Remove throws IOException from PipelineAggregationBuilder#create (#40222)

IOException are never thrown in any of the existing pipeline aggregation
builders. Removing the throws IOException from the create method allows
to remove it also from a couple of other methods which ends up simplifying
 AggregationPhase (one less catch).

Author: javanna

server/src/main/java/org/elasticsearch/search/aggregations/AggregationPhase.java

@@ -133,22 +133,18 @@ public void execute(SearchContext context) {
             }
         }
         context.queryResult().aggregations(new InternalAggregations(aggregations));
-        try {
-            List<PipelineAggregator> pipelineAggregators = context.aggregations().factories().createPipelineAggregators();
-            List<SiblingPipelineAggregator> siblingPipelineAggregators = new ArrayList<>(pipelineAggregators.size());
-            for (PipelineAggregator pipelineAggregator : pipelineAggregators) {
-                if (pipelineAggregator instanceof SiblingPipelineAggregator) {
-                    siblingPipelineAggregators.add((SiblingPipelineAggregator) pipelineAggregator);
-                } else {
-                    throw new AggregationExecutionException("Invalid pipeline aggregation named [" + pipelineAggregator.name()
-                            + "] of type [" + pipelineAggregator.getWriteableName() + "]. Only sibling pipeline aggregations are "
-                            + "allowed at the top level");
-                }
+        List<PipelineAggregator> pipelineAggregators = context.aggregations().factories().createPipelineAggregators();
+        List<SiblingPipelineAggregator> siblingPipelineAggregators = new ArrayList<>(pipelineAggregators.size());
+        for (PipelineAggregator pipelineAggregator : pipelineAggregators) {
+            if (pipelineAggregator instanceof SiblingPipelineAggregator) {
+                siblingPipelineAggregators.add((SiblingPipelineAggregator) pipelineAggregator);
+            } else {
+                throw new AggregationExecutionException("Invalid pipeline aggregation named [" + pipelineAggregator.name()
+                    + "] of type [" + pipelineAggregator.getWriteableName() + "]. Only sibling pipeline aggregations are "
+                    + "allowed at the top level");
             }
-            context.queryResult().pipelineAggregators(siblingPipelineAggregators);
-        } catch (IOException e) {
-            throw new AggregationExecutionException("Failed to build top level pipeline aggregators", e);
         }
+        context.queryResult().pipelineAggregators(siblingPipelineAggregators);
 
         // disable aggregations so that they don't run on next pages in case of scrolling
         context.aggregations(null);

server/src/main/java/org/elasticsearch/search/aggregations/AggregatorFactories.java

@@ -175,7 +175,7 @@ private AggregatorFactories(AggregatorFactory<?>[] factories, List<PipelineAggre
         this.pipelineAggregatorFactories = pipelineAggregators;
     }
 
-    public List<PipelineAggregator> createPipelineAggregators() throws IOException {
+    public List<PipelineAggregator> createPipelineAggregators() {
         List<PipelineAggregator> pipelineAggregators = new ArrayList<>(this.pipelineAggregatorFactories.size());
         for (PipelineAggregationBuilder factory : this.pipelineAggregatorFactories) {
             pipelineAggregators.add(factory.create());

server/src/main/java/org/elasticsearch/search/aggregations/PipelineAggregationBuilder.java

@@ -24,7 +24,6 @@
 import org.elasticsearch.search.aggregations.AggregatorFactories.Builder;
 import org.elasticsearch.search.aggregations.pipeline.PipelineAggregator;
 
-import java.io.IOException;
 import java.util.Collection;
 import java.util.Map;
 
@@ -76,7 +75,7 @@ protected abstract void validate(AggregatorFactory<?> parent, Collection<Aggrega
      *
      * @return The created aggregator
      */
-    protected abstract PipelineAggregator create() throws IOException;
+    protected abstract PipelineAggregator create();
 
     /** Associate metadata with this {@link PipelineAggregationBuilder}. */
     @Override

server/src/main/java/org/elasticsearch/search/aggregations/pipeline/AbstractPipelineAggregationBuilder.java

