mirror of
https://github.com/apple/swift-nio-extras.git
synced 2025-05-14 00:42:41 +08:00
9cdb93e321
Motivation Per SwiftNIO's formal version policy, we are ready to drop support for Swift 5.5. Modifications This patch removes the support for 5.5 and all supporting infrastructure. This includes the test generation functionality, which is no longer required, as well as the files generated by that functionality. It updates the dockerfile for 5.8, and it removes all conditional compilation checks that are now definitionally true. Result A nice, clean, 5.6+ codebase
97 lines
3.8 KiB
Swift
97 lines
3.8 KiB
Swift
//===----------------------------------------------------------------------===//
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//
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// This source file is part of the SwiftNIO open source project
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//
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// Copyright (c) 2017-2021 Apple Inc. and the SwiftNIO project authors
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// Licensed under Apache License v2.0
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//
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// See LICENSE.txt for license information
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// See CONTRIBUTORS.txt for the list of SwiftNIO project authors
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//
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// SPDX-License-Identifier: Apache-2.0
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//
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//===----------------------------------------------------------------------===//
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import NIOCore
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/// A decoder that splits incoming `ByteBuffer`s around line end
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/// character(s) (`'\n'` or `'\r\n'`).
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///
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/// Let's, for example, consider the following received buffer:
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///
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/// +----+-------+------------+
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/// | AB | C\nDE | F\r\nGHI\n |
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/// +----+-------+------------+
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///
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/// A instance of ``LineBasedFrameDecoder`` will split this buffer
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/// as follows:
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///
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/// +-----+-----+-----+
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/// | ABC | DEF | GHI |
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/// +-----+-----+-----+
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///
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public class LineBasedFrameDecoder: ByteToMessageDecoder {
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/// `ByteBuffer` is the expected type passed in.
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public typealias InboundIn = ByteBuffer
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/// `ByteBuffer`s will be passed to the next stage.
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public typealias InboundOut = ByteBuffer
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@available(*, deprecated, message: "No longer used")
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public var cumulationBuffer: ByteBuffer?
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// keep track of the last scan offset from the buffer's reader index (if we didn't find the delimiter)
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private var lastScanOffset = 0
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public init() { }
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/// Decode data in the supplied buffer.
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/// - Parameters:
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/// - context: Calling cotext
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/// - buffer: Buffer containing data to decode.
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/// - Returns: State describing if more data is required.
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public func decode(context: ChannelHandlerContext, buffer: inout ByteBuffer) throws -> DecodingState {
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if let frame = try self.findNextFrame(buffer: &buffer) {
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context.fireChannelRead(wrapInboundOut(frame))
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return .continue
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} else {
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return .needMoreData
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}
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}
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/// Decode all remaining data.
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/// If it is not possible to consume all the data then ``NIOExtrasErrors/LeftOverBytesError`` is reported via `context.fireErrorCaught`
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/// - Parameters:
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/// - context: Calling context.
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/// - buffer: Buffer containing the data to decode.
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/// - seenEOF: Has end of file been seen.
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/// - Returns: Always .needMoreData as all data will be consumed.
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public func decodeLast(context: ChannelHandlerContext, buffer: inout ByteBuffer, seenEOF: Bool) throws -> DecodingState {
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while try self.decode(context: context, buffer: &buffer) == .continue {}
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if buffer.readableBytes > 0 {
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context.fireErrorCaught(NIOExtrasErrors.LeftOverBytesError(leftOverBytes: buffer))
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}
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return .needMoreData
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}
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private func findNextFrame(buffer: inout ByteBuffer) throws -> ByteBuffer? {
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let view = buffer.readableBytesView.dropFirst(self.lastScanOffset)
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// look for the delimiter
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if let delimiterIndex = view.firstIndex(of: 0x0A) { // '\n'
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let length = delimiterIndex - buffer.readerIndex
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let dropCarriageReturn = delimiterIndex > buffer.readableBytesView.startIndex &&
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buffer.readableBytesView[delimiterIndex - 1] == 0x0D // '\r'
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let buff = buffer.readSlice(length: dropCarriageReturn ? length - 1 : length)
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// drop the delimiter (and trailing carriage return if appicable)
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buffer.moveReaderIndex(forwardBy: dropCarriageReturn ? 2 : 1)
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// reset the last scan start index since we found a line
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self.lastScanOffset = 0
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return buff
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}
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// next scan we start where we stopped
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self.lastScanOffset = buffer.readableBytes
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return nil
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}
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}
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@available(*, unavailable)
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extension LineBasedFrameDecoder: Sendable {}
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