fix Swift 5 warnings (mostly redundant modifiers (#642)

Motivation:

Swift 5 complains on redundant modifiers. For example declaring a
`public func` inside of a `public extension` is now a warning. I don't
agree with this but I dislike warnings even more, so...

Modifications:

remove all redundant modifiers that the compiler now warns about such as

    swift-nio/Sources/NIOPriorityQueue/PriorityQueue.swift:90:5: warning: 'public' modifier is redundant for property declared in a public extension

Result:

no warnings in Swift 5

Sources/NIO/BlockingIOThreadPool.swift

@@ -188,7 +188,7 @@ public extension BlockingIOThreadPool {
     ///     - eventLoop: The `EventLoop` the returned `EventLoopFuture` will fire on.
     ///     - body: The closure which performs some blocking work to be done on the thread pool.
     /// - returns: The `EventLoopFuture` of `promise` fulfilled with the result (or error) of the passed closure.
-    public func runIfActive<T>(eventLoop: EventLoop, _ body: @escaping () throws -> T) -> EventLoopFuture<T> {
+    func runIfActive<T>(eventLoop: EventLoop, _ body: @escaping () throws -> T) -> EventLoopFuture<T> {
         let promise: EventLoopPromise<T> = eventLoop.newPromise()
         self.submit { shouldRun in
             guard case shouldRun = BlockingIOThreadPool.WorkItemState.active else {

Sources/NIO/ByteBuffer-views.swift

@@ -63,7 +63,7 @@ public struct ByteBufferView: ContiguousCollection, RandomAccessCollection {
 
 public extension ByteBuffer {
     /// A view into the readable bytes of the `ByteBuffer`.
-    public var readableBytesView: ByteBufferView {
+    var readableBytesView: ByteBufferView {
         return ByteBufferView(buffer: self, range: self.readerIndex ..< self.readerIndex + self.readableBytes)
     }
 
@@ -73,7 +73,7 @@ public extension ByteBuffer {
     ///   - index: The index the view should start at
     ///   - length: The length of the view (in bytes)
     /// - returns A view into a portion of a `ByteBuffer`.
-    public func viewBytes(at index: Int, length: Int) -> ByteBufferView {
+    func viewBytes(at index: Int, length: Int) -> ByteBufferView {
         return ByteBufferView(buffer: self, range: index ..< index+length)
     }
 }

Sources/NIO/Channel.swift

@@ -226,29 +226,29 @@ public extension Channel {
     /// Write data into the `Channel`, automatically wrapping with `NIOAny`.
     ///
     /// - seealso: `ChannelOutboundInvoker.write`.
-    public func write<T>(_ any: T) -> EventLoopFuture<Void> {
+    func write<T>(_ any: T) -> EventLoopFuture<Void> {
         return self.write(NIOAny(any))
     }
 
     /// Write data into the `Channel`, automatically wrapping with `NIOAny`.
     ///
     /// - seealso: `ChannelOutboundInvoker.write`.
-    public func write<T>(_ any: T, promise: EventLoopPromise<Void>?) {
+    func write<T>(_ any: T, promise: EventLoopPromise<Void>?) {
         self.write(NIOAny(any), promise: promise)
     }
 
     /// Write and flush data into the `Channel`, automatically wrapping with `NIOAny`.
     ///
     /// - seealso: `ChannelOutboundInvoker.writeAndFlush`.
-    public func writeAndFlush<T>(_ any: T) -> EventLoopFuture<Void> {
+    func writeAndFlush<T>(_ any: T) -> EventLoopFuture<Void> {
         return self.writeAndFlush(NIOAny(any))
     }
 
