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package com.sun.faces.facelets.impl;
import javax.faces.view.facelets.FaceletCache;
import com.sun.faces.util.ConcurrentCache;
import com.sun.faces.util.ExpiringConcurrentCache;
import com.sun.faces.util.FacesLogger;
import javax.faces.FacesException;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.net.URLConnection;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.atomic.AtomicLong;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
* Default FaceletCache implementation.
*/
final class DefaultFaceletCache extends FaceletCache<DefaultFacelet> {
private final static Logger LOGGER = FacesLogger.FACELETS_FACTORY.getLogger();
/**
*Constructor
* @param refreshPeriod cache refresh period (in seconds).
* 0 means 'always refresh', negative value means 'never refresh'
*/
DefaultFaceletCache(final long refreshPeriod) {
// We will be delegating object storage to the ExpiringCocurrentCache
// Create Factory objects here for the cache. The objects will be delegating to our
// own instance factories
final boolean checkExpiry = (refreshPeriod > 0);
ConcurrentCache.Factory<URL, Record> faceletFactory =
new ConcurrentCache.Factory<URL, Record>() {
public Record newInstance(final URL key) throws IOException {
// Make sure that the expensive timestamp retrieval is not done
// if no expiry check is going to be performed
long lastModified = checkExpiry ? _getLastModified(key) : 0;
return new Record(System.currentTimeMillis(), lastModified,
getMemberFactory().newInstance(key), refreshPeriod);
}
};
ConcurrentCache.Factory<URL, Record> metadataFaceletFactory =
new ConcurrentCache.Factory<URL, Record>() {
public Record newInstance(final URL key) throws IOException {
// Make sure that the expensive timestamp retrieval is not done
// if no expiry check is going to be performed
long lastModified = checkExpiry ? _getLastModified(key) : 0;
return new Record(System.currentTimeMillis(), lastModified,
getMetadataMemberFactory().newInstance(key), refreshPeriod);
}
};
// No caching if refreshPeriod is 0
if (refreshPeriod == 0) {
_faceletCache = new NoCache(faceletFactory);
_metadataFaceletCache = new NoCache(metadataFaceletFactory);
} else {
ExpiringConcurrentCache.ExpiryChecker<URL, Record> checker =
(refreshPeriod > 0) ? new ExpiryChecker() : new NeverExpired();
_faceletCache =
new ExpiringConcurrentCache<URL, Record>(faceletFactory,
checker);
_metadataFaceletCache =
new ExpiringConcurrentCache<URL, Record>(metadataFaceletFactory,
checker);
}
}
@Override
public DefaultFacelet getFacelet(URL url) throws IOException {
com.sun.faces.util.Util.notNull("url", url);
DefaultFacelet f = null;
try {
f = _faceletCache.get(url).getFacelet();
} catch (ExecutionException e) {
_unwrapIOException(e);
}
return f;
}
@Override
public boolean isFaceletCached(URL url) {
com.sun.faces.util.Util.notNull("url", url);
return _faceletCache.containsKey(url);
}
@Override
public DefaultFacelet getViewMetadataFacelet(URL url) throws IOException {
com.sun.faces.util.Util.notNull("url", url);
DefaultFacelet f = null;
try {
f = _metadataFaceletCache.get(url).getFacelet();
} catch (ExecutionException e) {
_unwrapIOException(e);
}
return f;
}
@Override
public boolean isViewMetadataFaceletCached(URL url) {
com.sun.faces.util.Util.notNull("url", url);
return _metadataFaceletCache.containsKey(url);
}
private void _unwrapIOException(ExecutionException e) throws IOException {
Throwable t = e.getCause();
if (t instanceof IOException) {
throw (IOException)t;
}
if (t instanceof RuntimeException) {
throw (RuntimeException)t;
}
throw new FacesException(t);
}
private static long _getLastModified(URL url) {
InputStream is = null;
try {
URLConnection conn = url.openConnection();
is = conn.getInputStream();
return conn.getLastModified();
} catch (Exception e) {
throw new FacesException("Error Checking Last Modified for " +
url, e);
} finally {
if (is != null) {
try {
is.close();
} catch (Exception e) {
if (LOGGER.isLoggable(Level.FINEST)) {
LOGGER.log(Level.FINEST, "Closing stream", e);
}
}
}
}
}
private final ConcurrentCache<URL, Record> _faceletCache;
private final ConcurrentCache<URL, Record> _metadataFaceletCache;
/**
* This class holds the Facelet instance and its original URL's last modified time. It also produces
* the time when the next expiry check should be performed
*/
private static class Record {
Record(long creationTime, long lastModified, DefaultFacelet facelet, long refreshInterval) {
_facelet = facelet;
_creationTime = creationTime;
_lastModified = lastModified;
_refreshInterval = refreshInterval;
// There is no point in calculaing the next refresh time if we are refreshing always/never
_nextRefreshTime = (_refreshInterval > 0) ? new AtomicLong(creationTime + refreshInterval) : null;
}
DefaultFacelet getFacelet() {
return _facelet;
}
long getLastModified() {
return _lastModified;
}
long getNextRefreshTime() {
// There is no point in calculaing the next refresh time if we are refreshing always/never
return (_refreshInterval > 0) ? _nextRefreshTime.getAndAdd(_refreshInterval) : 0;
}
private final long _lastModified;
private final long _refreshInterval;
private final long _creationTime;
private final AtomicLong _nextRefreshTime;
private final DefaultFacelet _facelet;
}
private static class ExpiryChecker implements ExpiringConcurrentCache.ExpiryChecker<URL, Record> {
public boolean isExpired(URL url, Record record) {
// getNextRefreshTime() incremenets the next refresh time atomically
long ttl = record.getNextRefreshTime();
if (System.currentTimeMillis() > ttl) {
long lastModified = _getLastModified(url);
// The record is considered expired if its original last modified time
// is older than the URL's current last modified time
return (lastModified > record.getLastModified());
}
return false;
}
}
private static class NeverExpired implements ExpiringConcurrentCache.ExpiryChecker<URL, Record> {
public boolean isExpired(URL key, Record value) {
return false;
}
}
/**
* ConcurrentCache implementation that does no caching (always creates new instances)
*/
private static class NoCache extends ConcurrentCache<URL, Record> {
public NoCache(ConcurrentCache.Factory<URL, Record> f) {
super(f);
}
public Record get(final URL key) throws ExecutionException {
try {
return this.getFactory().newInstance(key);
} catch (Exception e) {
throw new ExecutionException(e);
}
}
public boolean containsKey(final URL key) {
return false;
}
}
}