bundles/org.eclipse.team.cvs.core/src/org/eclipse/team/internal/ccvs/core/util/SyncFileWriter.java - gerrit/platform/eclipse.platform.team - Git at Google

 package org.eclipse.team.internal.ccvs.core.util;

 /*
  * (c) Copyright IBM Corp. 2000, 2001.
  * All Rights Reserved.
  */

 import java.io.BufferedReader;
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.InputStreamReader;
 import java.io.OutputStream;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.TreeMap;

 import org.eclipse.core.resources.IContainer;
 import org.eclipse.core.resources.IFile;
 import org.eclipse.core.resources.IFolder;
 import org.eclipse.core.resources.IResource;
 import org.eclipse.core.resources.IResourceChangeEvent;
 import org.eclipse.core.resources.IResourceChangeListener;
 import org.eclipse.core.resources.IResourceDelta;
 import org.eclipse.core.resources.IResourceDeltaVisitor;
 import org.eclipse.core.resources.IWorkspaceRunnable;
 import org.eclipse.core.resources.ResourcesPlugin;
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IPath;
 import org.eclipse.core.runtime.IProgressMonitor;
 import org.eclipse.core.runtime.Path;
 import org.eclipse.core.runtime.QualifiedName;
 import org.eclipse.team.internal.ccvs.core.CVSException;
 import org.eclipse.team.internal.ccvs.core.CVSProviderPlugin;
 import org.eclipse.team.internal.ccvs.core.CVSTag;
 import org.eclipse.team.internal.ccvs.core.Policy;
 import org.eclipse.team.internal.ccvs.core.resources.CVSEntryLineTag;
 import org.eclipse.team.internal.ccvs.core.resources.EclipseSynchronizer;
 import org.eclipse.team.internal.ccvs.core.syncinfo.FolderSyncInfo;
 import org.eclipse.team.internal.ccvs.core.syncinfo.ResourceSyncInfo;

 /*
  * This is a helper class that knows the format of the CVS metafiles. It
  * provides a bridge between the CVS metafile formats and location to the
  * Eclipse CVS client ResourceSyncInfo and FolderSyncInfo types.
  */
 public class SyncFileWriter {

 	// the famous CVS meta directory name
 	public static final String CVS_DIRNAME = "CVS"; //$NON-NLS-1$

 	// CVS meta files located in the CVS subdirectory
 	public static final String REPOSITORY = "Repository"; //$NON-NLS-1$
 	public static final String ROOT = "Root"; //$NON-NLS-1$
 	public static final String STATIC = "Entries.Static";	 //$NON-NLS-1$
 	public static final String TAG = "Tag";	 //$NON-NLS-1$
 	public static final String ENTRIES = "Entries"; //$NON-NLS-1$
 	//private static final String PERMISSIONS = "Permissions"; //$NON-NLS-1$
 	public static final String ENTRIES_LOG="Entries.Log"; //$NON-NLS-1$

 	// the local workspace file that contains pattern for ignored resources
 	public static final String IGNORE_FILE = ".cvsignore"; //$NON-NLS-1$

 	// Some older CVS clients may of added a line to the entries file consisting
 	// of only a 'D'. It is safe to ingnore these entries.
 	private static final String FOLDER_TAG="D"; //$NON-NLS-1$

 	// Command characters found in the Entries.log file
 	private static final String ADD_TAG="A "; //$NON-NLS-1$
 	private static final String REMOVE_TAG="R "; //$NON-NLS-1$

