WIP: fixup the samples and rename things to make me less nervous

Author: milseman

Sources/Samples/Listen.swift

@@ -97,15 +97,15 @@ struct Listen: ParsableCommand {
     try socket.closeAfter {
       if udp {
         while true {
-          let (count, flags) = try socket.receiveMessage(bytes: buffer, sender: &client)
+          let (count, flags) = try socket.receiveMessage(into: buffer, sender: &client)
           print(prefix(client: client, flags: flags), terminator: "")
           try FileDescriptor.standardOutput.writeAll(buffer[..<count])
         }
       } else {
         let conn = try socket.accept(client: &client)
         complain("Connection from \(client.niceDescription)")
         while true {
-          let (count, flags) = try conn.receiveMessage(bytes: buffer, sender: &client)
+          let (count, flags) = try conn.receiveMessage(into: buffer, sender: &client)
           guard count > 0 else { break }
           print(prefix(client: client, flags: flags), terminator: "")
           try FileDescriptor.standardOutput.writeAll(buffer[..<count])

Sources/Samples/Util.swift

@@ -42,19 +42,10 @@ internal func complain(_ message: String) {
 
 extension SocketAddress {
   var niceDescription: String {
-    switch family {
-    case .ipv4:
-      if let ipv4 = IPv4(self) { return ipv4.description }
-      return self.description
-    case .ipv6:
-      if let ipv6 = IPv6(self) { return ipv6.description }
-      return self.description
-    case .local:
-      if let local = Local(self) { return local.description }
-      return self.description
-    default:
-      return self.description
-    }
+    if let ipv4 = self.ipv4 { return ipv4.description }
+    if let ipv6 = self.ipv6 { return ipv6.description }
+    if let local = self.local { return local.description }
+    return self.description
   }
 }
 

Sources/System/Sockets/SocketAddress.swift

@@ -164,18 +164,6 @@ extension SocketAddress {
   }
 }
 
-extension Optional where Wrapped == SocketAddress {
-  internal func _withUnsafeBytes<R>(
-    _ body: (UnsafeRawBufferPointer) throws -> R
-  ) rethrows -> R {
-    guard let address = self else {
-      return try body(UnsafeRawBufferPointer(start: nil, count: 0))
-    }
-    return try address.withUnsafeBytes(body)
-  }
-}
-
-
 // @available(macOS 9999, iOS 9999, watchOS 9999, tvOS 9999, *)
 extension SocketAddress {
   /// Calls `body` with an unsafe raw buffer pointer to the raw bytes of this

Sources/System/Sockets/SocketDescriptor+Messages.swift

@@ -165,9 +165,9 @@ extension SocketDescriptor {
   }
 }
 
-
+// Optional mapper helpers, for use in setting up message header structs.
 extension Optional where Wrapped == SocketDescriptor.AncillaryMessageBuffer {
-  internal func _withUnsafeBytes<R>(
+  fileprivate func _withUnsafeBytesOrNull<R>(
     _ body: (UnsafeRawBufferPointer) throws -> R
   ) rethrows -> R {
     guard let buffer = self else {
@@ -177,6 +177,56 @@ extension Optional where Wrapped == SocketDescriptor.AncillaryMessageBuffer {
   }
 }
 
