introducing parameter object for common request scoped things

algo/src/main/java/org/neo4j/gds/algorithms/RequestScopedDependencies.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.algorithms;
+
+import org.neo4j.gds.api.DatabaseId;
+import org.neo4j.gds.api.User;
+import org.neo4j.gds.termination.TerminationFlag;
+
+/**
+ * This is a handy class for transporting similar dependencies through layers.
+ * And especially useful when that list grows or shrinks - less sites to edit innit
+ */
+public final class RequestScopedDependencies {
+    private final DatabaseId databaseId;
+    private final TerminationFlag terminationFlag;
+    private final User user;
+
+    /**
+     * Over-doing it with a private constructor?
+     * <p>
+     * I just really like the <code>RequestScopedDependencies.builder().build()</code> form
+     */
+    private RequestScopedDependencies(
+        DatabaseId databaseId,
+        TerminationFlag terminationFlag,
+        User user
+    ) {
+        this.databaseId = databaseId;
+        this.terminationFlag = terminationFlag;
+        this.user = user;
+    }
+
+    public static RequestScopedDependenciesBuilder builder() {
+        return new RequestScopedDependenciesBuilder();
+    }
+
+    public DatabaseId getDatabaseId() {
+        return databaseId;
+    }
+
+    public TerminationFlag getTerminationFlag() {
+        return terminationFlag;
+    }
+
+    public User getUser() {
+        return user;
+    }
+
+    public static class RequestScopedDependenciesBuilder {
+        private DatabaseId databaseId = DatabaseId.DEFAULT;
+        private User user = User.DEFAULT;
+        private TerminationFlag terminationFlag = TerminationFlag.DEFAULT;
+
+        public RequestScopedDependenciesBuilder with(DatabaseId databaseId) {
+            this.databaseId = databaseId;
+            return this;
+        }
+
+        public RequestScopedDependenciesBuilder with(TerminationFlag terminationFlag) {
+            this.terminationFlag = terminationFlag;
+            return this;
+        }
+
+        public RequestScopedDependenciesBuilder with(User user) {
+            this.user = user;
+            return this;
+        }
+
+        public RequestScopedDependencies build() {
+            return new RequestScopedDependencies(databaseId, terminationFlag, user);
+        }
+    }
+}

algo/src/main/java/org/neo4j/gds/algorithms/runner/AlgorithmRunner.java

@@ -25,6 +25,7 @@
 import org.neo4j.gds.algorithms.AlgorithmComputationResult;
 import org.neo4j.gds.algorithms.AlgorithmMemoryEstimation;
 import org.neo4j.gds.algorithms.AlgorithmMemoryValidationService;
+import org.neo4j.gds.algorithms.RequestScopedDependencies;
 import org.neo4j.gds.api.DatabaseId;
 import org.neo4j.gds.api.GraphName;
 import org.neo4j.gds.api.User;
@@ -63,6 +64,10 @@ public AlgorithmRunner(
         this.log = log;
     }
 
+    /**
+     * @deprecated Strangle this one, use the other one
+     */
+    @Deprecated
     public <A extends Algorithm<R>, R, C extends AlgoBaseConfig> AlgorithmComputationResult<R> run(
         String graphName,
         C config,
@@ -71,6 +76,28 @@ public <A extends Algorithm<R>, R, C extends AlgoBaseConfig> AlgorithmComputatio
         User user,
         DatabaseId databaseId,
         TerminationFlag terminationFlag
+    ) {
+        var requestScopedDependencies = RequestScopedDependencies.builder()
+            .with(databaseId)
+            .with(terminationFlag)
+            .with(user)
+            .build();
+
+        return run(
+            requestScopedDependencies,
+            graphName,
+            config,
+            relationshipProperty,
+            algorithmFactory
+        );
+    }
+
+    public <A extends Algorithm<R>, R, C extends AlgoBaseConfig> AlgorithmComputationResult<R> run(
+        RequestScopedDependencies requestScopedDependencies,
+        String graphName,
+        C config,
+        Optional<String> relationshipProperty,
+        GraphAlgorithmFactory<A, C> algorithmFactory
     ) {
         // TODO: Is this the best place to check for preconditions???
         PreconditionsProvider.preconditions().check();
@@ -80,8 +107,8 @@ public <A extends Algorithm<R>, R, C extends AlgoBaseConfig> AlgorithmComputatio
             GraphName.parse(graphName),
             config,
             relationshipProperty,
-            user,
-            databaseId
+            requestScopedDependencies.getUser(),
+            requestScopedDependencies.getDatabaseId()
         );
 
