コード例 #1
0
ファイル: FileStateTests.cs プロジェクト: cameron314/msbuild
        public void ReadOnlyReset()
        {
            string file = null;

            try
            {
                file = FileUtilities.GetTemporaryFile();
                FileInfo info = new FileInfo(file);
                FileState state = new FileState(file);

                Assert.Equal(info.IsReadOnly, state.IsReadOnly);
                info.IsReadOnly = !info.IsReadOnly;
                state.Reset();
                Assert.Equal(true, state.IsReadOnly);
            }
            finally
            {
                (new FileInfo(file)).IsReadOnly = false;
                File.Delete(file);
            }
        }
コード例 #2
0
ファイル: FileStateTests.cs プロジェクト: cameron314/msbuild
        public void LastWriteTimeUtcReset()
        {
            string file = null;

            try
            {
                file = FileUtilities.GetTemporaryFile();
                FileInfo info = new FileInfo(file);
                FileState state = new FileState(file);

                Assert.Equal(info.LastWriteTimeUtc, state.LastWriteTimeUtcFast);

                var time = new DateTime(2111, 1, 1);
                info.LastWriteTime = time;

                Assert.NotEqual(time.ToUniversalTime(), state.LastWriteTimeUtcFast);
                state.Reset();
                Assert.Equal(time.ToUniversalTime(), state.LastWriteTimeUtcFast);
            }
            finally
            {
                File.Delete(file);
            }
        }
コード例 #3
0
ファイル: FileStateTests.cs プロジェクト: cameron314/msbuild
        public void LengthReset()
        {
            string file = null;

            try
            {
                file = FileUtilities.GetTemporaryFile();
                FileInfo info = new FileInfo(file);
                FileState state = new FileState(file);

                Assert.Equal(info.Length, state.Length);
                File.WriteAllText(file, "x");

                Assert.Equal(info.Length, state.Length);
                state.Reset();
                info.Refresh();
                Assert.Equal(info.Length, state.Length);
            }
            finally
            {
                File.Delete(file);
            }
        }
コード例 #4
0
ファイル: FileStateTests.cs プロジェクト: cameron314/msbuild
        public void ExistsReset()
        {
            string file = null;

            try
            {
                file = FileUtilities.GetTemporaryFile();
                FileInfo info = new FileInfo(file);
                FileState state = new FileState(file);

                Assert.Equal(info.Exists, state.FileExists);
                File.Delete(file);
                Assert.Equal(true, state.FileExists);
                state.Reset();
                Assert.Equal(false, state.FileExists);
            }
            finally
            {
                if (File.Exists(file))
                {
                    File.Delete(file);
                }
            }
        }
コード例 #5
0
ファイル: FileStateTests.cs プロジェクト: cameron314/msbuild
        public void NameReset()
        {
            string file = null;

            try
            {
                file = FileUtilities.GetTemporaryFile();
                FileInfo info = new FileInfo(file);
                FileState state = new FileState(file);

                Assert.Equal(info.FullName, state.Name);
                string originalName = info.FullName;
                string oldFile = file;
                file = oldFile + "2";
                File.Move(oldFile, file);
                Assert.Equal(originalName, state.Name);
                state.Reset();
                Assert.Equal(originalName, state.Name); // Name is from the constructor, didn't change
            }
            finally
            {
                File.Delete(file);
            }
        }
コード例 #6
0
        /// <summary>
        /// Copy one file from source to destination. Create the target directory if necessary and
        /// leave the file read-write.
        /// </summary>
        /// <returns>Return true to indicate success, return false to indicate failure and NO retry, return NULL to indicate retry.</returns>
        private bool?CopyFileWithLogging
        (
            FileState sourceFileState,      // The source file
            FileState destinationFileState  // The destination file
        )
        {
            bool destinationFileExists = false;

            if (destinationFileState.DirectoryExists)
            {
                Log.LogErrorWithCodeFromResources("Copy.DestinationIsDirectory", sourceFileState.Name, destinationFileState.Name);
                return(false);
            }

            if (sourceFileState.DirectoryExists)
            {
                // If the source file passed in is actually a directory instead of a file, log a nice
                // error telling the user so.  Otherwise, .NET Framework's File.Copy method will throw
                // an UnauthorizedAccessException saying "access is denied", which is not very useful
                // to the user.
                Log.LogErrorWithCodeFromResources("Copy.SourceIsDirectory", sourceFileState.Name);
                return(false);
            }

