QueryTimeout.java
/*
* Copyright 2017 gregorygraham.
*
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* or send a letter to Creative Commons, PO Box 1866, Mountain View, CA 94042, USA.
*
* You are free to:
* Share - copy and redistribute the material in any medium or format
* Adapt - remix, transform, and build upon the material
*
* The licensor cannot revoke these freedoms as long as you follow the license terms.
* Under the following terms:
*
* Attribution -
* You must give appropriate credit, provide a link to the license, and indicate if changes were made.
* You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
* NonCommercial -
* You may not use the material for commercial purposes.
* ShareAlike -
* If you remix, transform, or build upon the material,
* you must distribute your contributions under the same license as the original.
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package nz.co.gregs.dbvolution.internal.query;
import java.sql.SQLException;
import java.util.Date;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;
import java.util.logging.Level;
import java.util.logging.Logger;
import nz.co.gregs.dbvolution.databases.DBStatement;
/**
*
* @author gregorygraham
*/
public class QueryTimeout {
protected static final Logger LOGGER = Logger.getLogger(QueryTimeout.class.getName());
static final transient ScheduledExecutorService TIMER_SERVICE = Executors.newSingleThreadScheduledExecutor();
private final DBStatement statement;
private final Date timestamp;
private final String sql;
private boolean timeoutOccured = false;
private StatementDetails details = null;
private boolean stillRequired = true;
private static Long standardTimeoutOffset = null;
private static final long DEFAULT_TIMEOUT_MILLISECONDS = 15000L;
private ScheduledFuture<?> timeoutHandler;
private final TimeOut timeout = new TimeOut();
public QueryTimeout(StatementDetails details, Long timeoutTime) {
this.details = details;
this.statement = details.getDBStatement();
this.sql = details.getSql();
this.timestamp = new Date();
scheduleIfRequired(timeoutTime);
}
private void scheduleIfRequired(Long timeoutTime) {
// special cases first
if (timeoutTime == null || timeoutTime == 0L) {
// null or zero is not a valid timeout value, use the default instead
scheduleOnTimerService(DEFAULT_TIMEOUT_MILLISECONDS);
return;
}
if (timeoutTime < 0) {
// negative implies no timeout
this.timeoutHandler = null;
return;
}
// not a special case so proceed
scheduleOnTimerService(timeoutTime);
}
private void scheduleOnTimerService(Long timeoutTimeInMilliseconds) {
timeoutHandler = TIMER_SERVICE.schedule(timeout, timeoutTimeInMilliseconds, TimeUnit.MILLISECONDS);
}
public static Long getStandardTimeoutOffset() {
if (standardTimeoutOffset == null) {
long targetTicks = 2000l;
long ticks = 0;
Date startDate = new Date();
while (ticks < targetTicks) {
ticks++;
}
standardTimeoutOffset = Math.max(
DEFAULT_TIMEOUT_MILLISECONDS, // at least 10s timeout
((new Date()).getTime() - startDate.getTime()) * 15);// 15x1sec-equivalents
}
return standardTimeoutOffset;
}
public synchronized boolean queryTimedOut() {
return timeoutOccured;
}
public synchronized void noLongerRequired() {
stillRequired = false;
if (timeoutHandler != null) {
timeoutHandler.cancel(true);
}
}
private class TimeOut implements Runnable {
@Override
public void run() {
if (stillRequired) {
try {
if (details != null && !details.isIgnoreExceptions()) {
System.out.format("TIMEOUT: Cancelling query after {0} seconds {1} => {2}",
(0.0 + ((new Date()).getTime() - timestamp.getTime())) / 1000.0,
details.getLabel(),
sql);
LOGGER.log(
Level.WARNING,
"TIMEOUT: Cancelling query after {0} seconds {1} => {2}",
new Object[]{
(0.0 + ((new Date()).getTime() - timestamp.getTime())) / 1000.0,
details.getLabel(),
sql
});
}
statement.cancel();
} catch (SQLException ex) {
Logger.getLogger(QueryDetails.class.getName()).log(Level.SEVERE, "QueryCanceller caught an exception", ex);
} finally {
timeoutOccured = true;
}
}
}
}
}