         var graph = graphWithGraphStore.getLeft();
@@ -115,7 +142,7 @@ public <A extends Algorithm<R>, R, C extends AlgoBaseConfig> AlgorithmComputatio
         );
 
         // this really belongs in the factory build thing
-        algorithm.setTerminationFlag(terminationFlag);
+        algorithm.setTerminationFlag(requestScopedDependencies.getTerminationFlag());
 
         // run the algorithm
         try {

algo/src/test/java/org/neo4j/gds/algorithms/someotherpackage/RequestScopedDependenciesTest.java

@@ -0,0 +1,52 @@
+/*
+ * 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.algorithms.someotherpackage;
+
+import org.junit.jupiter.api.Test;
+import org.neo4j.gds.algorithms.RequestScopedDependencies;
+import org.neo4j.gds.api.DatabaseId;
+import org.neo4j.gds.api.User;
+import org.neo4j.gds.termination.TerminationFlag;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+class RequestScopedDependenciesTest {
+    @Test
+    void shouldBeSafeAndConvenient() {
+        var rsd = RequestScopedDependencies.builder().build();
+
+        assertThat(rsd.getDatabaseId()).isEqualTo(DatabaseId.DEFAULT);
+        assertThat(rsd.getUser()).isEqualTo(User.DEFAULT);
+        assertThat(rsd.getTerminationFlag()).isEqualTo(TerminationFlag.DEFAULT);
+    }
+
+    @Test
+    void shouldBuildBespokeProducts() {
+        var rsd = RequestScopedDependencies.builder()
+            .with(DatabaseId.of("IMDB"))
+            .with(TerminationFlag.STOP_RUNNING)
+            .with(new User("Colin Needham", true))
+            .build();
+
+        assertThat(rsd.getDatabaseId()).isEqualTo(DatabaseId.of("IMDB"));
+        assertThat(rsd.getTerminationFlag()).isEqualTo(TerminationFlag.STOP_RUNNING);
+        assertThat(rsd.getUser()).isEqualTo(new User("Colin Needham", true));
+    }
+}

core/src/main/java/org/neo4j/gds/api/DatabaseId.java

@@ -25,7 +25,8 @@
 import static org.neo4j.gds.utils.StringFormatting.toLowerCaseWithLocale;
 
 public final class DatabaseId {
-
+    // defaults to something that you will never find in the wild
+    public static final DatabaseId DEFAULT = DatabaseId.of("non-existent/" + UUID.randomUUID());
     public static final DatabaseId EMPTY = new DatabaseId("");
 
     public static DatabaseId of(String databaseName) {

core/src/main/java/org/neo4j/gds/api/User.java

@@ -23,8 +23,12 @@
 import org.apache.commons.lang3.builder.HashCodeBuilder;
 
 import java.util.Optional;
+import java.util.UUID;
 
 public class User {
+    // defaults to something that you will never find in the wild
+    public static final User DEFAULT = new User("anonymous/" + UUID.randomUUID(), false);
+
     private final String username;
     private final boolean isAdmin;
 

termination/src/main/java/org/neo4j/gds/termination/TerminationFlag.java

@@ -26,6 +26,8 @@
 public interface TerminationFlag {
 
     TerminationFlag RUNNING_TRUE = () -> true;
+    TerminationFlag DEFAULT = () -> true;
+    TerminationFlag STOP_RUNNING = () -> false;
 
     int RUN_CHECK_NODE_COUNT = 10_000;