Implement drop cypher db procedure

Author: soerenreichardt

alpha/alpha-proc/src/main/java/org/neo4j/gds/cypher/DropCypherDbProc.java

@@ -0,0 +1,90 @@
+/*
+ * Copyright (c) "Neo4j"
+ * Neo4j Sweden AB [http://neo4j.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.gds.cypher;
+
+import org.apache.commons.lang3.mutable.MutableLong;
+import org.neo4j.dbms.api.DatabaseManagementService;
+import org.neo4j.dbms.api.DatabaseNotFoundException;
+import org.neo4j.gds.BaseProc;
+import org.neo4j.gds.compat.GraphDatabaseApiProxy;
+import org.neo4j.gds.core.utils.ProgressTimer;
+import org.neo4j.gds.executor.ProcPreconditions;
+import org.neo4j.gds.storageengine.InMemoryDatabaseCreationCatalog;
+import org.neo4j.procedure.Description;
+import org.neo4j.procedure.Name;
+import org.neo4j.procedure.Procedure;
+
+import java.util.stream.Stream;
+
+import static org.neo4j.gds.utils.StringFormatting.formatWithLocale;
+import static org.neo4j.procedure.Mode.WRITE;
+
+public class DropCypherDbProc extends BaseProc {
+
+    private static final String DESCRIPTION = "Drop a database backed by an in-memory graph";
+
+    @Procedure(name = "gds.alpha.drop.cypherdb", mode = WRITE)
+    @Description(DESCRIPTION)
+    public Stream<DropCypherDbResult> dropDb(
+        @Name(value = "dbName") String dbName
+    ) {
+        ProcPreconditions.check();
+
+        DropCypherDbResult result = runWithExceptionLogging(
+            "Drop in-memory Cypher database failed",
+            () -> {
+                GraphCreateCypherDbProc.validateNeo4jEnterpriseEdition(databaseService);
+                var dbms = GraphDatabaseApiProxy.resolveDependency(databaseService, DatabaseManagementService.class);
+                validateDatabaseName(dbName, dbms);
+                var dropMillis = new MutableLong(0);
+                try (var ignored = ProgressTimer.start(dropMillis::setValue)) {
+                    dbms.dropDatabase(dbName);
+                }
+                return new DropCypherDbResult(dbName, dropMillis.getValue());
+            }
+        );
+
+        return Stream.of(result);
+    }
+
+    private static void validateDatabaseName(String dbName, DatabaseManagementService dbms) {
+        if (!dbms.listDatabases().contains(dbName)) {
+            throw new DatabaseNotFoundException(formatWithLocale("A database with name `%s` does not exist", dbName));
+        }
+
+        var graphName = InMemoryDatabaseCreationCatalog.getRegisteredDbCreationGraphName(dbName);
+        if (graphName == null) {
+            throw new IllegalArgumentException(formatWithLocale(
+                "Database with name `%s` is not an in-memory database",
+                dbName
+            ));
+        }
+    }
+
+    public static class DropCypherDbResult {
+        public final String dbName;
+        public final long dropMillis;
+
+        public DropCypherDbResult(String dbName, long dropMillis) {
+            this.dbName = dbName;
+            this.dropMillis = dropMillis;
+        }
+    }
+}

alpha/alpha-proc/src/main/java/org/neo4j/gds/cypher/GraphCreateCypherDbProc.java

@@ -27,6 +27,7 @@
 import org.neo4j.gds.compat.StorageEngineProxy;
 import org.neo4j.gds.core.utils.ProgressTimer;
 import org.neo4j.gds.storageengine.InMemoryDatabaseCreator;
+import org.neo4j.graphdb.GraphDatabaseService;
 import org.neo4j.procedure.Description;
 import org.neo4j.procedure.Name;
 import org.neo4j.procedure.Procedure;
@@ -52,7 +53,7 @@ public Stream<CreateCypherDbResult> createDb(
         CreateCypherDbResult result = runWithExceptionLogging(
             "In-memory Cypher database creation failed",
             () -> {
-                validateNeo4jEnterpriseEdition();
+                validateNeo4jEnterpriseEdition(databaseService);
                 MutableLong createMillis = new MutableLong(0);
                 try (ProgressTimer ignored = ProgressTimer.start(createMillis::setValue)) {
                     InMemoryDatabaseCreator.createDatabase(databaseService, username(), graphName, dbName);
@@ -78,7 +79,7 @@ public CreateCypherDbResult(String dbName, String graphName, long createMillis)
         }
     }
 
-    private void validateNeo4jEnterpriseEdition() {
+    static void validateNeo4jEnterpriseEdition(GraphDatabaseService databaseService) {
         var edition = StorageEngineProxy.dbmsEdition(databaseService);
         if (!(edition == Edition.ENTERPRISE)) {
             throw new DatabaseManagementException(formatWithLocale(

open-packaging/src/test/java/org/neo4j/gds/OpenGdsProcedureSmokeTest.java

@@ -52,6 +52,7 @@ class OpenGdsProcedureSmokeTest extends BaseProcTest {
         "gds.alpha.graph.sample.rwr",
 
         "gds.alpha.create.cypherdb",
+        "gds.alpha.drop.cypherdb",
 
         "gds.alpha.allShortestPaths.stream",
 
@@ -532,7 +533,7 @@ void countShouldMatch() {
         );
 
         // If you find yourself updating this count, please also update the count in SmokeTest.kt
-        int expectedCount = 377;
+        int expectedCount = 378;
         assertEquals(
             expectedCount,
             registeredProcedures.size(),