/// <summary>
/// Does the actual work of iterating the folder tree.
/// This is a breadth-first traversal.
/// Code was adapted from the MSDN documentation for
/// walking an NTFS directory.
/// </summary>
/// <param name="rootFolder">Folder to start the traversal from</param>
private Collection <ProcessedFileInfo> BreadthFirstTraversal(String rootFolder)
{
// Data structure to hold names of subfolders to be
// examined for files.
Stack <string> dirs = new Stack <string>(20);
if (System.IO.Directory.Exists(rootFolder))
{
//
OnDirectoryWalkStarted(new DirectoryWalkEventArgs(rootFolder,
String.Empty,
DirectoryWalkObjectType.Directory,
DirectoryWalkOperationResult.NotApplicable,
"Directory walk started."));
dirs.Push(rootFolder);
FileProcessorLengthFirst lengthFirstFileProc = new FileProcessorLengthFirst();
IFileProcessor fileProcessorInterface = lengthFirstFileProc as IFileProcessor;
fileProcessorInterface.Initialize();
while (dirs.Count > 0)
{
string currentDir = dirs.Pop();
string[] subDirs;
try
{
subDirs = System.IO.Directory.GetDirectories(currentDir);
OnFileAccessed(new DirectoryWalkEventArgs(currentDir,
String.Empty,
DirectoryWalkObjectType.Directory,
DirectoryWalkOperationResult.Success,
"Directory listing (subdirectories) taken successfully."));
}
// An UnauthorizedAccessException exception will be thrown if we do not have
// discovery permission on a folder or file. It may or may not be acceptable
// to ignore the exception and continue enumerating the remaining files and
// folders. It is also possible (but unlikely) that a DirectoryNotFound exception
// will be raised. This will happen if currentDir has been deleted by
// another application or thread after our call to Directory.Exists. The
// choice of which exceptions to catch depends entirely on the specific task
// you are intending to perform and also on how much you know with certainty
// about the systems on which this code will run.
catch (UnauthorizedAccessException)
{
OnFileAccessed(new DirectoryWalkEventArgs(currentDir,
String.Empty,
DirectoryWalkObjectType.Directory,
DirectoryWalkOperationResult.Failure,
"Directory listing (subdirectories) could not be taken - insufficient permissions."));
continue;
}
catch (System.IO.DirectoryNotFoundException)
{
OnFileAccessed(new DirectoryWalkEventArgs(currentDir,
String.Empty,
DirectoryWalkObjectType.Directory,
DirectoryWalkOperationResult.Error,
"Directory listing (subdirectories) could not be taken - directory was deleted or moved."));
continue;
}
string[] files = null;
try
{
files = System.IO.Directory.GetFiles(currentDir);
OnFileAccessed(new DirectoryWalkEventArgs(currentDir,
String.Empty,
DirectoryWalkObjectType.Directory,
DirectoryWalkOperationResult.Success,
"Directory listing (files) taken successfully."));
}
catch (UnauthorizedAccessException)
{
OnFileAccessed(new DirectoryWalkEventArgs(currentDir,
String.Empty,
DirectoryWalkObjectType.Directory,
DirectoryWalkOperationResult.Failure,
"Directory listing (files) could not be taken - insufficient permissions."));
continue;
}
catch (System.IO.DirectoryNotFoundException)
{
OnFileAccessed(new DirectoryWalkEventArgs(currentDir,
String.Empty,
DirectoryWalkObjectType.Directory,
DirectoryWalkOperationResult.Error,
"Directory listing (files) could not be taken - directory was deleted or moved."));
continue;
}
// Perform the required action on each file here.
// Modify this block to perform your required task.
foreach (string file in files)
{
try
{
OnFileAccessed(new DirectoryWalkEventArgs(currentDir,
Path.GetFileName(file),
DirectoryWalkObjectType.File,
DirectoryWalkOperationResult.NotApplicable,
"Accessing file."));
System.IO.FileInfo fi = new System.IO.FileInfo(file);
fileProcessorInterface.ProcessFile(fi);
OnFileProcessed(new DirectoryWalkEventArgs(currentDir,
Path.GetFileName(file),
DirectoryWalkObjectType.File,
DirectoryWalkOperationResult.Success,
"File processed."));
}
catch (System.IO.FileNotFoundException)
{
// If file was deleted by a separate application
// or thread since the call to TraverseTree()
// then just continue.
OnFileAccessed(new DirectoryWalkEventArgs(currentDir,
String.Empty,
DirectoryWalkObjectType.Directory,
DirectoryWalkOperationResult.Error,
"File could not be processed - it was deleted or moved."));
continue;
}
}
// Push the subdirectories onto the stack for traversal.
// This could also be done before handing the files.
foreach (string str in subDirs)
{
dirs.Push(str);
}
}
OnDirectoryWalkCompleted(new DirectoryWalkEventArgs(rootFolder,
String.Empty,
DirectoryWalkObjectType.Directory,
DirectoryWalkOperationResult.NotApplicable,
"Directory walk completed - computing hashes for length duplicates..."));
Collection <ProcessedFileInfo> duplicateFiles = lengthFirstFileProc.DuplicateFiles;
fileProcessorInterface.Close();
return(duplicateFiles);
}
else
{
// Root folder does not exist
throw new ArgumentException(String.Empty, "rootFolder");
}
} //BreadthFirstTraversal