Method: close()

1: /**
2: * Copyright (C) 2016 Czech Technical University in Prague
3: * <p>
4: * This program is free software: you can redistribute it and/or modify it under
5: * the terms of the GNU General Public License as published by the Free Software
6: * Foundation, either version 3 of the License, or (at your option) any
7: * later version.
8: * <p>
9: * This program is distributed in the hope that it will be useful, but WITHOUT
10: * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
11: * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
12: * details. You should have received a copy of the GNU General Public License
13: * along with this program. If not, see <http://www.gnu.org/licenses/>.
14: */
15: package cz.cvut.kbss.ontodriver.sesame;
16:
17: import cz.cvut.kbss.ontodriver.Closeable;
18: import cz.cvut.kbss.ontodriver.Wrapper;
19: import cz.cvut.kbss.ontodriver.config.DriverConfigParam;
20: import cz.cvut.kbss.ontodriver.config.DriverConfiguration;
21: import cz.cvut.kbss.ontodriver.descriptor.*;
22: import cz.cvut.kbss.ontodriver.exception.IdentifierGenerationException;
23: import cz.cvut.kbss.ontodriver.exception.OntoDriverException;
24: import cz.cvut.kbss.ontodriver.model.Axiom;
25: import cz.cvut.kbss.ontodriver.sesame.connector.Connector;
26: import cz.cvut.kbss.ontodriver.sesame.connector.StatementExecutor;
27: import cz.cvut.kbss.ontodriver.sesame.exceptions.SesameDriverException;
28: import cz.cvut.kbss.ontodriver.sesame.util.SesameUtils;
29: import cz.cvut.kbss.ontodriver.util.IdentifierUtils;
30: import cz.cvut.kbss.ontodriver.util.Transaction;
31: import org.eclipse.rdf4j.model.Resource;
32: import org.eclipse.rdf4j.model.Value;
33: import org.eclipse.rdf4j.model.ValueFactory;
34: import org.eclipse.rdf4j.model.vocabulary.RDF;
35:
36: import java.net.URI;
37: import java.util.ArrayList;
38: import java.util.Collection;
39: import java.util.List;
40:
41: class SesameAdapter implements Closeable, Wrapper {
42:
43: /**
44: * Maximum number of attempts to generate a unique identifier
45: */
46: private static final int ID_GENERATION_THRESHOLD = 64;
47:
48: private final Connector connector;
49: private final ValueFactory valueFactory;
50: private final String language;
51: private boolean open;
52: private final Transaction transaction;
53:
54: public SesameAdapter(Connector connector, DriverConfiguration configuration) {
55: assert connector != null;
56:
57: this.connector = connector;
58: this.valueFactory = connector.getValueFactory();
59: this.language = configuration.getProperty(DriverConfigParam.ONTOLOGY_LANGUAGE);
60: this.open = true;
61: this.transaction = new Transaction();
62: }
63:
64: Connector getConnector() {
65: return connector;
66: }
67:
68: ValueFactory getValueFactory() {
69: return valueFactory;
70: }
71:
72: String getLanguage() {
73: return language;
74: }
75:
76: @Override
77: public void close() throws OntoDriverException {
78:• if (!open) {
79: return;
80: }
81: try {
82: connector.close();
83: } finally {
84: this.open = false;
85: }
86: }
87:
88: @Override
89: public boolean isOpen() {
90: return open;
91: }
92:
93: void commit() throws SesameDriverException {
94: if (transaction.isActive()) {
95: transaction.commit();
96: connector.commit();
97: transaction.afterCommit();
98: }
99: }
100:
101: void rollback() throws SesameDriverException {
102: if (transaction.isActive()) {
103: transaction.rollback();
104: connector.rollback();
105: transaction.afterRollback();
106: }
107: }
108:
109: boolean isConsistent(URI context) {
110: // Sesame currently doesn't support any consistency checking
111: // functionality
112: return true;
113: }
114:
115: List<URI> getContexts() throws SesameDriverException {
116: final List<Resource> contextIds = connector.getContexts();
117: final List<URI> contexts = new ArrayList<>(contextIds.size());
118: for (Resource res : contextIds) {
119: final URI context = SesameUtils.toJavaUri(res);