 	// file and folder patterns that are ignored by default by the CVS server on import.
 	public static final String[] PREDEFINED_IGNORE_PATTERNS = {
 		"CVS", ".#*", "#*", ",*", "_$*", "*~", "*$", "*.a", "*.bak", "*.BAK",  //$NON-NLS-1$  //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$ //$NON-NLS-5$ //$NON-NLS-6$ //$NON-NLS-7$ //$NON-NLS-8$ //$NON-NLS-9$ //$NON-NLS-10$
 		"*.elc", "*.exe", "*.ln", "*.o", "*.obj", "*.olb", "*.old", "*.orig", "*.rej", "*.so", //$NON-NLS-1$  //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$ //$NON-NLS-5$ //$NON-NLS-6$ //$NON-NLS-7$ //$NON-NLS-8$ //$NON-NLS-9$ //$NON-NLS-10$
 		"*.Z", ".del-*", ".make.state", ".nse_depinfo", "CVS.adm", //$NON-NLS-1$  //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$ //$NON-NLS-5$
 		"cvslog.*", "RCS", "RCSLOG", "SCCS", "tags", "TAGS"}; //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$ //$NON-NLS-5$ //$NON-NLS-6$

 	// file and folder patterns that are ignored by default by the CVS server on import.
 	public static final String[] BASIC_IGNORE_PATTERNS = {"CVS", ".#*"}; //$NON-NLS-1$ //$NON-NLS-2$

 	// key for saving the mod stamp for each writen meta file
 	public static final QualifiedName MODSTAMP_KEY = new QualifiedName("org.eclipse.team.cvs.core", "meta-file-modtime"); //$NON-NLS-1$ //$NON-NLS-2$

 	/**
 	 * Reads the CVS/Entries, CVS/Entries.log and CVS/Permissions files from the
 	 * specified folder and returns ResourceSyncInfo instances for the data stored therein.
 	 * If the folder does not have a CVS subdirectory then <code>null</code> is returned.
 	 */
 	public static ResourceSyncInfo[] readAllResourceSync(IContainer parent) throws CVSException {
 		IFolder cvsSubDir = getCVSSubdirectory(parent);
 		if (! cvsSubDir.exists()) return null;

 		// process Entries file contents
 		String[] entries = readLines(cvsSubDir.getFile(ENTRIES));
 		if (entries == null) return null;
 		Map infos = new TreeMap();
 		for (int i = 0; i < entries.length; i++) {
 			String line = entries[i];
 			if(!FOLDER_TAG.equals(line) && !"".equals(line)) { //$NON-NLS-1$
 				ResourceSyncInfo info = new ResourceSyncInfo(line, null, null);
 				infos.put(info.getName(), info);
 			}
 		}

 		// process Entries.log file contents
 		String[] entriesLog = readLines(cvsSubDir.getFile(ENTRIES_LOG));
 		if (entriesLog != null) {
 			for (int i = 0; i < entriesLog.length; i++) {
 				String line = entriesLog[i];
 				if (line.startsWith(ADD_TAG)) {
 					line = line.substring(ADD_TAG.length());
 					ResourceSyncInfo info = new ResourceSyncInfo(line, null, null);
 					infos.put(info.getName(), info);
 				} else if (line.startsWith(REMOVE_TAG)) {
 					line = line.substring(REMOVE_TAG.length());
 					ResourceSyncInfo info = new ResourceSyncInfo(line, null, null);
 					infos.remove(info.getName());
 				}
 			}
 		}

 		// XXX no longer processes CVS/Permissions (was never written) -- should we?

 		return (ResourceSyncInfo[])infos.values().toArray(new ResourceSyncInfo[infos.size()]);
 	}

 	/**
 	 * Writes the CVS/Entries, CVS/Entries.log and CVS/Permissions files to the
 	 * specified folder using the data contained in the specified ResourceSyncInfo instance.
 	 * If the folder does not have a CVS subdirectory then <code>null</code> is returned.
 	 */
 	public static void writeAllResourceSync(IContainer parent, ResourceSyncInfo[] infos) throws CVSException {
 		try {
 			IFolder cvsSubDir = createCVSSubdirectory(parent);

 			// format file contents
 			String[] entries = new String[infos.length];
 			for (int i = 0; i < infos.length; i++) {
 				ResourceSyncInfo info = infos[i];
 				entries[i] = info.getEntryLine();
 			}

 			// write Entries
 			writeLines(cvsSubDir.getFile(ENTRIES), entries);

 			// delete Entries.log
 			cvsSubDir.getFile(ENTRIES_LOG).delete(IResource.NONE, null);
 		} catch(CoreException e) {
 			throw CVSException.wrapException(e);
 		}
 	}