            if (!sourceFileState.FileExists)
            {
                Log.LogErrorWithCodeFromResources("Copy.SourceFileNotFound", sourceFileState.Name);
                return(false);
            }

            string destinationFolder = Path.GetDirectoryName(destinationFileState.Name);

            if (!string.IsNullOrEmpty(destinationFolder) && !_directoriesKnownToExist.ContainsKey(destinationFolder))
            {
                if (!FileSystems.Default.DirectoryExists(destinationFolder))
                {
                    Log.LogMessageFromResources(MessageImportance.Normal, "Copy.CreatesDirectory", destinationFolder);
                    Directory.CreateDirectory(destinationFolder);
                }

                // It's very common for a lot of files to be copied to the same folder.
                // Eg., "c:\foo\a"->"c:\bar\a", "c:\foo\b"->"c:\bar\b" and so forth.
                // We don't want to check whether this folder exists for every single file we copy. So store which we've checked.
                _directoriesKnownToExist.TryAdd(destinationFolder, true);
            }

            if (OverwriteReadOnlyFiles)
            {
                MakeFileWriteable(destinationFileState, true);
                destinationFileExists = destinationFileState.FileExists;
            }

            bool   linkCreated  = false;
            string errorMessage = string.Empty;

            // If we want to create hard or symbolic links, then try that first
            if (UseHardlinksIfPossible)
            {
                TryCopyViaLink("Copy.HardLinkComment", MessageImportance.Normal, sourceFileState, destinationFileState, ref destinationFileExists, out linkCreated, ref errorMessage, (source, destination, errMessage) => NativeMethods.MakeHardLink(destination, source, ref errorMessage));
            }
            else if (UseSymboliclinksIfPossible)
            {
                TryCopyViaLink("Copy.SymbolicLinkComment", MessageImportance.Normal, sourceFileState, destinationFileState, ref destinationFileExists, out linkCreated, ref errorMessage, (source, destination, errMessage) => NativeMethods.MakeSymbolicLink(destination, source, ref errorMessage));
            }

            // If the link was not created (either because the user didn't want one, or because it couldn't be created)
            // then let's copy the file
            if (!linkCreated)
            {
                // Do not log a fake command line as well, as it's superfluous, and also potentially expensive
                string sourceFilePath      = FileUtilities.GetFullPathNoThrow(sourceFileState.Name);
                string destinationFilePath = FileUtilities.GetFullPathNoThrow(destinationFileState.Name);
                Log.LogMessageFromResources(MessageImportance.Normal, "Copy.FileComment", sourceFilePath, destinationFilePath);

                File.Copy(sourceFileState.Name, destinationFileState.Name, true);
            }

            destinationFileState.Reset();

            // If the destinationFile file exists, then make sure it's read-write.
            // The File.Copy command copies attributes, but our copy needs to
            // leave the file writeable.
            if (sourceFileState.IsReadOnly)
            {
                MakeFileWriteable(destinationFileState, false);
            }

            return(true);
        }
コード例 #7
0
        /// <summary>
        /// Copy one file with the appropriate number of retries if it fails.
        /// </summary>
        private bool DoCopyWithRetries(FileState sourceFileState, FileState destinationFileState, CopyFileWithState copyFile)
        {
            int retries = 0;

            while (!_cancellationTokenSource.IsCancellationRequested)
            {
                try
                {
                    bool?result = copyFile(sourceFileState, destinationFileState);
                    if (result.HasValue)
                    {
                        return(result.Value);
                    }
                }
                catch (OperationCanceledException)
                {
                    break;
                }
                catch (Exception e) when(ExceptionHandling.IsIoRelatedException(e))
                {
                    if (e is ArgumentException ||     // Invalid chars
                        e is NotSupportedException || // Colon in the middle of the path
                        e is PathTooLongException)
                    {
                        // No use retrying these cases
                        throw;
                    }

                    if (e is UnauthorizedAccessException || e is IOException) // Not clear why we can get one and not the other
                    {
                        int code = Marshal.GetHRForException(e);

