mirror of
https://github.com/apple/swift-nio-extras.git
synced 2025-05-14 00:42:41 +08:00
da7c04777b
* Improve documentation for NIOExtras Motivation: Docs will help users do things correctly. Modifications: Add missing comments, improve links. Result: Better docc documentation * Docc in NIOHTTPCompression * NIOSOCKS docc * Correct bad symbol * Minor typo Co-authored-by: Cory Benfield <lukasa@apple.com>
94 lines
3.8 KiB
Swift
94 lines
3.8 KiB
Swift
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This source file is part of the SwiftNIO open source project
|
|
//
|
|
// Copyright (c) 2017-2021 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
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
import NIOCore
|
|
|
|
/// A decoder that splits incoming `ByteBuffer`s around line end
|
|
/// character(s) (`'\n'` or `'\r\n'`).
|
|
///
|
|
/// Let's, for example, consider the following received buffer:
|
|
///
|
|
/// +----+-------+------------+
|
|
/// | AB | C\nDE | F\r\nGHI\n |
|
|
/// +----+-------+------------+
|
|
///
|
|
/// A instance of ``LineBasedFrameDecoder`` will split this buffer
|
|
/// as follows:
|
|
///
|
|
/// +-----+-----+-----+
|
|
/// | ABC | DEF | GHI |
|
|
/// +-----+-----+-----+
|
|
///
|
|
public class LineBasedFrameDecoder: ByteToMessageDecoder {
|
|
/// `ByteBuffer` is the expected type passed in.
|
|
public typealias InboundIn = ByteBuffer
|
|
/// `ByteBuffer`s will be passed to the next stage.
|
|
public typealias InboundOut = ByteBuffer
|
|
|
|
@available(*, deprecated, message: "No longer used")
|
|
public var cumulationBuffer: ByteBuffer?
|
|
// keep track of the last scan offset from the buffer's reader index (if we didn't find the delimiter)
|
|
private var lastScanOffset = 0
|
|
|
|
public init() { }
|
|
|
|
/// Decode data in the supplied buffer.
|
|
/// - Parameters:
|
|
/// - context: Calling cotext
|
|
/// - buffer: Buffer containing data to decode.
|
|
/// - Returns: State describing if more data is required.
|
|
public func decode(context: ChannelHandlerContext, buffer: inout ByteBuffer) throws -> DecodingState {
|
|
if let frame = try self.findNextFrame(buffer: &buffer) {
|
|
context.fireChannelRead(wrapInboundOut(frame))
|
|
return .continue
|
|
} else {
|
|
return .needMoreData
|
|
}
|
|
}
|
|
|
|
/// Decode all remaining data.
|
|
/// If it is not possible to consume all the data then ``NIOExtrasErrors/LeftOverBytesError`` is reported via `context.fireErrorCaught`
|
|
/// - Parameters:
|
|
/// - context: Calling context.
|
|
/// - buffer: Buffer containing the data to decode.
|
|
/// - seenEOF: Has end of file been seen.
|
|
/// - Returns: Always .needMoreData as all data will be consumed.
|
|
public func decodeLast(context: ChannelHandlerContext, buffer: inout ByteBuffer, seenEOF: Bool) throws -> DecodingState {
|
|
while try self.decode(context: context, buffer: &buffer) == .continue {}
|
|
if buffer.readableBytes > 0 {
|
|
context.fireErrorCaught(NIOExtrasErrors.LeftOverBytesError(leftOverBytes: buffer))
|
|
}
|
|
return .needMoreData
|
|
}
|
|
|
|
private func findNextFrame(buffer: inout ByteBuffer) throws -> ByteBuffer? {
|
|
let view = buffer.readableBytesView.dropFirst(self.lastScanOffset)
|
|
// look for the delimiter
|
|
if let delimiterIndex = view.firstIndex(of: 0x0A) { // '\n'
|
|
let length = delimiterIndex - buffer.readerIndex
|
|
let dropCarriageReturn = delimiterIndex > buffer.readableBytesView.startIndex &&
|
|
buffer.readableBytesView[delimiterIndex - 1] == 0x0D // '\r'
|
|
let buff = buffer.readSlice(length: dropCarriageReturn ? length - 1 : length)
|
|
// drop the delimiter (and trailing carriage return if appicable)
|
|
buffer.moveReaderIndex(forwardBy: dropCarriageReturn ? 2 : 1)
|
|
// reset the last scan start index since we found a line
|
|
self.lastScanOffset = 0
|
|
return buff
|
|
}
|
|
// next scan we start where we stopped
|
|
self.lastScanOffset = buffer.readableBytes
|
|
return nil
|
|
}
|
|
}
|