 	/**
 	 * Reads the CVS/Root, CVS/Repository, CVS/Tag, and CVS/Entries.static files from
 	 * the specified folder and returns a FolderSyncInfo instance for the data stored therein.
 	 * If the folder does not have a CVS subdirectory then <code>null</code> is returned.
 	 */
 	public static FolderSyncInfo readFolderSync(IContainer folder) throws CVSException {
 		IFolder cvsSubDir = getCVSSubdirectory(folder);
 		if (! cvsSubDir.exists()) return null;

 		// read CVS/Root
 		String root = readFirstLine(cvsSubDir.getFile(ROOT));
 		if (root == null) return null;

 		// read CVS/Repository
 		String repository = readFirstLine(cvsSubDir.getFile(REPOSITORY));
 		if (repository == null) return null;

 		// read CVS/Tag
 		String tag = readFirstLine(cvsSubDir.getFile(TAG));
 		CVSTag cvsTag = (tag != null) ? new CVSEntryLineTag(tag) : null;

 		// read Entries.Static
 		String staticDir = readFirstLine(cvsSubDir.getFile(STATIC));
 		boolean isStatic = (staticDir != null);

 		// return folder sync
 		return new FolderSyncInfo(repository, root, cvsTag, isStatic);
 	}

 	/**
 	 * Writes the CVS/Root, CVS/Repository, CVS/Tag, and CVS/Entries.static files to the
 	 * specified folder using the data contained in the specified FolderSyncInfo instance.
 	 */
 	public static void writeFolderSync(IContainer folder, FolderSyncInfo info) throws CVSException {
 		try {
 			IFolder cvsSubDir = createCVSSubdirectory(folder);

 			// write CVS/Root
 			writeLines(cvsSubDir.getFile(ROOT), new String[] {info.getRoot()});

 			// write CVS/Repository
 			writeLines(cvsSubDir.getFile(REPOSITORY), new String[] {info.getRepository()});

 			// write CVS/Tag
 			IFile tagFile = cvsSubDir.getFile(TAG);
 			if (info.getTag() != null) {
 				writeLines(tagFile, new String[] {info.getTag().toEntryLineFormat(false)});
 			} else {
 				if(tagFile.exists()) {
 					tagFile.delete(IResource.NONE, null);
 				}
 			}

 			// write CVS/Entries.Static
 			IFile staticFile = cvsSubDir.getFile(STATIC);
 			if(info.getIsStatic()) {
 				// the existance of the file is all that matters
 				writeLines(staticFile, new String[] {""}); //$NON-NLS-1$
 			} else {
 				if(staticFile.exists()) {
 					staticFile.delete(IResource.NONE, null);
 				}
 			}
 		} catch(CoreException e) {
 			throw CVSException.wrapException(e);
 		}
 	}

 	/**
 	 * Returns all .cvsignore entries for the specified folder.
 	 */
 	public static String[] readCVSIgnoreEntries(IContainer folder) throws CVSException {
 		IFile ignoreFile = folder.getFile(new Path(IGNORE_FILE));
 		if (ignoreFile != null) {
 			return readLines(ignoreFile);
 		}
 		return null;
 	}

 	/**
 	 * Writes all entries to the specified folder's .cvsignore file, overwriting any
 	 * previous edition of the file.
 	 */
 	public static void writeCVSIgnoreEntries(IContainer folder, String[] patterns) throws CVSException {
 		IFile ignoreFile = folder.getFile(new Path(IGNORE_FILE));
 		writeLines(ignoreFile, patterns);
 	}

 	/**
 	 * Delete folder sync is equilavent to removing the CVS subdir.
 	 */
 	public static void deleteFolderSync(IContainer folder) throws CVSException {
 		try {
 			getCVSSubdirectory(folder).delete(IResource.NONE, null);
 		} catch(CoreException e) {
 			throw CVSException.wrapException(e);
 		}
 	}

