Build list of the right length in #finalizeSampling (#124762)

iverase · web-flow · commit 6036a1ef0099 · 2025-03-13T17:14:20.000+01:00
Avoid oversize list in internal aggregations.
diff --git a/modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/histogram/InternalAutoDateHistogram.java b/modules/aggregations/src/main/java/org/elasticsearch/aggregations/bucket/histogram/InternalAutoDateHistogram.java
@@ -532,15 +532,11 @@ public InternalAggregation get() {
 
     @Override
     public InternalAggregation finalizeSampling(SamplingContext samplingContext) {
-        return new InternalAutoDateHistogram(
-            getName(),
-            buckets.stream().map(b -> b.finalizeSampling(samplingContext)).toList(),
-            targetBuckets,
-            bucketInfo,
-            format,
-            getMetadata(),
-            bucketInnerInterval
-        );
+        final List<Bucket> buckets = new ArrayList<>(this.buckets);
+        for (int i = 0; i < buckets.size(); i++) {
+            buckets.set(i, buckets.get(i).finalizeSampling(samplingContext));
+        }
+        return new InternalAutoDateHistogram(getName(), buckets, targetBuckets, bucketInfo, format, getMetadata(), bucketInnerInterval);
     }
 
     private BucketReduceResult maybeMergeConsecutiveBuckets(BucketReduceResult current, AggregationReduceContext reduceContext) {
diff --git a/server/src/main/java/org/elasticsearch/search/aggregations/bucket/composite/InternalComposite.java b/server/src/main/java/org/elasticsearch/search/aggregations/bucket/composite/InternalComposite.java
@@ -270,12 +270,16 @@ public InternalAggregation get() {
 
     @Override
     public InternalAggregation finalizeSampling(SamplingContext samplingContext) {
+        final List<InternalBucket> buckets = new ArrayList<>(this.buckets.size());
+        for (InternalBucket bucket : this.buckets) {
+            buckets.add(bucket.finalizeSampling(samplingContext));
+        }
         return new InternalComposite(
             name,
             size,
             sourceNames,
             buckets.isEmpty() ? formats : buckets.get(buckets.size() - 1).formats,
-            buckets.stream().map(b -> b.finalizeSampling(samplingContext)).toList(),
+            buckets,
             buckets.isEmpty() ? afterKey : buckets.get(buckets.size() - 1).getRawKey(),
             reverseMuls,
             missingOrders,
diff --git a/server/src/main/java/org/elasticsearch/search/aggregations/bucket/filter/InternalFilters.java b/server/src/main/java/org/elasticsearch/search/aggregations/bucket/filter/InternalFilters.java
@@ -223,13 +223,11 @@ public void close() {
 
     @Override
     public InternalAggregation finalizeSampling(SamplingContext samplingContext) {
-        return new InternalFilters(
-            name,
-            buckets.stream().map(b -> b.finalizeSampling(samplingContext)).toList(),
-            keyed,
-            keyedBucket,
-            getMetadata()
-        );
+        final List<InternalBucket> buckets = new ArrayList<>(this.buckets.size());
+        for (InternalBucket bucket : this.buckets) {
+            buckets.add(bucket.finalizeSampling(samplingContext));
+        }
+        return new InternalFilters(name, buckets, keyed, keyedBucket, getMetadata());
     }
 
     @Override
diff --git a/server/src/main/java/org/elasticsearch/search/aggregations/bucket/geogrid/InternalGeoGrid.java b/server/src/main/java/org/elasticsearch/search/aggregations/bucket/geogrid/InternalGeoGrid.java
@@ -23,6 +23,7 @@
 import org.elasticsearch.xcontent.XContentBuilder;
 
 import java.io.IOException;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
@@ -137,20 +138,17 @@ public void close() {
 
