rework cursor creation

benchmarks/src/test/java/org/apache/druid/benchmark/ExpressionAggregationBenchmark.java

@@ -20,11 +20,9 @@
 package org.apache.druid.benchmark;
 
 import com.google.common.collect.ImmutableList;
-import com.google.common.collect.Iterables;
 import org.apache.druid.common.config.NullHandling;
 import org.apache.druid.java.util.common.Intervals;
 import org.apache.druid.java.util.common.granularity.Granularities;
-import org.apache.druid.java.util.common.guava.Sequence;
 import org.apache.druid.java.util.common.io.Closer;
 import org.apache.druid.js.JavaScriptConfig;
 import org.apache.druid.query.aggregation.BufferAggregator;
@@ -35,9 +33,10 @@
 import org.apache.druid.segment.BaseFloatColumnValueSelector;
 import org.apache.druid.segment.ColumnSelectorFactory;
 import org.apache.druid.segment.Cursor;
+import org.apache.druid.segment.CursorBuildSpec;
+import org.apache.druid.segment.CursorMaker;
 import org.apache.druid.segment.QueryableIndex;
 import org.apache.druid.segment.QueryableIndexStorageAdapter;
-import org.apache.druid.segment.VirtualColumns;
 import org.apache.druid.segment.column.ValueType;
 import org.apache.druid.segment.generator.GeneratorColumnSchema;
 import org.apache.druid.segment.generator.GeneratorSchemaInfo;
@@ -60,7 +59,6 @@
 import org.openjdk.jmh.infra.Blackhole;
 
 import java.nio.ByteBuffer;
-import java.util.List;
 import java.util.concurrent.TimeUnit;
 import java.util.function.Function;
 
@@ -165,32 +163,26 @@ private double compute(final Function<ColumnSelectorFactory, BufferAggregator> a
   {
     final QueryableIndexStorageAdapter adapter = new QueryableIndexStorageAdapter(index);
 
-    final Sequence<Cursor> cursors = adapter.makeCursors(
-        null,
-        index.getDataInterval(),
-        VirtualColumns.EMPTY,
-        Granularities.ALL,
-        false,
-        null
-    );
+    final CursorBuildSpec buildSpec = CursorBuildSpec.builder()
+                                                     .setInterval(index.getDataInterval())
+                                                     .setGranularity(Granularities.ALL)
+                                                     .build();
+    try (final CursorMaker maker = adapter.asCursorMaker(buildSpec)) {
+      final Cursor cursor = maker.makeCursor();
 
-    final List<Double> results = cursors
-        .map(cursor -> {
-          final BufferAggregator bufferAggregator = aggregatorFactory.apply(cursor.getColumnSelectorFactory());
-          bufferAggregator.init(aggregationBuffer, 0);
+      final BufferAggregator bufferAggregator = aggregatorFactory.apply(cursor.getColumnSelectorFactory());
+      bufferAggregator.init(aggregationBuffer, 0);
 
-          while (!cursor.isDone()) {
-            bufferAggregator.aggregate(aggregationBuffer, 0);
-            cursor.advance();
-          }
+      while (!cursor.isDone()) {
+        bufferAggregator.aggregate(aggregationBuffer, 0);
+        cursor.advance();
+      }
 
-          final Double dbl = (Double) bufferAggregator.get(aggregationBuffer, 0);
-          bufferAggregator.close();
-          return dbl;
-        })
-        .toList();
+      final Double dbl = (Double) bufferAggregator.get(aggregationBuffer, 0);
+      bufferAggregator.close();
 
-    return Iterables.getOnlyElement(results);
+      return dbl;
+    }
   }
 
   private static class NativeBufferAggregator implements BufferAggregator

benchmarks/src/test/java/org/apache/druid/benchmark/ExpressionFilterBenchmark.java