                        LogDiagnostic("Got {0} copying {1} to {2} and HR is {3}", e.ToString(), sourceFileState.Name, destinationFileState.Name, code);
                        if (code == NativeMethods.ERROR_ACCESS_DENIED)
                        {
                            // ERROR_ACCESS_DENIED can either mean there's an ACL preventing us, or the file has the readonly bit set.
                            // In either case, that's likely not a race, and retrying won't help.
                            // Retrying is mainly for ERROR_SHARING_VIOLATION, where someone else is using the file right now.
                            // However, there is a limited set of circumstances where a copy failure will show up as access denied due
                            // to a failure to reset the readonly bit properly, in which case retrying will succeed.  This seems to be
                            // a pretty edge scenario, but since some of our internal builds appear to be hitting it, provide a secret
                            // environment variable to allow overriding the default behavior and forcing retries in this circumstance as well.
                            if (!s_alwaysRetryCopy)
                            {
                                throw;
                            }
                            else
                            {
                                LogDiagnostic("Retrying on ERROR_ACCESS_DENIED because MSBUILDALWAYSRETRY = 1");
                            }
                        }
                    }

                    if (e is IOException && DestinationFolder != null && FileSystems.Default.FileExists(DestinationFolder.ItemSpec))
                    {
                        // We failed to create the DestinationFolder because it's an existing file. No sense retrying.
                        // We don't check for this case upstream because it'd be another hit to the filesystem.
                        throw;
                    }

                    if (e is IOException)
                    {
                        // if this was just because the source and destination files are the
                        // same file, that's not a failure.
                        // Note -- we check this exceptional case here, not before the copy, for perf.
                        if (PathsAreIdentical(sourceFileState.Name, destinationFileState.Name))
                        {
                            return(true);
                        }
                    }

                    if (retries < Retries)
                    {
                        retries++;
                        Log.LogWarningWithCodeFromResources("Copy.Retrying", sourceFileState.Name,
                                                            destinationFileState.Name, retries, RetryDelayMilliseconds, e.Message,
                                                            GetLockedFileMessage(destinationFileState.Name));

                        // if we have to retry for some reason, wipe the state -- it may not be correct anymore.
                        destinationFileState.Reset();

                        Thread.Sleep(RetryDelayMilliseconds);
                        continue;
                    }
                    else if (Retries > 0)
                    {
                        // Exception message is logged in caller
                        Log.LogErrorWithCodeFromResources("Copy.ExceededRetries", sourceFileState.Name,
                                                          destinationFileState.Name, Retries, GetLockedFileMessage(destinationFileState.Name));
                        throw;
                    }
                    else
                    {
                        throw;
                    }
                }

                if (retries < Retries)
                {
                    retries++;
                    Log.LogWarningWithCodeFromResources("Copy.Retrying", sourceFileState.Name,
                                                        destinationFileState.Name, retries, RetryDelayMilliseconds, String.Empty /* no details */,
                                                        GetLockedFileMessage(destinationFileState.Name));

                    // if we have to retry for some reason, wipe the state -- it may not be correct anymore.
                    destinationFileState.Reset();

                    Thread.Sleep(RetryDelayMilliseconds);
                }
                else if (Retries > 0)
                {
                    Log.LogErrorWithCodeFromResources("Copy.ExceededRetries", sourceFileState.Name,
                                                      destinationFileState.Name, Retries, GetLockedFileMessage(destinationFileState.Name));
                    return(false);
                }
                else
                {
                    return(false);
                }
            }

            // Canceling
            return(false);
        }
コード例 #8
0
ファイル: Copy.cs プロジェクト: nikson/msbuild
        /// <summary>
        /// Copy one file with the appropriate number of retries if it fails.
        /// </summary>
        private bool DoCopyWithRetries(FileState sourceFileState, FileState destinationFileState, CopyFileWithState copyFile)
        {
            bool? result = null;
            int retries = 0;

            while (true && !_canceling)
            {
                try
                {
                    result = copyFile(sourceFileState, destinationFileState);
                    if (result.HasValue)
                    {
                        return result.Value;
                    }
                }
                catch (Exception e) when (ExceptionHandling.IsIoRelatedException(e))
                {
                    if (e is ArgumentException ||  // Invalid chars
                        e is NotSupportedException || // Colon in the middle of the path
                        e is PathTooLongException)
                    {
                        // No use retrying these cases
                        throw;
                    }

                    if (e is UnauthorizedAccessException || e is IOException) // Not clear why we can get one and not the other
                    {
                        int code = Marshal.GetHRForException(e);

