/*
* 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.sling.resourceresolver.impl;
import java.util.ArrayList;
import java.util.Dictionary;
import java.util.Hashtable;
import java.util.List;
import java.util.Map;
import org.osgi.framework.BundleContext;
import org.osgi.framework.Constants;
import org.osgi.framework.Filter;
import org.osgi.framework.InvalidSyntaxException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class FactoryPreconditions {
private static final class RequiredProvider {
public String pid;
public Filter filter;
public final List<Map<String, Object>> matchingServices = new ArrayList<Map<String,Object>>();
};
private final List<Map<String, Object>> earlyPropertiesList = new ArrayList<Map<String, Object>>();
private volatile List<RequiredProvider> requiredProviders;
private Boolean cachedResult = Boolean.FALSE;
public void activate(final BundleContext bc, final String[] configuration) {
final List<RequiredProvider> rps = new ArrayList<RequiredProvider>();
if ( configuration != null ) {
final Logger logger = LoggerFactory.getLogger(getClass());
for(final String r : configuration) {
if ( r != null && r.trim().length() > 0 ) {
final String value = r.trim();
RequiredProvider rp = new RequiredProvider();
if ( value.startsWith("(") ) {
try {
rp.filter = bc.createFilter(value);
} catch (final InvalidSyntaxException e) {
logger.warn("Ignoring invalid filter syntax for required provider: " + value, e);
rp = null;
}
} else {
rp.pid = value;
}
if ( rp != null ) {
rps.add(rp);
}
}
}
}
synchronized ( this ) {
this.requiredProviders = rps;
this.cachedResult = null;
for(final Map<String,Object> props : this.earlyPropertiesList) {
this.bindProvider(props);
}
this.earlyPropertiesList.clear();
}
}
public void deactivate() {
this.requiredProviders = null;
}
public boolean checkPreconditions() {
synchronized ( this ) {
if ( cachedResult != null ) {
return cachedResult;
}
boolean canRegister = false;
if ( this.requiredProviders != null) {
canRegister = true;
for(final RequiredProvider rp : this.requiredProviders) {
if ( rp.matchingServices.size() == 0 ) {
canRegister = false;
break;
}
}
}
this.cachedResult = canRegister;
return canRegister;
}
}
public void bindProvider(final Map<String, Object> props) {
synchronized ( this ) {
if ( this.requiredProviders == null ) {
this.earlyPropertiesList.add(props);
return;
}
Dictionary<String, Object> dict = null;
for(final RequiredProvider rp : this.requiredProviders) {
if ( rp.pid != null ) {
if ( rp.pid.equals(props.get(Constants.SERVICE_PID)) ) {
rp.matchingServices.add(props);
this.cachedResult = null;
}
} else {
if ( dict == null ) {
dict = new Hashtable<String, Object>(props);
}
if ( rp.filter.match(dict) ) {
rp.matchingServices.add(props);
this.cachedResult = null;
}
}
}
}
}
private boolean removeFromList(final List<Map<String, Object>> list, final Map<String, Object> props) {
final Long id = (Long) props.get(Constants.SERVICE_ID);
int index = 0;
while ( index < list.size() ) {
final Long currentId = (Long ) list.get(index).get(Constants.SERVICE_ID);
if ( currentId == id ) {
list.remove(index);
return true;
}
index++;
}
return false;
}
public void unbindProvider(final Map<String, Object> props) {
synchronized ( this ) {
if ( this.requiredProviders == null ) {
this.removeFromList(this.earlyPropertiesList, props);
return;
}
for(final RequiredProvider rp : this.requiredProviders) {
if ( this.removeFromList(rp.matchingServices, props) ) {
this.cachedResult = null;
}
}
}
}
}