Add support for creating workspace private project descriptions

resources/bundles/org.eclipse.core.resources/META-INF/MANIFEST.MF

@@ -2,7 +2,7 @@ Manifest-Version: 1.0
 Bundle-ManifestVersion: 2
 Bundle-Name: %pluginName
 Bundle-SymbolicName: org.eclipse.core.resources; singleton:=true
-Bundle-Version: 3.22.200.qualifier
+Bundle-Version: 3.23.0.qualifier
 Bundle-Activator: org.eclipse.core.resources.ResourcesPlugin
 Bundle-Vendor: %providerName
 Bundle-Localization: plugin

resources/bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/localstore/FileSystemResourceManager.java

@@ -683,7 +683,7 @@ public boolean internalWrite(IProject target, IProjectDescription description, i
 		if (hasPrivateChanges)
 			getWorkspace().getMetaArea().writePrivateDescription(target);
 		//can't do anything if there's no description
-		if (!hasPublicChanges || (description == null))
+		if (!hasPublicChanges || (description == null) || description.isWorkspacePrivate())
 			return false;
 
 		//write the model to a byte array
@@ -938,9 +938,15 @@ public ProjectDescription read(IProject target, boolean creation) throws CoreExc
 		if (creation) {
 			privateDescription = new ProjectDescription();
 			getWorkspace().getMetaArea().readPrivateDescription(target, privateDescription);
+			if (privateDescription.isWorkspacePrivate()) {
+				return privateDescription;
+			}
 			projectLocation = privateDescription.getLocationURI();
 		} else {
 			IProjectDescription description = ((Project) target).internalGetDescription();
+			if (description instanceof ProjectDescription impl && impl.isWorkspacePrivate()) {
+				return impl;
+			}
 			if (description != null && description.getLocationURI() != null) {
 				projectLocation = description.getLocationURI();
 			}

resources/bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/resources/LocalMetaArea.java

@@ -24,13 +24,17 @@
 import java.io.IOException;
 import java.net.URI;
 import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.Map;
+import java.util.Map.Entry;
 import org.eclipse.core.filesystem.URIUtil;
+import org.eclipse.core.internal.events.BuildCommand;
 import org.eclipse.core.internal.localstore.SafeChunkyInputStream;
 import org.eclipse.core.internal.localstore.SafeChunkyOutputStream;
 import org.eclipse.core.internal.utils.Messages;
 import org.eclipse.core.internal.utils.Policy;
 import org.eclipse.core.resources.IBuildConfiguration;
+import org.eclipse.core.resources.ICommand;
 import org.eclipse.core.resources.IProject;
 import org.eclipse.core.resources.IResource;
 import org.eclipse.core.resources.IResourceStatus;
@@ -322,14 +326,15 @@ public ProjectDescription readOldDescription(IProject project) throws CoreExcept
 	}
 