                        LogDiagnostic("Got {0} copying {1} to {2} and HR is {3}", e.ToString(), sourceFileState.Name, destinationFileState.Name, code);
                        if (code == Microsoft.Build.Tasks.NativeMethods.ERROR_ACCESS_DENIED)
                        {
                            // ERROR_ACCESS_DENIED can either mean there's an ACL preventing us, or the file has the readonly bit set.
                            // In either case, that's likely not a race, and retrying won't help.
                            // Retrying is mainly for ERROR_SHARING_VIOLATION, where someone else is using the file right now.
                            // However, there is a limited set of circumstances where a copy failure will show up as access denied due 
                            // to a failure to reset the readonly bit properly, in which case retrying will succeed.  This seems to be 
                            // a pretty edge scenario, but since some of our internal builds appear to be hitting it, provide a secret
                            // environment variable to allow overriding the default behavior and forcing retries in this circumstance as well. 
                            if (!s_alwaysRetryCopy)
                            {
                                throw;
                            }
                            else
                            {
                                LogDiagnostic("Retrying on ERROR_ACCESS_DENIED because MSBUILDALWAYSRETRY = 1");
                            }
                        }
                    }

                    if (e is IOException && DestinationFolder != null && File.Exists(DestinationFolder.ItemSpec))
                    {
                        // We failed to create the DestinationFolder because it's an existing file. No sense retrying.
                        // We don't check for this case upstream because it'd be another hit to the filesystem.
                        throw;
                    }

                    if (e is IOException)
                    {
                        // if this was just because the source and destination files are the
                        // same file, that's not a failure.
                        // Note -- we check this exceptional case here, not before the copy, for perf.
                        if (PathsAreIdentical(sourceFileState.Name, destinationFileState.Name))
                        {
                            return true;
                        }
                    }

                    if (retries < Retries)
                    {
                        retries++;
                        Log.LogWarningWithCodeFromResources("Copy.Retrying", sourceFileState.Name, destinationFileState.Name, retries, RetryDelayMilliseconds, e.Message);

                        // if we have to retry for some reason, wipe the state -- it may not be correct anymore. 
                        destinationFileState.Reset();

                        Thread.Sleep(RetryDelayMilliseconds);
                        continue;
                    }
                    else if (Retries > 0)
                    {
                        // Exception message is logged in caller
                        Log.LogErrorWithCodeFromResources("Copy.ExceededRetries", sourceFileState.Name, destinationFileState.Name, Retries);
                        throw;
                    }
                    else
                    {
                        throw;
                    }
                }

                if (retries < Retries)
                {
                    retries++;
                    Log.LogWarningWithCodeFromResources("Copy.Retrying", sourceFileState.Name, destinationFileState.Name, retries, RetryDelayMilliseconds, String.Empty /* no details */);

                    // if we have to retry for some reason, wipe the state -- it may not be correct anymore. 
                    destinationFileState.Reset();

                    Thread.Sleep(RetryDelayMilliseconds);
                }
                else if (Retries > 0)
                {
                    Log.LogErrorWithCodeFromResources("Copy.ExceededRetries", sourceFileState.Name, destinationFileState.Name, Retries);
                    return false;
                }
                else
                {
                    return false;
                }
            }

            // Canceling
            return false;
        }
コード例 #9
0
ファイル: Copy.cs プロジェクト: nikson/msbuild
        /// <summary>
        /// Ensure the read-only attribute on the specified file is off, so
        /// the file is writeable.
        /// </summary>
        private void MakeFileWriteable(FileState file, bool logActivity)
        {
            if (file.FileExists)
            {
                if (file.IsReadOnly)
                {
                    if (logActivity)
                    {
                        Log.LogMessageFromResources(MessageImportance.Low, "Copy.RemovingReadOnlyAttribute", file.Name);
                    }