     @Override
     public InternalAggregation finalizeSampling(SamplingContext samplingContext) {
-        return create(
-            getName(),
-            requiredSize,
-            buckets.stream()
-                .<InternalGeoGridBucket>map(
-                    b -> this.createBucket(
-                        b.hashAsLong,
-                        samplingContext.scaleUp(b.docCount),
-                        InternalAggregations.finalizeSampling(b.aggregations, samplingContext)
-                    )
+        final List<InternalGeoGridBucket> buckets = new ArrayList<>(this.buckets.size());
+        for (InternalGeoGridBucket bucket : this.buckets) {
+            buckets.add(
+                this.createBucket(
+                    bucket.hashAsLong,
+                    samplingContext.scaleUp(bucket.docCount),
+                    InternalAggregations.finalizeSampling(bucket.aggregations, samplingContext)
                 )
-                .toList(),
-            getMetadata()
-        );
+            );
+        }
+        return create(getName(), requiredSize, buckets, getMetadata());
     }
 
     protected abstract B createBucket(long hashAsLong, long docCount, InternalAggregations aggregations);
diff --git a/server/src/main/java/org/elasticsearch/search/aggregations/bucket/histogram/InternalDateHistogram.java b/server/src/main/java/org/elasticsearch/search/aggregations/bucket/histogram/InternalDateHistogram.java
@@ -515,9 +515,13 @@ public InternalAggregation get() {
 
     @Override
     public InternalAggregation finalizeSampling(SamplingContext samplingContext) {
+        final List<Bucket> buckets = new ArrayList<>(this.buckets.size());
+        for (Bucket bucket : this.buckets) {
+            buckets.add(bucket.finalizeSampling(samplingContext));
+        }
         return new InternalDateHistogram(
             getName(),
-            buckets.stream().map(b -> b.finalizeSampling(samplingContext)).toList(),
+            buckets,
             order,
             minDocCount,
             offset,
diff --git a/server/src/main/java/org/elasticsearch/search/aggregations/bucket/histogram/InternalHistogram.java b/server/src/main/java/org/elasticsearch/search/aggregations/bucket/histogram/InternalHistogram.java
@@ -446,16 +446,11 @@ public InternalAggregation get() {
 
     @Override
     public InternalAggregation finalizeSampling(SamplingContext samplingContext) {
-        return new InternalHistogram(
-            getName(),
-            buckets.stream().map(b -> b.finalizeSampling(samplingContext)).toList(),
-            order,
-            minDocCount,
-            emptyBucketInfo,
-            format,
-            keyed,
-            getMetadata()
-        );
+        final List<Bucket> buckets = new ArrayList<>(this.buckets.size());
+        for (Bucket bucket : this.buckets) {
+            buckets.add(bucket.finalizeSampling(samplingContext));
+        }
+        return new InternalHistogram(getName(), buckets, order, minDocCount, emptyBucketInfo, format, keyed, getMetadata());
     }
 
     @Override
diff --git a/server/src/main/java/org/elasticsearch/search/aggregations/bucket/histogram/InternalVariableWidthHistogram.java b/server/src/main/java/org/elasticsearch/search/aggregations/bucket/histogram/InternalVariableWidthHistogram.java
@@ -539,14 +539,11 @@ public InternalAggregation get() {
 
     @Override
     public InternalAggregation finalizeSampling(SamplingContext samplingContext) {
-        return new InternalVariableWidthHistogram(
-            getName(),
-            buckets.stream().map(b -> b.finalizeSampling(samplingContext)).toList(),
-            emptyBucketInfo,
-            targetNumBuckets,
-            format,
-            getMetadata()
-        );
+        final List<Bucket> buckets = new ArrayList<>(this.buckets.size());
+        for (Bucket bucket : this.buckets) {
+            buckets.add(bucket.finalizeSampling(samplingContext));
+        }
+        return new InternalVariableWidthHistogram(getName(), buckets, emptyBucketInfo, targetNumBuckets, format, getMetadata());
     }
 
     @Override
diff --git a/server/src/main/java/org/elasticsearch/search/aggregations/bucket/range/InternalBinaryRange.java b/server/src/main/java/org/elasticsearch/search/aggregations/bucket/range/InternalBinaryRange.java
@@ -25,6 +25,7 @@
 import org.elasticsearch.xcontent.XContentBuilder;
 
 import java.io.IOException;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
@@ -258,13 +259,11 @@ public void close() {
 
     @Override
     public InternalAggregation finalizeSampling(SamplingContext samplingContext) {
-        return new InternalBinaryRange(
-            name,
-            format,
-            keyed,
-            buckets.stream().map(b -> b.finalizeSampling(samplingContext)).toList(),
-            metadata
-        );
+        final List<Bucket> buckets = new ArrayList<>(this.buckets.size());
+        for (Bucket bucket : this.buckets) {
+            buckets.add(bucket.finalizeSampling(samplingContext));
+        }
+        return new InternalBinaryRange(name, format, keyed, buckets, metadata);
     }
 