 	/**
 	 * Returns the CVS subdirectory for this folder.
 	 */
 	private static IFolder getCVSSubdirectory(IContainer folder) throws CVSException {
 		return folder.getFolder(new Path(CVS_DIRNAME));
 	}

 	/**
 	 * Creates and makes team-private and returns a CVS subdirectory in this folder.
 	 */
 	private static IFolder createCVSSubdirectory(IContainer folder) throws CVSException {
 		try {
 			final IFolder cvsSubDir = getCVSSubdirectory(folder);
 			if (! cvsSubDir.exists()) {
 				// important to have both the folder creation and setting of team-private in the
 				// same runnable so that the team-private flag is set before other delta listeners
 				// sees the CVS folder creation.
 				ResourcesPlugin.getWorkspace().run(new IWorkspaceRunnable() {
 					public void run(IProgressMonitor monitor) throws CoreException {
 						cvsSubDir.create(false /*don't force*/, true /*make local*/, null);
 						cvsSubDir.setTeamPrivateMember(true);
 					}
 				}, null);
 			}
 			return cvsSubDir;
 		} catch (CoreException e) {
 			throw CVSException.wrapException(e);
 		}
 	}

 	/*
 	 * Reads the first line of the specified file.
 	 * Returns null if the file does not exist, or the empty string if it is blank.
 	 */
 	private static String readFirstLine(IFile file) throws CVSException {
 		if (! file.exists()) return null;
 		try {
 			BufferedReader reader = new BufferedReader(new InputStreamReader(file.getContents()));
 			try {
 				String line = reader.readLine();
 				if (line == null) return ""; //$NON-NLS-1$
 				return line;
 			} finally {
 				reader.close();
 			}
 		} catch (IOException e) {
 			throw CVSException.wrapException(e);
 		} catch (CoreException e) {
 			throw CVSException.wrapException(e);
 		}
 	}

 	/*
 	 * Reads all lines of the specified file.
 	 * Returns null if the file does not exist.
 	 */
 	private static String[] readLines(IFile file) throws CVSException {
 		if (! file.exists()) return null;
 		try {
 			BufferedReader reader = new BufferedReader(new InputStreamReader(file.getContents()));
 			List fileContentStore = new ArrayList();
 			try {
 				String line;
 				while ((line = reader.readLine()) != null) {
 					fileContentStore.add(line);
 				}
 				return (String[]) fileContentStore.toArray(new String[fileContentStore.size()]);
 			} finally {
 				reader.close();
 			}
 		} catch (IOException e) {
 			throw CVSException.wrapException(e);
 		}  catch (CoreException e) {
 			throw CVSException.wrapException(e);
 		}
 	}

 	/*
 	 * Writes all lines to the specified file, using linefeed terminators for
 	 * compatibility with other CVS clients.
 	 */
 	private static void writeLines(final IFile file, final String[] contents) throws CVSException {
 		try {
 			// The creation of sync files has to be in a runnable in order for the resulting delta
 			// to include the MODSTAMP value. If not in a runnable then create/setContents
 			// will trigger a delta and the SyncFileWriter change listener won't know that the delta
 			// was a result of our own creation.
 			ResourcesPlugin.getWorkspace().run(new IWorkspaceRunnable() {
 				public void run(IProgressMonitor monitor) throws CoreException {
 					try {
 						ByteArrayOutputStream os = new ByteArrayOutputStream();
 						writeLinesToStreamAndClose(os, contents);
 						if(!file.exists()) {
 							file.create(new ByteArrayInputStream(os.toByteArray()), IResource.NONE /*don't keep history and don't force*/, null);
 						} else {
 							file.setContents(new ByteArrayInputStream(os.toByteArray()), IResource.NONE /*don't keep history and don't force*/, null);
 						}
 						file.setSessionProperty(MODSTAMP_KEY, new Long(file.getModificationStamp()));
 					} catch(CVSException e) {
 						throw new CoreException(e.getStatus());
 					}
 				}
 			}, null);
 		} catch (CoreException e) {
 			throw CVSException.wrapException(e);
 		}
 	}

 	private static void writeLinesToStreamAndClose(OutputStream os, String[] contents) throws CVSException {
 		try {
 			try {
 				for (int i = 0; i < contents.length; i++) {
 					os.write(contents[i].getBytes()); // XXX should we specify a character encoding?
 					os.write(0x0A); // newline byte
 				}
 			} finally {
 				os.close();
 			}
 		} catch (IOException e) {
 			throw CVSException.wrapException(e);
 		}
 	}
 }
	package org.eclipse.team.internal.ccvs.core.util;

