Provide information about which indexes a query uses

Only works with Cypher version 3.2, support in older versions would
require changes to those versions and new releases.

community/common/src/main/java/org/neo4j/function/FailableConsumer.java

@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 2002-2017 "Neo Technology,"
+ * Network Engine for Objects in Lund AB [http://neotechnology.com]
+ *
+ * This file is part of Neo4j.
+ *
+ * Neo4j is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.neo4j.function;
+
+import java.util.function.Consumer;
+
+public interface FailableConsumer<TYPE> extends Consumer<TYPE>
+{
+    void fail( Exception failure );
+}

community/common/src/main/java/org/neo4j/function/Predicates.java

@@ -32,6 +32,9 @@
 import java.util.function.Supplier;
 import javax.annotation.Nonnull;
 
+import static org.neo4j.function.ThrowingPredicate.throwingPredicate;
+import static org.neo4j.function.ThrowingSupplier.throwingSupplier;
+
 /**
  * Constructors for basic {@link Predicate} types
  */
@@ -147,7 +150,7 @@ public static <TYPE> TYPE await( Supplier<TYPE> supplier, Predicate<TYPE> predic
     public static <TYPE> TYPE await( Supplier<TYPE> supplier, Predicate<TYPE> predicate, long timeout,
             TimeUnit timeoutUnit ) throws TimeoutException
     {
-        return awaitEx( supplier::get, predicate::test, timeout, timeoutUnit );
+        return awaitEx( throwingSupplier( supplier ), throwingPredicate( predicate ), timeout, timeoutUnit );
     }
 
     public static <TYPE, EXCEPTION extends Exception> TYPE awaitEx( ThrowingSupplier<TYPE,EXCEPTION> supplier,
@@ -159,8 +162,8 @@ public static <TYPE, EXCEPTION extends Exception> TYPE awaitEx( ThrowingSupplier
         return composed.lastInput();
     }
 
-    public static <TYPE, EXCEPTION extends Exception> TYPE awaitEx( ThrowingSupplier<TYPE,EXCEPTION> supplier,
-            ThrowingPredicate<TYPE,EXCEPTION> predicate, long timeout, TimeUnit timeoutUnit )
+    public static <TYPE, EXCEPTION extends Exception> TYPE awaitEx( ThrowingSupplier<TYPE,? extends EXCEPTION> supplier,
+            ThrowingPredicate<TYPE, ? extends EXCEPTION> predicate, long timeout, TimeUnit timeoutUnit )
             throws TimeoutException, EXCEPTION
     {
         Suppliers.ThrowingCapturingSupplier<TYPE,EXCEPTION> composed = Suppliers.compose( supplier, predicate );

community/common/src/main/java/org/neo4j/function/Suppliers.java

@@ -118,8 +118,9 @@ public T get()
         };
     }
 
-    public static <T, E extends Exception> ThrowingCapturingSupplier<T,E> compose( final ThrowingSupplier<T,E> input,
-            final ThrowingPredicate<T,E> predicate )
+    public static <T, E extends Exception> ThrowingCapturingSupplier<T,E> compose(
+            final ThrowingSupplier<T,? extends E> input,
+            final ThrowingPredicate<T,? extends E> predicate )
     {
         return new ThrowingCapturingSupplier<>( input, predicate );
     }
@@ -132,12 +133,12 @@ public static BooleanSupplier untilTimeExpired( long duration, TimeUnit unit )
 
     static class ThrowingCapturingSupplier<T, E extends Exception> implements ThrowingSupplier<Boolean,E>
     {
-        private final ThrowingSupplier<T,E> input;
-        private final ThrowingPredicate<T,E> predicate;
+        private final ThrowingSupplier<T,? extends E> input;
+        private final ThrowingPredicate<T,? extends E> predicate;
 
         private T current;
 
