com.tinkerpop.gremlin.structure.io.GraphReader Maven / Gradle / Ivy

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package com.tinkerpop.gremlin.structure.io;

import com.tinkerpop.gremlin.structure.Direction;
import com.tinkerpop.gremlin.structure.Edge;
import com.tinkerpop.gremlin.structure.Graph;
import com.tinkerpop.gremlin.structure.Vertex;
import com.tinkerpop.gremlin.util.function.SQuintFunction;
import com.tinkerpop.gremlin.util.function.STriFunction;

import java.io.IOException;
import java.io.InputStream;
import java.util.Iterator;

/**
 * Functions for reading a graph and its graph elements from a different format.
 *
 * @author Stephen Mallette (http://stephen.genoprime.com)
 */
public interface GraphReader {

    /**
     * Reads an entire graph from an {@link InputStream}.
     *
     * @param inputStream a stream containing a single vertex as defined by the accompanying {@link GraphWriter}
     */
    public void readGraph(final InputStream inputStream, final Graph graphToWriteTo) throws IOException;

    /**
     * Reads a single vertex from an {@link InputStream}.  This method will read vertex properties but not edges.
     *
     * @param inputStream a stream containing a single vertex as defined by the accompanying {@link GraphWriter}
     * @param vertexMaker a function to create a vertex where the first argument is the vertex identifier, the
     *                    second argument is vertex label and the last is the list of properties for it
     */
    public Vertex readVertex(final InputStream inputStream, final STriFunction vertexMaker) throws IOException;

    /**
     * Reads a single vertex from an {@link InputStream}.  This method will read vertex properties as well as edges
     * given the direction supplied as an argument.
     *
     * @param inputStream a stream containing a single vertex as defined by the accompanying {@link GraphWriter}
     * @param direction   the direction of edges to read.
     * @param vertexMaker a function to create a vertex where the first argument is the vertex identifier, the
     *                    second argument is vertex label and the last is the list of properties for it
     * @param edgeMaker   a function that creates an edge from the stream where the first argument is the edge
     *                    identifier, the second argument is the out vertex id, the third is the in vertex id,
     *                    the fourth is the label, and the fifth is the list of properties as key/value pairs.
     */
    public Vertex readVertex(final InputStream inputStream, final Direction direction,
                             final STriFunction vertexMaker,
                             final SQuintFunction edgeMaker) throws IOException;

    /**
     * Reads a set of vertices from an {@link InputStream} which were written by
     * {@link GraphWriter#writeVertices(java.io.OutputStream, com.tinkerpop.gremlin.process.Traversal)}.  This method
     * will read vertex properties as well as edges given the direction supplied as an argument.
     *
     * @param inputStream a stream containing a single vertex as defined by the accompanying {@link GraphWriter}
     * @param direction   the direction of edges to read.
     * @param vertexMaker a function to create a vertex where the first argument is the vertex identifier, the
     *                    second argument is vertex label and the last is the list of properties for it
     * @param edgeMaker   a function that creates an edge from the stream where the first argument is the edge
     *                    identifier, the second argument is the out vertex id, the third is the in vertex id,
     *                    the fourth is the label, and the fifth is the list of properties as key/value pairs.
     */
    public Iterator readVertices(final InputStream inputStream, final Direction direction,
                                         final STriFunction vertexMaker,
                                         final SQuintFunction edgeMaker) throws IOException;

    /**
     * Reads a single edge from an {@link InputStream}.
     *
     * @param inputStream a stream containing a single vertex as defined by the accompanying {@link GraphWriter}
     * @param edgeMaker   a function that creates an edge from the stream where the first argument is the edge
     *                    identifier, the second argument is the out vertex id, the third is the in vertex id,
     *                    the fourth is the label, and the fifth is the list of properties as key/value pairs.
     */
    public Edge readEdge(final InputStream inputStream, final SQuintFunction edgeMaker) throws IOException;

}