	/*
	* (c) Copyright IBM Corp. 2000, 2001.
	* All Rights Reserved.
	*/

	import java.io.BufferedReader;
	import java.io.ByteArrayInputStream;
	import java.io.ByteArrayOutputStream;
	import java.io.IOException;
	import java.io.InputStreamReader;
	import java.io.OutputStream;
	import java.util.ArrayList;
	import java.util.List;
	import java.util.Map;
	import java.util.TreeMap;

	import org.eclipse.core.resources.IContainer;
	import org.eclipse.core.resources.IFile;
	import org.eclipse.core.resources.IFolder;
	import org.eclipse.core.resources.IResource;
	import org.eclipse.core.resources.IResourceChangeEvent;
	import org.eclipse.core.resources.IResourceChangeListener;
	import org.eclipse.core.resources.IResourceDelta;
	import org.eclipse.core.resources.IResourceDeltaVisitor;
	import org.eclipse.core.resources.IWorkspaceRunnable;
	import org.eclipse.core.resources.ResourcesPlugin;
	import org.eclipse.core.runtime.CoreException;
	import org.eclipse.core.runtime.IPath;
	import org.eclipse.core.runtime.IProgressMonitor;
	import org.eclipse.core.runtime.Path;
	import org.eclipse.core.runtime.QualifiedName;
	import org.eclipse.team.internal.ccvs.core.CVSException;
	import org.eclipse.team.internal.ccvs.core.CVSProviderPlugin;
	import org.eclipse.team.internal.ccvs.core.CVSTag;
	import org.eclipse.team.internal.ccvs.core.Policy;
	import org.eclipse.team.internal.ccvs.core.resources.CVSEntryLineTag;
	import org.eclipse.team.internal.ccvs.core.resources.EclipseSynchronizer;
	import org.eclipse.team.internal.ccvs.core.syncinfo.FolderSyncInfo;
	import org.eclipse.team.internal.ccvs.core.syncinfo.ResourceSyncInfo;

	/*
	* This is a helper class that knows the format of the CVS metafiles. It
	* provides a bridge between the CVS metafile formats and location to the
	* Eclipse CVS client ResourceSyncInfo and FolderSyncInfo types.
	*/
	public class SyncFileWriter {

	// the famous CVS meta directory name
	public static final String CVS_DIRNAME = "CVS"; //$NON-NLS-1$

	// CVS meta files located in the CVS subdirectory
	public static final String REPOSITORY = "Repository"; //$NON-NLS-1$
	public static final String ROOT = "Root"; //$NON-NLS-1$
	public static final String STATIC = "Entries.Static"; //$NON-NLS-1$
	public static final String TAG = "Tag"; //$NON-NLS-1$
	public static final String ENTRIES = "Entries"; //$NON-NLS-1$
	//private static final String PERMISSIONS = "Permissions"; //$NON-NLS-1$
	public static final String ENTRIES_LOG="Entries.Log"; //$NON-NLS-1$

	// the local workspace file that contains pattern for ignored resources
	public static final String IGNORE_FILE = ".cvsignore"; //$NON-NLS-1$

	// Some older CVS clients may of added a line to the entries file consisting
	// of only a 'D'. It is safe to ingnore these entries.
	private static final String FOLDER_TAG="D"; //$NON-NLS-1$

	// Command characters found in the Entries.log file
	private static final String ADD_TAG="A "; //$NON-NLS-1$
	private static final String REMOVE_TAG="R "; //$NON-NLS-1$

