Copyright (c) 2000, 2015 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
    Baltasar Belyavsky (Texas Instruments) - [361675] Order mismatch when saving/restoring workspace trees
    Broadcom Corporation - ongoing development
    Lars Vogel  - Bug 473427
/*******************************************************************************
 * Copyright (c) 2000, 2015 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     Baltasar Belyavsky (Texas Instruments) - [361675] Order mismatch when saving/restoring workspace trees
 *     Broadcom Corporation - ongoing development
 *     Lars Vogel <Lars.Vogel@vogella.com> - Bug 473427
 *******************************************************************************/
package org.eclipse.core.internal.resources;

import java.io.DataInputStream;
import java.io.IOException;
import java.util.*;
import org.eclipse.core.internal.events.BuilderPersistentInfo;
import org.eclipse.core.internal.utils.Messages;
import org.eclipse.core.internal.utils.Policy;
import org.eclipse.core.internal.watson.ElementTree;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IResourceStatus;
import org.eclipse.core.runtime.*;

Reads version 2 of the workspace tree file format.
This version differs from version 1 in the amount of information that is persisted
for each builder. Version 1 only stored builder names and trees. Version
2 stores builder names, project names, trees, and interesting projects for
each builder.

Since 3.7 support has been added for persisting multiple delta trees for
multi-configuration builders.


To achieve backwards compatibility, the new additional information is
appended to the existing workspace tree file.  This allows the workspace
to be opened, and function, with older eclipse products.

/**
 * Reads version 2 of the workspace tree file format.
 *
 * This version differs from version 1 in the amount of information that is persisted
 * for each builder. Version 1 only stored builder names and trees. Version
 * 2 stores builder names, project names, trees, and interesting projects for
 * each builder.
 * <p>
 * Since 3.7 support has been added for persisting multiple delta trees for
 * multi-configuration builders.
 * </p>
 * <p>
 * To achieve backwards compatibility, the new additional information is
 * appended to the existing workspace tree file.  This allows the workspace
 * to be opened, and function, with older eclipse products.
 * </p>
 */
public class WorkspaceTreeReader_2 extends WorkspaceTreeReader_1 {

	private List<BuilderPersistentInfo> builderInfos;

	public WorkspaceTreeReader_2(Workspace workspace) {
		super(workspace);
	}

	@Override
	protected int getVersion() {
		return ICoreConstants.WORKSPACE_TREE_VERSION_2;
	}

	/*
	 * overwritten from WorkspaceTreeReader_1
	 */
	@Override
	protected void readBuildersPersistentInfo(IProject project, DataInputStream input, List<BuilderPersistentInfo> builders, IProgressMonitor monitor) throws IOException {
		monitor = Policy.monitorFor(monitor);
		try {
			int builderCount = input.readInt();
			for (int i = 0; i < builderCount; i++) {
				BuilderPersistentInfo info = readBuilderInfo(project, input, i);
				// read interesting projects
				int n = input.readInt();
				IProject[] projects = new IProject[n];
				for (int j = 0; j < n; j++)
					projects[j] = workspace.getRoot().getProject(input.readUTF());
				info.setInterestingProjects(projects);
				builders.add(info);
			}
		} finally {
			monitor.done();
		}
	}

	
Read a workspace tree storing information about multiple projects. Overrides WorkspaceTreeReader_1.readTree(DataInputStream, IProgressMonitor) /**
	 * Read a workspace tree storing information about multiple projects.
	 * Overrides {@link WorkspaceTreeReader_1#readTree(DataInputStream, IProgressMonitor)}
	 */
	@Override
	public void readTree(DataInputStream input, IProgressMonitor monitor) throws CoreException {
		monitor = Policy.monitorFor(monitor);
		String message;
		try {
			message = Messages.resources_reading;
			monitor.beginTask(message, Policy.totalWork);

			builderInfos = new ArrayList<>(20);

			// Read the version 2 part of the file, but don't set the builder info in
			// the projects. Store it in builderInfos instead.
			readWorkspaceFields(input, Policy.subMonitorFor(monitor, Policy.opWork * 20 / 100));

			HashMap<String, SavedState> savedStates = new HashMap<>(20);
			List<SavedState> pluginsToBeLinked = new ArrayList<>(20);
			readPluginsSavedStates(input, savedStates, pluginsToBeLinked, Policy.subMonitorFor(monitor, Policy.opWork * 10 / 100));
			workspace.getSaveManager().setPluginsSavedState(savedStates);

			int treeIndex = pluginsToBeLinked.size();

			List<BuilderPersistentInfo> buildersToBeLinked = new ArrayList<>(20);
			readBuildersPersistentInfo(null, input, buildersToBeLinked, Policy.subMonitorFor(monitor, Policy.opWork * 10 / 100));

			final ElementTree[] trees = readTrees(Path.ROOT, input, Policy.subMonitorFor(monitor, Policy.opWork * 40 / 100));
			linkPluginsSavedStateToTrees(pluginsToBeLinked, trees, Policy.subMonitorFor(monitor, Policy.opWork * 10 / 100));
			linkBuildersToTrees(buildersToBeLinked, trees, treeIndex, Policy.subMonitorFor(monitor, Policy.opWork * 10 / 100));

