carson-katri / skqueue

Monitor changes to files and directories using kernel event notifications (kqueue) in Swift

SKQueue

SKQueue is a simple and efficient Swift library that uses kernel event notifications (kernel queues or kqueue) to monitor changes to the filesystem. It allows you to watch any file or folder for changes and be notified immediately when they occur.

Installation

Swift Package Manager

1. Create a new project ex. swift package init --type executable
2. Add SKQueue as a dependency to your Package.swift

import PackageDescription

let package = Package(
  name: "SampleProject",
  dependencies: [
    .Package(url: "https://github.com/daniel-pedersen/SKQueue.git", majorVersion: 1)
  ]
)

3. Fetch dependencies. swift package fetch
4. (Optional) Generate and open an Xcode project. swift package generate-xcodeproj && open *.xcodeproj

Usage

Example

class SomeClass: SKQueueDelegate {
  func receivedNotification(_ notification: SKQueueNotification, path: String, queue: SKQueue) {
    print("\(notification.toStrings().map { $0.rawValue }) @ \(path)")
  }
}

let delegate = SomeClass()
let queue = SKQueue(delegate: delegate)!

queue.addPath("/some/file/or/directory")
queue.addPath("/some/other/file/or/directory")

Output samples

Action	Output
Add or remove file in /directory	["Write"] @ /directory
Add or remove directory in /directory	["Write", "SizeIncrease"] @ /directory
Write to file in /directory/file	["Rename", "SizeIncrease"] @ /directory/file

Contributing

1. Fork it!
2. Create your feature branch: git checkout -b my-new-feature
3. Commit your changes: git commit -am 'Add some feature'
4. Push to the branch: git push origin my-new-feature
5. Submit a pull request :D

History

v1.1

• Added method fileDescriptorForPath to SKQueue
• Added delegate parameter to SKQueue initializer

v1.0

• New API (see example above)
• Removed extension of the SKQueueDelegate protocol (see below)

v0.9

• Legacy API (see source)

Migrating to v1.0

The naming and ordering of parameters have changed, Xcode points this out at the appropriate locations.

If you have been using the overloaded receivedNotification that takes strings, you need to manually extend SKQueueDelegate as follows

extension SKQueueDelegate {
  func receivedNotification(_ queue: SKQueue, _ notificationName: SKQueueNotificationString, forPath path: String)
  func receivedNotification(_ queue: SKQueue, _ notification: SKQueueNotification, forPath path: String) {
    notification.toStrings().forEach { self.receivedNotification(queue, $0, forPath: path) }
  }
}