/// <inheritdoc />
protected override IEnumerable <UPath> EnumeratePathsImpl(UPath path, string searchPattern, SearchOption searchOption, SearchTarget searchTarget)
{
// Use the search pattern to normalize the path/search pattern
var search = SearchPattern.Parse(ref path, ref searchPattern);
var originalSrcPath = path;
// Internal method used to retrieve the list of root directories
SortedSet <UPath> GetRootDirectories()
{
var directories = new SortedSet <UPath>(UPath.DefaultComparerIgnoreCase);
lock (_mounts)
{
foreach (var mountName in _mounts.Keys)
{
directories.Add(mountName);
}
}
if (NextFileSystem != null)
{
foreach (var dir in NextFileSystem.EnumeratePaths(path, "*", SearchOption.TopDirectoryOnly, SearchTarget.Directory))
{
if (!directories.Contains(dir))
{
directories.Add(dir);
}
}
}
return(directories);
}
IEnumerable <UPath> EnumeratePathFromFileSystem(UPath subPath, bool failOnInvalidPath)
{
var fs = TryGetMountOrNext(ref subPath, out var mountPath);
if (fs == null)
{
if (failOnInvalidPath)
{
throw NewDirectoryNotFoundException(originalSrcPath);
}
yield break;
}
if (fs != NextFileSystem)
{
// In the case of a mount, we need to return the full path
Debug.Assert(!mountPath.IsNull);
foreach (var entry in fs.EnumeratePaths(subPath, searchPattern, searchOption, searchTarget))
{
yield return(mountPath / entry.ToRelative());
}
}
else
{
foreach (var entry in fs.EnumeratePaths(subPath, searchPattern, searchOption, searchTarget))
{
yield return(entry);
}
}
}
// Special case for the root as we have to return the list of mount directories
// and merge them with the underlying FileSystem
if (path == UPath.Root)
{
var entries = new SortedSet <UPath>(UPath.DefaultComparerIgnoreCase);
// Return the list of dircetories
var directories = GetRootDirectories();
// Process the files first
if (NextFileSystem != null && (searchTarget == SearchTarget.File || searchTarget == SearchTarget.Both))
{
foreach (var file in NextFileSystem.EnumeratePaths(path, searchPattern, SearchOption.TopDirectoryOnly, SearchTarget.File))
{
entries.Add(file);
}
}
if (searchTarget != SearchTarget.File)
{
foreach (var dir in directories)
{
if (search.Match(dir))
{
entries.Add(dir);
}
}
}
// Return all entries sorted
foreach (var entry in entries)
{
yield return(entry);
}
if (searchOption == SearchOption.AllDirectories)
{
foreach (var dir in directories)
{
foreach (var entry in EnumeratePathFromFileSystem(dir, false))
{
yield return(entry);
}
}
}
}
else
{
foreach (var entry in EnumeratePathFromFileSystem(path, true))
{
yield return(entry);
}
}
}