src/main/java/org/apache/sling/feature/apiregions/impl/ResolverHookImpl.java - sling-org-apache-sling-feature-apiregions - Git at Google

 /*
  * 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.feature.apiregions.impl;

 import java.util.AbstractMap;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.logging.Level;
 import java.util.stream.Collectors;

 import org.osgi.framework.Bundle;
 import org.osgi.framework.Version;
 import org.osgi.framework.hooks.resolver.ResolverHook;
 import org.osgi.framework.namespace.PackageNamespace;
 import org.osgi.framework.wiring.BundleCapability;
 import org.osgi.framework.wiring.BundleRequirement;
 import org.osgi.framework.wiring.BundleRevision;

 class ResolverHookImpl implements ResolverHook {

     final RegionConfiguration configuration;

     ResolverHookImpl(RegionConfiguration cfg) {
         this.configuration = cfg;
     }

     @Override
     public void filterResolvable(Collection<BundleRevision> candidates) {
         // Nothing to do
     }

     @Override
     public void filterSingletonCollisions(BundleCapability singleton, Collection<BundleCapability> collisionCandidates) {
         // Nothing to do
     }

     @Override
     public void filterMatches(BundleRequirement requirement, Collection<BundleCapability> candidates) {
         // Filtering is only on package resolution. Any other kind of resolution is not limited
         if (!PackageNamespace.PACKAGE_NAMESPACE.equals(requirement.getNamespace()))
             return;

         if (candidates.size() < 1)
             return;

         Object pkg = candidates.iterator().next().getAttributes().get(PackageNamespace.PACKAGE_NAMESPACE);
         if (!(pkg instanceof String)) {
             return;
         }
         String packageName = (String) pkg;

         Bundle reqBundle = requirement.getRevision().getBundle();
         long reqBundleID = reqBundle.getBundleId();

         Set<String> bareReqRegions = null; // Null means: not opting into API Regions
         Set<String> reqFeatures = getFeaturesForBundle(reqBundle);
         for (String feature : reqFeatures) {
             Set<String> fr = this.configuration.getFeatureRegionMap().get(feature);
             if (fr != null) {
                 if (bareReqRegions == null)
                     bareReqRegions = new HashSet<>();
                 bareReqRegions.addAll(fr);
             }
         }
         Set<String> reqRegions = new HashSet<>(this.configuration.getDefaultRegions());
         if (bareReqRegions != null)
             reqRegions.addAll(bareReqRegions);

         Map<BundleCapability, String> coveredCaps = new HashMap<>();
         Map<BundleCapability, String> bcFeatureMap = new HashMap<>();

         nextCapability:
         for (BundleCapability bc : candidates) {
             BundleRevision rev = bc.getRevision();

             Bundle capBundle = rev.getBundle();
             long capBundleID = capBundle.getBundleId();
             if (capBundleID == 0) {
                 // always allow capability from the system bundle
                 coveredCaps.put(bc, null); // null value means same bundle, same feature or system bundle
                 continue nextCapability;
             }

             if (capBundleID == reqBundleID) {
                 // always allow capability from same bundle

                 // Here we cover the case where the bundle is not in any feature which means that the package is in the 'global' region,
                 // however if the bundle is in a feature then it could be marked as more specific, with a 'null value', which may
                 // happen below.
                 coveredCaps.put(bc, RegionConstants.GLOBAL_REGION);

                 // note: don't continue to nextCapability here, this one may be overwritten later...
             }

             Set<String> capFeatures = getFeaturesForBundle(capBundle);
             if (capFeatures.isEmpty()) {
                 // Capability is not in any feature, everyone can access
                 coveredCaps.put(bc, RegionConstants.GLOBAL_REGION);
                 continue nextCapability;
             }

             for (String capFeat : capFeatures) {
                 if (reqFeatures.contains(capFeat)) {
                     // Within a single feature everything can wire to everything else

