Files
Jot/Carthage/Checkouts/PromiseKit/Extensions/SystemConfiguration/Sources/SCNetworkReachability+Promise.swift
James Griffin be7b6b5881 Add PromiseKit dependency
- Added PromiseKit dependency
2018-11-15 22:12:39 -04:00

63 lines
2.1 KiB
Swift

import SystemConfiguration
#if !PMKCocoaPods
import PromiseKit
#endif
public extension SCNetworkReachability {
enum PMKError: Error {
case couldNotInitializeReachability
}
static func promise() -> Promise<Void> {
do {
var zeroAddress = sockaddr()
zeroAddress.sa_len = UInt8(MemoryLayout<sockaddr>.size)
zeroAddress.sa_family = sa_family_t(AF_INET)
guard let ref = SCNetworkReachabilityCreateWithAddress(nil, &zeroAddress) else {
throw PMKError.couldNotInitializeReachability
}
var flags = SCNetworkReachabilityFlags()
if SCNetworkReachabilityGetFlags(ref, &flags), flags.contains(.reachable) {
return Promise()
}
return try Helper(ref: ref).pending.promise
} catch {
return Promise(error: error)
}
}
}
private func callback(reachability: SCNetworkReachability, flags: SCNetworkReachabilityFlags, info: UnsafeMutableRawPointer?) {
if let info = info, flags.contains(.reachable) {
Unmanaged<Helper>.fromOpaque(info).takeUnretainedValue().pending.resolver.fulfill(())
}
}
private class Helper {
let pending = Promise<Void>.pending()
let ref: SCNetworkReachability
init(ref: SCNetworkReachability) throws {
self.ref = ref
var context = SCNetworkReachabilityContext(version: 0, info: nil, retain: nil, release: nil, copyDescription: nil)
context.info = UnsafeMutableRawPointer(Unmanaged<Helper>.passUnretained(self).toOpaque())
guard SCNetworkReachabilitySetCallback(ref, callback, &context) else {
throw SCNetworkReachability.PMKError.couldNotInitializeReachability
}
guard SCNetworkReachabilitySetDispatchQueue(ref, .main) else {
SCNetworkReachabilitySetCallback(ref, nil, nil)
throw SCNetworkReachability.PMKError.couldNotInitializeReachability
}
_ = pending.promise.ensure {
SCNetworkReachabilitySetCallback(self.ref, nil, nil)
SCNetworkReachabilitySetDispatchQueue(self.ref, nil)
}
}
}