 	/**
-	 * Returns the portions of the project description that are private, and
-	 * adds them to the supplied project description. In particular, the
-	 * project location, the project's dynamic references and build configurations
-	 * are stored here.
-	 * The project location will be set to <code>null</code> if the default
-	 * location should be used. In the case of failure, log the exception and
-	 * return silently, thus reverting to using the default location and no
+	 * Returns the portions of the project description that are private, and adds
+	 * them to the supplied project description. In particular, the project
+	 * location, the project's dynamic references and build configurations are
+	 * stored here. The project location will be set to <code>null</code> if the
+	 * default location should be used. In the case of failure, log the exception
+	 * and return silently, thus reverting to using the default location and no
 	 * dynamic references. The current format of the location file is:
+	 *
+	 * <pre>
 	 *    UTF - project location
 	 *    int - number of dynamic project references
 	 *    UTF - project reference 1
@@ -347,9 +352,24 @@ public ProjectDescription readOldDescription(IProject project) throws CoreExcept
 	 *        UTF - configName if hasConfigName
 	 *        ... repeat for number of referenced configurations
 	 *      ... repeat for number of build configurations with references
+	 * since 3.23:
+	 *    bool - private flag if project should only be read from its private project configuration
+	 *    int - number of natures
+	 *      UTF - nature id
+	 *      ... repeated for N natures
+	 *    int - number of buildspecs
+	 *      byte - type of buildspec
+	 *        (type 1) UTF - name of builder
+	 *                 int - number of arguments
+	 *                  UTF arg key
+	 *                  UTF arg value
+	 *                 UTF - triggers string
+	 * </pre>
 	 */
 	public void readPrivateDescription(IProject target, ProjectDescription description) {
 		IPath locationFile = locationFor(target).append(F_PROJECT_LOCATION);
+		String name = target.getName();
+		description.setName(name);
 		java.io.File file = locationFile.toFile();
 		if (!file.exists()) {
 			locationFile = getBackupLocationFor(locationFile);
@@ -370,7 +390,7 @@ public void readPrivateDescription(IProject target, ProjectDescription descripti
 				}
 			} catch (Exception e) {
 				//don't allow failure to read the location to propagate
-				String msg = NLS.bind(Messages.resources_exReadProjectLocation, target.getName());
+				String msg = NLS.bind(Messages.resources_exReadProjectLocation, name);
 				Policy.log(new ResourceStatus(IStatus.ERROR, IResourceStatus.FAILED_READ_METADATA, target.getFullPath(), msg, e));
 			}
 			//try to read the dynamic references - will fail for old location files
@@ -408,6 +428,34 @@ public void readPrivateDescription(IProject target, ProjectDescription descripti
 				m.put(configName, refs);
 			}
 			description.setBuildConfigReferences(m);
+			// read parts since 3.23
+			description.setWorkspacePrivate(dataIn.readBoolean());
+			String[] natureIds = new String[dataIn.readInt()];
+			for (int i = 0; i < natureIds.length; i++) {
+				natureIds[i] = dataIn.readUTF();
+			}
+			description.setNatureIds(natureIds);
+			int buildspecs = dataIn.readInt();
+			ICommand[] buildSpecData = new ICommand[buildspecs];
+			for (int i = 0; i < buildSpecData.length; i++) {
+				BuildCommand command = new BuildCommand();
+				buildSpecData[i] = command;
+				int type = dataIn.read();
+				if (type == 1) {
+					command.setName(dataIn.readUTF());
+					int args = dataIn.readInt();
+					Map<String, String> map = new LinkedHashMap<>();
+					for (int j = 0; j < args; j++) {
+						map.put(dataIn.readUTF(), dataIn.readUTF());
+					}
+					command.setArguments(map);
+					String trigger = dataIn.readUTF();
+					if (!trigger.isEmpty()) {
+						ProjectDescriptionReader.parseBuildTriggers(command, trigger);
+					}
+				}
+				description.setBuildSpec(buildSpecData);
+			}
 		} catch (IOException e) {
 			//ignore - this is an old location file or an exception occurred
 			// closing the stream
@@ -470,6 +518,35 @@ public void writePrivateDescription(IProject target) throws CoreException {
 					}
 				}
 			}
+			// write parts since 3.23
+			dataOut.writeBoolean(desc.isWorkspacePrivate());
+			String[] natureIds = desc.getNatureIds();
+			dataOut.writeInt(natureIds.length);
+			for (String id : natureIds) {
+				dataOut.writeUTF(id);
+			}
+			ICommand[] buildSpec = desc.getBuildSpec(false);
+			dataOut.write(buildSpec.length);
+			for (ICommand command : buildSpec) {
+				if (command instanceof BuildCommand b) {
+					dataOut.write(1);
+					dataOut.writeUTF(b.getName());
+					Map<String, String> arguments = b.getArguments();
+					dataOut.writeInt(arguments.size());
+					for (Entry<String, String> entry : arguments.entrySet()) {
+						dataOut.writeUTF(entry.getKey());
+						dataOut.writeUTF(entry.getValue());
+					}
+					if (ModelObjectWriter.shouldWriteTriggers(b)) {
+						dataOut.writeUTF(ModelObjectWriter.triggerString(b));
+					} else {
+						dataOut.writeUTF(""); //$NON-NLS-1$
+					}
+				} else {
+					dataOut.write(0);
+				}
+			}
+			dataOut.flush();
 			output.succeed();
 		} catch (IOException e) {
 			String message = NLS.bind(Messages.resources_exSaveProjectLocation, target.getName());

resources/bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/resources/ModelObjectWriter.java