	// file and folder patterns that are ignored by default by the CVS server on import.
	public static final String[] PREDEFINED_IGNORE_PATTERNS = {
	"CVS", ".#", "#", ",", "_$", "~", "$", ".a", ".bak", "*.BAK", //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$ //$NON-NLS-5$ //$NON-NLS-6$ //$NON-NLS-7$ //$NON-NLS-8$ //$NON-NLS-9$ //$NON-NLS-10$
	".elc", ".exe", ".ln", ".o", ".obj", ".olb", ".old", ".orig", ".rej", ".so", //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$ //$NON-NLS-5$ //$NON-NLS-6$ //$NON-NLS-7$ //$NON-NLS-8$ //$NON-NLS-9$ //$NON-NLS-10$
	".Z", ".del-", ".make.state", ".nse_depinfo", "CVS.adm", //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$ //$NON-NLS-5$
	"cvslog.*", "RCS", "RCSLOG", "SCCS", "tags", "TAGS"}; //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$ //$NON-NLS-4$ //$NON-NLS-5$ //$NON-NLS-6$

	// file and folder patterns that are ignored by default by the CVS server on import.
	public static final String[] BASIC_IGNORE_PATTERNS = {"CVS", ".#*"}; //$NON-NLS-1$ //$NON-NLS-2$

	// key for saving the mod stamp for each writen meta file
	public static final QualifiedName MODSTAMP_KEY = new QualifiedName("org.eclipse.team.cvs.core", "meta-file-modtime"); //$NON-NLS-1$ //$NON-NLS-2$

	/**
	* Reads the CVS/Entries, CVS/Entries.log and CVS/Permissions files from the
	* specified folder and returns ResourceSyncInfo instances for the data stored therein.
	* If the folder does not have a CVS subdirectory then <code>null</code> is returned.
	*/
	public static ResourceSyncInfo[] readAllResourceSync(IContainer parent) throws CVSException {
	IFolder cvsSubDir = getCVSSubdirectory(parent);
	if (! cvsSubDir.exists()) return null;

	// process Entries file contents
	String[] entries = readLines(cvsSubDir.getFile(ENTRIES));
	if (entries == null) return null;
	Map infos = new TreeMap();
	for (int i = 0; i < entries.length; i++) {
	String line = entries[i];
	if(!FOLDER_TAG.equals(line) && !"".equals(line)) { //$NON-NLS-1$
	ResourceSyncInfo info = new ResourceSyncInfo(line, null, null);
	infos.put(info.getName(), info);
	}
	}

	// process Entries.log file contents
	String[] entriesLog = readLines(cvsSubDir.getFile(ENTRIES_LOG));
	if (entriesLog != null) {
	for (int i = 0; i < entriesLog.length; i++) {
	String line = entriesLog[i];
	if (line.startsWith(ADD_TAG)) {
	line = line.substring(ADD_TAG.length());
	ResourceSyncInfo info = new ResourceSyncInfo(line, null, null);
	infos.put(info.getName(), info);
	} else if (line.startsWith(REMOVE_TAG)) {
	line = line.substring(REMOVE_TAG.length());
	ResourceSyncInfo info = new ResourceSyncInfo(line, null, null);
	infos.remove(info.getName());
	}
	}
	}

	// XXX no longer processes CVS/Permissions (was never written) -- should we?

	return (ResourceSyncInfo[])infos.values().toArray(new ResourceSyncInfo[infos.size()]);
	}

	/**
	* Writes the CVS/Entries, CVS/Entries.log and CVS/Permissions files to the
	* specified folder using the data contained in the specified ResourceSyncInfo instance.
	* If the folder does not have a CVS subdirectory then <code>null</code> is returned.
	*/
	public static void writeAllResourceSync(IContainer parent, ResourceSyncInfo[] infos) throws CVSException {
	try {
	IFolder cvsSubDir = createCVSSubdirectory(parent);

	// format file contents
	String[] entries = new String[infos.length];
	for (int i = 0; i < infos.length; i++) {
	ResourceSyncInfo info = infos[i];
	entries[i] = info.getEntryLine();
	}

	// write Entries
	writeLines(cvsSubDir.getFile(ENTRIES), entries);

