dns_sd support for service browsing, on non-Darwin platforms

Author: lhoward

Examples/OCABrokerTest/BrokerTest.swift

@@ -26,7 +26,7 @@ private let connectionOptions = Ocp1ConnectionOptions(flags: [
 @main
 public enum BrokerTest {
   public static func main() async throws {
-    #if canImport(Darwin)
+    #if canImport(Darwin) || canImport(dnssd)
     let broker = await OcaConnectionBroker(connectionOptions: connectionOptions)
     print("waiting for events from broker...")
     for try await event in await broker.events {
@@ -40,7 +40,7 @@ public enum BrokerTest {
     }
     print("done!")
     #else
-    preconditionFailure("OcaConnectionBroker not yet supported on non-Darwin platforms")
+    preconditionFailure("OcaConnectionBroker not available on this platform")
     #endif
   }
 }

Sources/SwiftOCA/OCA/Browsing/ConnectionBroker.swift

@@ -14,7 +14,7 @@
 // limitations under the License.
 //
 
-#if canImport(Darwin)
+#if canImport(Darwin) || canImport(dnssd)
 
 import AsyncAlgorithms
 import AsyncExtensions
@@ -224,7 +224,11 @@ public actor OcaConnectionBroker {
     var browserMonitor: Task<(), Error>?
 
     init(serviceType: OcaNetworkAdvertisingServiceType, broker: OcaConnectionBroker) throws {
+      #if canImport(dnssd)
+      browser = try OcaDNSServiceBrowser(serviceType: serviceType)
+      #else
       browser = try OcaNetServiceBrowser(serviceType: serviceType)
+      #endif
       Task { try await browser.start() }
       browserMonitor = Task { [weak broker] in
         for try await result in browser.browseResults {