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/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.apache.openjpa.datacache;

import java.security.AccessController;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Arrays;
import java.util.Calendar;
import java.util.Date;
import java.util.Map;
import java.util.StringTokenizer;
import java.util.Map.Entry;
import java.util.concurrent.ConcurrentHashMap;

import org.apache.openjpa.conf.OpenJPAConfiguration;
import org.apache.openjpa.lib.log.Log;
import org.apache.openjpa.lib.util.Clearable;
import org.apache.openjpa.lib.util.J2DoPrivHelper;
import org.apache.openjpa.lib.util.Localizer;
import org.apache.openjpa.util.InvalidStateException;
import org.apache.openjpa.util.UserException;

import serp.util.Strings;

/**
 * Cron-style clearable eviction. Understands schedules based on cron format:
 * 
  • minute hour mday month wday
  • *
  • +minute
  • * For example: * 15,30 6,19 2,10 1 2 * Would run at 15 and 30 past the 6AM and 7PM, on the 2nd and 10th * of January when its a Monday. * */ public class ClearableScheduler implements Runnable { private static final Localizer _loc = Localizer.forPackage(ClearableScheduler.class); private Map _clearables = new ConcurrentHashMap(); private boolean _stop = false; private int _interval = 1; private Log _log; private Thread _thread; public ClearableScheduler(OpenJPAConfiguration conf) { _log = conf.getLogFactory().getLog(OpenJPAConfiguration.LOG_DATACACHE); } /** * The interval time in minutes between scheduler checks. Defaults to 1. */ public int getInterval() { return _interval; } /** * The interval time in minutes between scheduler checks. Defaults to 1. */ public void setInterval(int interval) { _interval = interval; } /** * Stop the associated thread if there and stop the current runnable. */ public synchronized void stop() { _stop = true; } private boolean isStopped() { return _stop; } /** * Schedule the given Clearable for clear to be called. Starts the scheduling thread * if not started. */ public synchronized void scheduleEviction(Clearable clearable, String times) { if (times == null) return; Schedule schedule = new Schedule(times); _clearables.put(clearable, schedule); _stop = false; if (_thread == null) { _thread = AccessController.doPrivileged(J2DoPrivHelper .newDaemonThreadAction(this, _loc.get("scheduler-name") .getMessage())); _thread.start(); if (_log.isTraceEnabled()) _log.trace(_loc.get("scheduler-start", _thread.getName())); } } /** * Remove the given Clearable from scheduling. */ public synchronized void removeFromSchedule(Clearable clearable) { _clearables.remove(clearable); if (_clearables.size() == 0) stop(); } public void run() { if (_log.isTraceEnabled()) _log.trace(_loc.get("scheduler-interval", _interval + "")); Date lastRun = new Date(); DateFormat fom = new SimpleDateFormat("E HH:mm:ss"); while (!isStopped()) { try { Thread.sleep(_interval * 60 * 1000); Date now = new Date(); for(Entry entry : _clearables.entrySet()){ Clearable clearable = entry.getKey(); Schedule schedule = entry.getValue(); if (schedule.matches(lastRun, now)) { if (_log.isTraceEnabled()) _log.trace(_loc.get("scheduler-clear", clearable, fom.format(now))); evict(clearable); } } lastRun = now; } catch (Exception e) { throw new InvalidStateException(_loc.get("scheduler-fail"), e). setFatal(true); } } _log.info(_loc.get("scheduler-stop")); synchronized (this) { if (isStopped()) _thread = null; // be sure to deref the thread so it can restart } } protected void evict(Clearable cache) { cache.clear(); } /** * Simple class which represents the given time schedule. */ private static class Schedule { static final int[] WILDCARD = new int[0]; static final int[] UNITS = { Calendar.MONTH, Calendar.DAY_OF_MONTH, Calendar.DAY_OF_WEEK, Calendar.HOUR_OF_DAY, Calendar.MINUTE }; final int[] month; final int[] dayOfMonth; final int[] dayOfWeek; final int[] hour; final int[] min; public Schedule(String date) { int[] tmin = null; if (date.startsWith("+")) { Calendar cal = Calendar.getInstance(); int interval = Integer.parseInt(date.substring(1)); int currMin = cal.get(Calendar.MINUTE); tmin = new int[60/interval]; for(int i = 0; i= 60 ){ temp -= 60; } tmin[i]=temp; } Arrays.sort(tmin); min = tmin; hour = WILDCARD; dayOfMonth = WILDCARD; month = WILDCARD; dayOfWeek = WILDCARD; }else{ StringTokenizer token = new StringTokenizer(date, " \t"); if (token.countTokens() != 5) throw new UserException(_loc.get("bad-count", date)).setFatal(true); try { min = parse(token.nextToken(), 0, 60); hour = parse(token.nextToken(), 0, 24); dayOfMonth = parse(token.nextToken(), 1, 31); month = parse(token.nextToken(), 1, 13); dayOfWeek = parse(token.nextToken(), 1, 8); } catch (Throwable t) { throw new UserException(_loc.get("bad-schedule", date), t).setFatal(true); } } } private int[] parse(String token, int min, int max) { if ("*".equals(token.trim())) return WILDCARD; String[] tokens = Strings.split(token, ",", 0); int [] times = new int[tokens.length]; for (int i = 0; i < tokens.length; i++) { try { times[i] = Integer.parseInt(tokens[i]); } catch (Throwable t) { throw new UserException(_loc.get("not-number", token)). setFatal(true); } if (times[i] < min || times[i] >= max) throw new UserException(_loc.get("not-range", token, String.valueOf(min), String.valueOf(max))). setFatal(true); } return times; } boolean matches(Date last, Date now) { Calendar time = Calendar.getInstance(); time.setTime(now); time.set(Calendar.SECOND, 0); time.set(Calendar.MILLISECOND, 0); int[][] all = new int[][]{ month, dayOfMonth, dayOfWeek, hour, min }; return matches(last, now, time, all, 0); } private boolean matches(Date last, Date now, Calendar time, int[][] times, int depth) { if (depth == UNITS.length) { Date compare = time.getTime(); return compare.compareTo(last) >= 0 && compare.compareTo(now) < 0; } if (times[depth] != WILDCARD) { for (int i = 0; i < times[depth].length; i++) { time.set(UNITS[depth], times[depth][i]); if (matches(last, now, time, times, depth + 1)) return true; } } return matches(last, now, time, times, depth + 1); } } }




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