Github user spmallette commented on a diff in the pull request:
https://github.com/apache/tinkerpop/pull/569#discussion_r106412544
--- Diff:
gremlin-server/src/main/java/org/apache/tinkerpop/gremlin/server/util/DefaultGraphManager.java
---
@@ -0,0 +1,201 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tinkerpop.gremlin.server.util;
+
+import org.apache.tinkerpop.gremlin.process.traversal.TraversalSource;
+import org.apache.tinkerpop.gremlin.server.GraphManager;
+import org.apache.tinkerpop.gremlin.server.GremlinServer;
+import org.apache.tinkerpop.gremlin.server.Settings;
+import org.apache.tinkerpop.gremlin.structure.Graph;
+import org.apache.tinkerpop.gremlin.structure.Transaction;
+import org.apache.tinkerpop.gremlin.structure.util.GraphFactory;
+import org.apache.tinkerpop.gremlin.util.iterator.IteratorUtils;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import javax.script.Bindings;
+import javax.script.SimpleBindings;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.function.Predicate;
+import java.util.function.Supplier;
+
+/**
+ * Holder for {@link Graph} and {@link TraversalSource} instances
configured for the server to be passed to script
+ * engine bindings. The {@link Graph} instances are read from the {@link
Settings} for Gremlin Server as defined in
+ * the configuration file. The {@link TraversalSource} instances are
rebound to the {@code GraphManager} once
+ * initialization scripts construct them.
+ */
+public final class DefaultGraphManager implements GraphManager {
+ private static final Logger logger =
LoggerFactory.getLogger(GremlinServer.class);
+
+ private final Map<String, Graph> graphs = new ConcurrentHashMap<>();
+ private final Map<String, TraversalSource> traversalSources = new
ConcurrentHashMap<>();
+
+ /**
+ * Create a new instance using the {@link Settings} from Gremlin
Server.
+ */
+ public DefaultGraphManager(final Settings settings) {
+ settings.graphs.entrySet().forEach(e -> {
+ try {
+ final Graph newGraph = GraphFactory.open(e.getValue());
+ graphs.put(e.getKey(), newGraph);
+ logger.info("Graph [{}] was successfully configured via
[{}].", e.getKey(), e.getValue());
+ } catch (RuntimeException re) {
+ logger.warn(String.format("Graph [%s] configured at [%s]
could not be instantiated and will not be available in Gremlin Server.
GraphFactory message: %s",
+ e.getKey(), e.getValue(), re.getMessage()), re);
+ if (re.getCause() != null) logger.debug("GraphFactory
exception", re.getCause());
+ }
+ });
+ }
+
+ /**
+ * Get a list of the {@link Graph} instances and their binding names
as defined in the Gremlin Server
+ * configuration file.
+ *
+ * @return a {@link Map} where the key is the name of the {@link
Graph} and the value is the {@link Graph} itself
+ */
+ public Map<String, Graph> getGraphs() {
+ return graphs;
+ }
+
+ public Graph getGraph(String gName) {
+ return graphs.get(gName);
+ }
+
+ public void addGraph(String gName, Graph g) {
+ graphs.put(gName, g);
+ }
+
+ /**
+ * Get a list of the {@link TraversalSource} instances and their
binding names as defined by Gremlin Server
+ * initialization scripts.
+ *
+ * @return a {@link Map} where the key is the name of the {@link
TraversalSource} and the value is the
+ * {@link TraversalSource} itself
+ */
+ public Map<String, TraversalSource> getTraversalSources() {
+ return traversalSources;
+ }
+
+ public TraversalSource getTraversalSource(String tsName) {
+ return traversalSources.get(tsName);
+ }
+
+ public void addTraversalSource(String tsName, TraversalSource ts) {
+ traversalSources.put(tsName, ts);
+ }
+
+ /**
+ * Get the {@link Graph} and {@link TraversalSource} list as a set of
bindings.
+ */
+ public Bindings getAsBindings() {
+ final Bindings bindings = new SimpleBindings();
+ graphs.forEach(bindings::put);
+ traversalSources.forEach(bindings::put);
+ return bindings;
+ }
+
+ /**
+ * Rollback transactions across all {@link Graph} objects.
+ */
+ public void rollbackAll() {
+ graphs.entrySet().forEach(e -> {
+ final Graph graph = e.getValue();
+ if (graph.features().graph().supportsTransactions() &&
graph.tx().isOpen())
+ graph.tx().rollback();
+ });
+ }
+
+ /**
+ * Selectively rollback transactions on the specified graphs or the
graphs of traversal sources.
+ */
+ public void rollback(final Set<String> graphSourceNamesToCloseTxOn) {
+ closeTx(graphSourceNamesToCloseTxOn, Transaction.Status.ROLLBACK);
+ }
+
+ /**
+ * Commit transactions across all {@link Graph} objects.
+ */
+ public void commitAll() {
+ graphs.entrySet().forEach(e -> {
+ final Graph graph = e.getValue();
+ if (graph.features().graph().supportsTransactions() &&
graph.tx().isOpen())
+ graph.tx().commit();
+ });
+ }
+
+ /**
+ * Selectively commit transactions on the specified graphs or the
graphs of traversal sources.
+ */
+ public void commit(final Set<String> graphSourceNamesToCloseTxOn) {
+ closeTx(graphSourceNamesToCloseTxOn, Transaction.Status.COMMIT);
+ }
+
+ /**
+ * Basic graphManager has basic openGraph function.
+ */
+ public Graph openGraph(String graphName, Supplier<Graph> supplier) {
+ final Graph graph = graphs.get(graphName);
+ if (null != graph) {
+ return graph;
+ }
+ return supplier.get();
+ }
+
+ /**
+ * Close graph
+ */
+ public void closeGraph(Graph graph) {
+ try {
+ graph.close();
--- End diff --
What does it mean to actually call `closeGraph()`? If "closed" does that
mean it should still be in the available set of graphs? If so it would still be
accessible to requests but it would be in a closed state. Different graphs will
have different semantics with respect to what `close()` will do. Anyway, just
posing the issue for thought at this point....not sure i have a strong opinion
yet on what the behavior should be.
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