/*******************************************************************************
* Copyright (c) 2000, 2011 IBM Corporation and others.
* 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:
* IBM Corporation - initial API and implementation
* James Blackburn (Broadcom Corp.) - ongoing development
*******************************************************************************/
package org.eclipse.core.internal.resources;
import java.util.*;
import org.eclipse.core.internal.events.ILifecycleListener;
import org.eclipse.core.internal.events.LifecycleEvent;
import org.eclipse.core.internal.utils.Messages;
import org.eclipse.core.internal.utils.Policy;
import org.eclipse.core.resources.*;
import org.eclipse.core.runtime.*;
import org.eclipse.osgi.util.NLS;
/**
* Maintains collection of known nature descriptors, and implements
* nature-related algorithms provided by the workspace.
*/
public class NatureManager implements ILifecycleListener, IManager {
//maps String (nature ID) -> descriptor objects
private Map<String, IProjectNatureDescriptor> descriptors;
//maps IProject -> String[] of enabled natures for that project
private final Map<Project, String[]> natureEnablements = new HashMap<Project, String[]>(20);
//maps String (builder ID) -> String (nature ID)
private Map<String, String> buildersToNatures;
//colour constants used in cycle detection algorithm
private static final byte WHITE = 0;
private static final byte GREY = 1;
private static final byte BLACK = 2;
protected NatureManager() {
super();
}
/**
* Computes the list of natures that are enabled for the given project.
* Enablement computation is subtly different from nature set
* validation, because it must find and remove all inconsistencies.
*/
protected String[] computeNatureEnablements(Project project) {
final ProjectDescription description = project.internalGetDescription();
if (description == null)
return new String[0];//project deleted concurrently
String[] natureIds = description.getNatureIds();
int count = natureIds.length;
if (count == 0)
return natureIds;
//set of the nature ids being validated (String (id))
HashSet<String> candidates = new HashSet<String>(count * 2);
//table of String(set ID) -> ArrayList (nature IDs that belong to that set)
HashMap<String, ArrayList<String>> setsToNatures = new HashMap<String, ArrayList<String>>(count);
for (int i = 0; i < count; i++) {
String id = natureIds[i];
ProjectNatureDescriptor desc = (ProjectNatureDescriptor) getNatureDescriptor(id);
if (desc == null)
continue;
if (!desc.hasCycle)
candidates.add(id);
//build set to nature map
String[] setIds = desc.getNatureSetIds();
for (int j = 0; j < setIds.length; j++) {
String set = setIds[j];
ArrayList<String> current = setsToNatures.get(set);
if (current == null) {
current = new ArrayList<String>(5);
setsToNatures.put(set, current);
}
current.add(id);
}
}
//now remove all natures that belong to sets with more than one member
for (Iterator<ArrayList<String>> it = setsToNatures.values().iterator(); it.hasNext();) {
ArrayList<String> setMembers = it.next();
if (setMembers.size() > 1) {
candidates.removeAll(setMembers);
}
}
//now walk over the set and ensure all pre-requisite natures are present
//need to walk in prereq order because if A requires B and B requires C, and C is
//disabled for some other reason, we must ensure both A and B are disabled
String[] orderedCandidates = candidates.toArray(new String[candidates.size()]);
orderedCandidates = sortNatureSet(orderedCandidates);
for (int i = 0; i < orderedCandidates.length; i++) {
String id = orderedCandidates[i];
IProjectNatureDescriptor desc = getNatureDescriptor(id);
String[] required = desc.getRequiredNatureIds();
for (int j = 0; j < required.length; j++) {
if (!candidates.contains(required[j])) {
candidates.remove(id);
break;
}
}
}
//remaining candidates are enabled
return candidates.toArray(new String[candidates.size()]);
}
/* (non-Javadoc)
* @see IWorkspace#getNatureDescriptor(String)
*/
public synchronized IProjectNatureDescriptor getNatureDescriptor(String natureId) {
lazyInitialize();
return descriptors.get(natureId);
}
/* (non-Javadoc)
* @see IWorkspace#getNatureDescriptors()
*/
public synchronized IProjectNatureDescriptor[] getNatureDescriptors() {
lazyInitialize();
Collection<IProjectNatureDescriptor> values = descriptors.values();
return values.toArray(new IProjectNatureDescriptor[values.size()]);
}
public void handleEvent(LifecycleEvent event) {
switch (event.kind) {
case LifecycleEvent.POST_PROJECT_CHANGE :
case LifecycleEvent.PRE_PROJECT_CLOSE :
case LifecycleEvent.PRE_PROJECT_DELETE :
case LifecycleEvent.PRE_PROJECT_MOVE :
case LifecycleEvent.PRE_PROJECT_OPEN :
flushEnablements((IProject) event.resource);
}
}
/**
* Configures the nature with the given ID for the given project.