@@ -89,15 +89,15 @@ public final void validate(AggregatorFactory<?> parent, Collection<AggregationBu
         doValidate(parent, factories, pipelineAggregatorFactories);
     }
 
-    protected abstract PipelineAggregator createInternal(Map<String, Object> metaData) throws IOException;
+    protected abstract PipelineAggregator createInternal(Map<String, Object> metaData);
 
     /**
      * Creates the pipeline aggregator
      *
      * @return The created aggregator
      */
     @Override
-    public final PipelineAggregator create() throws IOException {
+    public final PipelineAggregator create() {
         PipelineAggregator aggregator = createInternal(this.metaData);
         return aggregator;
     }

server/src/main/java/org/elasticsearch/search/aggregations/pipeline/AvgBucketPipelineAggregationBuilder.java

@@ -46,7 +46,7 @@ protected void innerWriteTo(StreamOutput out) throws IOException {
     }
 
     @Override
-    protected PipelineAggregator createInternal(Map<String, Object> metaData) throws IOException {
+    protected PipelineAggregator createInternal(Map<String, Object> metaData) {
         return new AvgBucketPipelineAggregator(name, bucketsPaths, gapPolicy(), formatter(), metaData);
     }
 

server/src/main/java/org/elasticsearch/search/aggregations/pipeline/BucketMetricsPipelineAggregationBuilder.java

@@ -104,7 +104,7 @@ public GapPolicy gapPolicy() {
     }
 
     @Override
-    protected abstract PipelineAggregator createInternal(Map<String, Object> metaData) throws IOException;
+    protected abstract PipelineAggregator createInternal(Map<String, Object> metaData);
 
     @Override
     public void doValidate(AggregatorFactory<?> parent, Collection<AggregationBuilder> aggBuilders,

server/src/main/java/org/elasticsearch/search/aggregations/pipeline/BucketScriptPipelineAggregationBuilder.java

@@ -139,7 +139,7 @@ public GapPolicy gapPolicy() {
     }
 
     @Override
-    protected PipelineAggregator createInternal(Map<String, Object> metaData) throws IOException {
+    protected PipelineAggregator createInternal(Map<String, Object> metaData) {
         return new BucketScriptPipelineAggregator(name, bucketsPathsMap, script, formatter(), gapPolicy, metaData);
     }
 

server/src/main/java/org/elasticsearch/search/aggregations/pipeline/BucketSelectorPipelineAggregationBuilder.java

@@ -108,7 +108,7 @@ public GapPolicy gapPolicy() {
     }
 
     @Override
-    protected PipelineAggregator createInternal(Map<String, Object> metaData) throws IOException {
+    protected PipelineAggregator createInternal(Map<String, Object> metaData) {
         return new BucketSelectorPipelineAggregator(name, bucketsPathsMap, script, gapPolicy, metaData);
     }
 

server/src/main/java/org/elasticsearch/search/aggregations/pipeline/BucketSortPipelineAggregationBuilder.java

@@ -139,7 +139,7 @@ public BucketSortPipelineAggregationBuilder gapPolicy(GapPolicy gapPolicy) {
     }
 
     @Override
-    protected PipelineAggregator createInternal(Map<String, Object> metaData) throws IOException {
+    protected PipelineAggregator createInternal(Map<String, Object> metaData) {
         return new BucketSortPipelineAggregator(name, sorts, from, size, gapPolicy, metaData);
     }
 

server/src/main/java/org/elasticsearch/search/aggregations/pipeline/CumulativeSumPipelineAggregationBuilder.java

@@ -88,7 +88,7 @@ protected DocValueFormat formatter() {
     }
 
     @Override
-    protected PipelineAggregator createInternal(Map<String, Object> metaData) throws IOException {
+    protected PipelineAggregator createInternal(Map<String, Object> metaData) {
         return new CumulativeSumPipelineAggregator(name, bucketsPaths, formatter(), metaData);
     }