-        ThrowingCapturingSupplier( ThrowingSupplier<T,E> input, ThrowingPredicate<T,E> predicate )
+        ThrowingCapturingSupplier( ThrowingSupplier<T,? extends E> input, ThrowingPredicate<T,? extends E> predicate )
         {
             this.input = input;
             this.predicate = predicate;
@@ -154,5 +155,11 @@ public Boolean get() throws E
             current = input.get();
             return predicate.test( current );
         }
+
+        @Override
+        public String toString()
+        {
+            return String.format( "%s on %s", predicate, input );
+        }
     }
 }

community/common/src/main/java/org/neo4j/function/ThrowingPredicate.java

@@ -19,6 +19,8 @@
  */
 package org.neo4j.function;
 
+import java.util.function.Predicate;
+
 /**
  * Represents a predicate (boolean-valued function) of one argument.
  *
@@ -35,4 +37,22 @@ public interface ThrowingPredicate<T, E extends Exception>
      * @throws E an exception if the predicate fails
      */
     boolean test( T t ) throws E;
+
+    static <TYPE> ThrowingPredicate<TYPE,RuntimeException> throwingPredicate( Predicate<TYPE> predicate )
+    {
+        return new ThrowingPredicate<TYPE,RuntimeException>()
+        {
+            @Override
+            public boolean test( TYPE value )
+            {
+                return predicate.test( value );
+            }
+
+            @Override
+            public String toString()
+            {
+                return predicate.toString();
+            }
+        };
+    }
 }

community/common/src/main/java/org/neo4j/function/ThrowingSupplier.java

@@ -19,6 +19,8 @@
  */
 package org.neo4j.function;
 
+import java.util.function.Supplier;
+
 /**
  * Represents a supplier of results, that may throw an exception.
  *
@@ -34,4 +36,22 @@ public interface ThrowingSupplier<T, E extends Exception>
      * @throws E an exception if the function fails
      */
     T get() throws E;
+
+    static <TYPE> ThrowingSupplier<TYPE,RuntimeException> throwingSupplier( Supplier<TYPE> supplier )
+    {
+        return new ThrowingSupplier<TYPE,RuntimeException>()
+        {
+            @Override
+            public TYPE get()
+            {
+                return supplier.get();
+            }
+
+            @Override
+            public String toString()
+            {
+                return supplier.toString();
+            }
+        };
+    }
 }

community/cypher/cypher-compiler-3.2/src/main/scala/org/neo4j/cypher/internal/compiler/v3_2/BuildCompiledExecutionPlan.scala

@@ -81,6 +81,8 @@ object BuildCompiledExecutionPlan extends Phase {
     override def runtimeUsed = CompiledRuntimeName
 
     override def notifications(planContext: PlanContext): Seq[InternalNotification] = Seq.empty
+
+    override def plannedIndexUsage: Seq[IndexUsage] = compiled.plannedIndexUsage
   }
 
 

community/cypher/cypher-compiler-3.2/src/main/scala/org/neo4j/cypher/internal/compiler/v3_2/BuildInterpretedExecutionPlan.scala

@@ -62,6 +62,8 @@ object BuildInterpretedExecutionPlan extends Phase {
       override def runtimeUsed = InterpretedRuntimeName
 
       override def notifications(planContext: PlanContext) = checkForNotifications(pipe, planContext, context.config)
+
+      override def plannedIndexUsage = logicalPlan.indexUsage
     }
 
     from.copy(maybeExecutionPlan = Some(execPlan))

community/cypher/cypher-compiler-3.2/src/main/scala/org/neo4j/cypher/internal/compiler/v3_2/codegen/CodeGenerator.scala

@@ -72,7 +72,7 @@ class CodeGenerator(val structure: CodeStructure[GeneratedQuery], clock: Clock,
           }
         }
 
-        CompiledPlan(updating = false, None, fp, plannerName, description, res.columns, builder)
+        CompiledPlan(updating = false, None, fp, plannerName, description, res.columns, builder, plan.indexUsage)
 
       case _ => throw new CantCompileQueryException("Can only compile plans with ProduceResult on top")
     }

community/cypher/cypher-compiler-3.2/src/main/scala/org/neo4j/cypher/internal/compiler/v3_2/executionplan/ExecutionPlan.scala

@@ -19,7 +19,7 @@
  */
 package org.neo4j.cypher.internal.compiler.v3_2.executionplan
 