     @Override
diff --git a/server/src/main/java/org/elasticsearch/search/aggregations/bucket/range/InternalRange.java b/server/src/main/java/org/elasticsearch/search/aggregations/bucket/range/InternalRange.java
@@ -325,24 +325,20 @@ public void close() {
     @Override
     public InternalAggregation finalizeSampling(SamplingContext samplingContext) {
         InternalRange.Factory<B, R> factory = getFactory();
-        return factory.create(
-            name,
-            ranges.stream()
-                .map(
-                    b -> factory.createBucket(
-                        b.getKey(),
-                        b.from,
-                        b.to,
-                        samplingContext.scaleUp(b.getDocCount()),
-                        InternalAggregations.finalizeSampling(b.getAggregations(), samplingContext),
-                        b.format
-                    )
+        final List<B> buckets = new ArrayList<>(ranges.size());
+        for (B range : ranges) {
+            buckets.add(
+                factory.createBucket(
+                    range.getKey(),
+                    range.from,
+                    range.to,
+                    samplingContext.scaleUp(range.getDocCount()),
+                    InternalAggregations.finalizeSampling(range.getAggregations(), samplingContext),
+                    range.format
                 )
-                .toList(),
-            format,
-            keyed,
-            getMetadata()
-        );
+            );
+        }
+        return factory.create(name, buckets, format, keyed, getMetadata());
     }
 
     @Override
diff --git a/server/src/main/java/org/elasticsearch/search/aggregations/bucket/sampler/random/InternalRandomSampler.java b/server/src/main/java/org/elasticsearch/search/aggregations/bucket/sampler/random/InternalRandomSampler.java
@@ -24,6 +24,8 @@
 import org.elasticsearch.xcontent.XContentBuilder;
 
 import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
 import java.util.Map;
 
 public class InternalRandomSampler extends InternalSingleBucketAggregation implements Sampler {
@@ -105,7 +107,12 @@ public InternalAggregation get() {
                 InternalAggregations aggs = subAggregatorReducer.get();
                 if (reduceContext.isFinalReduce() && aggs != null) {
                     SamplingContext context = buildContext();
-                    aggs = InternalAggregations.from(aggs.asList().stream().map(agg -> agg.finalizeSampling(context)).toList());
+                    final List<InternalAggregation> aaggregationList = aggs.asList();
+                    final List<InternalAggregation> sampledAggregations = new ArrayList<>(aaggregationList.size());
+                    for (InternalAggregation agg : aaggregationList) {
+                        sampledAggregations.add(agg.finalizeSampling(context));
+                    }
+                    aggs = InternalAggregations.from(sampledAggregations);
                 }
                 return newAggregation(getName(), docCount, aggs);
             }
diff --git a/server/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/AbstractInternalTerms.java b/server/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/AbstractInternalTerms.java
@@ -344,18 +344,21 @@ private BucketOrder getThisReduceOrder() {
 
     @Override
     public InternalAggregation finalizeSampling(SamplingContext samplingContext) {
+        final List<B> originalBuckets = getBuckets();
+        final List<B> buckets = new ArrayList<>(originalBuckets.size());
+        for (B bucket : originalBuckets) {
+            buckets.add(
+                createBucket(
+                    samplingContext.scaleUp(bucket.getDocCount()),
+                    InternalAggregations.finalizeSampling(bucket.getAggregations(), samplingContext),
+                    getShowDocCountError() ? samplingContext.scaleUp(bucket.getDocCountError()) : 0,
+                    bucket
+                )
+            );
+        }
         return create(
             name,
-            getBuckets().stream()
-                .map(
-                    b -> createBucket(
-                        samplingContext.scaleUp(b.getDocCount()),
-                        InternalAggregations.finalizeSampling(b.getAggregations(), samplingContext),
-                        getShowDocCountError() ? samplingContext.scaleUp(b.getDocCountError()) : 0,
-                        b
-                    )
-                )
-                .toList(),
+            buckets,
             getOrder(),
             samplingContext.scaleUp(getDocCountError()),
             samplingContext.scaleUp(getSumOfOtherDocCounts())
diff --git a/server/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/InternalMappedRareTerms.java b/server/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/InternalMappedRareTerms.java
@@ -147,19 +147,18 @@ private B reduceBucket(List<B> buckets, AggregationReduceContext context) {
 