 
     /// Write and flush data into the `Channel`, automatically wrapping with `NIOAny`.
     ///
     /// - seealso: `ChannelOutboundInvoker.writeAndFlush`.
-    public func writeAndFlush<T>(_ any: T, promise: EventLoopPromise<Void>?) {
+    func writeAndFlush<T>(_ any: T, promise: EventLoopPromise<Void>?) {
         self.writeAndFlush(NIOAny(any), promise: promise)
     }
 }
@@ -270,7 +270,7 @@ public extension ChannelCore {
     ///     - as: The type to extract from the `NIOAny`.
     /// - returns: The content of the `NIOAny`.
     @_inlineable
-    public func unwrapData<T>(_ data: NIOAny, as: T.Type = T.self) -> T {
+    func unwrapData<T>(_ data: NIOAny, as: T.Type = T.self) -> T {
         return data.forceAs()
     }
 
@@ -283,7 +283,7 @@ public extension ChannelCore {
     ///
     /// - parameters:
     ///     - channel: The `Channel` whose `ChannelPipeline` will be closed.
-    public func removeHandlers(channel: Channel) {
+    func removeHandlers(channel: Channel) {
         channel.pipeline.removeHandlers()
     }
 }

Sources/NIO/EventLoopFuture.swift

@@ -962,7 +962,7 @@ public extension EventLoopFuture {
     /// - parameters:
     ///     - target: The `EventLoop` that the returned `EventLoopFuture` will run on.
     /// - returns: An `EventLoopFuture` whose callbacks run on `target` instead of the original loop.
-    public func hopTo(eventLoop target: EventLoop) -> EventLoopFuture<T> {
+    func hopTo(eventLoop target: EventLoop) -> EventLoopFuture<T> {
         if target === self.eventLoop {
             // We're already on that event loop, nothing to do here. Save an allocation.
             return self

Sources/NIO/PendingDatagramWritesManager.swift

@@ -48,7 +48,7 @@ fileprivate extension Error {
     /// Returns whether the error is "recoverable" from the perspective of datagram sending.
     ///
     /// - returns: `true` if the error is recoverable, `false` otherwise.
-    fileprivate var isRecoverable: Bool {
+    var isRecoverable: Bool {
         switch self {
         case let e as IOError where e.errnoCode == EMSGSIZE,
              let e as IOError where e.errnoCode == EHOSTUNREACH:

Sources/NIO/Selector.swift

@@ -661,7 +661,7 @@ struct SelectorEvent<R> {
 
 internal extension Selector where R == NIORegistration {
     /// Gently close the `Selector` after all registered `Channel`s are closed.
-    internal func closeGently(eventLoop: EventLoop) -> EventLoopFuture<Void> {
+    func closeGently(eventLoop: EventLoop) -> EventLoopFuture<Void> {
         guard self.lifecycleState == .open else {
             return eventLoop.newFailedFuture(error: IOError(errnoCode: EBADF, reason: "can't close selector gently as it's \(self.lifecycleState)."))
         }

Sources/NIO/SocketOptionProvider.swift

@@ -88,15 +88,15 @@ public extension SocketOptionProvider {
     ///     - value: The value to set SO_LINGER to.
     /// - returns: An `EventLoopFuture` that fires when the option has been set,
     ///     or if an error has occurred.
-    public func setSoLinger(_ value: linger) -> EventLoopFuture<Void> {
+    func setSoLinger(_ value: linger) -> EventLoopFuture<Void> {
         return self.unsafeSetSocketOption(level: SocketOptionLevel(SOL_SOCKET), name: SO_LINGER, value: value)
     }
 
     /// Gets the value of the socket option SO_LINGER.
     ///
     /// - returns: An `EventLoopFuture` containing the value of the socket option, or
     ///     any error that occurred while retrieving the socket option.
-    public func getSoLinger() -> EventLoopFuture<linger> {
+    func getSoLinger() -> EventLoopFuture<linger> {
         return self.unsafeGetSocketOption(level: SocketOptionLevel(SOL_SOCKET), name: SO_LINGER)
     }
 
