (Exception e) {
+            throw new IllegalStateException("Cannot convert " + value + " to sortable long", e);
+        }
+    }
+
+    @Override
+    public Double toStarTreeNumericTypeValue(Long value, StarTreeNumericType type) {
+        try {
+            return type.getDoubleValue(value);
+        } catch (Exception e) {
+            throw new IllegalStateException("Cannot convert " + value + " to sortable aggregation type", e);
+        }
+    }
+}

server/src/main/java/org/opensearch/index/compositeindex/datacube/startree/aggregators/MinValueAggregator.java

@@ -0,0 +1,75 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+package org.opensearch.index.compositeindex.datacube.startree.aggregators;
+
+import org.apache.lucene.util.NumericUtils;
+import org.opensearch.index.compositeindex.datacube.MetricStat;
+import org.opensearch.index.compositeindex.datacube.startree.aggregators.numerictype.StarTreeNumericType;
+
+/**
+ * Min value aggregator for star tree
+ *
+ * @opensearch.experimental
+ */
+public class MinValueAggregator implements ValueAggregator<Double> {
+
+    public static final StarTreeNumericType VALUE_AGGREGATOR_TYPE = StarTreeNumericType.DOUBLE;
+
+    @Override
+    public MetricStat getAggregationType() {
+        return MetricStat.MIN;
+    }
+
+    @Override
+    public StarTreeNumericType getAggregatedValueType() {
+        return VALUE_AGGREGATOR_TYPE;
+    }
+
+    @Override
+    public Double getInitialAggregatedValueForSegmentDocValue(Long segmentDocValue, StarTreeNumericType starTreeNumericType) {
+        return starTreeNumericType.getDoubleValue(segmentDocValue);
+    }
+
+    @Override
+    public Double mergeAggregatedValueAndSegmentValue(Double value, Long segmentDocValue, StarTreeNumericType starTreeNumericType) {
+        return Math.min(value, starTreeNumericType.getDoubleValue(segmentDocValue));
+    }
+
+    @Override
+    public Double mergeAggregatedValues(Double value, Double aggregatedValue) {
+        return Math.min(value, aggregatedValue);
+    }
+
+    @Override
+    public Double getInitialAggregatedValue(Double value) {
+        return value;
+    }
+
+    @Override
+    public int getMaxAggregatedValueByteSize() {
+        return Double.BYTES;
+    }
+
+    @Override
+    public Long toLongValue(Double value) {
+        try {
+            return NumericUtils.doubleToSortableLong(value);
+        } catch (Exception e) {
+            throw new IllegalStateException("Cannot convert " + value + " to sortable long", e);
+        }
+    }
+
+    @Override
+    public Double toStarTreeNumericTypeValue(Long value, StarTreeNumericType type) {
+        try {
+            return type.getDoubleValue(value);
+        } catch (Exception e) {
+            throw new IllegalStateException("Cannot convert " + value + " to sortable aggregation type", e);
+        }
+    }
+}

server/src/main/java/org/opensearch/index/compositeindex/datacube/startree/aggregators/ValueAggregatorFactory.java

@@ -26,11 +26,15 @@ private ValueAggregatorFactory() {}
      */
     public static ValueAggregator getValueAggregator(MetricStat aggregationType) {
         switch (aggregationType) {
-            // other metric types (count, min, max, avg) will be supported in the future
+            // avg aggregator will be covered in the part of query (using count and sum)
             case SUM:
                 return new SumValueAggregator();
             case COUNT:
                 return new CountValueAggregator();
+            case MIN:
+                return new MinValueAggregator();
+            case MAX:
+                return new MaxValueAggregator();
             default:
                 throw new IllegalStateException("Unsupported aggregation type: " + aggregationType);
         }
@@ -49,6 +53,10 @@ public static StarTreeNumericType getAggregatedValueType(MetricStat aggregationT
                 return SumValueAggregator.VALUE_AGGREGATOR_TYPE;
             case COUNT:
                 return CountValueAggregator.VALUE_AGGREGATOR_TYPE;
+            case MIN:
+                return MinValueAggregator.VALUE_AGGREGATOR_TYPE;
+            case MAX:
+                return MaxValueAggregator.VALUE_AGGREGATOR_TYPE;
             default:
                 throw new IllegalStateException("Unsupported aggregation type: " + aggregationType);
         }

server/src/test/java/org/opensearch/index/compositeindex/datacube/startree/aggregators/MaxValueAggregatorTests.java