@@ -44,7 +44,7 @@ public class ModelObjectWriter implements IModelObjectConstants {
 	 * Returns the string representing the serialized set of build triggers for
 	 * the given command
 	 */
-	private static String triggerString(BuildCommand command) {
+	static String triggerString(BuildCommand command) {
 		StringBuilder buf = new StringBuilder();
 		if (command.isBuilding(IncrementalProjectBuilder.AUTO_BUILD))
 			buf.append(TRIGGER_AUTO).append(',');
@@ -83,7 +83,7 @@ protected void write(BuildCommand command, XMLWriter writer) {
 	/**
 	 * Returns whether the build triggers for this command should be written.
 	 */
-	private boolean shouldWriteTriggers(BuildCommand command) {
+	static boolean shouldWriteTriggers(BuildCommand command) {
 		//only write triggers if command is configurable and there exists a trigger
 		//that the builder does NOT respond to.  I.e., don't write out on the default
 		//cases to avoid dirtying .project files unnecessarily.

resources/bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/resources/Project.java

@@ -326,7 +326,7 @@ public void create(IProjectDescription description, int updateFlags, IProgressMo
 					updateDescription();
 					// make sure the .location file is written
 					workspace.getMetaArea().writePrivateDescription(this);
-				} else {
+				} else if (!desc.isWorkspacePrivate()) {
 					// write out the project
 					writeDescription(IResource.FORCE);
 				}

resources/bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/resources/ProjectDescription.java

@@ -29,6 +29,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
+import java.util.Objects;
 import java.util.Set;
 import org.eclipse.core.filesystem.URIUtil;
 import org.eclipse.core.internal.events.BuildCommand;
@@ -124,6 +125,7 @@ public class ProjectDescription extends ModelObject implements IProjectDescripti
 	protected URI location = null;
 	protected volatile String[] natures = EMPTY_STRING_ARRAY;
 	protected URI snapshotLocation = null;
+	private boolean privateFlag;
 
 	public ProjectDescription() {
 		super();
@@ -546,6 +548,14 @@ public boolean hasPrivateChanges(ProjectDescription description) {
 		// Configuration level references
 		if (configRefsHaveChanges(dynamicConfigRefs, description.dynamicConfigRefs))
 			return true;
+		// has natures changed?
+		if (!Set.of(natures).equals(Set.of(description.natures))) {
+			return true;
+		}
+		// has buildspec changed?
+		if (!Objects.deepEquals(buildSpec, description.buildSpec)) {
+			return true;
+		}
 
 		return false;
 	}
@@ -978,4 +988,14 @@ private static IProject[] computeDynamicReferencesForProject(IBuildConfiguration
 		}
 		return result.toArray(new IProject[0]);
 	}
+
+	@Override
+	public boolean isWorkspacePrivate() {
+		return privateFlag;
+	}
+
+	@Override
+	public void setWorkspacePrivate(boolean privateFlag) {
+		this.privateFlag = privateFlag;
+	}
 }

resources/bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/resources/ProjectDescriptionReader.java