                    File.SetAttributes(file.Name, FileAttributes.Normal);
                    file.Reset();
                }
            }
        }
コード例 #10
0
ファイル: Copy.cs プロジェクト: nikson/msbuild
        /// <summary>
        /// Copy one file from source to destination. Create the target directory if necessary and 
        /// leave the file read-write.
        /// </summary>
        /// <param name="sourceFile"></param>
        /// <param name="destinationFile"></param>
        /// <returns>Return true to indicate success, return false to indicate failure and NO retry, return NULL to indicate retry.</returns>
        private bool? CopyFileWithLogging
        (
            FileState sourceFileState,      // The source file
            FileState destinationFileState  // The destination file
        )
        {
            bool destinationFileExists = false;

            if (destinationFileState.DirectoryExists)
            {
                Log.LogErrorWithCodeFromResources("Copy.DestinationIsDirectory", sourceFileState.Name, destinationFileState.Name);
                return false;
            }

            if (sourceFileState.DirectoryExists)
            {
                // If the source file passed in is actually a directory instead of a file, log a nice
                // error telling the user so.  Otherwise, .NET Framework's File.Copy method will throw
                // an UnauthorizedAccessException saying "access is denied", which is not very useful
                // to the user.
                Log.LogErrorWithCodeFromResources("Copy.SourceIsDirectory", sourceFileState.Name);
                return false;
            }

            if (!sourceFileState.FileExists)
            {
                Log.LogErrorWithCodeFromResources("Copy.SourceFileNotFound", sourceFileState.Name);
                return false;
            }

            string destinationFolder = Path.GetDirectoryName(destinationFileState.Name);

            if (destinationFolder != null && destinationFolder.Length > 0 && !_directoriesKnownToExist.Contains(destinationFolder))
            {
                if (!Directory.Exists(destinationFolder))
                {
                    Log.LogMessageFromResources(MessageImportance.Normal, "Copy.CreatesDirectory", destinationFolder);
                    Directory.CreateDirectory(destinationFolder);
                }

                // It's very common for a lot of files to be copied to the same folder. 
                // Eg., "c:\foo\a"->"c:\bar\a", "c:\foo\b"->"c:\bar\b" and so forth.
                // We don't want to check whether this folder exists for every single file we copy. So store which we've checked.
                _directoriesKnownToExist.Add(destinationFolder);
            }

            if (_overwriteReadOnlyFiles)
            {
                MakeFileWriteable(destinationFileState, true);
                destinationFileExists = destinationFileState.FileExists;
            }

            bool linkCreated = false;

            // If we want to create hard or symbolic links, then try that first
            if (UseHardlinksIfPossible)
                TryCopyViaLink("Copy.HardLinkComment", MessageImportance.High, sourceFileState, destinationFileState, ref destinationFileExists, ref linkCreated, (source, destination) => NativeMethods.CreateHardLink(destination, source, IntPtr.Zero /* reserved, must be NULL */));
            else if (UseSymboliclinksIfPossible)
                TryCopyViaLink("Copy.SymbolicLinkComment", MessageImportance.High, sourceFileState, destinationFileState, ref destinationFileExists, ref linkCreated, (source, destination) => NativeMethods.CreateSymbolicLink(destination, source, SymbolicLink.File));

            // If the link was not created (either because the user didn't want one, or because it couldn't be created)
            // then let's copy the file
            if (!linkCreated)
            {
                // Do not log a fake command line as well, as it's superfluous, and also potentially expensive
                Log.LogMessageFromResources(MessageImportance.Normal, "Copy.FileComment", sourceFileState.Name, destinationFileState.Name);
                File.Copy(sourceFileState.Name, destinationFileState.Name, true);
            }

            destinationFileState.Reset();

            // If the destinationFile file exists, then make sure it's read-write.
            // The File.Copy command copies attributes, but our copy needs to
            // leave the file writeable.
            if (sourceFileState.IsReadOnly)
            {
                MakeFileWriteable(destinationFileState, false);
            }

            return true;
        }
コード例 #11
0
ファイル: Copy.cs プロジェクト: simonthum/msbuild
        /// <summary>
        /// Copy one file from source to destination. Create the target directory if necessary and
        /// leave the file read-write.
        /// </summary>
        /// <param name="sourceFile"></param>
        /// <param name="destinationFile"></param>
        /// <returns>Return true to indicate success, return false to indicate failure and NO retry, return NULL to indicate retry.</returns>
        private bool?CopyFileWithLogging
        (
            FileState sourceFileState,      // The source file
            FileState destinationFileState  // The destination file
        )
        {
            bool destinationFileExists = false;

            if (destinationFileState.DirectoryExists)
            {
                Log.LogErrorWithCodeFromResources("Copy.DestinationIsDirectory", sourceFileState.Name, destinationFileState.Name);
                return(false);
            }