@@ -0,0 +1,58 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.index.compositeindex.datacube.startree.aggregators;
+
+import org.apache.lucene.util.NumericUtils;
+import org.opensearch.index.compositeindex.datacube.MetricStat;
+import org.opensearch.index.compositeindex.datacube.startree.aggregators.numerictype.StarTreeNumericType;
+import org.opensearch.test.OpenSearchTestCase;
+
+public class MaxValueAggregatorTests extends OpenSearchTestCase {
+    private final MaxValueAggregator aggregator = new MaxValueAggregator();
+
+    public void testGetAggregationType() {
+        assertEquals(MetricStat.MAX.getTypeName(), aggregator.getAggregationType().getTypeName());
+    }
+
+    public void testGetAggregatedValueType() {
+        assertEquals(MaxValueAggregator.VALUE_AGGREGATOR_TYPE, aggregator.getAggregatedValueType());
+    }
+
+    public void testGetInitialAggregatedValueForSegmentDocValue() {
+        assertEquals(1.0, aggregator.getInitialAggregatedValueForSegmentDocValue(1L, StarTreeNumericType.LONG), 0.0);
+        assertThrows(
+            NullPointerException.class,
+            () -> aggregator.getInitialAggregatedValueForSegmentDocValue(null, StarTreeNumericType.DOUBLE)
+        );
+    }
+
+    public void testMergeAggregatedValueAndSegmentValue() {
+        assertEquals(3.0, aggregator.mergeAggregatedValueAndSegmentValue(2.0, 3L, StarTreeNumericType.LONG), 0.0);
+    }
+
+    public void testMergeAggregatedValues() {
+        assertEquals(3.0, aggregator.mergeAggregatedValues(2.0, 3.0), 0.0);
+    }
+
+    public void testGetInitialAggregatedValue() {
+        assertEquals(3.0, aggregator.getInitialAggregatedValue(3.0), 0.0);
+    }
+
+    public void testGetMaxAggregatedValueByteSize() {
+        assertEquals(Double.BYTES, aggregator.getMaxAggregatedValueByteSize());
+    }
+
+    public void testToLongValue() {
+        assertEquals(NumericUtils.doubleToSortableLong(3.0), aggregator.toLongValue(3.0), 0.0);
+    }
+
+    public void testToStarTreeNumericTypeValue() {
+        assertEquals(NumericUtils.sortableLongToDouble(3L), aggregator.toStarTreeNumericTypeValue(3L, StarTreeNumericType.DOUBLE), 0.0);
+    }
+}

server/src/test/java/org/opensearch/index/compositeindex/datacube/startree/aggregators/MinValueAggregatorTests.java

@@ -0,0 +1,58 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.index.compositeindex.datacube.startree.aggregators;
+
+import org.apache.lucene.util.NumericUtils;
+import org.opensearch.index.compositeindex.datacube.MetricStat;
+import org.opensearch.index.compositeindex.datacube.startree.aggregators.numerictype.StarTreeNumericType;
+import org.opensearch.test.OpenSearchTestCase;
+
+public class MinValueAggregatorTests extends OpenSearchTestCase {
+    private final MinValueAggregator aggregator = new MinValueAggregator();
+
+    public void testGetAggregationType() {
+        assertEquals(MetricStat.MIN.getTypeName(), aggregator.getAggregationType().getTypeName());
+    }
+
+    public void testGetAggregatedValueType() {
+        assertEquals(MinValueAggregator.VALUE_AGGREGATOR_TYPE, aggregator.getAggregatedValueType());
+    }
+
+    public void testGetInitialAggregatedValueForSegmentDocValue() {
+        assertEquals(1.0, aggregator.getInitialAggregatedValueForSegmentDocValue(1L, StarTreeNumericType.LONG), 0.0);
+        assertThrows(
+            NullPointerException.class,
+            () -> aggregator.getInitialAggregatedValueForSegmentDocValue(null, StarTreeNumericType.DOUBLE)
+        );
+    }
+
+    public void testMergeAggregatedValueAndSegmentValue() {
+        assertEquals(2.0, aggregator.mergeAggregatedValueAndSegmentValue(2.0, 3L, StarTreeNumericType.LONG), 0.0);
+    }
+
+    public void testMergeAggregatedValues() {
+        assertEquals(2.0, aggregator.mergeAggregatedValues(2.0, 3.0), 0.0);
+    }
+
+    public void testGetInitialAggregatedValue() {
+        assertEquals(3.0, aggregator.getInitialAggregatedValue(3.0), 0.0);
+    }
+
+    public void testGetMaxAggregatedValueByteSize() {
+        assertEquals(Double.BYTES, aggregator.getMaxAggregatedValueByteSize());
+    }
+
+    public void testToLongValue() {
+        assertEquals(NumericUtils.doubleToSortableLong(3.0), aggregator.toLongValue(3.0), 0.0);
+    }
+
+    public void testToStarTreeNumericTypeValue() {
+        assertEquals(NumericUtils.sortableLongToDouble(3L), aggregator.toStarTreeNumericTypeValue(3L, StarTreeNumericType.DOUBLE), 0.0);
+    }
+}