使用SwiftNIO和SwiftNIOHTTP2作为HTTP2客户端
我目前正在使用SwiftNIO和SwiftNIOHTTP2测试版在Swift中开发一个简单的HTTP2客户端。 我的实现如下所示:使用SwiftNIO和SwiftNIOHTTP2作为HTTP2客户端,swift,http2,nghttp2,swift-nio,Swift,Http2,Nghttp2,Swift Nio,我目前正在使用SwiftNIO和SwiftNIOHTTP2测试版在Swift中开发一个简单的HTTP2客户端。 我的实现如下所示: let group = MultiThreadedEventLoopGroup(numberOfThreads: 1) let bootstrap = ClientBootstrap(group: group) .channelOption(ChannelOptions.socket(SocketOptionLevel(SOL_SOCKET), SO_REU
let group = MultiThreadedEventLoopGroup(numberOfThreads: 1)
let bootstrap = ClientBootstrap(group: group)
.channelOption(ChannelOptions.socket(SocketOptionLevel(SOL_SOCKET), SO_REUSEADDR), value: 1)
.channelInitializer { channel in
channel.pipeline.add(handler: HTTP2Parser(mode: .client)).then {
let multiplexer = HTTP2StreamMultiplexer { (channel, streamID) -> EventLoopFuture<Void> in
return channel.pipeline.add(handler: HTTP2ToHTTP1ClientCodec(streamID: streamID, httpProtocol: .https))
}
return channel.pipeline.add(handler: multiplexer)
}
}
defer {
try! group.syncShutdownGracefully()
}
let url = URL(string: "https://strnmn.me")!
_ = try bootstrap.connect(host: url.host!, port: url.port ?? 443)
.wait()
let group=multi-threadedeventloopgroup(线程数:1)
let bootstrap=ClientBootstrap(组:group)
.channelOption(ChannelOptions.socket(SocketOptionLevel(SOL\u socket),SO\u REUSEADDR),值:1)
.channelInitializer{channel in
channel.pipeline.add(处理程序:HTTP2Parser(模式:.client))。然后{
让多路复用器=HTTP2StreamMultiplexer{(通道,streamID)->未来的事件循环
返回channel.pipeline.add(处理程序:http2tohtp1clientcodec(streamID:streamID,httpProtocol:.https))
}
返回channel.pipeline.add(处理程序:多路复用器)
}
}
推迟{
试试!group.syncShutdownGracefully()
}
让url=url(字符串:https://strnmn.me")!
_=尝试引导.connect(主机:url.host!,端口:url.port??443)
.等等
不幸的是,连接总是失败并出现错误:
nghttp2错误:当我们需要设置帧时,远程对等方返回了意外数据。也许,peer不正确地支持HTTP/2
但是,从命令行使用nghttp2连接并发出一个简单的请求可以正常工作
$ nghttp -vn https://strnmn.me
[ 0.048] Connected
The negotiated protocol: h2
[ 0.110] recv SETTINGS frame <length=18, flags=0x00, stream_id=0>
(niv=3)
[SETTINGS_MAX_CONCURRENT_STREAMS(0x03):128]
[SETTINGS_INITIAL_WINDOW_SIZE(0x04):65536]
[SETTINGS_MAX_FRAME_SIZE(0x05):16777215]
[ 0.110] recv WINDOW_UPDATE frame <length=4, flags=0x00, stream_id=0>
(window_size_increment=2147418112)
[ 0.110] send SETTINGS frame <length=12, flags=0x00, stream_id=0>
(niv=2)
[SETTINGS_MAX_CONCURRENT_STREAMS(0x03):100]
[SETTINGS_INITIAL_WINDOW_SIZE(0x04):65535]
[ 0.110] send SETTINGS frame <length=0, flags=0x01, stream_id=0>
; ACK
(niv=0)
[ 0.110] send PRIORITY frame <length=5, flags=0x00, stream_id=3>
(dep_stream_id=0, weight=201, exclusive=0)
[ 0.110] send PRIORITY frame <length=5, flags=0x00, stream_id=5>
(dep_stream_id=0, weight=101, exclusive=0)
[ 0.110] send PRIORITY frame <length=5, flags=0x00, stream_id=7>
(dep_stream_id=0, weight=1, exclusive=0)
[ 0.110] send PRIORITY frame <length=5, flags=0x00, stream_id=9>
(dep_stream_id=7, weight=1, exclusive=0)
[ 0.110] send PRIORITY frame <length=5, flags=0x00, stream_id=11>
(dep_stream_id=3, weight=1, exclusive=0)
[ 0.111] send HEADERS frame <length=35, flags=0x25, stream_id=13>
; END_STREAM | END_HEADERS | PRIORITY
(padlen=0, dep_stream_id=11, weight=16, exclusive=0)
; Open new stream
:method: GET
:path: /
:scheme: https
:authority: strnmn.me
accept: */*
accept-encoding: gzip, deflate
user-agent: nghttp2/1.34.0
[ 0.141] recv SETTINGS frame <length=0, flags=0x01, stream_id=0>
; ACK
(niv=0)
[ 0.141] recv (stream_id=13) :status: 200
[ 0.141] recv (stream_id=13) server: nginx
[ 0.141] recv (stream_id=13) date: Sat, 24 Nov 2018 16:29:13 GMT
[ 0.141] recv (stream_id=13) content-type: text/html