                     // null value means same bundle, same feature or system bundle, but if exported into global region, use 'global' instead
                     coveredCaps.put(bc, isInGlobalRegion(packageName, capFeat) ? RegionConstants.GLOBAL_REGION : null);
                     continue nextCapability;
                 }

                 Set<String> capRegions = this.configuration.getFeatureRegionMap().get(capFeat);
                 if (capRegions == null || capRegions.size() == 0) {
                     // If the feature hosting the capability has no regions defined, everyone can access
                     coveredCaps.put(bc, RegionConstants.GLOBAL_REGION);
                     continue nextCapability;
                 }
                 bcFeatureMap.put(bc, capFeat);

                 List<String> sharedRegions = new ArrayList<>(reqRegions);
                 sharedRegions.retainAll(capRegions);

                 // Look at specific regions first as they take precedence over the global region
                 for (String region : sharedRegions) {
                     Set<String> regionPackages = this.configuration.getRegionPackageMap().get(region);
                     if (regionPackages != null && regionPackages.contains(packageName)) {
                         // If the export is in a region that the feature is also in, then allow
                         coveredCaps.put(bc, region);
                         continue nextCapability;
                     }
                 }

                 // Now check the global region
                 Set<String> globalPackages = this.configuration.getRegionPackageMap().get(RegionConstants.GLOBAL_REGION);
                 if (globalPackages != null && globalPackages.contains(packageName)) {
                     // If the export is in the global region everyone can access
                     coveredCaps.put(bc, RegionConstants.GLOBAL_REGION);
                     continue nextCapability;
                 }
             }
         }

         pruneCoveredCaps(bareReqRegions, coveredCaps);

         List<BundleCapability> removedCandidates = new ArrayList<>(candidates);
         // Remove any capabilities that are not covered
         candidates.retainAll(coveredCaps.keySet());

         Level logLevel;
         if (candidates.isEmpty()) {
             logLevel = Level.WARNING;
         } else {
             logLevel = Level.INFO;
         }
         removedCandidates.removeAll(candidates);

         if (!removedCandidates.isEmpty()) {
             StringBuilder sb = new StringBuilder();
             boolean first = true;
             for (BundleCapability bc : removedCandidates) {
                 if (first)
                     first = false;
                 else
                     sb.append(", ");

                 String capFeat = bcFeatureMap.get(bc);
                 sb.append(bc.toString());
                 sb.append("[Regions: ");
                 sb.append(getRegionsForPackage(packageName, capFeat));
                 sb.append(", Feature: ");
                 sb.append(capFeat);
                 sb.append("]");
             }

             Activator.LOG.log(logLevel,
                     "API-Regions removed candidates {0} for requirement {1} as the requirement is in the following regions: {2} and in feature: {3}",
                     new Object[] {sb, requirement, reqRegions, reqFeatures});
         }
     }

     /**
      * Check if the package is exported in the global region
      * @param packageName The package
      * @param capFeat The feature where it is found
      * @return If the feature exports to the global region and the package is exported into the global region
      */
     private boolean isInGlobalRegion(String packageName, String capFeat) {
         Set<String> capRegions = this.configuration.getFeatureRegionMap().get(capFeat);
         if (capRegions != null) {
             if (capRegions.contains(RegionConstants.GLOBAL_REGION)) {
                 Set<String> globalPackages = this.configuration.getRegionPackageMap().get(RegionConstants.GLOBAL_REGION);
                 if (globalPackages.contains(packageName)) {
                     return true;
                 }
             }
         }
         return false;
     }

     /**
      * If there are multiple choices of capabilities and some of the capabilities are in the global
      * region while others are in another named region or in a feature-private region, take out the
      * capabilities from the global region so that the requirement gets wired to the more 'specific'
      * one than the global one.
      * Capabilities that are considered specific but not in a named region are marked in the CapMap
      * with a {@code null} region value.
      *
      * @param reqRegions The regions declared in the requiring feature. If {@code null} is passed in
      * the requirement did not opt into the API Regions
      * @param capMap The map of capabilities to regions where they are found in
      */
     private void pruneCoveredCaps(Set<String> reqRegions, Map<BundleCapability,String> capMap) {
         if (reqRegions == null) {
             // No regions (other than global) for the requirement: do nothing
             return;
         }