@@ -106,15 +106,15 @@ public extension SocketOptionProvider {
     ///     - value: The value to set IP_MULTICAST_IF to.
     /// - returns: An `EventLoopFuture` that fires when the option has been set,
     ///     or if an error has occurred.
-    public func setIPMulticastIF(_ value: in_addr) -> EventLoopFuture<Void> {
+    func setIPMulticastIF(_ value: in_addr) -> EventLoopFuture<Void> {
         return self.unsafeSetSocketOption(level: IPPROTO_IP, name: IP_MULTICAST_IF, value: value)
     }
 
     /// Gets the value of the socket option IP_MULTICAST_IF.
     ///
     /// - returns: An `EventLoopFuture` containing the value of the socket option, or
     ///     any error that occurred while retrieving the socket option.
-    public func getIPMulticastIF() -> EventLoopFuture<in_addr> {
+    func getIPMulticastIF() -> EventLoopFuture<in_addr> {
         return self.unsafeGetSocketOption(level: IPPROTO_IP, name: IP_MULTICAST_IF)
     }
 
@@ -124,15 +124,15 @@ public extension SocketOptionProvider {
     ///     - value: The value to set IP_MULTICAST_TTL to.
     /// - returns: An `EventLoopFuture` that fires when the option has been set,
     ///     or if an error has occurred.
-    public func setIPMulticastTTL(_ value: CUnsignedChar) -> EventLoopFuture<Void> {
+    func setIPMulticastTTL(_ value: CUnsignedChar) -> EventLoopFuture<Void> {
         return self.unsafeSetSocketOption(level: IPPROTO_IP, name: IP_MULTICAST_TTL, value: value)
     }
 
     /// Gets the value of the socket option IP_MULTICAST_TTL.
     ///
     /// - returns: An `EventLoopFuture` containing the value of the socket option, or
     ///     any error that occurred while retrieving the socket option.
-    public func getIPMulticastTTL() -> EventLoopFuture<CUnsignedChar> {
+    func getIPMulticastTTL() -> EventLoopFuture<CUnsignedChar> {
         return self.unsafeGetSocketOption(level: IPPROTO_IP, name: IP_MULTICAST_TTL)
     }
 
@@ -142,15 +142,15 @@ public extension SocketOptionProvider {
     ///     - value: The value to set IP_MULTICAST_LOOP to.
     /// - returns: An `EventLoopFuture` that fires when the option has been set,
     ///     or if an error has occurred.
-    public func setIPMulticastLoop(_ value: CUnsignedChar) -> EventLoopFuture<Void> {
+    func setIPMulticastLoop(_ value: CUnsignedChar) -> EventLoopFuture<Void> {
         return self.unsafeSetSocketOption(level: IPPROTO_IP, name: IP_MULTICAST_LOOP, value: value)
     }
 
     /// Gets the value of the socket option IP_MULTICAST_LOOP.
     ///
     /// - returns: An `EventLoopFuture` containing the value of the socket option, or
     ///     any error that occurred while retrieving the socket option.
-    public func getIPMulticastLoop() -> EventLoopFuture<CUnsignedChar> {
+    func getIPMulticastLoop() -> EventLoopFuture<CUnsignedChar> {
         return self.unsafeGetSocketOption(level: IPPROTO_IP, name: IP_MULTICAST_LOOP)
     }
 
@@ -160,15 +160,15 @@ public extension SocketOptionProvider {
     ///     - value: The value to set IPV6_MULTICAST_IF to.
     /// - returns: An `EventLoopFuture` that fires when the option has been set,
     ///     or if an error has occurred.
-    public func setIPv6MulticastIF(_ value: CUnsignedInt) -> EventLoopFuture<Void> {
+    func setIPv6MulticastIF(_ value: CUnsignedInt) -> EventLoopFuture<Void> {
         return self.unsafeSetSocketOption(level: IPPROTO_IPV6, name: IPV6_MULTICAST_IF, value: value)
     }
 