*/
protected void configureNature(final Project project, final String natureID, final MultiStatus errors) {
ISafeRunnable code = new ISafeRunnable() {
public void run() throws Exception {
IProjectNature nature = createNature(project, natureID);
nature.configure();
ProjectInfo info = (ProjectInfo) project.getResourceInfo(false, true);
info.setNature(natureID, nature);
}
public void handleException(Throwable exception) {
if (exception instanceof CoreException)
errors.add(((CoreException) exception).getStatus());
else
errors.add(new ResourceStatus(IResourceStatus.INTERNAL_ERROR, project.getFullPath(), NLS.bind(Messages.resources_errorNature, natureID), exception));
}
};
if (Policy.DEBUG_NATURES) {
System.out.println("Configuring nature: " + natureID + " on project: " + project.getName()); //$NON-NLS-1$ //$NON-NLS-2$
}
SafeRunner.run(code);
}
/**
* Configures the natures for the given project. Natures found in the new description
* that weren't present in the old description are added, and natures missing from the
* new description are removed. Updates the old description so that it reflects
* the new set of the natures. Errors are added to the given multi-status.
*/
@SuppressWarnings("unchecked")
public void configureNatures(Project project, ProjectDescription oldDescription, ProjectDescription newDescription, MultiStatus status) {
// Be careful not to rely on much state because (de)configuring a nature
// may well result in recursive calls to this method.
HashSet<String> oldNatures = new HashSet<String>(Arrays.asList(oldDescription.getNatureIds(false)));
HashSet<String> newNatures = new HashSet<String>(Arrays.asList(newDescription.getNatureIds(false)));
if (oldNatures.equals(newNatures))
return;
HashSet<String> deletions = (HashSet<String>) oldNatures.clone();
HashSet<String> additions = (HashSet<String>) newNatures.clone();
additions.removeAll(oldNatures);
deletions.removeAll(newNatures);
//do validation of the changes. If any single change is invalid, fail the whole operation
IStatus result = validateAdditions(newNatures, additions, project);
if (!result.isOK()) {
status.merge(result);
return;
}
result = validateRemovals(newNatures, deletions);
if (!result.isOK()) {
status.merge(result);
return;
}
// set the list of nature ids BEFORE (de)configuration so recursive calls will
// not try to do the same work.
oldDescription.setNatureIds(newDescription.getNatureIds(true));
flushEnablements(project);
//(de)configure in topological order to maintain consistency of configured set
String[] ordered = null;
if (deletions.size() > 0) {
ordered = sortNatureSet(deletions.toArray(new String[deletions.size()]));
for (int i = ordered.length; --i >= 0;)
deconfigureNature(project, ordered[i], status);
}
if (additions.size() > 0) {
ordered = sortNatureSet(additions.toArray(new String[additions.size()]));
for (int i = 0; i < ordered.length; i++)
configureNature(project, ordered[i], status);
}
}
/**
* Finds the nature extension, and initializes and returns an instance.