         Set<String> reqNonGlobalRegions = new HashSet<>(reqRegions);
         reqNonGlobalRegions.remove(RegionConstants.GLOBAL_REGION);

         if (capMap.size() <= 1) {
             // Shortcut: there is only 0 or 1 capability, nothing to do
             return;
         }

         List<BundleCapability> specificCaps = new ArrayList<>();
         for (Iterator<Map.Entry<BundleCapability,String>> it = capMap.entrySet().iterator(); it.hasNext(); ) {
             Map.Entry<BundleCapability,String> entry = it.next();

             String capRegion = entry.getValue();
             if (capRegion == null) {
                 // This one came from the same bundle, the same feature or bundle 0 -> always allow
                 specificCaps.add(entry.getKey());
                 continue;
             }

             if (reqNonGlobalRegions.contains(capRegion)) {
                 // the requirement has the region from the capability
                 specificCaps.add(entry.getKey());
             }
         }

         if (specificCaps.size() == 0) {
             // There are no capabilities that are either in the same bundle, same feature or overlapping specific
             // feature. We should just allow all, including the global region
             return;
         }

         // There are specific capabilities, therefore we should remove the Global region is any from the capabilities
         // We have collected the capabilities we want to keep in specificCaps
         for (Iterator<BundleCapability> it = capMap.keySet().iterator(); it.hasNext(); ) {
             BundleCapability cap = it.next();
             if (!specificCaps.contains(cap)) {
                 it.remove();
                 Activator.LOG.log(Level.INFO, "Removing candidate {0} which is in region {1} as more specific candidate(s) are available in regions {2}",
                         new Object[] {
                                 cap, capMap.get(cap),
                                 specificCaps.stream().map(c -> "" + c + " region " + capMap.get(c)).collect(Collectors.joining("/"))
                         });
             }
         }
     }

     Set<String> getFeaturesForBundle(Bundle bundle) {
         // Look up the bsn and bundle version initially associated with the location. If the bundle
         // for the specified location was later updated, the initial bsn+version is still used to look up the
         // api regions configuration
         Map.Entry<String, Version> bsnVer = this.configuration.getBundleLocationConfigMap()
                 .computeIfAbsent(bundle.getLocation(), l -> new AbstractMap.SimpleEntry<>(
                         bundle.getSymbolicName(), bundle.getVersion()));

         return getFeaturesForBundleFromConfig(bsnVer.getKey(), bsnVer.getValue());
     }

     private Set<String> getFeaturesForBundleFromConfig(String bundleName, Version bundleVersion) {
         Set<String> newSet = new HashSet<>();
         List<String> aids = this.configuration.getBsnVerMap().get(
                 new AbstractMap.SimpleEntry<String, Version>(bundleName, bundleVersion));
         if (aids != null) {
             for (String aid : aids) {
                 Set<String> fid = this.configuration.getBundleFeatureMap().get(aid);
                 if (fid != null)
                     newSet.addAll(fid);
             }
         }

         return Collections.unmodifiableSet(newSet);
     }

     List<String> getRegionsForPackage(String packageName, String feature) {
         if (packageName == null)
             return Collections.emptyList();

         Set<String> regions = this.configuration.getFeatureRegionMap().get(feature);
         if (regions == null)
             return Collections.emptyList();

         List<String> res = new ArrayList<>();
         for (String region : regions) {
             Set<String> packages = this.configuration.getRegionPackageMap().get(region);
             if (packages == null)
                 continue;

             if (packages.contains(packageName)) {
                 res.add(region);
             }
         }
         return res;
     }

