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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one
3    * or more contributor license agreements.  See the NOTICE file
4    * distributed with this work for additional information
5    * regarding copyright ownership.  The ASF licenses this file
6    * to you under the Apache License, Version 2.0 (the
7    * "License"); you may not use this file except in compliance
8    * with the License.  You may obtain a copy of the License at
9    *
10   *   http://www.apache.org/licenses/LICENSE-2.0
11   *
12   * Unless required by applicable law or agreed to in writing,
13   * software distributed under the License is distributed on an
14   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   * KIND, either express or implied.  See the License for the
16   * specific language governing permissions and limitations
17   * under the License.
18   */
19  package org.eclipse.aether.internal.impl.synccontext.named;
20  
21  import java.util.ArrayDeque;
22  import java.util.Collection;
23  import java.util.Deque;
24  import java.util.concurrent.TimeUnit;
25  
26  import org.eclipse.aether.ConfigurationProperties;
27  import org.eclipse.aether.RepositorySystemSession;
28  import org.eclipse.aether.SyncContext;
29  import org.eclipse.aether.artifact.Artifact;
30  import org.eclipse.aether.metadata.Metadata;
31  import org.eclipse.aether.named.NamedLock;
32  import org.eclipse.aether.named.NamedLockFactory;
33  import org.eclipse.aether.named.NamedLockKey;
34  import org.eclipse.aether.named.providers.FileLockNamedLockFactory;
35  import org.eclipse.aether.util.ConfigUtils;
36  import org.slf4j.Logger;
37  import org.slf4j.LoggerFactory;
38  
39  import static java.util.Objects.requireNonNull;
40  
41  /**
42   * Adapter to adapt {@link NamedLockFactory} and {@link NamedLock} to {@link SyncContext}.
43   */
44  public final class NamedLockFactoryAdapter {
45      public static final String CONFIG_PROPS_PREFIX = ConfigurationProperties.PREFIX_SYNC_CONTEXT + "named.";
46  
47      /**
48       * The maximum of time amount to be blocked to obtain lock.
49       *
50       * @since 1.7.0
51       * @configurationSource {@link RepositorySystemSession#getConfigProperties()}
52       * @configurationType {@link java.lang.Long}
53       * @configurationDefaultValue {@link #DEFAULT_TIME}
54       */
55      public static final String CONFIG_PROP_TIME = CONFIG_PROPS_PREFIX + "time";
56  
57      public static final long DEFAULT_TIME = 30L;
58  
59      /**
60       * The unit of maximum time amount to be blocked to obtain lock. Use TimeUnit enum names.
61       *
62       * @since 1.7.0
63       * @configurationSource {@link RepositorySystemSession#getConfigProperties()}
64       * @configurationType {@link java.lang.String}
65       * @configurationDefaultValue {@link #DEFAULT_TIME_UNIT}
66       */
67      public static final String CONFIG_PROP_TIME_UNIT = CONFIG_PROPS_PREFIX + "time.unit";
68  
69      public static final String DEFAULT_TIME_UNIT = "SECONDS";
70  
71      /**
72       * The amount of retries on time-out.
73       *
74       * @since 1.7.0
75       * @configurationSource {@link RepositorySystemSession#getConfigProperties()}
76       * @configurationType {@link java.lang.Integer}
77       * @configurationDefaultValue {@link #DEFAULT_RETRY}
78       */
79      public static final String CONFIG_PROP_RETRY = CONFIG_PROPS_PREFIX + "retry";
80  
81      public static final int DEFAULT_RETRY = 1;
82  
83      /**
84       * The amount of milliseconds to wait between retries on time-out.
85       *
86       * @since 1.7.0
87       * @configurationSource {@link RepositorySystemSession#getConfigProperties()}
88       * @configurationType {@link java.lang.Long}
89       * @configurationDefaultValue {@link #DEFAULT_RETRY_WAIT}
90       */
91      public static final String CONFIG_PROP_RETRY_WAIT = CONFIG_PROPS_PREFIX + "retry.wait";
92  
93      public static final long DEFAULT_RETRY_WAIT = 200L;
94  
95      private final NameMapper nameMapper;
96  
97      private final NamedLockFactory namedLockFactory;
98  
99      public NamedLockFactoryAdapter(final NameMapper nameMapper, final NamedLockFactory namedLockFactory) {
100         this.nameMapper = requireNonNull(nameMapper);
101         this.namedLockFactory = requireNonNull(namedLockFactory);
102         // TODO: this is ad-hoc "validation", experimental and likely to change
103         if (this.namedLockFactory instanceof FileLockNamedLockFactory && !this.nameMapper.isFileSystemFriendly()) {
104             throw new IllegalArgumentException(
105                     "Misconfiguration: FileLockNamedLockFactory lock factory requires FS friendly NameMapper");
106         }
107     }
108 
109     public SyncContext newInstance(final RepositorySystemSession session, final boolean shared) {
110         return new AdaptedLockSyncContext(session, shared, nameMapper, namedLockFactory);
111     }
112 
113     /**
114      * @since 1.9.1
115      */
116     public NameMapper getNameMapper() {
117         return nameMapper;
118     }
119 
120     /**
121      * @since 1.9.1
122      */
123     public NamedLockFactory getNamedLockFactory() {
124         return namedLockFactory;
125     }
126 
127     public String toString() {
128         return getClass().getSimpleName()
129                 + "(nameMapper=" + nameMapper
130                 + ", namedLockFactory=" + namedLockFactory
131                 + ")";
132     }
133 
134     private static class AdaptedLockSyncContext implements SyncContext {
135         private static final Logger LOGGER = LoggerFactory.getLogger(AdaptedLockSyncContext.class);
136 
137         private final RepositorySystemSession session;
138 
139         private final boolean shared;
140 
141         private final NameMapper lockNaming;
142 