     /// Gets the value of the socket option IPV6_MULTICAST_IF.
     ///
     /// - returns: An `EventLoopFuture` containing the value of the socket option, or
     ///     any error that occurred while retrieving the socket option.
-    public func getIPv6MulticastIF() -> EventLoopFuture<CUnsignedInt> {
+    func getIPv6MulticastIF() -> EventLoopFuture<CUnsignedInt> {
         return self.unsafeGetSocketOption(level: IPPROTO_IPV6, name: IPV6_MULTICAST_IF)
     }
 
@@ -178,15 +178,15 @@ public extension SocketOptionProvider {
     ///     - value: The value to set IPV6_MULTICAST_HOPS to.
     /// - returns: An `EventLoopFuture` that fires when the option has been set,
     ///     or if an error has occurred.
-    public func setIPv6MulticastHops(_ value: CInt) -> EventLoopFuture<Void> {
+    func setIPv6MulticastHops(_ value: CInt) -> EventLoopFuture<Void> {
         return self.unsafeSetSocketOption(level: IPPROTO_IPV6, name: IPV6_MULTICAST_HOPS, value: value)
     }
 
     /// Gets the value of the socket option IPV6_MULTICAST_HOPS.
     ///
     /// - returns: An `EventLoopFuture` containing the value of the socket option, or
     ///     any error that occurred while retrieving the socket option.
-    public func getIPv6MulticastHops() -> EventLoopFuture<CInt> {
+    func getIPv6MulticastHops() -> EventLoopFuture<CInt> {
         return self.unsafeGetSocketOption(level: IPPROTO_IPV6, name: IPV6_MULTICAST_HOPS)
     }
 
@@ -196,15 +196,15 @@ public extension SocketOptionProvider {
     ///     - value: The value to set IPV6_MULTICAST_LOOP to.
     /// - returns: An `EventLoopFuture` that fires when the option has been set,
     ///     or if an error has occurred.
-    public func setIPv6MulticastLoop(_ value: CUnsignedInt) -> EventLoopFuture<Void> {
+    func setIPv6MulticastLoop(_ value: CUnsignedInt) -> EventLoopFuture<Void> {
         return self.unsafeSetSocketOption(level: IPPROTO_IPV6, name: IPV6_MULTICAST_LOOP, value: value)
     }
 
     /// Gets the value of the socket option IPV6_MULTICAST_LOOP.
     ///
     /// - returns: An `EventLoopFuture` containing the value of the socket option, or
     ///     any error that occurred while retrieving the socket option.
-    public func getIPv6MulticastLoop() -> EventLoopFuture<CUnsignedInt> {
+    func getIPv6MulticastLoop() -> EventLoopFuture<CUnsignedInt> {
         return self.unsafeGetSocketOption(level: IPPROTO_IPV6, name: IPV6_MULTICAST_LOOP)
     }
 }

Sources/NIOHTTP1/HTTPPipelineSetup.swift

@@ -28,7 +28,7 @@ public extension ChannelPipeline {
     ///              or at the tail.
     /// - returns: An `EventLoopFuture` that will fire when the pipeline is configured.
     @available(*, deprecated, message: "Please use configureHTTPServerPipeline")
-    public func addHTTPServerHandlers(first: Bool = false) -> EventLoopFuture<Void> {
+    func addHTTPServerHandlers(first: Bool = false) -> EventLoopFuture<Void> {
         return addHandlers(HTTPResponseEncoder(), HTTPRequestDecoder(), first: first)
     }
 
@@ -38,7 +38,7 @@ public extension ChannelPipeline {
     ///     - first: Whether to add the HTTP client at the head of the channel pipeline,
     ///              or at the tail.
     /// - returns: An `EventLoopFuture` that will fire when the pipeline is configured.
-    public func addHTTPClientHandlers(first: Bool = false) -> EventLoopFuture<Void> {
+    func addHTTPClientHandlers(first: Bool = false) -> EventLoopFuture<Void> {
         return addHandlers(HTTPRequestEncoder(), HTTPResponseDecoder(), first: first)
     }
 