     @Override
     public void end() {
         // Nothing to do
     }
 }
	/*
	* 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.feature.apiregions.impl;

	import java.util.AbstractMap;
	import java.util.ArrayList;
	import java.util.Collection;
	import java.util.Collections;
	import java.util.HashMap;
	import java.util.HashSet;
	import java.util.Iterator;
	import java.util.List;
	import java.util.Map;
	import java.util.Set;
	import java.util.logging.Level;
	import java.util.stream.Collectors;

	import org.osgi.framework.Bundle;
	import org.osgi.framework.Version;
	import org.osgi.framework.hooks.resolver.ResolverHook;
	import org.osgi.framework.namespace.PackageNamespace;
	import org.osgi.framework.wiring.BundleCapability;
	import org.osgi.framework.wiring.BundleRequirement;
	import org.osgi.framework.wiring.BundleRevision;

	class ResolverHookImpl implements ResolverHook {

	final RegionConfiguration configuration;

	ResolverHookImpl(RegionConfiguration cfg) {
	this.configuration = cfg;
	}

	@Override
	public void filterResolvable(Collection<BundleRevision> candidates) {
	// Nothing to do
	}

	@Override
	public void filterSingletonCollisions(BundleCapability singleton, Collection<BundleCapability> collisionCandidates) {
	// Nothing to do
	}

	@Override
	public void filterMatches(BundleRequirement requirement, Collection<BundleCapability> candidates) {
	// Filtering is only on package resolution. Any other kind of resolution is not limited
	if (!PackageNamespace.PACKAGE_NAMESPACE.equals(requirement.getNamespace()))
	return;

	if (candidates.size() < 1)
	return;

	Object pkg = candidates.iterator().next().getAttributes().get(PackageNamespace.PACKAGE_NAMESPACE);
	if (!(pkg instanceof String)) {
	return;
	}
	String packageName = (String) pkg;

	Bundle reqBundle = requirement.getRevision().getBundle();
	long reqBundleID = reqBundle.getBundleId();

	Set<String> bareReqRegions = null; // Null means: not opting into API Regions
	Set<String> reqFeatures = getFeaturesForBundle(reqBundle);
	for (String feature : reqFeatures) {
	Set<String> fr = this.configuration.getFeatureRegionMap().get(feature);
	if (fr != null) {
	if (bareReqRegions == null)
	bareReqRegions = new HashSet<>();
	bareReqRegions.addAll(fr);
	}
	}
	Set<String> reqRegions = new HashSet<>(this.configuration.getDefaultRegions());
	if (bareReqRegions != null)
	reqRegions.addAll(bareReqRegions);

	Map<BundleCapability, String> coveredCaps = new HashMap<>();
	Map<BundleCapability, String> bcFeatureMap = new HashMap<>();

	nextCapability:
	for (BundleCapability bc : candidates) {
	BundleRevision rev = bc.getRevision();

	Bundle capBundle = rev.getBundle();
	long capBundleID = capBundle.getBundleId();
	if (capBundleID == 0) {
	// always allow capability from the system bundle
	coveredCaps.put(bc, null); // null value means same bundle, same feature or system bundle
	continue nextCapability;
	}

	if (capBundleID == reqBundleID) {
	// always allow capability from same bundle

	// Here we cover the case where the bundle is not in any feature which means that the package is in the 'global' region,
	// however if the bundle is in a feature then it could be marked as more specific, with a 'null value', which may
	// happen below.
	coveredCaps.put(bc, RegionConstants.GLOBAL_REGION);

	// note: don't continue to nextCapability here, this one may be overwritten later...
	}

	Set<String> capFeatures = getFeaturesForBundle(capBundle);
	if (capFeatures.isEmpty()) {
	// Capability is not in any feature, everyone can access
	coveredCaps.put(bc, RegionConstants.GLOBAL_REGION);
	continue nextCapability;
	}

	for (String capFeat : capFeatures) {
	if (reqFeatures.contains(capFeat)) {
	// Within a single feature everything can wire to everything else

