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JTrim Task Graph

There is a newer version: 2.0.7

package org.jtrim2.taskgraph;

import java.util.HashSet;
import java.util.Objects;
import java.util.Set;
import org.jtrim2.taskgraph.basic.DependencyDag;

import static java.util.Collections.*;
import static org.jtrim2.utils.ExceptionHelper.*;

/**
 * Defines a whole task execution graph. That is, the set of nodes and the
 * edges.
 *
 * Thread safety
 * Instances of {@code BuiltGraph} are immutable and so can be used safely by
 * multiple threads concurrently.
 *
 * Synchronization transparency
 * The methods of {@code BuiltGraph} are synchronization transparent.
 */
public final class BuiltGraph {
    private final Set> nodes;
    private final DependencyDag> graph;

    /**
     * Creates a new task execution graph with the given edges and nodes.
     *
     * @param nodes specifies the set of all the nodes of the task execution
     *   graph. This argument cannot be {@code null} and cannot contain
     *   {@code null} elements.
     * @param graph defines the edges of the task execution graph. That is,
     *   the dependencies between the nodes. This argument cannot be {@code null}.
     */
    public BuiltGraph(
            Set> nodes,
            DependencyDag> graph) {
        this.nodes = unmodifiableSet(checkNotNullElements(new HashSet<>(nodes), "nodes"));
        this.graph = Objects.requireNonNull(graph, "graph");
    }

    /**
     * Returns the nodes of the task execution graph.
     *
     * @return the nodes of the task execution graph. The returned set is never
     *   {@code null} and is not modifiable.
     */
    public Set> getNodes() {
        return nodes;
    }

    /**
     * Returns the edges of the task execution graph. That is, the dependencies
     * between the nodes.
     *
     * @return the edges of the task execution graph. This method never returns
     *   {@code null}.
     */
    public DependencyDag> getGraph() {
        return graph;
    }
}