All Downloads are FREE. Search and download functionalities are using the official Maven repository.

com.google.common.graph.GraphBuilder Maven / Gradle / Ivy

Go to download

This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up with different versions on classes on the class path).

There is a newer version: 34.0.0.Final
Show newest version
/*
 * Copyright (C) 2016 The Guava Authors
 *
 * 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 com.google.common.graph;

import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.graph.Graphs.checkNonNegative;

import com.google.common.annotations.Beta;
import com.google.common.base.Optional;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import com.google.errorprone.annotations.DoNotMock;

/**
 * A builder for constructing instances of {@link MutableGraph} or {@link ImmutableGraph} with
 * user-defined properties.
 *
 * 
A {@code Graph} built by this class has the following default properties:
 *
 * 
    
 *   
  • does not allow self-loops
 *   
  • orders {@link Graph#nodes()} in the order in which the elements were added (insertion
 *       order)
 * 

 *
 * 
{@code Graph}s built by this class also guarantee that each collection-returning accessor
 * returns a (live) unmodifiable view; see the external
 * documentation for details.
 *
 * 
Examples of use:
 *
 * 
{@code
 * // Building a mutable graph
 * MutableGraph graph = GraphBuilder.undirected().allowsSelfLoops(true).build();
 * graph.putEdge("bread", "bread");
 * graph.putEdge("chocolate", "peanut butter");
 * graph.putEdge("peanut butter", "jelly");
 *
 * // Building an immutable graph
 * ImmutableGraph immutableGraph =
 *     GraphBuilder.undirected()
 *         .allowsSelfLoops(true)
 *         .immutable()
 *         .putEdge("bread", "bread")
 *         .putEdge("chocolate", "peanut butter")
 *         .putEdge("peanut butter", "jelly")
 *         .build();
 * }

 *
 * @author James Sexton
 * @author Joshua O'Madadhain
 * @param  The most general node type this builder will support. This is normally {@code Object}
 *     unless it is constrained by using a method like {@link #nodeOrder}, or the builder is
 *     constructed based on an existing {@code Graph} using {@link #from(Graph)}.
 * @since 20.0
 */
@Beta
@DoNotMock
@ElementTypesAreNonnullByDefault
public final class GraphBuilder extends AbstractGraphBuilder {

  /** Creates a new instance with the specified edge directionality. */
  private GraphBuilder(boolean directed) {
    super(directed);
  }

  /** Returns a {@link GraphBuilder} for building directed graphs. */
  public static GraphBuilder directed() {
    return new GraphBuilder<>(true);
  }

  /** Returns a {@link GraphBuilder} for building undirected graphs. */
  public static GraphBuilder undirected() {
    return new GraphBuilder<>(false);
  }

  /**
   * Returns a {@link GraphBuilder} initialized with all properties queryable from {@code graph}.
   *
   * 
The "queryable" properties are those that are exposed through the {@link Graph} interface,
   * such as {@link Graph#isDirected()}. Other properties, such as {@link #expectedNodeCount(int)},
   * are not set in the new builder.
   */
  public static  GraphBuilder from(Graph graph) {
    return new GraphBuilder(graph.isDirected())
        .allowsSelfLoops(graph.allowsSelfLoops())
        .nodeOrder(graph.nodeOrder())
        .incidentEdgeOrder(graph.incidentEdgeOrder());
  }

  /**
   * Returns an {@link ImmutableGraph.Builder} with the properties of this {@link GraphBuilder}.
   *
   * 
The returned builder can be used for populating an {@link ImmutableGraph}.
   *
   * 
Note that the returned builder will always have {@link #incidentEdgeOrder} set to {@link
   * ElementOrder#stable()}, regardless of the value that was set in this builder.
   *
   * @since 28.0
   */
  public  ImmutableGraph.Builder immutable() {
    GraphBuilder castBuilder = cast();
    return new ImmutableGraph.Builder<>(castBuilder);
  }

  /**
   * Specifies whether the graph will allow self-loops (edges that connect a node to itself).
   * Attempting to add a self-loop to a graph that does not allow them will throw an {@link
   * UnsupportedOperationException}.
   *
   * 
The default value is {@code false}.
   */
  @CanIgnoreReturnValue
  public GraphBuilder allowsSelfLoops(boolean allowsSelfLoops) {
    this.allowsSelfLoops = allowsSelfLoops;
    return this;
  }

  /**
   * Specifies the expected number of nodes in the graph.
   *
   * @throws IllegalArgumentException if {@code expectedNodeCount} is negative
   */
  @CanIgnoreReturnValue
  public GraphBuilder expectedNodeCount(int expectedNodeCount) {
    this.expectedNodeCount = Optional.of(checkNonNegative(expectedNodeCount));
    return this;
  }

  /**
   * Specifies the order of iteration for the elements of {@link Graph#nodes()}.
   *
   * 
The default value is {@link ElementOrder#insertion() insertion order}.
   */
  public  GraphBuilder nodeOrder(ElementOrder nodeOrder) {
    GraphBuilder newBuilder = cast();
    newBuilder.nodeOrder = checkNotNull(nodeOrder);
    return newBuilder;
  }

  /**
   * Specifies the order of iteration for the elements of {@link Graph#edges()}, {@link
   * Graph#adjacentNodes(Object)}, {@link Graph#predecessors(Object)}, {@link
   * Graph#successors(Object)} and {@link Graph#incidentEdges(Object)}.
   *
   * 
The default value is {@link ElementOrder#unordered() unordered} for mutable graphs. For
   * immutable graphs, this value is ignored; they always have a {@link ElementOrder#stable()
   * stable} order.
   *
   * @throws IllegalArgumentException if {@code incidentEdgeOrder} is not either {@code
   *     ElementOrder.unordered()} or {@code ElementOrder.stable()}.
   * @since 29.0
   */
  public  GraphBuilder incidentEdgeOrder(ElementOrder incidentEdgeOrder) {
    checkArgument(
        incidentEdgeOrder.type() == ElementOrder.Type.UNORDERED
            || incidentEdgeOrder.type() == ElementOrder.Type.STABLE,
        "The given elementOrder (%s) is unsupported. incidentEdgeOrder() only supports"
            + " ElementOrder.unordered() and ElementOrder.stable().",
        incidentEdgeOrder);
    GraphBuilder newBuilder = cast();
    newBuilder.incidentEdgeOrder = checkNotNull(incidentEdgeOrder);
    return newBuilder;
  }

  /** Returns an empty {@link MutableGraph} with the properties of this {@link GraphBuilder}. */
  public  MutableGraph build() {
    return new StandardMutableGraph<>(this);
  }

  GraphBuilder copy() {
    GraphBuilder newBuilder = new GraphBuilder<>(directed);
    newBuilder.allowsSelfLoops = allowsSelfLoops;
    newBuilder.nodeOrder = nodeOrder;
    newBuilder.expectedNodeCount = expectedNodeCount;
    newBuilder.incidentEdgeOrder = incidentEdgeOrder;
    return newBuilder;
  }

  @SuppressWarnings("unchecked")
  private  GraphBuilder cast() {
    return (GraphBuilder) this;
  }
}
    

    

    

            

    

            



    
    






    
© 2015 - 2024 Weber Informatics LLC | Privacy Policy