chore: import upstream snapshot with attribution

2026-07-13 12:25:30 +08:00
commit 680845cb1c
445 changed files with 103779 additions and 0 deletions
@@ -0,0 +1,101 @@
+//===----------------------------------------------------------------------===//
+// Copyright © 2025-2026 Apple Inc. and the Containerization project authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//   https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//===----------------------------------------------------------------------===//
+
+import Foundation
+import SystemPackage
+
+extension EXT4 {
+    class FileTree {
+        class FileTreeNode {
+            let inode: InodeNumber
+            let name: String
+            var children: [Ptr<FileTreeNode>] = []
+            var blocks: (start: UInt32, end: UInt32)?
+            var additionalBlocks: [(start: UInt32, end: UInt32)]?
+            var link: InodeNumber?
+            private weak var parent: Ptr<FileTreeNode>?
+
+            init(
+                inode: InodeNumber,
+                name: String,
+                parent: Ptr<FileTreeNode>?,
+                children: [Ptr<FileTreeNode>] = [],
+                blocks: (start: UInt32, end: UInt32)? = nil,
+                additionalBlocks: [(start: UInt32, end: UInt32)]? = nil,
+                link: InodeNumber? = nil
+            ) {
+                self.inode = inode
+                self.name = name
+                self.children = children
+                self.blocks = blocks
+                self.additionalBlocks = additionalBlocks
+                self.link = link
+                self.parent = parent
+            }
+
+            deinit {
+                self.children.removeAll()
+                self.children = []
+                self.blocks = nil
+                self.additionalBlocks = nil
+                self.link = nil
+            }
+
+            var path: FilePath? {
+                var components: [String] = [self.name]
+                var _ptr = self.parent
+                while let ptr = _ptr {
+                    components.append(ptr.pointee.name)
+                    _ptr = ptr.pointee.parent
+                }
+                let path = components.reversed().joined(separator: "/")
+                return FilePath(path).lexicallyNormalized()
+            }
+        }
+
+        var root: Ptr<FileTreeNode>
+
+        init(_ root: InodeNumber, _ name: String) {
+            self.root = Ptr(FileTreeNode(inode: root, name: name, parent: nil))
+        }
+
+        func lookup(path: FilePath) -> Ptr<FileTreeNode>? {
+            var components: [String] = path.items
+            var node = self.root
+            if components.first == "/" {
+                components = Array(components.dropFirst())
+            }
+            if components.count == 0 {
+                return node
+            }
+            for component in components {
+                var found = false
+                for childPtr in node.pointee.children {
+                    let child = childPtr.pointee
+                    if child.name == component {
+                        node = childPtr
+                        found = true
+                        break
+                    }
+                }
+                guard found else {
+                    return nil
+                }
+            }
+            return node
+        }
+    }
+}