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package org.crosswire.jsword.book.sword.state; |
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import java.util.HashMap; |
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import java.util.Iterator; |
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import java.util.Map; |
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import java.util.Queue; |
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import java.util.concurrent.ConcurrentLinkedQueue; |
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import java.util.concurrent.Executors; |
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import java.util.concurrent.ScheduledFuture; |
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import java.util.concurrent.ThreadFactory; |
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import java.util.concurrent.TimeUnit; |
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import org.crosswire.jsword.book.BookException; |
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import org.crosswire.jsword.book.BookMetaData; |
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import org.crosswire.jsword.book.sword.BlockType; |
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import org.slf4j.Logger; |
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import org.slf4j.LoggerFactory; |
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62 | 0 | public final class OpenFileStateManager { |
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66 | 0 | private OpenFileStateManager(final int cleanupIntervalSeconds, final int maxExpiry) { |
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68 | 0 | this.monitoringThread = Executors.newScheduledThreadPool(1, new ThreadFactory() { |
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public Thread newThread(Runnable r) { |
70 | 0 | Thread t = new Thread(r); |
71 | 0 | t.setDaemon(true); |
72 | 0 | return t; |
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} |
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|
75 | 0 | }).scheduleWithFixedDelay(new Runnable() { |
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public void run() { |
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79 | 0 | long currentTime = System.currentTimeMillis(); |
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81 | 0 | for (Queue<OpenFileState> e : OpenFileStateManager.this.metaToStates.values()) { |
82 | 0 | for (Iterator<OpenFileState> iterator = e.iterator(); iterator.hasNext(); ) { |
83 | 0 | final OpenFileState state = iterator.next(); |
84 | 0 | if (state.getLastAccess() + maxExpiry * 1000 < currentTime) { |
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86 | 0 | state.releaseResources(); |
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89 | 0 | iterator.remove(); |
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} |
91 | 0 | } |
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} |
93 | 0 | } |
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}, 0, cleanupIntervalSeconds, TimeUnit.SECONDS); |
95 | 0 | } |
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public static synchronized void init(final int cleanupIntervalSeconds, final int maxExpiry) { |
105 | 0 | if (manager == null) { |
106 | 0 | manager = new OpenFileStateManager(cleanupIntervalSeconds, maxExpiry); |
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} else { |
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109 | 0 | LOGGER.warn("The OpenFileStateManager has already been initialised, potentially with its default settings. The following values were ignored: cleanUpInterval [{}], maxExpiry=[{}]", Integer.toString(cleanupIntervalSeconds), Integer.toString(maxExpiry)); |
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} |
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112 | 0 | } |
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public static OpenFileStateManager instance() { |
119 | 0 | if (manager == null) { |
120 | 0 | synchronized (OpenFileStateManager.class) { |
121 | 0 | init(60, 60); |
122 | 0 | } |
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} |
124 | 0 | return manager; |
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} |
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public RawBackendState getRawBackendState(BookMetaData metadata) throws BookException { |
128 | 0 | ensureNotShuttingDown(); |
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130 | 0 | RawBackendState state = getInstance(metadata); |
131 | 0 | if (state == null) { |
132 | 0 | LOGGER.trace("Initializing: {}", metadata.getInitials()); |
133 | 0 | return new RawBackendState(metadata); |
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} |
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136 | 0 | LOGGER.trace("Reusing: {}", metadata.getInitials()); |
137 | 0 | return state; |
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} |
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public RawFileBackendState getRawFileBackendState(BookMetaData metadata) throws BookException { |
141 | 0 | ensureNotShuttingDown(); |
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143 | 0 | RawFileBackendState state = getInstance(metadata); |
144 | 0 | if (state == null) { |
145 | 0 | LOGGER.trace("Initializing: {}", metadata.getInitials()); |
146 | 0 | return new RawFileBackendState(metadata); |
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} |
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149 | 0 | LOGGER.trace("Reusing: {}", metadata.getInitials()); |
150 | 0 | return state; |
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} |
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public GenBookBackendState getGenBookBackendState(BookMetaData metadata) throws BookException { |
154 | 0 | ensureNotShuttingDown(); |
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156 | 0 | GenBookBackendState state = getInstance(metadata); |
157 | 0 | if (state == null) { |