*/
protected IProjectNature createNature(Project project, String natureID) throws CoreException {
IExtension extension = Platform.getExtensionRegistry().getExtension(ResourcesPlugin.PI_RESOURCES, ResourcesPlugin.PT_NATURES, natureID);
if (extension == null) {
String message = NLS.bind(Messages.resources_natureExtension, natureID);
throw new ResourceException(Platform.PLUGIN_ERROR, project.getFullPath(), message, null);
}
IConfigurationElement[] configs = extension.getConfigurationElements();
if (configs.length < 1) {
String message = NLS.bind(Messages.resources_natureClass, natureID);
throw new ResourceException(Platform.PLUGIN_ERROR, project.getFullPath(), message, null);
}
//find the runtime configuration element
IConfigurationElement config = null;
for (int i = 0; config == null && i < configs.length; i++)
if ("runtime".equalsIgnoreCase(configs[i].getName())) //$NON-NLS-1$
config = configs[i];
if (config == null) {
String message = NLS.bind(Messages.resources_natureFormat, natureID);
throw new ResourceException(Platform.PLUGIN_ERROR, project.getFullPath(), message, null);
}
try {
IProjectNature nature = (IProjectNature) config.createExecutableExtension("run"); //$NON-NLS-1$
nature.setProject(project);
return nature;
} catch (ClassCastException e) {
String message = NLS.bind(Messages.resources_natureImplement, natureID);
throw new ResourceException(Platform.PLUGIN_ERROR, project.getFullPath(), message, e);
}
}
/**
* Deconfigures the nature with the given ID for the given project.
*/
protected void deconfigureNature(final Project project, final String natureID, final MultiStatus status) {
final ProjectInfo info = (ProjectInfo) project.getResourceInfo(false, true);
IProjectNature existingNature = info.getNature(natureID);
if (existingNature == null) {
// if there isn't a nature then create one so we can deconfig it.
try {
existingNature = createNature(project, natureID);
} catch (CoreException e) {
// Ignore - we are removing a nature that no longer exists in the install
return;
}
}
final IProjectNature nature = existingNature;
ISafeRunnable code = new ISafeRunnable() {
public void run() throws Exception {
nature.deconfigure();
info.setNature(natureID, null);
}
public void handleException(Throwable exception) {
if (exception instanceof CoreException)
status.add(((CoreException) exception).getStatus());
else
status.add(new ResourceStatus(IResourceStatus.INTERNAL_ERROR, project.getFullPath(), NLS.bind(Messages.resources_natureDeconfig, natureID), exception));
}
};
if (Policy.DEBUG_NATURES) {
System.out.println("Deconfiguring nature: " + natureID + " on project: " + project.getName()); //$NON-NLS-1$ //$NON-NLS-2$
}
SafeRunner.run(code);
}
/**
* Marks all nature descriptors that are involved in cycles
*/
private void detectCycles() {
Collection<IProjectNatureDescriptor> values = descriptors.values();
ProjectNatureDescriptor[] natures = values.toArray(new ProjectNatureDescriptor[values.size()]);
for (int i = 0; i < natures.length; i++)
if (natures[i].colour == WHITE)
hasCycles(natures[i]);
}
/**
* Returns a status indicating failure to configure natures.
*/
protected IStatus failure(String reason) {
return new ResourceStatus(IResourceStatus.INVALID_NATURE_SET, reason);
}
/**
* Returns the ID of the project nature that claims ownership of the
* builder with the given ID. Returns null if no nature owns that builder.
