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/** * Copyright (C) 2012 Red Hat, Inc. (jdcasey@commonjava.org) * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.commonjava.maven.atlas.graph; import java.io.Closeable; import java.io.IOException; import java.util.Arrays; import java.util.HashMap; import java.util.HashSet; import java.util.Iterator; import java.util.Map; import java.util.Set; import java.util.Timer; import java.util.TimerTask; import org.apache.commons.lang.StringUtils; import org.commonjava.maven.atlas.graph.spi.RelationshipGraphConnection; import org.commonjava.maven.atlas.graph.spi.RelationshipGraphConnectionException; import org.commonjava.maven.atlas.graph.spi.RelationshipGraphConnectionFactory; import org.slf4j.Logger; import org.slf4j.LoggerFactory; public final class RelationshipGraphFactory implements Closeable { private final Logger logger = LoggerFactory.getLogger(getClass()); private final RelationshipGraphConnectionFactory connectionManager; private final Map<String, ConnectionCache> connectionCaches = new HashMap<String, ConnectionCache>(); private final Set<RelationshipGraphListenerFactory> listenerFactories = new HashSet<RelationshipGraphListenerFactory>(); private boolean closed; private final Timer timer = new Timer(true); public RelationshipGraphFactory(final RelationshipGraphConnectionFactory connectionFactory, final RelationshipGraphListenerFactory... listenerFactories) { this.connectionManager = connectionFactory; if (listenerFactories.length > 0) { this.listenerFactories.addAll(Arrays.asList(listenerFactories)); } } public synchronized RelationshipGraph open(final ViewParams params, final boolean create) throws RelationshipGraphException { checkClosed(); final String wsid = params.getWorkspaceId(); ConnectionCache cache = connectionCaches.get(wsid); if (cache == null || !cache.isOpen()) { final RelationshipGraphConnection connection = connectionManager.openConnection(params.getWorkspaceId(), create); cache = new ConnectionCache(timer, connectionCaches, connection, wsid); connectionCaches.put(wsid, cache); // logger.info( "Created new connection to graph db: {}\nVia:\n {}", params.getWorkspaceId(), // join( Thread.currentThread() // .getStackTrace(), "\n " ) ); } // else // { // logger.info( "Reusing connection to graph db: {}\nVia:\n {}", params.getWorkspaceId(), // join( Thread.currentThread() // .getStackTrace(), "\n " ) ); // } RelationshipGraph graph = cache.getGraph(params); if (graph == null) { graph = new RelationshipGraph(params, cache.getConnection()); graph.addListener(cache); cache.registerGraph(params, graph); } else { graph.incrementGraphOwnership(); } return graph; } public Set<String> listWorkspaces() { return connectionManager.listWorkspaces(); } public void store(final RelationshipGraph graph) throws RelationshipGraphException { checkClosed(); connectionManager.flush(graph.getConnection()); } public boolean deleteWorkspace(final String workspaceId) throws RelationshipGraphException { checkClosed(); boolean result; try { result = connectionManager.delete(workspaceId); } finally { final ConnectionCache connectionCache = connectionCaches.get(workspaceId); if (connectionCache != null) { try { connectionCache.closeNow(); } catch (final IOException ex) { logger.error("Error when trying to close connection cache: {}", ex); } catch (final RuntimeException ex) { logger.error("Unexpected error when trying to close connection cache: {}", ex); } } } return result; } private void checkClosed() throws RelationshipGraphException { if (closed) { throw new RelationshipGraphException("Graph factory is closed!"); } } public synchronized void close() throws IOException { closed = true; timer.cancel(); for (final ConnectionCache cache : connectionCaches.values()) { cache.closeNow(); } connectionCaches.clear(); connectionManager.close(); } public boolean workspaceExists(final String workspaceId) { return connectionManager.exists(workspaceId); } private static final class ConnectionCache extends AbstractRelationshipGraphListener implements Iterable<RelationshipGraph> { private static final long CLOSE_WAIT_TIMEOUT = 5000; private final Logger logger = LoggerFactory.getLogger(getClass()); private RelationshipGraphConnection connection; private final String wsid; private final Map<ViewParams, RelationshipGraph> graphs = new HashMap<ViewParams, RelationshipGraph>(); private final Timer timer; private TimerTask closeTimer; private final Map<String, ConnectionCache> mapOfCaches; ConnectionCache(final Timer timer, final Map<String, ConnectionCache> mapOfCaches, final RelationshipGraphConnection connection, final String wsid) { this.timer = timer; this.mapOfCaches = mapOfCaches; this.connection = connection; this.wsid = wsid; } public synchronized void closeNow() throws IOException { mapOfCaches.remove(wsid); graphs.clear(); final RelationshipGraphConnection conn = connection; connection = null; if (conn != null && !conn.isClosed()) { conn.close(); } } public synchronized void startCloseTimer() { closeTimer = new TimerTask() { @Override public void run() { if (isEmpty()) { try { closeNow(); } catch (final IOException e) { logger.error("Failed to close graph connection cache: " + connection, e); } } } }; if (connection == null) { logger.warn("Attempt to close an already closed ConnectionCache. Called from:\n {}", StringUtils.join((new Exception()).getStackTrace(), "\n ")); } else { logger.info("Starting close-cache countdown for: {} ({}ms)", connection.getWorkspaceId(), CLOSE_WAIT_TIMEOUT); } timer.schedule(closeTimer, CLOSE_WAIT_TIMEOUT); } public synchronized boolean isOpen() { return connection != null; } RelationshipGraph getGraph(final ViewParams params) { final RelationshipGraph graph = graphs.get(params); logger.info("Returning existing graph for: {}", params.getWorkspaceId()); if (graph != null) { cancelCloseTimer(); } return graph; } private synchronized void cancelCloseTimer() { if (closeTimer != null) { logger.info("Canceling close-cache countdown for: {} (was scheduled to run in: {}ms)", connection.getWorkspaceId(), (closeTimer.scheduledExecutionTime() - System.currentTimeMillis())); closeTimer.cancel(); closeTimer = null; } } RelationshipGraphConnection getConnection() { return connection; } synchronized void registerGraph(final ViewParams params, final RelationshipGraph graph) { logger.info("Registering new connection to: {}", params.getWorkspaceId()); graphs.put(params, graph); cancelCloseTimer(); } synchronized void deregisterGraph(final ViewParams params) { graphs.remove(params); if (isEmpty()) { startCloseTimer(); } } boolean isEmpty() { return graphs.isEmpty(); } @Override public synchronized Iterator<RelationshipGraph> iterator() { return new HashSet<RelationshipGraph>(graphs.values()).iterator(); } @Override public void closed(final RelationshipGraph graph) throws RelationshipGraphException { // TODO: It'd be nice to be able to flush to disk without wrecking the connection for all other views on the // same workspace... // factory.flush( cache.getConnection() ); deregisterGraph(graph.getParams()); } @Override public int hashCode() { return connection.getWorkspaceId().hashCode() + 13; } @Override public boolean equals(final Object obj) { if (this == obj) { return true; } if (obj == null) { return false; } if (getClass() != obj.getClass()) { return false; } final ConnectionCache other = (ConnectionCache) obj; return connection.getWorkspaceId().equals(other.connection.getWorkspaceId()); } } }