/*******************************************************************************
* Copyright (c) 2010-present Sonatype, Inc.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* Stuart McCulloch (Sonatype, Inc.) - initial API and implementation
*******************************************************************************/
package org.eclipse.sisu.osgi;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.regex.Pattern;
import org.eclipse.sisu.inject.BindingPublisher;
import org.eclipse.sisu.inject.BindingSubscriber;
import org.eclipse.sisu.inject.Logs;
import org.osgi.framework.BundleContext;
import com.google.inject.Binding;
/**
* On-demand publisher of {@link Binding}s from the OSGi service registry.
*/
public final class ServiceBindings
implements BindingPublisher
{
// ----------------------------------------------------------------------
// Constants
// ----------------------------------------------------------------------
private static final Pattern GLOB_SYNTAX = Pattern.compile( "(?:\\w+|\\*)(?:\\.?(?:\\w+|\\*))*" );
// ----------------------------------------------------------------------
// Implementation fields
// ----------------------------------------------------------------------
private final ConcurrentMap<String, BindingTracker<?>> trackers =
new ConcurrentHashMap<String, BindingTracker<?>>( 16, 0.75f, 1 );
private final BundleContext context;
private final Pattern[] allowed;
private final Pattern[] ignored;
private final int maxRank;
// ----------------------------------------------------------------------
// Constructors
// ----------------------------------------------------------------------
/**
* Creates new publisher of service bindings, using the given OSGi {@link BundleContext} to track services.<br>
* <br>
* The globbed patterns control whether tracking requests for particular types are allowed or ignored.<br>
* Any published bindings are ranked according to their service ranking (up to the given maximum).
*
* @param context The tracking context
* @param allow Globbed pattern of packages/types to allow
* @param ignore Globbed pattern of packages/types to ignore
* @param maxRank Maximum binding rank
*/
public ServiceBindings( final BundleContext context, final String allow, final String ignore, final int maxRank )
{
this.context = context;
this.maxRank = maxRank;
allowed = parseGlobs( allow );
ignored = parseGlobs( ignore );
}
/**
* Creates new publisher of service bindings, using the given OSGi {@link BundleContext} to track services.<br>
* <br>
* Uses default allow/ignore settings and assigns any published services the lowest possible ranking.
*
* @param context The tracking context
*/
public ServiceBindings( final BundleContext context )
{
this( context, defaultAllow(), defaultIgnore(), Integer.MIN_VALUE );
}
// ----------------------------------------------------------------------
// Public methods
// ----------------------------------------------------------------------
/**
* @return Globbed pattern of types to allow
* @see {@code org.eclipse.sisu.osgi.ServiceBindings.allow} system property
*/
public static String defaultAllow()
{
return System.getProperty( ServiceBindings.class.getName() + ".allow", "" );
}
/**
* @return Globbed pattern of types to ignore
* @see {@code org.eclipse.sisu.osgi.ServiceBindings.ignore} system property
*/
public static String defaultIgnore()
{
return System.getProperty( ServiceBindings.class.getName() + ".ignore", "" );
}
@SuppressWarnings( { "rawtypes", "unchecked" } )
public <T> void subscribe( final BindingSubscriber<T> subscriber )
{
final String clazzName = subscriber.type().getRawType().getName();
if ( shouldTrack( clazzName ) )
{
BindingTracker tracker = trackers.get( clazzName );
if ( null == tracker )
{
tracker = new BindingTracker<T>( context, maxRank, clazzName );
final BindingTracker oldTracker = trackers.putIfAbsent( clazzName, tracker );
if ( null != oldTracker )
{
tracker = oldTracker; // someone got there first, use their tracker
}
}
tracker.subscribe( subscriber );
}
}
@SuppressWarnings( { "rawtypes", "unchecked" } )
public <T> void unsubscribe( final BindingSubscriber<T> subscriber )
{
final String clazzName = subscriber.type().getRawType().getName();
final BindingTracker tracker = trackers.get( clazzName );
if ( null != tracker )
{
tracker.unsubscribe( subscriber );
}
}
public int maxBindingRank()
{
return maxRank;
}
public <T> T adapt( final Class<T> type )
{
return null;
}
// ----------------------------------------------------------------------
// Implementation methods
// ----------------------------------------------------------------------
private boolean shouldTrack( final String clazzName )
{
for ( final Pattern allow : allowed )
{
if ( allow.matcher( clazzName ).matches() )
{
for ( final Pattern ignore : ignored )
{
if ( ignore.matcher( clazzName ).matches() )
{
return false;
}
}
return true;
}
}
return false;
}
private static Pattern[] parseGlobs( final String globs )
{
final List<Pattern> patterns = new ArrayList<Pattern>();
for ( final String glob : globs.split( "\\s*,\\s*" ) )
{
if ( GLOB_SYNTAX.matcher( glob ).matches() )
{
patterns.add( Pattern.compile( glob.replace( ".", "\\." ).replace( "*", ".*" ) ) );
}
else if ( glob.length() > 0 )
{
Logs.warn( "Ignoring malformed glob pattern: {}", glob, null );
}
}
return patterns.toArray( new Pattern[patterns.size()] );
}
}