*/
public synchronized String findNatureForBuilder(String builderID) {
if (buildersToNatures == null) {
buildersToNatures = new HashMap<String, String>(10);
IProjectNatureDescriptor[] descs = getNatureDescriptors();
for (int i = 0; i < descs.length; i++) {
String natureId = descs[i].getNatureId();
String[] builders = ((ProjectNatureDescriptor) descs[i]).getBuilderIds();
for (int j = 0; j < builders.length; j++) {
//FIXME: how to handle multiple natures specifying same builder
buildersToNatures.put(builders[j], natureId);
}
}
}
return buildersToNatures.get(builderID);
}
private synchronized void flushEnablements(IProject project) {
natureEnablements.remove(project);
}
/**
* Returns the cached array of enabled natures for this project,
* or null if there is nothing in the cache.
*/
protected synchronized String[] getEnabledNatures(Project project) {
String[] enabled = natureEnablements.get(project);
if (enabled != null)
return enabled;
enabled = computeNatureEnablements(project);
natureEnablements.put(project, enabled);
return enabled;
}
/**
* Returns true if there are cycles in the graph of nature
* dependencies starting at root i. Returns false otherwise.
* Marks all descriptors that are involved in the cycle as invalid.
*/
protected boolean hasCycles(ProjectNatureDescriptor desc) {
if (desc.colour == BLACK) {
//this subgraph has already been traversed, so we know the answer
return desc.hasCycle;
}
//if we are already grey, then we have found a cycle
if (desc.colour == GREY) {
desc.hasCycle = true;
desc.colour = BLACK;
return true;
}
//colour current descriptor GREY to indicate it is being visited
desc.colour = GREY;
//visit all dependents of nature i
String[] required = desc.getRequiredNatureIds();
for (int i = 0; i < required.length; i++) {
ProjectNatureDescriptor dependency = (ProjectNatureDescriptor) getNatureDescriptor(required[i]);
//missing dependencies cannot create cycles
if (dependency != null && hasCycles(dependency)) {
desc.hasCycle = true;
desc.colour = BLACK;
return true;
}
}
desc.hasCycle = false;
desc.colour = BLACK;
return false;
}
/**
* Returns true if the given project has linked resources, and false otherwise.
*/
protected boolean hasLinks(IProject project) {
try {
IResource[] children = project.members();
for (int i = 0; i < children.length; i++)
if (children[i].isLinked())
return true;
} catch (CoreException e) {
//not possible for project to be inaccessible
Policy.log(e.getStatus());
}
return false;
}
/**
* Checks if the two natures have overlapping "one-of-nature" set
* memberships. Returns the name of one such overlap, or null if
* there is no set overlap.
*/
protected String hasSetOverlap(IProjectNatureDescriptor one, IProjectNatureDescriptor two) {
if (one == null || two == null) {
return null;
}
//efficiency not so important because these sets are very small
String[] setsOne = one.getNatureSetIds();
String[] setsTwo = two.getNatureSetIds();
for (int iOne = 0; iOne < setsOne.length; iOne++) {
for (int iTwo = 0; iTwo < setsTwo.length; iTwo++) {
if (setsOne[iOne].equals(setsTwo[iTwo])) {
return setsOne[iOne];
}
}
}
return null;
}
/**
* Perform depth-first insertion of the given nature ID into the result list.
*/
protected void insert(ArrayList<String> list, Set<String> seen, String id) {
if (seen.contains(id))
return;
seen.add(id);
//insert prerequisite natures
IProjectNatureDescriptor desc = getNatureDescriptor(id);
if (desc != null) {
String[] prereqs = desc.getRequiredNatureIds();
for (int i = 0; i < prereqs.length; i++)
insert(list, seen, prereqs[i]);
}
list.add(id);
}
/* (non-Javadoc)
* Returns true if the given nature is enabled for the given project.
*
* @see IProject#isNatureEnabled(String)
*/
public boolean isNatureEnabled(Project project, String id) {
String[] enabled = getEnabledNatures(project);
for (int i = 0; i < enabled.length; i++) {
if (enabled[i].equals(id))
return true;
}
return false;
}
/**
* Only initialize the descriptor cache when we know it is actually needed.
* Running programs may never need to refer to this cache.