-import org.neo4j.cypher.internal.compiler.v3_2.spi.{PlanContext, GraphStatistics, QueryContext}
+import org.neo4j.cypher.internal.compiler.v3_2.spi.{GraphStatistics, PlanContext, QueryContext}
 import org.neo4j.cypher.internal.compiler.v3_2.{ExecutionMode, PlannerName, RuntimeName}
 import org.neo4j.cypher.internal.frontend.v3_2.notification.InternalNotification
 
@@ -30,4 +30,14 @@ abstract class ExecutionPlan {
   def isStale(lastTxId: () => Long, statistics: GraphStatistics): Boolean
   def runtimeUsed: RuntimeName
   def notifications(planContext: PlanContext): Seq[InternalNotification]
+  def plannedIndexUsage: Seq[IndexUsage] = Seq.empty
 }
+
+sealed trait IndexUsage {
+  def identifier:String
+}
+
+final case class SchemaIndexSeekUsage(identifier: String, label: String, propertyKey: String) extends IndexUsage
+final case class SchemaIndexScanUsage(identifier: String, label: String, propertyKey: String) extends IndexUsage
+final case class LegacyNodeIndexUsage(identifier: String, index: String) extends IndexUsage
+final case class LegacyRelationshipIndexUsage(identifier: String, index: String) extends IndexUsage

community/cypher/cypher-compiler-3.2/src/main/scala/org/neo4j/cypher/internal/compiler/v3_2/executionplan/ExecutionPlanBuilder.scala

@@ -45,7 +45,8 @@ case class CompiledPlan(updating: Boolean,
                         plannerUsed: PlannerName,
                         planDescription: InternalPlanDescription,
                         columns: Seq[String],
-                        executionResultBuilder: RunnablePlan )
+                        executionResultBuilder: RunnablePlan,
+                        plannedIndexUsage: Seq[IndexUsage] = Seq.empty )
 
 case class PipeInfo(pipe: Pipe,
                     updating: Boolean,

community/cypher/cypher-compiler-3.2/src/main/scala/org/neo4j/cypher/internal/compiler/v3_2/planner/logical/plans/LogicalPlan.scala

@@ -22,10 +22,11 @@ package org.neo4j.cypher.internal.compiler.v3_2.planner.logical.plans
 import java.lang.reflect.Method
 
 import org.neo4j.cypher.internal.compiler.v3_2.commands.QueryExpression
+import org.neo4j.cypher.internal.compiler.v3_2.executionplan._
 import org.neo4j.cypher.internal.compiler.v3_2.planner.{CardinalityEstimation, PlannerQuery}
 import org.neo4j.cypher.internal.frontend.v3_2.Foldable._
 import org.neo4j.cypher.internal.frontend.v3_2.Rewritable._
-import org.neo4j.cypher.internal.frontend.v3_2.ast.Expression
+import org.neo4j.cypher.internal.frontend.v3_2.ast.{Expression, NodeByIdentifiedIndex, NodeByIndexQuery, RelationshipByIdentifiedIndex, RelationshipByIndexQuery}
 import org.neo4j.cypher.internal.frontend.v3_2.{InternalException, Rewritable}
 import org.neo4j.cypher.internal.ir.v3_2.{IdName, Strictness}
 
@@ -113,6 +114,26 @@ abstract class LogicalPlan
   def debugId: String = f"0x${hashCode()}%08x"
 