+extension Optional where Wrapped == SocketAddress {
+  fileprivate func _withUnsafeBytesOrNull<R>(
+    _ body: (UnsafeRawBufferPointer) throws -> R
+  ) rethrows -> R {
+    guard let address = self else {
+      return try body(UnsafeRawBufferPointer(start: nil, count: 0))
+    }
+    return try address.withUnsafeBytes(body)
+  }
+}
+extension Optional where Wrapped == UnsafeMutablePointer<SocketAddress> {
+  fileprivate func _withMutableCInteropOrNull<R>(
+    entireCapacity: Bool,
+    _ body: (
+      UnsafeMutablePointer<CInterop.SockAddr>?,
+      inout CInterop.SockLen
+    ) throws -> R
+  ) rethrows -> R {
+    guard let ptr = self else {
+      var c: CInterop.SockLen = 0
+      let result = try body(nil, &c)
+      precondition(c == 0)
+      return result
+    }
+    return try ptr.pointee._withMutableCInterop(
+      entireCapacity: entireCapacity,
+      body)
+  }
+}
+
+extension Optional
+where Wrapped == UnsafeMutablePointer<SocketDescriptor.AncillaryMessageBuffer>
+{
+  internal func _withMutableCInterop<R>(
+    entireCapacity: Bool,
+    _ body: (UnsafeMutableRawPointer?, inout CInterop.SockLen) throws -> R
+  ) rethrows -> R {
+    guard let buffer = self else {
+      var length: CInterop.SockLen = 0
+      let r = try body(nil, &length)
+      precondition(length == 0)
+      return r
+    }
+    return try buffer.pointee._withMutableCInterop(
+      entireCapacity: entireCapacity,
+      body
+    )
+  }
+}
+
 // @available(macOS 9999, iOS 9999, watchOS 9999, tvOS 9999, *)
 extension SocketDescriptor.AncillaryMessageBuffer: Collection {
   /// The index type in an ancillary message buffer.
@@ -365,8 +415,8 @@ extension SocketDescriptor {
     flags: MessageFlags,
     retryOnInterrupt: Bool
   ) -> Result<Int, Errno> {
-    recipient._withUnsafeBytes { recipient in
-      ancillary._withUnsafeBytes { ancillary in
+    recipient._withUnsafeBytesOrNull { recipient in
+      ancillary._withUnsafeBytesOrNull { ancillary in
         var iov = CInterop.IOVec()
         iov.iov_base = UnsafeMutableRawPointer(mutating: bytes.baseAddress)
         iov.iov_len = bytes.count
@@ -487,46 +537,6 @@ extension SocketDescriptor {
   }
 }
 
-extension Optional where Wrapped == UnsafeMutablePointer<SocketAddress> {
-  internal func _withMutableCInterop<R>(
-    entireCapacity: Bool,
-    _ body: (
-      UnsafeMutablePointer<CInterop.SockAddr>?,
-      inout CInterop.SockLen
-    ) throws -> R
-  ) rethrows -> R {
-    guard let ptr = self else {
-      var c: CInterop.SockLen = 0
-      let result = try body(nil, &c)
-      precondition(c == 0)
-      return result
-    }
-    return try ptr.pointee._withMutableCInterop(
-      entireCapacity: entireCapacity,
-      body)
-  }
-}
-
-extension Optional
-where Wrapped == UnsafeMutablePointer<SocketDescriptor.AncillaryMessageBuffer>
-{
-  internal func _withMutableCInterop<R>(
-    entireCapacity: Bool,
-    _ body: (UnsafeMutableRawPointer?, inout CInterop.SockLen) throws -> R
-  ) rethrows -> R {
-    guard let buffer = self else {
-      var length: CInterop.SockLen = 0
-      let r = try body(nil, &length)
-      precondition(length == 0)
-      return r
-    }
-    return try buffer.pointee._withMutableCInterop(
-      entireCapacity: entireCapacity,
-      body
-    )
-  }
-}
-
 extension SocketDescriptor {
   @usableFromInline
   internal func _receiveMessage(
@@ -539,7 +549,7 @@ extension SocketDescriptor {
     let result: Result<Int, Errno>
     let receivedFlags: CInt
     (result, receivedFlags) =
-      sender._withMutableCInterop(entireCapacity: true) { adr, adrlen in
+      sender._withMutableCInteropOrNull(entireCapacity: true) { adr, adrlen in
         ancillary._withMutableCInterop(entireCapacity: true) { anc, anclen in
           var iov = CInterop.IOVec()
           iov.iov_base = bytes.baseAddress