*/
private void lazyInitialize() {
if (descriptors != null)
return;
IExtensionPoint point = Platform.getExtensionRegistry().getExtensionPoint(ResourcesPlugin.PI_RESOURCES, ResourcesPlugin.PT_NATURES);
IExtension[] extensions = point.getExtensions();
descriptors = new HashMap<String, IProjectNatureDescriptor>(extensions.length * 2 + 1);
for (int i = 0, imax = extensions.length; i < imax; i++) {
IProjectNatureDescriptor desc = null;
try {
desc = new ProjectNatureDescriptor(extensions[i]);
} catch (CoreException e) {
Policy.log(e.getStatus());
}
if (desc != null)
descriptors.put(desc.getNatureId(), desc);
}
//do cycle detection now so it only has to be done once
//cycle detection on a graph subset is a pain
detectCycles();
}
public void shutdown(IProgressMonitor monitor) {
// do nothing
}
/* (non-Javadoc)
* @see IWorkspace#sortNatureSet(String[])
*/
public String[] sortNatureSet(String[] natureIds) {
int count = natureIds.length;
if (count == 0)
return natureIds;
ArrayList<String> result = new ArrayList<String>(count);
HashSet<String> seen = new HashSet<String>(count);//for cycle and duplicate detection
for (int i = 0; i < count; i++)
insert(result, seen, natureIds[i]);
//remove added prerequisites that didn't exist in original list
seen.clear();
seen.addAll(Arrays.asList(natureIds));
for (Iterator<String> it = result.iterator(); it.hasNext();) {
Object id = it.next();
if (!seen.contains(id))
it.remove();
}
return result.toArray(new String[result.size()]);
}
public void startup(IProgressMonitor monitor) {
((Workspace) ResourcesPlugin.getWorkspace()).addLifecycleListener(this);
}
/**
* Validates the given nature additions in the nature set for this
* project. Tolerates existing inconsistencies in the nature set.
* @param newNatures the complete new set of nature IDs for the project,
* including additions
* @param additions the subset of newNatures that represents natures
* being added
* @return An OK status if all additions are valid, and an error status
* if any of the additions introduce new inconsistencies.
*/
protected IStatus validateAdditions(HashSet<String> newNatures, HashSet<String> additions, IProject project) {
Boolean hasLinks = null;//three states: true, false, null (not yet computed)
//perform checks in order from least expensive to most expensive
for (Iterator<String> added = additions.iterator(); added.hasNext();) {
String id = added.next();
// check for adding a nature that is not available.
IProjectNatureDescriptor desc = getNatureDescriptor(id);
if (desc == null) {
return failure(NLS.bind(Messages.natures_missingNature, id));
}
// check for adding a nature that creates a circular dependency
if (((ProjectNatureDescriptor) desc).hasCycle) {
return failure(NLS.bind(Messages.natures_hasCycle, id));
}
// check for adding a nature that has a missing prerequisite.
String[] required = desc.getRequiredNatureIds();
for (int i = 0; i < required.length; i++) {
if (!newNatures.contains(required[i])) {
return failure(NLS.bind(Messages.natures_missingPrerequisite, id, required[i]));
}
}
// check for adding a nature that creates a duplicated set member.
for (Iterator<String> all = newNatures.iterator(); all.hasNext();) {
String current = all.next();
if (!current.equals(id)) {
String overlap = hasSetOverlap(desc, getNatureDescriptor(current));
if (overlap != null) {
return failure(NLS.bind(Messages.natures_multipleSetMembers, overlap));
}
}
}
//check for adding a nature that has linked resource veto
if (!desc.isLinkingAllowed()) {
if (hasLinks == null) {
hasLinks = hasLinks(project) ? Boolean.TRUE : Boolean.FALSE;
}
if (hasLinks.booleanValue())
return failure(NLS.bind(Messages.links_vetoNature, project.getName(), id));
}
}
return Status.OK_STATUS;
}
/**
* Validates whether a project with the given set of natures should allow
* linked resources. Returns an OK status if linking is allowed,
* otherwise a non-OK status indicating why linking is not allowed.