	// null value means same bundle, same feature or system bundle, but if exported into global region, use 'global' instead
	coveredCaps.put(bc, isInGlobalRegion(packageName, capFeat) ? RegionConstants.GLOBAL_REGION : null);
	continue nextCapability;
	}

	Set<String> capRegions = this.configuration.getFeatureRegionMap().get(capFeat);
	if (capRegions == null \|\| capRegions.size() == 0) {
	// If the feature hosting the capability has no regions defined, everyone can access
	coveredCaps.put(bc, RegionConstants.GLOBAL_REGION);
	continue nextCapability;
	}
	bcFeatureMap.put(bc, capFeat);

	List<String> sharedRegions = new ArrayList<>(reqRegions);
	sharedRegions.retainAll(capRegions);

	// Look at specific regions first as they take precedence over the global region
	for (String region : sharedRegions) {
	Set<String> regionPackages = this.configuration.getRegionPackageMap().get(region);
	if (regionPackages != null && regionPackages.contains(packageName)) {
	// If the export is in a region that the feature is also in, then allow
	coveredCaps.put(bc, region);
	continue nextCapability;
	}
	}

	// Now check the global region
	Set<String> globalPackages = this.configuration.getRegionPackageMap().get(RegionConstants.GLOBAL_REGION);
	if (globalPackages != null && globalPackages.contains(packageName)) {
	// If the export is in the global region everyone can access
	coveredCaps.put(bc, RegionConstants.GLOBAL_REGION);
	continue nextCapability;
	}
	}
	}

	pruneCoveredCaps(bareReqRegions, coveredCaps);

	List<BundleCapability> removedCandidates = new ArrayList<>(candidates);
	// Remove any capabilities that are not covered
	candidates.retainAll(coveredCaps.keySet());

	Level logLevel;
	if (candidates.isEmpty()) {
	logLevel = Level.WARNING;
	} else {
	logLevel = Level.INFO;
	}
	removedCandidates.removeAll(candidates);

	if (!removedCandidates.isEmpty()) {
	StringBuilder sb = new StringBuilder();
	boolean first = true;
	for (BundleCapability bc : removedCandidates) {
	if (first)
	first = false;
	else
	sb.append(", ");

	String capFeat = bcFeatureMap.get(bc);
	sb.append(bc.toString());
	sb.append("[Regions: ");
	sb.append(getRegionsForPackage(packageName, capFeat));
	sb.append(", Feature: ");
	sb.append(capFeat);
	sb.append("]");
	}

	Activator.LOG.log(logLevel,
	"API-Regions removed candidates {0} for requirement {1} as the requirement is in the following regions: {2} and in feature: {3}",
	new Object[] {sb, requirement, reqRegions, reqFeatures});
	}
	}

	/**
	* Check if the package is exported in the global region
	* @param packageName The package
	* @param capFeat The feature where it is found
	* @return If the feature exports to the global region and the package is exported into the global region
	*/
	private boolean isInGlobalRegion(String packageName, String capFeat) {
	Set<String> capRegions = this.configuration.getFeatureRegionMap().get(capFeat);
	if (capRegions != null) {
	if (capRegions.contains(RegionConstants.GLOBAL_REGION)) {
	Set<String> globalPackages = this.configuration.getRegionPackageMap().get(RegionConstants.GLOBAL_REGION);
	if (globalPackages.contains(packageName)) {
	return true;
	}
	}
	}
	return false;
	}

	/**
	* If there are multiple choices of capabilities and some of the capabilities are in the global
	* region while others are in another named region or in a feature-private region, take out the
	* capabilities from the global region so that the requirement gets wired to the more 'specific'
	* one than the global one.
	* Capabilities that are considered specific but not in a named region are marked in the CapMap
	* with a {@code null} region value.
	*
	* @param reqRegions The regions declared in the requiring feature. If {@code null} is passed in
	* the requirement did not opt into the API Regions
	* @param capMap The map of capabilities to regions where they are found in
	*/
	private void pruneCoveredCaps(Set<String> reqRegions, Map<BundleCapability,String> capMap) {
	if (reqRegions == null) {
	// No regions (other than global) for the requirement: do nothing
	return;
	}

