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.stream.file;
033
034import java.io.IOException;
035import java.io.OutputStream;
036import java.io.Writer;
037
038import org.graphstream.graph.Graph;
039import org.graphstream.stream.Sink;
040
041/**
042 * Output a graph or graph events to a file.
043 * 
044 * <p>
045 * File outputs can work in two modes:
046 * <ul>
047 * <li>In the "writeAll()" mode, the file output is done "all at once" writing a
048 * "snapshot" of the graph at this particular instant in time. This mode cannot
049 * convey the dynamics of the graph.</li>
050 * <li>In "begin()/end()" mode, the output is listener of an input (a graph or
051 * any other sort of graph events producer) and it write events as they come,
052 * conveying the dynamics of the graph correctly.</li>
053 * </ul>
054 * </p>
055 */
056public interface FileSink extends Sink {
057        /**
058         * Write the current graph state in one big non-interruptible operation.
059         * This operation is a "snapshot" of the graph, it will never convey the
060         * dynamics of the graph. To ensure you store the graph
061         * "as it evolves in time" you must use the {@link #begin(OutputStream)} or
062         * {@link #begin(String)} as soon as the graph appears (or any source of
063         * graph event, any descendant of {@link Source} will do).
064         * 
065         * @param graph
066         *            The graph to send as events to the file.
067         * @param fileName
068         *            Name of the file to write.
069         * @throws IOException
070         *             if an I/O error occurs while writing.
071         */
072        void writeAll(Graph graph, String fileName) throws IOException;
073
074        /**
075         * Write the current graph state in one big non-interruptible operation.
076         * This operation is a "snapshot" of the graph, it will never convey the
077         * dynamics of the graph. To ensure you store the graph
078         * "as it evolves in time" you must use the {@link #begin(Writer)} or
079         * {@link #begin(OutputStream)} or {@link #begin(String)} as soon as the
080         * graph appears (or any source of graph event, any descendant of
081         * {@link Source} will do).
082         * 
083         * @param graph
084         *            The graph to send as events to the file.
085         * @param stream
086         *            The stream where the graph is sent.
087         * @throws IOException
088         *             if an I/O error occurs while writing.
089         */
090        void writeAll(Graph graph, OutputStream stream) throws IOException;
091
092        /**
093         * Write the current graph state in one big non-interruptible operation.
094         * This operation is a "snapshot" of the graph, it will never convey the
095         * dynamics of the graph. To ensure you store the graph
096         * "as it evolves in time" you must use the {@link #begin(Writer)} or
097         * {@link #begin(OutputStream)} or {@link #begin(String)} as soon as the
098         * graph appears (or any source of graph event, any descendant of
099         * {@link Source} will do).
100         * 
101         * @param graph
102         *            The graph to send as events to the file.
103         * @param writer
104         *            The writer where the graph is sent.
105         * @throws IOException
106         *             if an I/O error occurs while writing.
107         */
108        void writeAll(Graph graph, Writer writer) throws IOException;
109
110        /**
111         * Begin the output of the given stream of graph events. The graph events
112         * can come from any input (implementation of {@link Source} or you can
113         * directly use the methods inherited from {@link Sink}. Once the writing is
114         * started using begin(), you must close it using {@link #end()} when done
115         * to ensure data is correctly stored in the file.
116         * 
117         * @param fileName
118         *            The name of the file where to output the graph events.
119         * @throws IOException
120         *             If an I/O error occurs while writing.
121         */
122        void begin(String fileName) throws IOException;
123
124        /**
125         * Begin the output of the given stream of graph events. The graph events
126         * can come from any input (implementation of {@link Source} or you can
127         * directly use the methods inherited from {@link Sink}. Once the writing is
128         * started using begin(), you must close it using {@link #end()} when done
129         * to ensure data is correctly stored in the file.
130         * 
131         * @param stream
132         *            The file stream where to output the graph events.
133         * @throws IOException
134         *             If an I/O error occurs while writing.
135         */
136        void begin(OutputStream stream) throws IOException;
137
138        /**
139         * Begin the output of the given stream of graph events. The graph events
140         * can come from any input (implementation of {@link Source} or you can
141         * directly use the methods inherited from {@link Sink}. Once the writing is
142         * started using begin(), you must close it using {@link #end()} when done
143         * to ensure data is correctly stored in the file.
144         * 
145         * @param writer
146         *            The writer where to output the graph events.
147         * @throws IOException
148         *             If an I/O error occurs while writing.
149         */
150        void begin(Writer writer) throws IOException;
151
152        /**
153         * Ensure all data sent to the output are correctly written.
154         * 
155         * @throws IOException
156         *             If an I/O error occurs during write.
157         */
158        void flush() throws IOException;
159
160        /**
161         * End the writing process started with {@link #begin(OutputStream)} or
162         * {@link #begin(String)}.
163         * 
164         * @throws IOException
165         */
166        void end() throws IOException;
167}