* Linking is allowed if there is no project nature that explicitly disallows it.
* No validation is done on the nature ids themselves (ids that don't have
* a corresponding nature definition will be ignored).
*/
public IStatus validateLinkCreation(String[] natureIds) {
for (int i = 0; i < natureIds.length; i++) {
IProjectNatureDescriptor desc = getNatureDescriptor(natureIds[i]);
if (desc != null && !desc.isLinkingAllowed()) {
String msg = NLS.bind(Messages.links_natureVeto, desc.getLabel());
return new ResourceStatus(IResourceStatus.LINKING_NOT_ALLOWED, msg);
}
}
return Status.OK_STATUS;
}
/**
* Validates the given nature removals in the nature set for this
* project. Tolerates existing inconsistencies in the nature set.
*
* @param newNatures the complete new set of nature IDs for the project,
* excluding deletions
* @param deletions the nature IDs that are being removed from the set.
* @return An OK status if all removals are valid, and a not OK status
* if any of the deletions introduce new inconsistencies.
*/
protected IStatus validateRemovals(HashSet<String> newNatures, HashSet<String> deletions) {
//iterate over new nature set, and ensure that none of their prerequisites are being deleted
for (Iterator<String> it = newNatures.iterator(); it.hasNext();) {
String currentID = it.next();
IProjectNatureDescriptor desc = getNatureDescriptor(currentID);
if (desc != null) {
String[] required = desc.getRequiredNatureIds();
for (int i = 0; i < required.length; i++) {
if (deletions.contains(required[i])) {
return failure(NLS.bind(Messages.natures_invalidRemoval, required[i], currentID));
}
}
}
}
return Status.OK_STATUS;
}
/* (non-Javadoc)
* @see IWorkspace#validateNatureSet(String[])
*/
public IStatus validateNatureSet(String[] natureIds) {
int count = natureIds.length;
if (count == 0)
return Status.OK_STATUS;
String msg = Messages.natures_invalidSet;
MultiStatus result = new MultiStatus(ResourcesPlugin.PI_RESOURCES, IResourceStatus.INVALID_NATURE_SET, msg, null);
//set of the nature ids being validated (String (id))
HashSet<String> natures = new HashSet<String>(count * 2);
//set of nature sets for which a member nature has been found (String (id))
HashSet<String> sets = new HashSet<String>(count);
for (int i = 0; i < count; i++) {
String id = natureIds[i];
ProjectNatureDescriptor desc = (ProjectNatureDescriptor) getNatureDescriptor(id);
if (desc == null) {
result.add(failure(NLS.bind(Messages.natures_missingNature, id)));
continue;
}
if (desc.hasCycle)
result.add(failure(NLS.bind(Messages.natures_hasCycle, id)));
if (!natures.add(id))
result.add(failure(NLS.bind(Messages.natures_duplicateNature, id)));
//validate nature set one-of constraint
String[] setIds = desc.getNatureSetIds();
for (int j = 0; j < setIds.length; j++) {
if (!sets.add(setIds[j]))
result.add(failure(NLS.bind(Messages.natures_multipleSetMembers, setIds[j])));
}
}
//now walk over the set and ensure all pre-requisite natures are present
for (int i = 0; i < count; i++) {
IProjectNatureDescriptor desc = getNatureDescriptor(natureIds[i]);
if (desc == null)
continue;
String[] required = desc.getRequiredNatureIds();
for (int j = 0; j < required.length; j++)
if (!natures.contains(required[j]))
result.add(failure(NLS.bind(Messages.natures_missingPrerequisite, natureIds[i], required[j])));
}
//if there are no problems we must return a status whose code is OK
return result.isOK() ? Status.OK_STATUS : (IStatus) result;
}
}