/// <summary>
/// Initializes a new instance of the <see cref="NamespaceEnumerator" /> class.
/// </summary>
/// <param name="listeners">The listeners.</param>
public NamespaceEnumerator(IList <INamespaceEnumeratorListener> listeners)
{
_listeners = listeners;
_namespaceInfo = new NamespaceInfo();
}
/// <summary>
/// implementation of post-order traversal of directory tree
/// it is done this way to guarantee that by the time we finish any directory
/// all of its subdirectories/files had been visited
/// Note:
/// if operaiton is cancelled - not all notifications will be emited,
/// and namespace information will be partial.
/// </summary>
/// <param name="root">directory to scan</param>
/// <param name="cancelationCallback">function to consult with for cancelation</param>
/// <exception cref="System.IO.DirectoryNotFoundException">Cannot access directory: {root.FullName}</exception>
private void EnumeratePostOrderNonRecursive(IDirectoryInfo root, Func <bool> cancelationCallback = null)
{
// handle the case than this is actually network share.
if (!root.Exists())
{
throw new System.IO.DirectoryNotFoundException(string.Format(StorageSyncResources.NamespaceEnumeratorErrorFormat, root.FullName));
}
_namespaceInfo = new NamespaceInfo
{
Path = root.FullName,
IsComplete = false
};
Stack <IDirectoryInfo> stack1 = new Stack <IDirectoryInfo>(5000);
Stack <IDirectoryInfo> stack2 = new Stack <IDirectoryInfo>(5000);
Func <bool> shouldCancel = () =>
{
if (System.Diagnostics.Debugger.IsAttached)
{
return(false);
}
return(cancelationCallback == null ? false : cancelationCallback.Invoke());
};
stack1.Push(root);
_namespaceInfo.NumberOfDirectories++;
while (stack1.Count > 0)
{
if (shouldCancel())
{
return;
}
IDirectoryInfo currentDirectory = stack1.Pop();
stack2.Push(currentDirectory);
// notify we have started processing directory
// processing means accessing subdirectories and files
NotifyBeginDir(currentDirectory);
IList <IDirectoryInfo> subdirs = null;
try
{
subdirs = new List <IDirectoryInfo>(currentDirectory.EnumerateDirectories());
}
catch (UnauthorizedAccessException)
{
NotifyUnauthorizedDir(currentDirectory);
continue;
}
NotifyNamespaceHints(subdirs.Count, 0);
foreach (IDirectoryInfo subdir in subdirs)
{
stack1.Push(subdir);
_namespaceInfo.NumberOfDirectories++;
}
}
while (stack2.Count > 0)
{
if (shouldCancel())
{
return;
}
IDirectoryInfo currentDirectory = stack2.Pop();
IList <IFileInfo> files = new List <IFileInfo>(currentDirectory.EnumerateFiles());
NotifyNamespaceHints(0, files.Count);
foreach (IFileInfo file in files)
{
_namespaceInfo.NumberOfFiles++;
_namespaceInfo.TotalFileSizeInBytes += file.Length;
NotifyNextFile(file);
}
// notify we have finished processing directory
NotifyEndDir(currentDirectory);
}
_namespaceInfo.IsComplete = true;
}