@@ -54,9 +54,9 @@ public extension ChannelPipeline {
     ///                                 complete.
     /// - returns: An `EventLoopFuture` that will fire when the pipeline is configured.
     @available(*, deprecated, message: "Please use configureHTTPServerPipeline")
-    public func addHTTPServerHandlersWithUpgrader(first: Bool = false,
-                                                  upgraders: [HTTPProtocolUpgrader],
-                                                  _ upgradeCompletionHandler: @escaping (ChannelHandlerContext) -> Void) -> EventLoopFuture<Void> {
+    func addHTTPServerHandlersWithUpgrader(first: Bool = false,
+                                           upgraders: [HTTPProtocolUpgrader],
+                                           _ upgradeCompletionHandler: @escaping (ChannelHandlerContext) -> Void) -> EventLoopFuture<Void> {
         let responseEncoder = HTTPResponseEncoder()
         let requestDecoder = HTTPRequestDecoder(leftOverBytesStrategy: .forwardBytes)
         let upgrader = HTTPServerUpgradeHandler(upgraders: upgraders,
@@ -93,10 +93,10 @@ public extension ChannelPipeline {
     ///         failure to parse the HTTP request) by sending 400 errors. Defaults to `false` for
     ///         backward-compatibility reasons.
     /// - returns: An `EventLoopFuture` that will fire when the pipeline is configured.
-    public func configureHTTPServerPipeline(first: Bool = false,
-                                            withPipeliningAssistance pipelining: Bool = true,
-                                            withServerUpgrade upgrade: HTTPUpgradeConfiguration? = nil,
-                                            withErrorHandling errorHandling: Bool = false) -> EventLoopFuture<Void> {
+    func configureHTTPServerPipeline(first: Bool = false,
+                                     withPipeliningAssistance pipelining: Bool = true,
+                                     withServerUpgrade upgrade: HTTPUpgradeConfiguration? = nil,
+                                     withErrorHandling errorHandling: Bool = false) -> EventLoopFuture<Void> {
         let responseEncoder = HTTPResponseEncoder()
         let requestDecoder = HTTPRequestDecoder(leftOverBytesStrategy: upgrade == nil ? .dropBytes : .forwardBytes)
 

Sources/NIOHTTP1/HTTPTypes.swift

@@ -786,7 +786,7 @@ public protocol _DeprecateHTTPHeaderIterator: Sequence { }
 extension HTTPHeaders: _DeprecateHTTPHeaderIterator { }
 public extension _DeprecateHTTPHeaderIterator {
   @available(*, deprecated, message: "Please use the HTTPHeaders.Iterator type")
-  public func makeIterator() -> AnyIterator<Element> {
+  func makeIterator() -> AnyIterator<Element> {
     return AnyIterator(makeIterator() as Iterator)
   }
 }

Sources/NIOPriorityQueue/PriorityQueue.swift

@@ -87,7 +87,7 @@ extension PriorityQueue: Sequence {
 @available(*, deprecated, message: "The NIOPriorityQueue module is deprecated and will be removed in the next major release.")
 public extension PriorityQueue {
     @available(*, deprecated, message: "The NIOPriorityQueue module is deprecated and will be removed in the next major release.")
-    public var count: Int {
+    var count: Int {
         return self.heap.count
     }
 }

Sources/NIOWebSocket/WebSocketErrorCodes.swift

@@ -150,7 +150,7 @@ public extension ByteBuffer {
     /// This method increments the reader index.
     ///
     /// - returns: The error code, or `nil` if there were not enough readable bytes.
-    public mutating func readWebSocketErrorCode() -> WebSocketErrorCode? {
+    mutating func readWebSocketErrorCode() -> WebSocketErrorCode? {
         return self.readInteger(as: UInt16.self).map { WebSocketErrorCode(networkInteger: $0) }
     }
 