120: // We support only named contexts (no blank nodes)
121: if (context != null) {
122: contexts.add(context);
123: }
124: }
125: return contexts;
126: }
127:
128: URI generateIdentifier(URI classUri) throws SesameDriverException {
129: startTransactionIfNotActive();
130: boolean unique = false;
131: URI id = null;
132: int counter = 0;
133: while (!unique && counter++ < ID_GENERATION_THRESHOLD) {
134: id = IdentifierUtils.generateIdentifier(classUri);
135: unique = isIdentifierUnique(id, classUri);
136: }
137: if (!unique) {
138: throw new IdentifierGenerationException("Unable to generate a unique identifier.");
139: }
140: return id;
141:
142: }
143:
144: private void startTransactionIfNotActive() throws SesameDriverException {
145: if (!transaction.isActive()) {
146: connector.begin();
147: transaction.begin();
148: }
149: }
150:
151: private boolean isIdentifierUnique(URI identifier, URI classUri) throws SesameDriverException {
152: return !connector.containsStatement(
153: SesameUtils.toSesameIri(identifier, valueFactory), RDF.TYPE,
154: SesameUtils.toSesameIri(classUri, valueFactory), true);
155: }
156:
157: boolean contains(Axiom<?> axiom, URI context) throws SesameDriverException {
158: startTransactionIfNotActive();
159: Value value;
160: if (SesameUtils.isResourceIdentifier(axiom.getValue().getValue())) {
161: value = valueFactory.createIRI(axiom.getValue().stringValue());
162: } else {
163: value = SesameUtils.createDataPropertyLiteral(axiom.getValue().getValue(), language,
164: valueFactory);
165: }
166: final org.eclipse.rdf4j.model.IRI sesameContext = SesameUtils.toSesameIri(context, valueFactory);
167: return connector.containsStatement(
168: SesameUtils.toSesameIri(axiom.getSubject().getIdentifier(), valueFactory),
169: SesameUtils.toSesameIri(axiom.getAssertion().getIdentifier(), valueFactory), value,
170: axiom.getAssertion().isInferred(), sesameContext);
171:
172: }
173:
174: Collection<Axiom<?>> find(AxiomDescriptor axiomDescriptor) throws SesameDriverException {
175: startTransactionIfNotActive();
176: return new AxiomLoader(connector, valueFactory, language).loadAxioms(axiomDescriptor);
177: }
178:
179: void persist(AxiomValueDescriptor axiomDescriptor) throws SesameDriverException {
180: startTransactionIfNotActive();
181: new AxiomSaver(connector, valueFactory, language).persistAxioms(axiomDescriptor);
182: }
183:
184: void update(AxiomValueDescriptor axiomDescriptor) throws SesameDriverException {
185: startTransactionIfNotActive();
186: new EpistemicAxiomRemover(connector, valueFactory, language).remove(axiomDescriptor);
187: new AxiomSaver(connector, valueFactory, language).persistAxioms(axiomDescriptor);
188: }
189:
190: void remove(AxiomDescriptor axiomDescriptor) throws SesameDriverException {
191: startTransactionIfNotActive();
192: new EpistemicAxiomRemover(connector, valueFactory, language).remove(axiomDescriptor);
193: }
194:
195: StatementExecutor getQueryExecutor() {
196: return connector;
197: }
198:
199: ListHandler<SimpleListDescriptor, SimpleListValueDescriptor> getSimpleListHandler() throws SesameDriverException {
200: startTransactionIfNotActive();
201: return ListHandler.createForSimpleList(connector, valueFactory);
202: }
203:
204: ListHandler<ReferencedListDescriptor, ReferencedListValueDescriptor> getReferencedListHandler() throws
205: SesameDriverException {
206: startTransactionIfNotActive();
207: return ListHandler.createForReferencedList(connector, valueFactory);
208: }
209:
210: TypesHandler getTypesHandler() throws SesameDriverException {
211: startTransactionIfNotActive();
212: return new TypesHandler(connector, valueFactory);
213: }
214:
215: @Override
216: public <T> T unwrap(Class<T> cls) throws OntoDriverException {
217: if (cls.isAssignableFrom(this.getClass())) {
218: return cls.cast(this);
219: } else if (cls.isAssignableFrom(valueFactory.getClass())) {
220: return cls.cast(valueFactory);
221: }
222: return connector.unwrap(cls);
223: }
224: }