	// delete Entries.log
	cvsSubDir.getFile(ENTRIES_LOG).delete(IResource.NONE, null);
	} catch(CoreException e) {
	throw CVSException.wrapException(e);
	}
	}

	/**
	* Reads the CVS/Root, CVS/Repository, CVS/Tag, and CVS/Entries.static files from
	* the specified folder and returns a FolderSyncInfo instance for the data stored therein.
	* If the folder does not have a CVS subdirectory then <code>null</code> is returned.
	*/
	public static FolderSyncInfo readFolderSync(IContainer folder) throws CVSException {
	IFolder cvsSubDir = getCVSSubdirectory(folder);
	if (! cvsSubDir.exists()) return null;

	// read CVS/Root
	String root = readFirstLine(cvsSubDir.getFile(ROOT));
	if (root == null) return null;

	// read CVS/Repository
	String repository = readFirstLine(cvsSubDir.getFile(REPOSITORY));
	if (repository == null) return null;

	// read CVS/Tag
	String tag = readFirstLine(cvsSubDir.getFile(TAG));
	CVSTag cvsTag = (tag != null) ? new CVSEntryLineTag(tag) : null;

	// read Entries.Static
	String staticDir = readFirstLine(cvsSubDir.getFile(STATIC));
	boolean isStatic = (staticDir != null);

	// return folder sync
	return new FolderSyncInfo(repository, root, cvsTag, isStatic);
	}

	/**
	* Writes the CVS/Root, CVS/Repository, CVS/Tag, and CVS/Entries.static files to the
	* specified folder using the data contained in the specified FolderSyncInfo instance.
	*/
	public static void writeFolderSync(IContainer folder, FolderSyncInfo info) throws CVSException {
	try {
	IFolder cvsSubDir = createCVSSubdirectory(folder);

	// write CVS/Root
	writeLines(cvsSubDir.getFile(ROOT), new String[] {info.getRoot()});

	// write CVS/Repository
	writeLines(cvsSubDir.getFile(REPOSITORY), new String[] {info.getRepository()});

	// write CVS/Tag
	IFile tagFile = cvsSubDir.getFile(TAG);
	if (info.getTag() != null) {
	writeLines(tagFile, new String[] {info.getTag().toEntryLineFormat(false)});
	} else {
	if(tagFile.exists()) {
	tagFile.delete(IResource.NONE, null);
	}
	}

	// write CVS/Entries.Static
	IFile staticFile = cvsSubDir.getFile(STATIC);
	if(info.getIsStatic()) {
	// the existance of the file is all that matters
	writeLines(staticFile, new String[] {""}); //$NON-NLS-1$
	} else {
	if(staticFile.exists()) {
	staticFile.delete(IResource.NONE, null);
	}
	}
	} catch(CoreException e) {
	throw CVSException.wrapException(e);
	}
	}

	/**
	* Returns all .cvsignore entries for the specified folder.
	*/
	public static String[] readCVSIgnoreEntries(IContainer folder) throws CVSException {
	IFile ignoreFile = folder.getFile(new Path(IGNORE_FILE));
	if (ignoreFile != null) {
	return readLines(ignoreFile);
	}
	return null;
	}

	/**
	* Writes all entries to the specified folder's .cvsignore file, overwriting any
	* previous edition of the file.
	*/
	public static void writeCVSIgnoreEntries(IContainer folder, String[] patterns) throws CVSException {
	IFile ignoreFile = folder.getFile(new Path(IGNORE_FILE));
	writeLines(ignoreFile, patterns);
	}

	/**
	* Delete folder sync is equilavent to removing the CVS subdir.
	*/
	public static void deleteFolderSync(IContainer folder) throws CVSException {
	try {
	getCVSSubdirectory(folder).delete(IResource.NONE, null);
	} catch(CoreException e) {
	throw CVSException.wrapException(e);
	}
	}

	/**
	* Returns the CVS subdirectory for this folder.
	*/
	private static IFolder getCVSSubdirectory(IContainer folder) throws CVSException {
	return folder.getFolder(new Path(CVS_DIRNAME));
	}