@@ -233,26 +233,31 @@ private void endBuildTriggersElement(String elementName) {
 			state = S_BUILD_COMMAND;
 			BuildCommand command = (BuildCommand) objectStack.peek();
 			//presence of this element indicates the builder is configurable
+			String string = charBuffer.toString();
 			command.setConfigurable(true);
 			//clear all existing values
-			command.setBuilding(IncrementalProjectBuilder.AUTO_BUILD, false);
-			command.setBuilding(IncrementalProjectBuilder.CLEAN_BUILD, false);
-			command.setBuilding(IncrementalProjectBuilder.FULL_BUILD, false);
-			command.setBuilding(IncrementalProjectBuilder.INCREMENTAL_BUILD, false);
-
-			//set new values according to value in the triggers element
-			StringTokenizer tokens = new StringTokenizer(charBuffer.toString(), ","); //$NON-NLS-1$
-			while (tokens.hasMoreTokens()) {
-				String next = tokens.nextToken();
-				if (next.equalsIgnoreCase(TRIGGER_AUTO)) {
-					command.setBuilding(IncrementalProjectBuilder.AUTO_BUILD, true);
-				} else if (next.equalsIgnoreCase(TRIGGER_CLEAN)) {
-					command.setBuilding(IncrementalProjectBuilder.CLEAN_BUILD, true);
-				} else if (next.equalsIgnoreCase(TRIGGER_FULL)) {
-					command.setBuilding(IncrementalProjectBuilder.FULL_BUILD, true);
-				} else if (next.equalsIgnoreCase(TRIGGER_INCREMENTAL)) {
-					command.setBuilding(IncrementalProjectBuilder.INCREMENTAL_BUILD, true);
-				}
+			parseBuildTriggers(command, string);
+		}
+	}
+
+	static void parseBuildTriggers(BuildCommand command, String string) {
+		command.setBuilding(IncrementalProjectBuilder.AUTO_BUILD, false);
+		command.setBuilding(IncrementalProjectBuilder.CLEAN_BUILD, false);
+		command.setBuilding(IncrementalProjectBuilder.FULL_BUILD, false);
+		command.setBuilding(IncrementalProjectBuilder.INCREMENTAL_BUILD, false);
+
+		// set new values according to value in the triggers element
+		StringTokenizer tokens = new StringTokenizer(string, ","); //$NON-NLS-1$
+		while (tokens.hasMoreTokens()) {
+			String next = tokens.nextToken();
+			if (next.equalsIgnoreCase(TRIGGER_AUTO)) {
+				command.setBuilding(IncrementalProjectBuilder.AUTO_BUILD, true);
+			} else if (next.equalsIgnoreCase(TRIGGER_CLEAN)) {
+				command.setBuilding(IncrementalProjectBuilder.CLEAN_BUILD, true);
+			} else if (next.equalsIgnoreCase(TRIGGER_FULL)) {
+				command.setBuilding(IncrementalProjectBuilder.FULL_BUILD, true);
+			} else if (next.equalsIgnoreCase(TRIGGER_INCREMENTAL)) {
+				command.setBuilding(IncrementalProjectBuilder.INCREMENTAL_BUILD, true);
 			}
 		}
 	}

resources/bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/resources/SaveManager.java

@@ -1371,6 +1371,9 @@ protected void saveMetaInfo(MultiStatus problems, IProgressMonitor monitor) thro
 	 * @return Status object containing non-critical warnings, or an OK status.
 	 */
 	protected IStatus saveMetaInfo(Project project, IProgressMonitor monitor) throws CoreException {
+		if (project.internalGetDescription().isWorkspacePrivate()) {
+			return Status.OK_STATUS;
+		}
 		long start = System.currentTimeMillis();
 		//if there is nothing on disk, write the description
 		if (!workspace.getFileSystemManager().hasSavedDescription(project)) {

resources/bundles/org.eclipse.core.resources/src/org/eclipse/core/resources/IProjectDescription.java

@@ -175,6 +175,13 @@ public interface IProjectDescription {
 	 */
 	ICommand newCommand();
 
+	/**
+	 * @return <code>true</code> if this project is only persisted in the private
+	 *         workspace area
+	 * @since 3.23
+	 */
+	boolean isWorkspacePrivate();
+
 	/**
 	 * Sets the active configuration for the described project.
 	 * <p>
@@ -385,4 +392,12 @@ public interface IProjectDescription {
 	 * @see #getReferencedProjects()
 	 */
 	void setReferencedProjects(IProject[] projects);
+
+	/**
+	 * Sets the project to be only persisted into the private workspace area and not
+	 * into a physical <code>.project</code> file in the root of the project folder.
+	 *
+	 * @since 3.23
+	 */
+	void setWorkspacePrivate(boolean privateFlag);
 }