     @Override
     public A finalizeSampling(SamplingContext samplingContext) {
-        return createWithFilter(
-            name,
-            getBuckets().stream()
-                .map(
-                    b -> createBucket(
-                        samplingContext.scaleUp(b.getDocCount()),
-                        InternalAggregations.finalizeSampling(b.aggregations, samplingContext),
-                        b
-                    )
+        final List<B> originalBuckets = getBuckets();
+        final List<B> buckets = new ArrayList<>(originalBuckets.size());
+        for (B bucket : originalBuckets) {
+            buckets.add(
+                createBucket(
+                    samplingContext.scaleUp(bucket.getDocCount()),
+                    InternalAggregations.finalizeSampling(bucket.aggregations, samplingContext),
+                    bucket
                 )
-                .toList(),
-            filter
-        );
+            );
+        }
+        return createWithFilter(name, buckets, filter);
     }
 
     public abstract boolean containsTerm(SetBackedScalingCuckooFilter filter, B bucket);
diff --git a/server/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/InternalSignificantTerms.java b/server/src/main/java/org/elasticsearch/search/aggregations/bucket/terms/InternalSignificantTerms.java
@@ -27,6 +27,7 @@
 import org.elasticsearch.xcontent.XContentBuilder;
 
 import java.io.IOException;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
@@ -284,20 +285,19 @@ private ReducerAndExtraInfo(BucketReducer<B> reducer) {
     public InternalAggregation finalizeSampling(SamplingContext samplingContext) {
         long supersetSize = samplingContext.scaleUp(getSupersetSize());
         long subsetSize = samplingContext.scaleUp(getSubsetSize());
-        return create(
-            subsetSize,
-            supersetSize,
-            getBuckets().stream()
-                .map(
-                    b -> createBucket(
-                        samplingContext.scaleUp(b.subsetDf),
-                        samplingContext.scaleUp(b.supersetDf),
-                        InternalAggregations.finalizeSampling(b.aggregations, samplingContext),
-                        b
-                    )
+        final List<B> originalBuckets = getBuckets();
+        final List<B> buckets = new ArrayList<>(originalBuckets.size());
+        for (B bucket : originalBuckets) {
+            buckets.add(
+                createBucket(
+                    samplingContext.scaleUp(bucket.subsetDf),
+                    samplingContext.scaleUp(bucket.supersetDf),
+                    InternalAggregations.finalizeSampling(bucket.aggregations, samplingContext),
+                    bucket
                 )
-                .toList()
-        );
+            );
+        }
+        return create(subsetSize, supersetSize, buckets);
     }
 
     abstract B createBucket(long subsetDf, long supersetDf, InternalAggregations aggregations, B prototype);
diff --git a/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/aggs/categorization/InternalCategorizationAggregation.java b/x-pack/plugin/ml/src/main/java/org/elasticsearch/xpack/ml/aggs/categorization/InternalCategorizationAggregation.java
@@ -360,22 +360,17 @@ public InternalAggregation get() {
 
     @Override
     public InternalAggregation finalizeSampling(SamplingContext samplingContext) {
-        return new InternalCategorizationAggregation(
-            name,
-            requiredSize,
-            minDocCount,
-            similarityThreshold,
-            metadata,
-            buckets.stream()
-                .map(
-                    b -> new Bucket(
-                        new SerializableTokenListCategory(b.getSerializableCategory(), samplingContext.scaleUp(b.getDocCount())),
-                        b.getBucketOrd(),
-                        InternalAggregations.finalizeSampling(b.aggregations, samplingContext)
-                    )
+        final List<Bucket> buckets = new ArrayList<>(this.buckets.size());
+        for (Bucket bucket : this.buckets) {
+            buckets.add(
+                new Bucket(
+                    new SerializableTokenListCategory(bucket.getSerializableCategory(), samplingContext.scaleUp(bucket.getDocCount())),
+                    bucket.getBucketOrd(),
+                    InternalAggregations.finalizeSampling(bucket.aggregations, samplingContext)
                 )
-                .collect(Collectors.toList())
-        );
+            );
+        }
+        return new InternalCategorizationAggregation(name, requiredSize, minDocCount, similarityThreshold, metadata, buckets);
     }
 
     public int getSimilarityThreshold() {