@@ -162,15 +162,15 @@ public extension ByteBuffer {
     /// - parameters:
     ///     - index: The index into the buffer to read the error code from.
     /// - returns: The error code, or `nil` if there were not enough bytes at that index.
-    public func getWebSocketErrorCode(at index: Int) -> WebSocketErrorCode? {
+    func getWebSocketErrorCode(at index: Int) -> WebSocketErrorCode? {
         return self.getInteger(at: index, as: UInt16.self).map { WebSocketErrorCode(networkInteger: $0) }
     }
 
     /// Write the given error code to the buffer.
     ///
     /// - parameters:
     ///     - code: The code to write into the buffer.
-    public mutating func write(webSocketErrorCode code: WebSocketErrorCode) {
+    mutating func write(webSocketErrorCode code: WebSocketErrorCode) {
         self.write(integer: UInt16(webSocketErrorCode: code))
     }
 }
@@ -180,7 +180,7 @@ public extension UInt16 {
     ///
     /// - parameters:
     ///     - code: The `WebSocketErrorCode`.
-    public init(webSocketErrorCode code: WebSocketErrorCode) {
+    init(webSocketErrorCode code: WebSocketErrorCode) {
         switch code {
         case .normalClosure:
             self = 1000

Sources/NIOWebSocket/WebSocketFrameDecoder.swift

@@ -28,7 +28,7 @@ public enum NIOWebSocketError: Error {
 }
 
 internal extension WebSocketErrorCode {
-    internal init(_ error: NIOWebSocketError) {
+    init(_ error: NIOWebSocketError) {
         switch error {
         case .invalidFrameLength:
             self = .messageTooLarge
@@ -44,7 +44,7 @@ public extension ByteBuffer {
     ///
     /// - parameters:
     ///     - maskingKey: The masking key.
-    public mutating func webSocketUnmask(_ maskingKey: WebSocketMaskingKey, indexOffset: Int = 0) {
+    mutating func webSocketUnmask(_ maskingKey: WebSocketMaskingKey, indexOffset: Int = 0) {
         /// Shhhh: secretly unmasking and masking are the same operation!
         webSocketMask(maskingKey, indexOffset: indexOffset)
     }
@@ -57,7 +57,7 @@ public extension ByteBuffer {
     ///         This is used when masking multiple "contiguous" byte buffers, to ensure that
     ///         the masking key is applied uniformly to the collection rather than from the
     ///         start each time.
-    public mutating func webSocketMask(_ maskingKey: WebSocketMaskingKey, indexOffset: Int = 0) {
+    mutating func webSocketMask(_ maskingKey: WebSocketMaskingKey, indexOffset: Int = 0) {
         self.withUnsafeMutableReadableBytes {
             for (index, byte) in $0.enumerated() {
                 $0[index] = byte ^ maskingKey[(index + indexOffset) % 4]

Sources/NIOWebSocket/WebSocketOpcode.swift

@@ -96,7 +96,7 @@ public extension UInt8 {
     ///
     /// - parameters:
     ///     - opcode: The `WebSocketOpcode`.
-    public init?(webSocketOpcode opcode: WebSocketOpcode) {
+    init?(webSocketOpcode opcode: WebSocketOpcode) {
         switch opcode {
         case .continuation:
             self = 0x0

Sources/NIOWebSocket/WebSocketUpgrader.swift

@@ -29,7 +29,7 @@ public enum NIOWebSocketUpgradeError: Error {
 }
 
 fileprivate extension HTTPHeaders {
-    fileprivate func nonListHeader(_ name: String) throws -> String {
+    func nonListHeader(_ name: String) throws -> String {
         let fields = self[canonicalForm: name]
         guard fields.count == 1 else {
             throw NIOWebSocketUpgradeError.invalidUpgradeHeader