1 /*******************************************************************************
2 * SAT4J: a SATisfiability library for Java Copyright (C) 2004, 2012 Artois University and CNRS
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 * Contributors:
28 * CRIL - initial API and implementation
29 *******************************************************************************/
30 package org.sat4j.reader;
31
32 import java.io.FileInputStream;
33 import java.io.FileNotFoundException;
34 import java.io.IOException;
35 import java.io.InputStream;
36 import java.io.PrintWriter;
37 import java.net.URL;
38 import java.util.zip.GZIPInputStream;
39
40 import org.sat4j.specs.ContradictionException;
41 import org.sat4j.specs.IProblem;
42
43 /**
44 * A reader is responsible to feed an ISolver from a text file and to convert
45 * the model found by the solver to a textual representation.
46 *
47 * @author leberre
48 */
49 public abstract class Reader {
50
51 /**
52 * This is the usual method to feed a solver with a benchmark.
53 *
54 * @param filename
55 * the fully qualified name of the benchmark. The filename
56 * extension may by used to detect which type of benchmarks it is
57 * (SAT, OPB, MAXSAT, etc).
58 * @return the problem to solve (an ISolver in fact).
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 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 } catch (IllegalStateException e) {
94 if (e.getCause() instanceof ContradictionException) {
95 throw ((ContradictionException) e.getCause());
96 } else {
97 throw e;
98 }
99 } finally {
100 if (in != null) {
101 in.close();
102 }
103 }
104 }
105
106 /**
107 * Read a file from a stream.
108 *
109 * It is important to note that benchmarks are usually encoded in ASCII, not
110 * UTF8. As such, the only reasonable way to feed a solver from a stream is
111 * to use a stream.
112 *
113 * @param in
114 * a stream containing the benchmark.
115 * @return the problem to solve (an ISolver in fact).
116 * @throws ParseFormatException
117 * if an error occurs during parsing.
118 * @throws IOException
119 * if an I/O error occurs.
120 * @throws ContradictionException
121 * if the problem is found trivially inconsistent.
122 */
123 public abstract IProblem parseInstance(final InputStream in)
124 throws ParseFormatException, ContradictionException, IOException;
125
126 /**
127 * Read a file from a reader.
128 *
129 * Do not use that method, it is no longer supported.
130 *
131 * @param in
132 * a stream containing the benchmark.
133 * @return the problem to solve (an ISolver in fact).
134 * @throws ParseFormatException
135 * if an error occurs during parsing.
136 * @throws IOException
137 * if an I/O error occurs.
138 * @throws ContradictionException
139 * if the problem is found trivially inconsistent.
140 * @see #parseInstance(InputStream)
141 */
142 @Deprecated
143 public IProblem parseInstance(java.io.Reader in)
144 throws ParseFormatException, ContradictionException, IOException {
145 throw new UnsupportedOperationException(
146 "Use #parseInstance(InputStream) instead");
147 }
148
149 /**
150 * Produce a model using the reader format.
151 *
152 * @param model
153 * a model using the Dimacs format.
154 * @return a human readable view of the model.
155 */
156 @Deprecated
157 public abstract String decode(int[] model);
158
159 /**
160 * Produce a model using the reader format on a provided printwriter.
161 *
162 * @param model
163 * a model using the Dimacs format.
164 * @param out
165 * the place where to display the model
166 */
167 public abstract void decode(int[] model, PrintWriter out);
168
169 public boolean isVerbose() {
170 return this.verbose;
171 }
172
173 public void setVerbosity(boolean b) {
174 this.verbose = b;
175 }
176
177 private boolean verbose = false;
178 }