swift-nio/Sources/NIOCore/IOData.swift

71 lines
2.4 KiB
Swift

//===----------------------------------------------------------------------===//
//
// This source file is part of the SwiftNIO open source project
//
// Copyright (c) 2017-2018 Apple Inc. and the SwiftNIO project authors
// Licensed under Apache License v2.0
//
// See LICENSE.txt for license information
// See CONTRIBUTORS.txt for the list of SwiftNIO project authors
//
// SPDX-License-Identifier: Apache-2.0
//
//===----------------------------------------------------------------------===//
/// `IOData` unifies standard SwiftNIO types that are raw bytes of data; currently `ByteBuffer` and `FileRegion`.
///
/// Many `ChannelHandler`s receive or emit bytes and in most cases this can be either a `ByteBuffer` or a `FileRegion`
/// from disk. To still form a well-typed `ChannelPipeline` such handlers should receive and emit value of type `IOData`.
public enum IOData {
/// A `ByteBuffer`.
case byteBuffer(ByteBuffer)
/// A `FileRegion`.
///
/// Sending a `FileRegion` through the `ChannelPipeline` using `write` can be useful because some `Channel`s can
/// use `sendfile` to send a `FileRegion` more efficiently.
case fileRegion(FileRegion)
}
/// `IOData` objects are comparable just like the values they wrap.
extension IOData: Equatable {}
@available(*, unavailable)
extension IOData: Sendable {}
/// `IOData` provide a number of readable bytes.
extension IOData {
/// Returns the number of readable bytes in this `IOData`.
public var readableBytes: Int {
switch self {
case .byteBuffer(let buf):
return buf.readableBytes
case .fileRegion(let region):
return region.readableBytes
}
}
/// Move the readerIndex forward by `offset`.
public mutating func moveReaderIndex(forwardBy: Int) {
switch self {
case .byteBuffer(var buffer):
buffer.moveReaderIndex(forwardBy: forwardBy)
self = .byteBuffer(buffer)
case .fileRegion(var fileRegion):
fileRegion.moveReaderIndex(forwardBy: forwardBy)
self = .fileRegion(fileRegion)
}
}
}
extension IOData: CustomStringConvertible {
public var description: String {
switch self {
case .byteBuffer(let byteBuffer):
return "IOData { \(byteBuffer) }"
case .fileRegion(let fileRegion):
return "IOData { \(fileRegion) }"
}
}
}