143         private final NamedLockFactory namedLockFactory;
144 
145         private final long time;
146 
147         private final TimeUnit timeUnit;
148 
149         private final int retry;
150 
151         private final long retryWait;
152 
153         private final Deque<NamedLock> locks;
154 
155         private AdaptedLockSyncContext(
156                 final RepositorySystemSession session,
157                 final boolean shared,
158                 final NameMapper lockNaming,
159                 final NamedLockFactory namedLockFactory) {
160             this.session = session;
161             this.shared = shared;
162             this.lockNaming = lockNaming;
163             this.namedLockFactory = namedLockFactory;
164             this.time = getTime(session);
165             this.timeUnit = getTimeUnit(session);
166             this.retry = getRetry(session);
167             this.retryWait = getRetryWait(session);
168             this.locks = new ArrayDeque<>();
169 
170             if (time < 0L) {
171                 throw new IllegalArgumentException(CONFIG_PROP_TIME + " value cannot be negative");
172             }
173             if (retry < 0L) {
174                 throw new IllegalArgumentException(CONFIG_PROP_RETRY + " value cannot be negative");
175             }
176             if (retryWait < 0L) {
177                 throw new IllegalArgumentException(CONFIG_PROP_RETRY_WAIT + " value cannot be negative");
178             }
179         }
180 
181         private long getTime(final RepositorySystemSession session) {
182             return ConfigUtils.getLong(session, DEFAULT_TIME, CONFIG_PROP_TIME);
183         }
184 
185         private TimeUnit getTimeUnit(final RepositorySystemSession session) {
186             return TimeUnit.valueOf(ConfigUtils.getString(session, DEFAULT_TIME_UNIT, CONFIG_PROP_TIME_UNIT));
187         }
188 
189         private int getRetry(final RepositorySystemSession session) {
190             return ConfigUtils.getInteger(session, DEFAULT_RETRY, CONFIG_PROP_RETRY);
191         }
192 
193         private long getRetryWait(final RepositorySystemSession session) {
194             return ConfigUtils.getLong(session, DEFAULT_RETRY_WAIT, CONFIG_PROP_RETRY_WAIT);
195         }
196 
197         @Override
198         public void acquire(Collection<? extends Artifact> artifacts, Collection<? extends Metadata> metadatas) {
199             Collection<NamedLockKey> keys = lockNaming.nameLocks(session, artifacts, metadatas);
200             if (keys.isEmpty()) {
201                 return;
202             }
203 
204             final String timeStr = time + " " + timeUnit;
205             final String lockKind = shared ? "shared" : "exclusive";
206             final NamedLock namedLock = namedLockFactory.getLock(keys);
207             if (LOGGER.isTraceEnabled()) {
208                 LOGGER.trace(
209                         "Need {} lock for {} from {}",
210                         lockKind,
211                         namedLock.key().resources(),
212                         namedLock.key().name());
213             }
214 
215             final int attempts = retry + 1;
216             for (int attempt = 1; attempt <= attempts; attempt++) {
217                 if (LOGGER.isTraceEnabled()) {
218                     LOGGER.trace(
219                             "Attempt {}: Acquire {} lock from {}",
220                             attempt,
221                             lockKind,
222                             namedLock.key().name());
223                 }
224                 try {
225                     if (attempt > 1) {
226                         Thread.sleep(retryWait);
227                     }
228                     boolean locked;
229                     if (shared) {
230                         locked = namedLock.lockShared(time, timeUnit);
231                     } else {
232                         locked = namedLock.lockExclusively(time, timeUnit);
233                     }
234 
235                     if (locked) {
236                         // we are done, get out
237                         locks.push(namedLock);
238                         return;
239                     }
240 
241                     // we failed; retry
242                     if (LOGGER.isTraceEnabled()) {
243                         LOGGER.trace(
244                                 "Failed to acquire {} lock for '{}' in {}",
245                                 lockKind,
246                                 namedLock.key().name(),
247                                 timeStr);
248                     }
249                 } catch (InterruptedException e) {
250                     // if we are here, means we were interrupted: fail
251                     close();
252                     Thread.currentThread().interrupt();
253                     throw new RuntimeException(e);
254                 }
255             }
256             // if we are here, means all attempts were unsuccessful: fail
257             close();
258             IllegalStateException ex = new IllegalStateException("Could not acquire " + lockKind + " lock for "
259                     + namedLock.key().resources() + " using lock "
260                     + namedLock.key().name() + " in " + timeStr);
261             throw namedLockFactory.onFailure(ex);
262         }
263 
264         @Override
265         public void close() {
266             while (!locks.isEmpty()) {
267                 try (NamedLock namedLock = locks.pop()) {
268                     namedLock.unlock();
269                     if (LOGGER.isTraceEnabled()) {
270                         LOGGER.trace(
271                                 "Unlocked and closed {} lock of {}", shared ? "shared" : "exclusive", namedLock.key());
272                     }
273                 }
274             }
275         }
276     }
277 }