@@ -23,7 +23,6 @@
 import org.apache.druid.common.config.NullHandling;
 import org.apache.druid.java.util.common.Intervals;
 import org.apache.druid.java.util.common.granularity.Granularities;
-import org.apache.druid.java.util.common.guava.Sequence;
 import org.apache.druid.java.util.common.io.Closer;
 import org.apache.druid.math.expr.ExpressionProcessing;
 import org.apache.druid.query.expression.TestExprMacroTable;
@@ -33,9 +32,10 @@
 import org.apache.druid.query.filter.SelectorDimFilter;
 import org.apache.druid.segment.ColumnValueSelector;
 import org.apache.druid.segment.Cursor;
+import org.apache.druid.segment.CursorBuildSpec;
+import org.apache.druid.segment.CursorMaker;
 import org.apache.druid.segment.QueryableIndex;
 import org.apache.druid.segment.QueryableIndexStorageAdapter;
-import org.apache.druid.segment.VirtualColumns;
 import org.apache.druid.segment.column.ValueType;
 import org.apache.druid.segment.generator.GeneratorColumnSchema;
 import org.apache.druid.segment.generator.GeneratorSchemaInfo;
@@ -58,7 +58,6 @@
 import org.openjdk.jmh.infra.Blackhole;
 
 import java.util.Arrays;
-import java.util.List;
 import java.util.concurrent.TimeUnit;
 
 @State(Scope.Benchmark)
@@ -146,52 +145,38 @@ public void tearDown() throws Exception
   @Benchmark
   public void expressionFilter(Blackhole blackhole)
   {
-    final Sequence<Cursor> cursors = new QueryableIndexStorageAdapter(index).makeCursors(
-        expressionFilter.toFilter(),
-        index.getDataInterval(),
-        VirtualColumns.EMPTY,
-        Granularities.ALL,
-        false,
-        null
-    );
-    final List<?> results = cursors
-        .map(cursor -> {
-          final ColumnValueSelector selector = cursor.getColumnSelectorFactory().makeColumnValueSelector("x");
-          consumeString(cursor, selector, blackhole);
-          return null;
-        })
-        .toList();
-
-    blackhole.consume(results);
+    final CursorBuildSpec buildSpec = CursorBuildSpec.builder()
+                                                     .setFilter(expressionFilter.toFilter())
+                                                     .setInterval(index.getDataInterval())
+                                                     .setGranularity(Granularities.ALL)
+                                                     .build();
+    try (final CursorMaker maker = new QueryableIndexStorageAdapter(index).asCursorMaker(buildSpec)) {
+      final Cursor cursor = maker.makeCursor();
+
+
+      final ColumnValueSelector selector = cursor.getColumnSelectorFactory().makeColumnValueSelector("x");
+      while (!cursor.isDone()) {
+        blackhole.consume(selector.getObject());
+        cursor.advance();
+      }
+    }
   }
 
   @Benchmark
   public void nativeFilter(Blackhole blackhole)
   {
-    final Sequence<Cursor> cursors = new QueryableIndexStorageAdapter(index).makeCursors(
-        nativeFilter.toFilter(),
-        index.getDataInterval(),
-        VirtualColumns.EMPTY,
-        Granularities.ALL,
-        false,
-        null
-    );
-    final List<?> results = cursors
-        .map(cursor -> {
-          final ColumnValueSelector selector = cursor.getColumnSelectorFactory().makeColumnValueSelector("x");
-          consumeString(cursor, selector, blackhole);
-          return null;
-        })
-        .toList();
-
-    blackhole.consume(results);
-  }
-
-  private void consumeString(final Cursor cursor, final ColumnValueSelector selector, final Blackhole blackhole)
-  {
-    while (!cursor.isDone()) {
-      blackhole.consume(selector.getLong());
-      cursor.advance();
+    final CursorBuildSpec buildSpec = CursorBuildSpec.builder()
+                                                     .setFilter(nativeFilter.toFilter())
+                                                     .setInterval(index.getDataInterval())
+                                                     .setGranularity(Granularities.ALL)
+                                                     .build();
+    try (final CursorMaker maker = new QueryableIndexStorageAdapter(index).asCursorMaker(buildSpec)) {
+      final Cursor cursor = maker.makeCursor();
+      final ColumnValueSelector selector = cursor.getColumnSelectorFactory().makeColumnValueSelector("x");
+      while (!cursor.isDone()) {
+        blackhole.consume(selector.getObject());
+        cursor.advance();
+      }
     }
   }
 }