001/*
002 * Copyright 2006 - 2013
003 *     Stefan Balev     <stefan.balev@graphstream-project.org>
004 *     Julien Baudry    <julien.baudry@graphstream-project.org>
005 *     Antoine Dutot    <antoine.dutot@graphstream-project.org>
006 *     Yoann Pigné      <yoann.pigne@graphstream-project.org>
007 *     Guilhelm Savin   <guilhelm.savin@graphstream-project.org>
008 * 
009 * This file is part of GraphStream <http://graphstream-project.org>.
010 * 
011 * GraphStream is a library whose purpose is to handle static or dynamic
012 * graph, create them from scratch, file or any source and display them.
013 * 
014 * This program is free software distributed under the terms of two licenses, the
015 * CeCILL-C license that fits European law, and the GNU Lesser General Public
016 * License. You can  use, modify and/ or redistribute the software under the terms
017 * of the CeCILL-C license as circulated by CEA, CNRS and INRIA at the following
018 * URL <http://www.cecill.info> or under the terms of the GNU LGPL as published by
019 * the Free Software Foundation, either version 3 of the License, or (at your
020 * option) any later version.
021 * 
022 * This program is distributed in the hope that it will be useful, but WITHOUT ANY
023 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
024 * PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more details.
025 * 
026 * You should have received a copy of the GNU Lesser General Public License
027 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
028 * 
029 * The fact that you are presently reading this means that you have had
030 * knowledge of the CeCILL-C and LGPL licenses and that you accept their terms.
031 */
032package org.graphstream.algorithm.flow;
033
034import org.graphstream.algorithm.Algorithm;
035import org.graphstream.graph.Graph;
036import org.graphstream.graph.Node;
037
038/**
039 * Defines algorithm used to compute maximum flow.
040 */
041public interface FlowAlgorithm extends Algorithm {
042        /**
043         * Get flow value of edge (u,v).
044         * 
045         * @param u
046         * @param v
047         * @return flow of (u,v)
048         */
049        double getFlow(Node u, Node v);
050
051        /**
052         * Set flow of edge (u,v).
053         * 
054         * @param u
055         * @param v
056         * @param flow
057         *            new flow
058         */
059        void setFlow(Node u, Node v, double flow);
060
061        /**
062         * Get capacity of edge (u,v).
063         * 
064         * @param u
065         * @param v
066         * @return capacity of (u,v)s
067         */
068        double getCapacity(Node u, Node v);
069
070        /**
071         * Set capacity of (u,v). Capacities should be set between calls to
072         * {@link #init(Graph, String, String)} and {@link #compute()}.
073         * 
074         * @param u
075         * @param v
076         * @param capacity
077         *            new capacity of (u,v)
078         */
079        void setCapacity(Node u, Node v, double capacity);
080
081        /**
082         * Set the key of the attribute from which capacities will be loaded.
083         * Attribute values of edge (u,v) should be an array of double where first
084         * element is the value of the capacity of (u,v) and second the capacity of
085         * (v,u). If there is only one value, the value of (v,u) will be zero. If no
086         * value is available, both capacities will be zero.
087         * 
088         * If capacity attribute is null, you have to set capacities before calling
089         * {@link #compute()}.
090         * 
091         * @param attribute
092         */
093        void setCapacityAttribute(String attribute);
094
095        /**
096         * Get the key attribute from which capacities are loaded.
097         * 
098         * @see #setCapacityAttribute(String)
099         * @return key attribute of capacities
100         */
101        String getCapacityAttribute();
102
103        /**
104         * Get maximum flow compute by {@link #compute()}.
105         * 
106         * @return maximum flow
107         */
108        double getMaximumFlow();
109
110        /**
111         * Get id of the source.
112         * 
113         * @return id of the source
114         */
115        String getFlowSourceId();
116
117        /**
118         * Get id of the sink.
119         * 
120         * @return id of the sink
121         */
122        String getFlowSinkId();
123
124        /**
125         * Init the algorithm. This method replaces the {@link #init(Graph)} method
126         * of Algorithm so users just have to call this new method.
127         * 
128         * @param g
129         *            graph that should be used by the algorithm
130         * @param sourceId
131         *            id of the source of the flow
132         * @param sinkId
133         *            id of the sink of the flow
134         */
135        void init(Graph g, String sourceId, String sinkId);
136}