Performance "unit test" for profiling the fix

engine/table/src/test/java/io/deephaven/engine/table/impl/ManyLocationsTest.java

@@ -0,0 +1,64 @@
+//
+// Copyright (c) 2016-2024 Deephaven Data Labs and Patent Pending
+//
+package io.deephaven.engine.table.impl;
+
+import io.deephaven.engine.context.ExecutionContext;
+import io.deephaven.engine.table.ColumnDefinition;
+import io.deephaven.engine.table.Table;
+import io.deephaven.engine.table.TableDefinition;
+import io.deephaven.engine.table.impl.sources.regioned.RegionedTableComponentFactoryImpl;
+import io.deephaven.engine.testutil.ControlledUpdateGraph;
+import io.deephaven.engine.testutil.locations.TableBackedTableLocationProvider;
+import io.deephaven.engine.testutil.testcase.RefreshingTableTestCase;
+import io.deephaven.engine.util.TableTools;
+import io.deephaven.test.types.OutOfBandTest;
+import org.junit.experimental.categories.Category;
+
+import java.util.Map;
+
+@Category(OutOfBandTest.class)
+public class ManyLocationsTest extends RefreshingTableTestCase {
+
+    private static final boolean DISABLE_PERFORMANCE_TEST = true;
+
+    public void testManyLocationsCoalesce() {
+        if (DISABLE_PERFORMANCE_TEST) {
+            return;
+        }
+
+        final long startConstructionNanos = System.nanoTime();
+        final ControlledUpdateGraph updateGraph = ExecutionContext.getContext().getUpdateGraph().cast();
+        final TableBackedTableLocationProvider tlp = new TableBackedTableLocationProvider(
+                updateGraph,
+                true,
+                TableUpdateMode.APPEND_ONLY,
+                TableUpdateMode.APPEND_ONLY);
+        final Table singleLocationTable = TableTools.emptyTable(1000).update("AA=ii");
+        final Table past = new PartitionAwareSourceTable(
+                TableDefinition.of(
+                        ColumnDefinition.ofInt("PI").withPartitioning(),
+                        ColumnDefinition.ofLong("AA")),
+                "TestTable",
+                RegionedTableComponentFactoryImpl.INSTANCE,
+                tlp,
+                updateGraph);
+        final long endConstructionNanos = System.nanoTime();
+        System.out.printf("Construction time: %.2fs%n",
+                (endConstructionNanos - startConstructionNanos) / 1_000_000_000D);
+
+        final long startCreationNanos = System.nanoTime();
+        for (int pi = 0; pi < 100_000; ++pi) {
+            tlp.add(singleLocationTable, Map.of("PI", pi));
+        }
+        final long endCreationNanos = System.nanoTime();
+        System.out.printf("Creation time: %.2fs%n", (endCreationNanos - startCreationNanos) / 1_000_000_000D);
+
+        final long startCoalesceNanos = System.nanoTime();
+        past.coalesce();
+        final long endCoalesceNanos = System.nanoTime();
+        System.out.printf("Coalesce time: %.2fs%n", (endCoalesceNanos - startCoalesceNanos) / 1_000_000_000D);
+
+        System.out.printf("Total time: %.2fs%n", (endCoalesceNanos - startConstructionNanos) / 1_000_000_000D);
+    }
+}