Skip to content

Foundation: avoid unnecessary disk IO on windows file enumeration #4748

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 1 commit into from
Jun 13, 2023
Merged

Foundation: avoid unnecessary disk IO on windows file enumeration #4748

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
34 changes: 20 additions & 14 deletions Sources/Foundation/FileManager+Win32.swift
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -929,15 +929,14 @@ extension FileManager {
var _options : FileManager.DirectoryEnumerationOptions
var _errorHandler : ((URL, Error) -> Bool)?
var _stack: [URL]
var _lastReturned: URL
var _rootDepth : Int
var _lastReturned: URL?
var _root: URL

init(url: URL, options: FileManager.DirectoryEnumerationOptions, errorHandler: (/* @escaping */ (URL, Error) -> Bool)?) {
_options = options
_errorHandler = errorHandler
_stack = []
_rootDepth = url.pathComponents.count
_lastReturned = url
_root = url
}

override func nextObject() -> Any? {
Expand All @@ -955,17 +954,22 @@ extension FileManager {
return nil
}

// If we most recently returned a directory, decend into it
guard let attrs = try? FileManager.default.windowsFileAttributes(atPath: _lastReturned.path) else {
guard let handler = _errorHandler,
handler(_lastReturned, _NSErrorWithWindowsError(GetLastError(), reading: true, paths: [_lastReturned.path]))
else { return nil }
return firstValidItem()
if _lastReturned == nil {
guard let attrs = try? FileManager.default.windowsFileAttributes(atPath: _root.path) else {
guard let handler = _errorHandler else { return nil }
if !handler(_root, _NSErrorWithWindowsError(GetLastError(), reading: true, paths: [_root.path])) {
return nil
}
return firstValidItem()
}

let isDirectory = attrs.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY == FILE_ATTRIBUTE_DIRECTORY && attrs.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT != FILE_ATTRIBUTE_REPARSE_POINT
_lastReturned = URL(fileURLWithPath: _root.path, isDirectory: isDirectory)
}

let isDir = attrs.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY == FILE_ATTRIBUTE_DIRECTORY &&
attrs.dwFileAttributes & FILE_ATTRIBUTE_REPARSE_POINT == 0
if isDir && (level == 0 || !_options.contains(.skipsSubdirectoryDescendants)) {
guard let _lastReturned else { return firstValidItem() }

if _lastReturned.hasDirectoryPath && (level == 0 || !_options.contains(.skipsSubdirectoryDescendants)) {
var ffd = WIN32_FIND_DATAW()
let capacity = MemoryLayout.size(ofValue: ffd.cFileName)

Expand All @@ -991,11 +995,13 @@ extension FileManager {
_stack.append(_lastReturned.appendingPathComponent(file, isDirectory: isDirectory))
} while FindNextFileW(handle, &ffd)
}

return firstValidItem()
}

override var level: Int {
return _lastReturned.pathComponents.count - _rootDepth
guard let _lastReturned else { return 0 }
return _lastReturned.pathComponents.count - _root.pathComponents.count
}

override func skipDescendants() {
Expand Down