1 /*******************************************************************************
2 * SAT4J: a SATisfiability library for Java Copyright (C) 2004-2008 Daniel Le Berre
3 *
4 * All rights reserved. This program and the accompanying materials
5 * are made available under the terms of the Eclipse Public License v1.0
6 * which accompanies this distribution, and is available at
7 * http://www.eclipse.org/legal/epl-v10.html
8 *
9 * Alternatively, the contents of this file may be used under the terms of
10 * either the GNU Lesser General Public License Version 2.1 or later (the
11 * "LGPL"), in which case the provisions of the LGPL are applicable instead
12 * of those above. If you wish to allow use of your version of this file only
13 * under the terms of the LGPL, and not to allow others to use your version of
14 * this file under the terms of the EPL, indicate your decision by deleting
15 * the provisions above and replace them with the notice and other provisions
16 * required by the LGPL. If you do not delete the provisions above, a recipient
17 * may use your version of this file under the terms of the EPL or the LGPL.
18 *
19 * Based on the original MiniSat specification from:
20 *
21 * An extensible SAT solver. Niklas Een and Niklas Sorensson. Proceedings of the
22 * Sixth International Conference on Theory and Applications of Satisfiability
23 * Testing, LNCS 2919, pp 502-518, 2003.
24 *
25 * See www.minisat.se for the original solver in C++.
26 *
27 *******************************************************************************/
28 package org.sat4j.reader;
29
30 import java.io.FileInputStream;
31 import java.io.FileNotFoundException;
32 import java.io.IOException;
33 import java.io.InputStream;
34 import java.io.PrintWriter;
35 import java.net.URL;
36 import java.util.zip.GZIPInputStream;
37
38 import org.sat4j.specs.ContradictionException;
39 import org.sat4j.specs.IProblem;
40
41 /**
42 * A reader is responsible to feed an ISolver from a text file and to convert
43 * the model found by the solver to a textual representation.
44 *
45 * @author leberre
46 */
47 public abstract class Reader {
48
49 /**
50 * This is the usual method to feed a solver with a benchmark.
51 *
52 * @param filename
53 * the fully qualified name of the benchmark. The filename
54 * extension may by used to detect which type of benchmarks it is
55 * (SAT, OPB, MAXSAT, etc).
56 * @return the problem to solve (an ISolver in fact).
57 * @throws FileNotFoundException
58 * if the file cannot be found.
59 * @throws ParseFormatException
60 * if an error occurs during parsing.
61 * @throws IOException
62 * if an I/O error occurs.
63 * @throws ContradictionException
64 * if the problem is found trivially inconsistent.
65 */
66 public IProblem parseInstance(final String filename)
67 throws FileNotFoundException, ParseFormatException, IOException,
68 ContradictionException {
69 InputStream in = null;
70 try {
71 if (filename.startsWith("http://")) {
72 in = (new URL(filename)).openStream();
73 } else {
74 in = new FileInputStream(filename);
75 }
76 if (filename.endsWith(".gz")) {
77 in = new GZIPInputStream(in);
78 } else if (filename.endsWith(".bz2")) {
79 in = Runtime.getRuntime().exec("bunzip2 -c " + filename)
80 .getInputStream();
81 }
82 IProblem problem;
83 problem = parseInstance(in);
84 return problem;
85 } catch (FileNotFoundException e) {
86 throw e;
87 } catch (ParseFormatException e) {
88 throw e;
89 } catch (IOException e) {
90 throw e;
91 } catch (ContradictionException e) {
92 throw e;
93 } finally {
94 if (in != null) {
95 in.close();
96 }
97 }
98 }
99
100 /**
101 * Read a file from a stream.
102 *
103 * It is important to note that benchmarks are usually encoded in ASCII, not
104 * UTF8. As such, the only reasonable way to feed a solver from a stream is
105 * to use a stream.
106 *
107 * @param in
108 * a stream containing the benchmark.
109 * @return the problem to solve (an ISolver in fact).
110 * @throws ParseFormatException
111 * if an error occurs during parsing.
112 * @throws IOException
113 * if an I/O error occurs.
114 * @throws ContradictionException
115 * if the problem is found trivially inconsistent.
116 */
117 public abstract IProblem parseInstance(final InputStream in)
118 throws ParseFormatException, ContradictionException, IOException;
119
120 /**
121 * Read a file from a reader.
122 *
123 * Do not use that method, it is no longer supported.
124 *
125 * @param in
126 * a stream containing the benchmark.
127 * @return the problem to solve (an ISolver in fact).
128 * @throws ParseFormatException
129 * if an error occurs during parsing.
130 * @throws IOException
131 * if an I/O error occurs.
132 * @throws ContradictionException
133 * if the problem is found trivially inconsistent.
134 * @see #parseInstance(InputStream)
135 */
136 @Deprecated
137 public IProblem parseInstance(java.io.Reader in)
138 throws ParseFormatException, ContradictionException, IOException {
139 throw new UnsupportedOperationException(
140 "Use #parseInstance(InputStream) instead");
141 }
142
143 /**
144 * Produce a model using the reader format.
145 *
146 * @param model
147 * a model using the Dimacs format.
148 * @return a human readable view of the model.
149 */
150 @Deprecated
151 public abstract String decode(int[] model);
152
153 /**
154 * Produce a model using the reader format on a provided printwriter.
155 *
156 * @param model
157 * a model using the Dimacs format.
158 * @param out
159 * the place where to display the model
160 */
161 public abstract void decode(int[] model, PrintWriter out);
162
163 public boolean isVerbose() {
164 return verbose;
165 }
166
167 public void setVerbosity(boolean b) {
168 verbose = b;
169 }
170
171 private boolean verbose = false;
172 }