/// <summary>
/// Tests if specified folder, or any of its ancestors, is excluded by the filter
/// </summary>
/// <param name="folder">Folder to test</param>
/// <param name="filter">Filter</param>
/// <param name="cache">Cache of excluded folders (optional)</param>
/// <returns>True if excluded, false otherwise</returns>
private bool IsFolderOrAncestorsExcluded(string folder, Utility.Utility.EnumerationFilterDelegate filter, IDictionary <string, bool> cache)
{
List <string> parents = null;
while (folder != null)
{
if (m_token.IsCancellationRequested)
{
break;
}
// first check cache
if (cache.TryGetValue(folder, out var include))
{
if (include)
{
return(false);
}
break; // hit!
}
// remember folder for cache
if (parents == null)
{
parents = new List <string>(); // create on-demand
}
parents.Add(folder);
var attr = m_snapshot.DirectoryExists(folder) ? m_snapshot.GetAttributes(folder) : FileAttributes.Directory;
if (!filter(folder, folder, attr))
{
break; // excluded
}
folder = Utility.Utility.GetParent(folder, true);
}
if (folder != null)
{
// update cache
parents?.ForEach(p => cache[p] = false);
}
return(folder != null);
}
