mirror of
https://github.com/apple/container.git
synced 2026-10-16 02:59:21 +00:00
Kameron Kilchrist
450d44ecb6
- `FileTree.lookup` resolved each path component by linearly scanning the node's `children` array. This changes the node's child storage to an `OrderedDictionary<String, Ptr<FileTreeNode>>` (from swift-collections, which is already a package dependency) keyed by name, so `lookup` resolves each component in O(1) while iteration keeps the existing insertion order. - Little or no difference in unpack time for images with ~10k files, significant improvement for images with ~100k files or more.
108 lines
3.8 KiB
Swift
108 lines
3.8 KiB
Swift
//===----------------------------------------------------------------------===//
|
|
// 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 OrderedCollections
|
|
import SystemPackage
|
|
|
|
extension EXT4 {
|
|
class FileTree {
|
|
class FileTreeNode {
|
|
let inode: InodeNumber
|
|
let name: String
|
|
// Children keyed by name for O(1) lookup, preserving insertion order.
|
|
private(set) var childrenByName: OrderedDictionary<String, Ptr<FileTreeNode>> = [:]
|
|
var children: OrderedDictionary<String, Ptr<FileTreeNode>>.Values {
|
|
childrenByName.values
|
|
}
|
|
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.blocks = blocks
|
|
self.additionalBlocks = additionalBlocks
|
|
self.link = link
|
|
self.parent = parent
|
|
for child in children {
|
|
self.addChild(child)
|
|
}
|
|
}
|
|
|
|
deinit {
|
|
self.childrenByName.removeAll()
|
|
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()
|
|
}
|
|
|
|
func addChild(_ child: Ptr<FileTreeNode>) {
|
|
childrenByName[child.pointee.name] = child
|
|
}
|
|
|
|
func removeChild(named name: String) {
|
|
childrenByName.removeValue(forKey: name)
|
|
}
|
|
}
|
|
|
|
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 {
|
|
guard let childPtr = node.pointee.childrenByName[component] else {
|
|
return nil
|
|
}
|
|
node = childPtr
|
|
}
|
|
return node
|
|
}
|
|
}
|
|
}
|