TinkerPop implementation for WebGraph

Provides the ability to execute Gremlin queries on graphs compressed with WebGraph.

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Build

mvn compile assembly:single

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Execute query (Java 11)

java -cp target/webgraph-tinkerpop-*.jar org.webgraph.tinkerpop.Main <graph_path> <query> [--profile]

if specified --profile will output query metrics instead of the results.

Example

Print vertices

java -cp target/webgraph-tinkerpop-*.jar org.webgraph.tinkerpop.Main "src/main/resources/example/example" "g.V()" 

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Usage

Open a WebGraphGraph instance with one of the open methods. Use WebgraphGremlinQueryExecutor to execute Gremlin queries.

Properties and labels

In order for Gremlin to access your properties, you need to provide an implementation of WebGraphPropertyProvider . The implementation will let Gremlin access node/edge properties by id. You can either use SimpleWebGraphPropertyProvider , or provide your own implementation.

Example (swh-graph)

Server.java

public class Server {
    public Server(String graphPath) throws IOException {
        this.graphPath = graphPath;
        this.graph = Graph.loadLabelled(graphPath); // Load graph into memory. Labels will provide edge properties.
        this.graph.loadAuthorTimestamp(); // Load a property file.
        
        this.propertyProvider = new SwhWebGraphPropertyProvider(graph);
    }

    public void printQuery(String query) {
        try (WebGraphGraph g = WebGraphGraph.open(graph.getGraph(), graphSettings, graphPath)) {
            WebgraphGremlinQueryExecutor e = new WebgraphGremlinQueryExecutor(g);
            e.print(query);
        }
    }
}

SwhWebGraphPropertyProvider.java

public class SwhWebGraphPropertyProvider implements WebGraphPropertyProvider {
    private final Graph graph;

    public SwhWebGraphPropertyProvider(Graph graph) {
        this.graph = graph;
    }

    @Override
    public String vertexLabel(long nodeId) {
        return graph.getNodeType(nodeId).toString();
    }

    @Override
    public String[] vertexProperties(long nodeId) {
        return new String[]{"author_timestamp"};
    }

    @Override
    public Object vertexProperty(String key, long nodeId) {
        if (!"author_timestamp".equals(key)) {
            throw new RuntimeException("Unknown property key: " + key);
        }
        long authorTimestamp = graph.getAuthorTimestamp(nodeId);
        return authorTimestamp == Long.MIN_VALUE ? null : authorTimestamp;
    }

    @Override
    public String[] edgeProperties(long fromId, long toId) {
        return new String[]{"dir_entry"};
    }

    @Override
    public String edgeLabel(long fromId, long toId) {
        return "edge";
    }

    @Override
    public Object edgeProperty(String key, long fromId, long toId) {
        if (!key.equals("dir_entry")) {
            throw new RuntimeException("Unknown property key: " + key);
        }
        var s = graph.labelledSuccessors(fromId);
        long succ;
        while ((succ = s.nextLong()) != -1) {
            if (succ == toId) {
                return s.label().get();
            }
        }
        return null;
    }
}

Example with SimpleWebGraphPropertyProvider

Server.java

public class Server {
    public Server(String graphPath) throws IOException {
        this.graph = Graph.loadLabelled(graphPath);  // Load graph into memory. Labels will provide edge properties.
        this.propertyProvider = new SimpleWebGraphPropertyProvider();
        this.propertyProvider.addVertexProperty(new FileVertexProperty<>("author_timestamp", Long.class, Path.of(path + ".property.author_timestamp.bin"))); // FileVertexProperty will read the property value from disk
        this.propertyProvider.addEdgeProperty(new ArcLabelEdgeProperty<>((ArcLabelledImmutableGraph) graph.getGraph().getForwardGraph())); // Use arc labels as edge property.
        this.propertyProvider.setVertexLabeller(id -> graph.getNodeType(id).toString()); // Provide custom vertex labels
    }

    public void printQuery(String query) {
        try (WebGraphGraph g = WebGraphGraph.open(graph.getGraph(), graphSettings, graphPath)) {
            WebgraphGremlinQueryExecutor e = new WebgraphGremlinQueryExecutor(g);
            e.print(query);
        }
    }
}