   def flatten: Seq[LogicalPlan] = Flattener.create(this)
+
+  def indexUsage: Seq[IndexUsage] = {
+    import org.neo4j.cypher.internal.frontend.v3_2.Foldable._
+    this.fold(Seq.empty[IndexUsage]) {
+      case NodeIndexSeek(idName, label, propertyKey, _, _) =>
+        (acc) => acc :+ SchemaIndexSeekUsage(idName.name, label.name, propertyKey.name)
+      case NodeUniqueIndexSeek(idName, label, propertyKey, _, _) =>
+        (acc) => acc :+ SchemaIndexSeekUsage(idName.name, label.name, propertyKey.name)
+      case NodeIndexScan(idName, label, propertyKey, _) =>
+        (acc) => acc :+ SchemaIndexScanUsage(idName.name, label.name, propertyKey.name)
+      case LegacyNodeIndexSeek(idName, NodeByIdentifiedIndex(_, index, _, _), _) =>
+        (acc) => acc :+ LegacyNodeIndexUsage(idName.name, index)
+      case LegacyNodeIndexSeek(idName, NodeByIndexQuery(_, index, _), _) =>
+        (acc) => acc :+ LegacyNodeIndexUsage(idName.name, index)
+      case LegacyRelationshipIndexSeek(idName, RelationshipByIdentifiedIndex(_, index, _, _), _) =>
+        (acc) => acc :+ LegacyRelationshipIndexUsage(idName.name, index)
+      case LegacyRelationshipIndexSeek(idName, RelationshipByIndexQuery(_, index, _), _) =>
+        (acc) => acc :+ LegacyRelationshipIndexUsage(idName.name, index)
+    }
+  }
 }
 
 abstract class LogicalLeafPlan extends LogicalPlan with LazyLogicalPlan {
@@ -135,4 +156,4 @@ case object Flattener extends TreeBuilder[Seq[LogicalPlan]] {
   override protected def build(plan: LogicalPlan, source: Seq[LogicalPlan]): Seq[LogicalPlan] = plan +: source
 
   override protected def build(plan: LogicalPlan, lhs: Seq[LogicalPlan], rhs: Seq[LogicalPlan]): Seq[LogicalPlan] = (plan +: lhs) ++ rhs
-}
+}

community/cypher/cypher/src/main/scala/org/neo4j/cypher/internal/compatibility/v2_3/Compatibility.scala

@@ -19,6 +19,8 @@
  */
 package org.neo4j.cypher.internal.compatibility.v2_3
 
+import java.util.Collections.emptyList
+
 import org.neo4j.cypher.internal._
 import org.neo4j.cypher.internal.compatibility._
 import org.neo4j.cypher.internal.compiler.v2_3.executionplan.{EntityAccessor, ExecutionPlan => ExecutionPlan_v2_3}
@@ -31,7 +33,7 @@ import org.neo4j.cypher.internal.spi.v3_2.TransactionalContextWrapper
 import org.neo4j.graphdb.{Node, Relationship}
 import org.neo4j.kernel.GraphDatabaseQueryService
 import org.neo4j.kernel.api.ExecutingQuery.PlannerInfo
-import org.neo4j.kernel.api.KernelAPI
+import org.neo4j.kernel.api.{IndexUsage, KernelAPI}
 import org.neo4j.kernel.impl.core.NodeManager
 import org.neo4j.kernel.impl.query.QueryExecutionMonitor
 import org.neo4j.kernel.monitoring.{Monitors => KernelMonitors}
@@ -114,7 +116,7 @@ trait Compatibility {
     def isStale(lastCommittedTxId: LastCommittedTxIdProvider, ctx: TransactionalContextWrapper): Boolean =
       inner.isStale(lastCommittedTxId, TransactionBoundGraphStatistics(ctx.readOperations))
 
-    override def plannerInfo = new PlannerInfo(inner.plannerUsed.name, inner.runtimeUsed.name)
+    override def plannerInfo = new PlannerInfo(inner.plannerUsed.name, inner.runtimeUsed.name, emptyList[IndexUsage])
   }
 
 }

community/cypher/cypher/src/main/scala/org/neo4j/cypher/internal/compatibility/v3_1/Compatibility.scala