	Set<String> reqNonGlobalRegions = new HashSet<>(reqRegions);
	reqNonGlobalRegions.remove(RegionConstants.GLOBAL_REGION);

	if (capMap.size() <= 1) {
	// Shortcut: there is only 0 or 1 capability, nothing to do
	return;
	}

	List<BundleCapability> specificCaps = new ArrayList<>();
	for (Iterator<Map.Entry<BundleCapability,String>> it = capMap.entrySet().iterator(); it.hasNext(); ) {
	Map.Entry<BundleCapability,String> entry = it.next();

	String capRegion = entry.getValue();
	if (capRegion == null) {
	// This one came from the same bundle, the same feature or bundle 0 -> always allow
	specificCaps.add(entry.getKey());
	continue;
	}

	if (reqNonGlobalRegions.contains(capRegion)) {
	// the requirement has the region from the capability
	specificCaps.add(entry.getKey());
	}
	}

	if (specificCaps.size() == 0) {
	// There are no capabilities that are either in the same bundle, same feature or overlapping specific
	// feature. We should just allow all, including the global region
	return;
	}

	// There are specific capabilities, therefore we should remove the Global region is any from the capabilities
	// We have collected the capabilities we want to keep in specificCaps
	for (Iterator<BundleCapability> it = capMap.keySet().iterator(); it.hasNext(); ) {
	BundleCapability cap = it.next();
	if (!specificCaps.contains(cap)) {
	it.remove();
	Activator.LOG.log(Level.INFO, "Removing candidate {0} which is in region {1} as more specific candidate(s) are available in regions {2}",
	new Object[] {
	cap, capMap.get(cap),
	specificCaps.stream().map(c -> "" + c + " region " + capMap.get(c)).collect(Collectors.joining("/"))
	});
	}
	}
	}

	Set<String> getFeaturesForBundle(Bundle bundle) {
	// Look up the bsn and bundle version initially associated with the location. If the bundle
	// for the specified location was later updated, the initial bsn+version is still used to look up the
	// api regions configuration
	Map.Entry<String, Version> bsnVer = this.configuration.getBundleLocationConfigMap()
	.computeIfAbsent(bundle.getLocation(), l -> new AbstractMap.SimpleEntry<>(
	bundle.getSymbolicName(), bundle.getVersion()));

	return getFeaturesForBundleFromConfig(bsnVer.getKey(), bsnVer.getValue());
	}

	private Set<String> getFeaturesForBundleFromConfig(String bundleName, Version bundleVersion) {
	Set<String> newSet = new HashSet<>();
	List<String> aids = this.configuration.getBsnVerMap().get(
	new AbstractMap.SimpleEntry<String, Version>(bundleName, bundleVersion));
	if (aids != null) {
	for (String aid : aids) {
	Set<String> fid = this.configuration.getBundleFeatureMap().get(aid);
	if (fid != null)
	newSet.addAll(fid);
	}
	}

	return Collections.unmodifiableSet(newSet);
	}

	List<String> getRegionsForPackage(String packageName, String feature) {
	if (packageName == null)
	return Collections.emptyList();

	Set<String> regions = this.configuration.getFeatureRegionMap().get(feature);
	if (regions == null)
	return Collections.emptyList();

	List<String> res = new ArrayList<>();
	for (String region : regions) {
	Set<String> packages = this.configuration.getRegionPackageMap().get(region);
	if (packages == null)
	continue;

	if (packages.contains(packageName)) {
	res.add(region);
	}
	}
	return res;
	}

	@Override
	public void end() {
	// Nothing to do
	}
	}