Wireguard Configuration in SQLite (#263)

#241

Apple/Shared/NewlineProtocolFramer.swift

@@ -0,0 +1,54 @@
+import Foundation
+import Network
+
+final class NewlineProtocolFramer: NWProtocolFramerImplementation {
+    private static let delimeter: UInt8 = 10 // `\n`
+
+    static let definition = NWProtocolFramer.Definition(implementation: NewlineProtocolFramer.self)
+    static let label = "Lines"
+
+    init(framer: NWProtocolFramer.Instance) { }
+
+    func start(framer: NWProtocolFramer.Instance) -> NWProtocolFramer.StartResult { .ready }
+    func stop(framer: NWProtocolFramer.Instance) -> Bool { true }
+
+    func wakeup(framer: NWProtocolFramer.Instance) { }
+    func cleanup(framer: NWProtocolFramer.Instance) { }
+
+    func handleInput(framer: NWProtocolFramer.Instance) -> Int {
+        while true {
+            var result: [Data] = []
+            let parsed = framer.parseInput(minimumIncompleteLength: 1, maximumLength: 16_000) { buffer, _ in
+                guard let buffer else { return 0 }
+                var lines = buffer
+                    .split(separator: Self.delimeter, omittingEmptySubsequences: false)
+                    .map { Data($0) }
+                guard lines.count > 1 else { return 0 }
+                _ = lines.popLast()
+
+                result = lines
+                return lines.reduce(lines.count) { $0 + $1.count }
+            }
+
+            guard parsed && !result.isEmpty else { break }
+
+            for line in result {
+                framer.deliverInput(data: line, message: .init(instance: framer), isComplete: true)
+            }
+        }
+        return 0
+    }
+
+    func handleOutput(
+        framer: NWProtocolFramer.Instance,
+        message: NWProtocolFramer.Message,
+        messageLength: Int,
+        isComplete: Bool
+    ) {
+        do {
+            try framer.writeOutputNoCopy(length: messageLength)
+            framer.writeOutput(data: [Self.delimeter])
+        } catch {
+        }
+    }
+}