	/**
	* Creates and makes team-private and returns a CVS subdirectory in this folder.
	*/
	private static IFolder createCVSSubdirectory(IContainer folder) throws CVSException {
	try {
	final IFolder cvsSubDir = getCVSSubdirectory(folder);
	if (! cvsSubDir.exists()) {
	// important to have both the folder creation and setting of team-private in the
	// same runnable so that the team-private flag is set before other delta listeners
	// sees the CVS folder creation.
	ResourcesPlugin.getWorkspace().run(new IWorkspaceRunnable() {
	public void run(IProgressMonitor monitor) throws CoreException {
	cvsSubDir.create(false /don't force/, true /make local/, null);
	cvsSubDir.setTeamPrivateMember(true);
	}
	}, null);
	}
	return cvsSubDir;
	} catch (CoreException e) {
	throw CVSException.wrapException(e);
	}
	}

	/*
	* Reads the first line of the specified file.
	* Returns null if the file does not exist, or the empty string if it is blank.
	*/
	private static String readFirstLine(IFile file) throws CVSException {
	if (! file.exists()) return null;
	try {
	BufferedReader reader = new BufferedReader(new InputStreamReader(file.getContents()));
	try {
	String line = reader.readLine();
	if (line == null) return ""; //$NON-NLS-1$
	return line;
	} finally {
	reader.close();
	}
	} catch (IOException e) {
	throw CVSException.wrapException(e);
	} catch (CoreException e) {
	throw CVSException.wrapException(e);
	}
	}

	/*
	* Reads all lines of the specified file.
	* Returns null if the file does not exist.
	*/
	private static String[] readLines(IFile file) throws CVSException {
	if (! file.exists()) return null;
	try {
	BufferedReader reader = new BufferedReader(new InputStreamReader(file.getContents()));
	List fileContentStore = new ArrayList();
	try {
	String line;
	while ((line = reader.readLine()) != null) {
	fileContentStore.add(line);
	}
	return (String[]) fileContentStore.toArray(new String[fileContentStore.size()]);
	} finally {
	reader.close();
	}
	} catch (IOException e) {
	throw CVSException.wrapException(e);
	} catch (CoreException e) {
	throw CVSException.wrapException(e);
	}
	}

	/*
	* Writes all lines to the specified file, using linefeed terminators for
	* compatibility with other CVS clients.
	*/
	private static void writeLines(final IFile file, final String[] contents) throws CVSException {
	try {
	// The creation of sync files has to be in a runnable in order for the resulting delta
	// to include the MODSTAMP value. If not in a runnable then create/setContents
	// will trigger a delta and the SyncFileWriter change listener won't know that the delta
	// was a result of our own creation.
	ResourcesPlugin.getWorkspace().run(new IWorkspaceRunnable() {
	public void run(IProgressMonitor monitor) throws CoreException {
	try {
	ByteArrayOutputStream os = new ByteArrayOutputStream();
	writeLinesToStreamAndClose(os, contents);
	if(!file.exists()) {
	file.create(new ByteArrayInputStream(os.toByteArray()), IResource.NONE /don't keep history and don't force/, null);
	} else {
	file.setContents(new ByteArrayInputStream(os.toByteArray()), IResource.NONE /don't keep history and don't force/, null);
	}
	file.setSessionProperty(MODSTAMP_KEY, new Long(file.getModificationStamp()));
	} catch(CVSException e) {
	throw new CoreException(e.getStatus());
	}
	}
	}, null);
	} catch (CoreException e) {
	throw CVSException.wrapException(e);
	}
	}

	private static void writeLinesToStreamAndClose(OutputStream os, String[] contents) throws CVSException {
	try {
	try {
	for (int i = 0; i < contents.length; i++) {
	os.write(contents[i].getBytes()); // XXX should we specify a character encoding?
	os.write(0x0A); // newline byte
	}
	} finally {
	os.close();
	}
	} catch (IOException e) {
	throw CVSException.wrapException(e);
	}
	}
	}