			// Since 3.7: Read the per-configuration trees if available
			if (input.available() > 0) {
				treeIndex += buildersToBeLinked.size();

				buildersToBeLinked.clear();
				readBuildersPersistentInfo(null, input, buildersToBeLinked, Policy.subMonitorFor(monitor, Policy.opWork * 10 / 100));
				linkBuildersToTrees(buildersToBeLinked, trees, treeIndex, Policy.subMonitorFor(monitor, Policy.opWork * 10 / 100));

				for (BuilderPersistentInfo builderPersistentInfo : builderInfos)
					builderPersistentInfo.setConfigName(input.readUTF());
			}

			// Set the builder infos on the projects
			setBuilderInfos(builderInfos);

		} catch (IOException e) {
			message = Messages.resources_readProjectTree;
			throw new ResourceException(IResourceStatus.FAILED_READ_METADATA, null, message, e);
		} finally {
			monitor.done();
		}
	}

	
Read a workspace tree storing information about a single project. Overrides readTree(IProject, DataInputStream, IProgressMonitor) /**
	 * Read a workspace tree storing information about a single project.
	 * Overrides {@link WorkspaceTreeReader_2#readTree(IProject, DataInputStream, IProgressMonitor)}
	 */
	@Override
	public void readTree(IProject project, DataInputStream input, IProgressMonitor monitor) throws CoreException {
		monitor = Policy.monitorFor(monitor);
		String message;
		try {
			message = Messages.resources_reading;
			monitor.beginTask(message, 10);

			builderInfos = new ArrayList<>(20);

			// Read the version 2 part of the file, but don't set the builder info in
			// the projects. It is stored in builderInfos instead.

			int treeIndex = 0;

			List<BuilderPersistentInfo> buildersToBeLinked = new ArrayList<>(20);
			readBuildersPersistentInfo(project, input, buildersToBeLinked, Policy.subMonitorFor(monitor, 1));

			ElementTree[] trees = readTrees(project.getFullPath(), input, Policy.subMonitorFor(monitor, 8));
			linkBuildersToTrees(buildersToBeLinked, trees, treeIndex, Policy.subMonitorFor(monitor, 1));

			// Since 3.7: Read the additional builder information
			if (input.available() > 0) {
				treeIndex += buildersToBeLinked.size();

				List<BuilderPersistentInfo> infos = new ArrayList<>(5);
				readBuildersPersistentInfo(project, input, infos, Policy.subMonitorFor(monitor, 1));
				linkBuildersToTrees(infos, trees, treeIndex, Policy.subMonitorFor(monitor, 1));

				for (BuilderPersistentInfo builderPersistentInfo : builderInfos)
					builderPersistentInfo.setConfigName(input.readUTF());
			}

			// Set the builder info on the projects
			setBuilderInfos(builderInfos);

		} catch (IOException e) {
			message = Messages.resources_readProjectTree;
			throw new ResourceException(IResourceStatus.FAILED_READ_METADATA, null, message, e);
		} finally {
			monitor.done();
		}
	}

	
This implementation allows pre-3.7 version 2 and post-3.7 version 2 information to be loaded in separate passes. Links trees with the given builders, but does not add them to the projects. Overrides WorkspaceTreeReader_1.linkBuildersToTrees(List<BuilderPersistentInfo>, ElementTree[], int, IProgressMonitor) /**
	 * This implementation allows pre-3.7 version 2 and post-3.7 version 2 information to be loaded in separate passes.
	 * Links trees with the given builders, but does not add them to the projects.
	 * Overrides {@link WorkspaceTreeReader_1#linkBuildersToTrees(List, ElementTree[], int, IProgressMonitor)}
	 */
	@Override
	protected void linkBuildersToTrees(List<BuilderPersistentInfo> buildersToBeLinked, ElementTree[] trees, int index, IProgressMonitor monitor) {
		monitor = Policy.monitorFor(monitor);
		try {
			for (int i = 0; i < buildersToBeLinked.size(); i++) {
				BuilderPersistentInfo info = buildersToBeLinked.get(i);
				info.setLastBuildTree(trees[index++]);
				builderInfos.add(info);
			}
		} finally {
			monitor.done();
		}
	}

	
Given a list of builder infos, group them by project and set them on the project.
/**
	 * Given a list of builder infos, group them by project and set them on the project.
	 */
	private void setBuilderInfos(List<BuilderPersistentInfo> infos) {
		Map<String, List<BuilderPersistentInfo>> groupedInfos = new HashMap<>();
		for (BuilderPersistentInfo info : infos) {
			if (!groupedInfos.containsKey(info.getProjectName()))
				groupedInfos.put(info.getProjectName(), new ArrayList<>());
			groupedInfos.get(info.getProjectName()).add(info);
		}
		for (Map.Entry<String, List<BuilderPersistentInfo>> entry : groupedInfos.entrySet()) {
			IProject proj = workspace.getRoot().getProject(entry.getKey());
			workspace.getBuildManager().setBuildersPersistentInfo(proj, entry.getValue());
		}
	}

}