            if (sourceFileState.DirectoryExists)
            {
                // If the source file passed in is actually a directory instead of a file, log a nice
                // error telling the user so.  Otherwise, .NET Framework's File.Copy method will throw
                // an UnauthorizedAccessException saying "access is denied", which is not very useful
                // to the user.
                Log.LogErrorWithCodeFromResources("Copy.SourceIsDirectory", sourceFileState.Name);
                return(false);
            }

            if (!sourceFileState.FileExists)
            {
                Log.LogErrorWithCodeFromResources("Copy.SourceFileNotFound", sourceFileState.Name);
                return(false);
            }

            string destinationFolder = Path.GetDirectoryName(destinationFileState.Name);

            if (destinationFolder != null && destinationFolder.Length > 0 && !_directoriesKnownToExist.Contains(destinationFolder))
            {
                if (!Directory.Exists(destinationFolder))
                {
                    Log.LogMessageFromResources(MessageImportance.Normal, "Copy.CreatesDirectory", destinationFolder);
                    Directory.CreateDirectory(destinationFolder);
                }

                // It's very common for a lot of files to be copied to the same folder.
                // Eg., "c:\foo\a"->"c:\bar\a", "c:\foo\b"->"c:\bar\b" and so forth.
                // We don't want to check whether this folder exists for every single file we copy. So store which we've checked.
                _directoriesKnownToExist.Add(destinationFolder);
            }

            if (_overwriteReadOnlyFiles)
            {
                MakeFileWriteable(destinationFileState, true);
                destinationFileExists = destinationFileState.FileExists;
            }

            bool hardLinkCreated = false;

            // If we want to create hard links, then try that first
            if (UseHardlinksIfPossible)
            {
                // Do not log a fake command line as well, as it's superfluous, and also potentially expensive
                Log.LogMessageFromResources(MessageImportance.Normal, "Copy.HardLinkComment", sourceFileState.Name, destinationFileState.Name);

                if (!_overwriteReadOnlyFiles)
                {
                    destinationFileExists = destinationFileState.FileExists;
                }

                // CreateHardLink cannot overwrite an existing file or hard link
                // so we need to delete the existing entry before we create the hard link.
                // We need to do a best-effort check to see if the files are the same
                // if they are the same then we won't delete, just in case they refer to the same
                // physical file on disk.
                // Since we'll fall back to a copy (below) this will fail and issue a correct
                // message in the case that the source and destination are in fact the same file.
                if (destinationFileExists && !IsMatchingSizeAndTimeStamp(sourceFileState, destinationFileState))
                {
                    FileUtilities.DeleteNoThrow(destinationFileState.Name);
                }

                hardLinkCreated = NativeMethods.CreateHardLink(destinationFileState.Name, sourceFileState.Name, IntPtr.Zero /* reserved, must be NULL */);

                if (!hardLinkCreated)
                {
                    int       errorCode         = Marshal.GetHRForLastWin32Error();
                    Exception hardLinkException = Marshal.GetExceptionForHR(errorCode);
                    // This is only a message since we don't want warnings when copying to network shares etc.
                    Log.LogMessageFromResources(MessageImportance.Low, "Copy.RetryingAsFileCopy", sourceFileState.Name, destinationFileState.Name, hardLinkException.Message);
                }
            }

            // If the hard link was not created (either because the user didn't want one, or because it couldn't be created)
            // then let's copy the file
            if (!hardLinkCreated)
            {
                // Do not log a fake command line as well, as it's superfluous, and also potentially expensive
                Log.LogMessageFromResources(MessageImportance.Normal, "Copy.FileComment", sourceFileState.Name, destinationFileState.Name);
                File.Copy(sourceFileState.Name, destinationFileState.Name, true);
            }

            destinationFileState.Reset();

            // If the destinationFile file exists, then make sure it's read-write.
            // The File.Copy command copies attributes, but our copy needs to
            // leave the file writeable.
            if (sourceFileState.IsReadOnly)
            {
                MakeFileWriteable(destinationFileState, false);
            }

            return(true);
        }
コード例 #12
0
ファイル: Copy.cs プロジェクト: akrisiun/msbuild
        /// <summary>
        /// Copy one file from source to destination. Create the target directory if necessary and 
        /// leave the file read-write.
        /// </summary>
        /// <param name="sourceFile"></param>
        /// <param name="destinationFile"></param>
        /// <returns>Return true to indicate success, return false to indicate failure and NO retry, return NULL to indicate retry.</returns>
        private bool? CopyFileWithLogging
        (
            FileState sourceFileState,      // The source file
            FileState destinationFileState  // The destination file
        )
        {
            bool destinationFileExists = false;