@@ -19,6 +19,8 @@
  */
 package org.neo4j.cypher.internal.compatibility.v3_1
 
+import java.util.Collections.emptyList
+
 import org.neo4j.cypher.internal._
 import org.neo4j.cypher.internal.compatibility._
 import org.neo4j.cypher.internal.compatibility.v3_1.helpers._
@@ -31,7 +33,7 @@ import org.neo4j.cypher.internal.spi.v3_1.{TransactionalContextWrapper => Transa
 import org.neo4j.cypher.internal.spi.v3_2.{TransactionalContextWrapper => TransactionalContextWrapperV3_2}
 import org.neo4j.kernel.GraphDatabaseQueryService
 import org.neo4j.kernel.api.ExecutingQuery.PlannerInfo
-import org.neo4j.kernel.api.KernelAPI
+import org.neo4j.kernel.api.{IndexUsage, KernelAPI}
 import org.neo4j.kernel.impl.query.QueryExecutionMonitor
 import org.neo4j.kernel.monitoring.{Monitors => KernelMonitors}
 import org.neo4j.logging.Log
@@ -115,7 +117,7 @@ trait Compatibility {
     def isStale(lastCommittedTxId: LastCommittedTxIdProvider, ctx: TransactionalContextWrapperV3_2): Boolean =
       inner.isStale(lastCommittedTxId, TransactionBoundGraphStatistics(ctx.readOperations))
 
-    override def plannerInfo = new PlannerInfo(inner.plannerUsed.name, inner.runtimeUsed.name)
+    override def plannerInfo = new PlannerInfo(inner.plannerUsed.name, inner.runtimeUsed.name, emptyList[IndexUsage])
   }
 }
 

community/cypher/cypher/src/main/scala/org/neo4j/cypher/internal/compatibility/v3_2/Compatibility.scala

@@ -22,12 +22,13 @@ package org.neo4j.cypher.internal.compatibility.v3_2
 import org.neo4j.cypher.internal._
 import org.neo4j.cypher.internal.compatibility._
 import org.neo4j.cypher.internal.compiler.v3_2
-import org.neo4j.cypher.internal.compiler.v3_2.executionplan.{ExecutionPlan => ExecutionPlan_v3_2}
+import org.neo4j.cypher.internal.compiler.v3_2.executionplan.{LegacyNodeIndexUsage, LegacyRelationshipIndexUsage, SchemaIndexScanUsage, SchemaIndexSeekUsage, ExecutionPlan => ExecutionPlan_v3_2}
 import org.neo4j.cypher.internal.compiler.v3_2.tracing.rewriters.RewriterStepSequencer
 import org.neo4j.cypher.internal.compiler.v3_2.{InfoLogger, ExplainMode => ExplainModev3_2, NormalMode => NormalModev3_2, ProfileMode => ProfileModev3_2, _}
 import org.neo4j.cypher.internal.spi.v3_2.TransactionBoundQueryContext.IndexSearchMonitor
 import org.neo4j.cypher.internal.spi.v3_2._
 import org.neo4j.kernel.api.ExecutingQuery.PlannerInfo
+import org.neo4j.kernel.api.IndexUsage.{legacyIndexUsage, schemaIndexUsage}
 import org.neo4j.kernel.api.KernelAPI
 import org.neo4j.kernel.impl.query.QueryExecutionMonitor
 import org.neo4j.kernel.monitoring.{Monitors => KernelMonitors}
@@ -108,7 +109,15 @@ trait Compatibility {
     def isStale(lastCommittedTxId: LastCommittedTxIdProvider, ctx: TransactionalContextWrapper): Boolean =
       inner.isStale(lastCommittedTxId, TransactionBoundGraphStatistics(ctx.readOperations))
 
-    override def plannerInfo = new PlannerInfo(inner.plannerUsed.name, inner.runtimeUsed.name)
+    override def plannerInfo = {
+      import scala.collection.JavaConverters._
+      new PlannerInfo(inner.plannerUsed.name, inner.runtimeUsed.name, inner.plannedIndexUsage.map {
+        case SchemaIndexSeekUsage(identifier, label, propertyKey) => schemaIndexUsage(identifier, label, propertyKey)
+        case SchemaIndexScanUsage(identifier, label, propertyKey) => schemaIndexUsage(identifier, label, propertyKey)
+        case LegacyNodeIndexUsage(identifier, index) => legacyIndexUsage(identifier, "NODE", index)
+        case LegacyRelationshipIndexUsage(identifier, index) => legacyIndexUsage(identifier, "RELATIONSHIP", index)
+      }.asJava)
+    }
   }
 }