ch.rasc.edsutil.optimizer.graph.Graph.java Source code

Introduction

Here is the source code for ch.rasc.edsutil.optimizer.graph.Graph.java

Source

/**
 * Copyright 2013-2015 Ralph Schaer <ralphschaer@gmail.com>
 *
 * Licensed 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 ch.rasc.edsutil.optimizer.graph;

import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.springframework.core.io.Resource;

public class Graph {

    private final Map<String, Node> nodesDb = new HashMap<>();

    public Node createNode(Resource resource) {
        Node newNode = this.nodesDb.get(resource.getDescription());
        if (newNode == null) {
            newNode = new Node(resource);
            this.nodesDb.put(resource.getDescription(), newNode);
        }
        return newNode;
    }

    public List<Node> resolveDependencies() throws CircularReferenceException, IOException {
        List<Node> resolved = new ArrayList<>();
        Set<Node> unresolved = new HashSet<>();
        for (Node node : this.nodesDb.values()) {
            if (!resolved.contains(node)) {
                depResolve(node, resolved, unresolved);
            }
        }
        return resolved;
    }

    private void depResolve(Node node, List<Node> resolved, Set<Node> unresolved)
            throws CircularReferenceException, IOException {
        unresolved.add(node);
        for (Node edge : node.getEdges()) {
            if (!resolved.contains(edge)) {
                if (unresolved.contains(edge)) {
                    throw new CircularReferenceException(node, edge);
                }
                depResolve(edge, resolved, unresolved);
            }
        }
        resolved.add(node);
        unresolved.remove(node);
    }
}