            if (destinationFileState.DirectoryExists)
            {
                Log.LogErrorWithCodeFromResources("Copy.DestinationIsDirectory", sourceFileState.Name, destinationFileState.Name);
                return false;
            }

            if (sourceFileState.DirectoryExists)
            {
                // If the source file passed in is actually a directory instead of a file, log a nice
                // error telling the user so.  Otherwise, .NET Framework's File.Copy method will throw
                // an UnauthorizedAccessException saying "access is denied", which is not very useful
                // to the user.
                Log.LogErrorWithCodeFromResources("Copy.SourceIsDirectory", sourceFileState.Name);
                return false;
            }

            if (!sourceFileState.FileExists)
            {
                Log.LogErrorWithCodeFromResources("Copy.SourceFileNotFound", sourceFileState.Name);
                return false;
            }

            string destinationFolder = Path.GetDirectoryName(destinationFileState.Name);

            if (destinationFolder != null && destinationFolder.Length > 0 && !_directoriesKnownToExist.Contains(destinationFolder))
            {
                if (!Directory.Exists(destinationFolder))
                {
                    Log.LogMessageFromResources(MessageImportance.Normal, "Copy.CreatesDirectory", destinationFolder);
                    Directory.CreateDirectory(destinationFolder);
                }

                // It's very common for a lot of files to be copied to the same folder. 
                // Eg., "c:\foo\a"->"c:\bar\a", "c:\foo\b"->"c:\bar\b" and so forth.
                // We don't want to check whether this folder exists for every single file we copy. So store which we've checked.
                _directoriesKnownToExist.Add(destinationFolder);
            }

            if (_overwriteReadOnlyFiles)
            {
                MakeFileWriteable(destinationFileState, true);
                destinationFileExists = destinationFileState.FileExists;
            }

            bool hardLinkCreated = false;

            // If we want to create hard links, then try that first
            if (UseHardlinksIfPossible)
            {
                // Do not log a fake command line as well, as it's superfluous, and also potentially expensive
                Log.LogMessageFromResources(MessageImportance.Normal, "Copy.HardLinkComment", sourceFileState.Name, destinationFileState.Name);

                if (!_overwriteReadOnlyFiles)
                {
                    destinationFileExists = destinationFileState.FileExists;
                }

                // CreateHardLink cannot overwrite an existing file or hard link
                // so we need to delete the existing entry before we create the hard link.
                // We need to do a best-effort check to see if the files are the same
                // if they are the same then we won't delete, just in case they refer to the same
                // physical file on disk.
                // Since we'll fall back to a copy (below) this will fail and issue a correct
                // message in the case that the source and destination are in fact the same file.
                if (destinationFileExists && !IsMatchingSizeAndTimeStamp(sourceFileState, destinationFileState))
                {
                    FileUtilities.DeleteNoThrow(destinationFileState.Name);
                }

                hardLinkCreated = NativeMethods.CreateHardLink(destinationFileState.Name, sourceFileState.Name, IntPtr.Zero /* reserved, must be NULL */);

                if (!hardLinkCreated)
                {
                    int errorCode = Marshal.GetHRForLastWin32Error();
                    Exception hardLinkException = Marshal.GetExceptionForHR(errorCode);
                    // This is only a message since we don't want warnings when copying to network shares etc.
                    Log.LogMessageFromResources(MessageImportance.Low, "Copy.RetryingAsFileCopy", sourceFileState.Name, destinationFileState.Name, hardLinkException.Message);
                }
            }

            // If the hard link was not created (either because the user didn't want one, or because it couldn't be created)
            // then let's copy the file
            if (!hardLinkCreated)
            {
                // Do not log a fake command line as well, as it's superfluous, and also potentially expensive
                Log.LogMessageFromResources(MessageImportance.Normal, "Copy.FileComment", sourceFileState.Name, destinationFileState.Name);
                File.Copy(sourceFileState.Name, destinationFileState.Name, true);
            }

            destinationFileState.Reset();

            // If the destinationFile file exists, then make sure it's read-write.
            // The File.Copy command copies attributes, but our copy needs to
            // leave the file writeable.
            if (sourceFileState.IsReadOnly)
            {
                MakeFileWriteable(destinationFileState, false);
            }

            return true;
        }