158 | 0 | LOGGER.trace("Initializing: {}", metadata.getInitials()); |
159 | 0 | return new GenBookBackendState(metadata); |
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} |
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162 | 0 | LOGGER.trace("Reusing: {}", metadata.getInitials()); |
163 | 0 | return state; |
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} |
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public RawLDBackendState getRawLDBackendState(BookMetaData metadata) throws BookException { |
167 | 0 | ensureNotShuttingDown(); |
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169 | 0 | RawLDBackendState state = getInstance(metadata); |
170 | 0 | if (state == null) { |
171 | 0 | LOGGER.trace("Initializing: {}", metadata.getInitials()); |
172 | 0 | return new RawLDBackendState(metadata); |
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} |
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175 | 0 | LOGGER.trace("Reusing: {}", metadata.getInitials()); |
176 | 0 | return state; |
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} |
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public ZLDBackendState getZLDBackendState(BookMetaData metadata) throws BookException { |
180 | 0 | ensureNotShuttingDown(); |
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182 | 0 | ZLDBackendState state = getInstance(metadata); |
183 | 0 | if (state == null) { |
184 | 0 | LOGGER.trace("Initializing: {}", metadata.getInitials()); |
185 | 0 | return new ZLDBackendState(metadata); |
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} |
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188 | 0 | LOGGER.trace("Reusing: {}", metadata.getInitials()); |
189 | 0 | return state; |
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} |
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public ZVerseBackendState getZVerseBackendState(BookMetaData metadata, BlockType blockType) throws BookException { |
193 | 0 | ensureNotShuttingDown(); |
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195 | 0 | ZVerseBackendState state = getInstance(metadata); |
196 | 0 | if (state == null) { |
197 | 0 | LOGGER.trace("Initializing: {}", metadata.getInitials()); |
198 | 0 | return new ZVerseBackendState(metadata, blockType); |
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} |
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201 | 0 | LOGGER.trace("Reusing: {}", metadata.getInitials()); |
202 | 0 | return state; |
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} |
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@SuppressWarnings("unchecked") |
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private <T extends OpenFileState> T getInstance(BookMetaData metadata) { |
207 | 0 | Queue<OpenFileState> availableStates = getQueueForMeta(metadata); |
208 | 0 | final T state = (T) availableStates.poll(); |
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214 | 0 | if (state != null) { |
215 | 0 | state.setLastAccess(System.currentTimeMillis()); |
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} |
217 | 0 | return state; |
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} |
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private Queue<OpenFileState> getQueueForMeta(BookMetaData metadata) { |
221 | 0 | Queue<OpenFileState> availableStates = metaToStates.get(metadata); |
222 | 0 | if (availableStates == null) { |
223 | 0 | synchronized (OpenFileState.class) { |
224 | 0 | availableStates = new ConcurrentLinkedQueue<OpenFileState>(); |
225 | 0 | metaToStates.put(metadata, availableStates); |
226 | 0 | } |
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} |
228 | 0 | return availableStates; |
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} |
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public void release(OpenFileState fileState) { |
232 | 0 | if (fileState == null) { |
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235 | 0 | return; |
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} |
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238 | 0 | fileState.setLastAccess(System.currentTimeMillis()); |
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241 | 0 | BookMetaData bmd = fileState.getBookMetaData(); |
242 | 0 | Queue<OpenFileState> queueForMeta = getQueueForMeta(bmd); |
243 | 0 | LOGGER.trace("Offering to releasing: {}", bmd.getInitials()); |
244 | 0 | boolean offered = queueForMeta.offer(fileState); |
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247 | 0 | if (!offered) { |
248 | 0 | LOGGER.trace("Released: {}", bmd.getInitials()); |
249 | 0 | fileState.releaseResources(); |
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} |
251 | 0 | } |
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public void shutDown() { |
257 | 0 | shuttingDown = true; |
258 | 0 | this.monitoringThread.cancel(true); |
259 | 0 | for (Queue<OpenFileState> e : metaToStates.values()) { |
260 | 0 | OpenFileState state = null; |
261 | 0 | while ((state = e.poll()) != null) { |
262 | 0 | state.releaseResources(); |
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} |
264 | 0 | } |
265 | 0 | } |
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private void ensureNotShuttingDown() throws BookException { |
268 | 0 | if (shuttingDown) { |
269 | 0 | throw new BookException("Unable to read book, application is shutting down."); |
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} |
271 | 0 | } |
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private final ScheduledFuture<?> monitoringThread; |
274 | 0 | private final Map<BookMetaData, Queue<OpenFileState>> metaToStates = new HashMap<BookMetaData, Queue<OpenFileState>>(); |
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private volatile boolean shuttingDown; |
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private static volatile OpenFileStateManager manager; |
278 | 0 | private static final Logger LOGGER = LoggerFactory.getLogger(OpenFileStateManager.class); |
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} |