[ 0.141] recv (stream_id=13) last-modified: Sat, 01 Jul 2017 20:23:11 GMT
[ 0.141] recv (stream_id=13) vary: Accept-Encoding
[ 0.141] recv (stream_id=13) etag: W/"595804af-8a"
[ 0.141] recv (stream_id=13) expires: Sat, 24 Nov 2018 16:39:13 GMT
[ 0.141] recv (stream_id=13) cache-control: max-age=600
[ 0.141] recv (stream_id=13) x-frame-options: SAMEORIGIN
[ 0.141] recv (stream_id=13) content-encoding: gzip
[ 0.141] recv HEADERS frame <length=185, flags=0x04, stream_id=13>
; END_HEADERS
(padlen=0)
; First response header
[ 0.142] recv DATA frame <length=114, flags=0x01, stream_id=13>
; END_STREAM
[ 0.142] send GOAWAY frame <length=8, flags=0x00, stream_id=0>
(last_stream_id=0, error_code=NO_ERROR(0x00), opaque_data(0)=[])
$nghttp-vnhttps://strnmn.me
[0.048]已连接
谈判达成的议定书:h2
[0.110]recv设置帧
(niv=3)
[设置\u最大\u并发\u流(0x03):128]
[设置\初始\窗口\大小(0x04):65536]
[设置最大帧大小(0x05):16777215]
[0.110]记录窗口\更新帧
(窗口大小增量=2147418112)
[0.110]发送设置帧
(niv=2)
[设置\u最大\u并发\u流(0x03):100]
[设置\初始\窗口大小(0x04):65535]
[0.110]发送设置帧
; 阿克
(niv=0)
[0.110]发送优先级帧
(dep_stream_id=0,weight=201,exclusive=0)
[0.110]发送优先级帧
(dep_stream_id=0,weight=101,exclusive=0)
[0.110]发送优先级帧
(dep_stream_id=0,weight=1,exclusive=0)
[0.110]发送优先级帧
(dep_stream_id=7,weight=1,exclusive=0)
[0.110]发送优先级帧
(dep_stream_id=3,weight=1,exclusive=0)
[0.111]发送标题帧
; 结束流|结束头|优先级
(padlen=0,dep\u stream\u id=11,weight=16,exclusive=0)
; 开源节流
:方法:获取
:路径:/
:scheme:https
:权威:strnmn.me
接受:*/*
接受编码:gzip,deflate
用户代理:nghttp2/1.34.0
[0.141]recv设置帧
; 阿克
(niv=0)
[0.141]recv(流id=13):状态:200
[0.141]recv(stream_id=13)服务器:nginx
[0.141]recv(stream_id=13)日期:2018年11月24日星期六格林威治标准时间16:29:13
[0.141]recv(stream_id=13)内容类型:text/html
[0.141]recv(stream_id=13)最后修改时间:2017年7月1日星期六20:23:11 GMT
[0.141]recv(流id=13)变化:接受编码
[0.141]recv(stream_id=13)etag:W/“595804af-8a”
[0.141]recv(stream_id=13)到期时间:2018年11月24日星期六格林威治标准时间16:39:13
[0.141]recv(流id=13)缓存控制:最大年龄=600
[0.141]recv(stream_id=13)x帧选项:SAMEORIGIN
[0.141]recv(stream_id=13)内容编码:gzip
[0.141]接收头帧
; 端头
(padlen=0)
; 第一响应头
[0.142]recv数据帧
; 尾流
[0.142]发送球门框架
(最后一个\u流\u id=0,错误\u代码=无错误(0x00),不透明\u数据(0)=[])
如何使用SwiftNIOHTTP2建立会话并发出GET请求?这是一个非常好的问题!让我们首先分析为什么这比发送HTTP/1.x请求更复杂。从广义上讲,这些问题分为两类:
443
),因此我们需要告诉服务器我们想要说HTTP/2,因为为了向后兼容,默认值仍然是HTTP/1。我们可以使用一个名为的机制来实现这一点,另一个选项是执行HTTP/1升级到HTTP2,但这更复杂,性能也更低,所以我们不要在这里这样做“h2”
ALPN协议标识符,它将告诉服务器我们想要使用HTTP/2,如中所述
好的,让我们添加TLS,并在其前面设置sslContext
:
let sslHandler = try! OpenSSLClientHandler(context: sslContext, serverHostname: hostname)
同样重要的是,我们告诉OpenSSLClientHandler
服务器的主机名,以便它能够正确验证证书
最后,我们需要做3a(创建一个新的HTTP/2流来发出我们的请求),这可以使用ChannelHandler
轻松完成:
/// Creates a new HTTP/2 stream when our channel is active and adds the `SendAGETRequestHandler` so a request is sent.
final class CreateRequestStreamHandler: ChannelInboundHandler {
typealias InboundIn = Never
private let multiplexer: HTTP2StreamMultiplexer
private let responseReceivedPromise: EventLoopPromise<[HTTPClientResponsePart]>
init(multiplexer: HTTP2StreamMultiplexer, responseReceivedPromise: EventLoopPromise<[HTTPClientResponsePart]>) {
self.multiplexer = multiplexer
self.responseReceivedPromise = responseReceivedPromise
}
func channelActive(ctx: ChannelHandlerContext) {
func requestStreamInitializer(channel: Channel, streamID: HTTP2StreamID) -> EventLoopFuture<Void> {
return channel.pipeline.addHandlers([HTTP2ToHTTP1ClientCodec(streamID: streamID, httpProtocol: .https),
SendAGETRequestHandler(responseReceivedPromise: self.responseReceivedPromise)],
first: false)
}
// this is the most important line: When the channel is active we add the `HTTP2ToHTTP1ClientCodec` to deal in HTTP/1 messages as well as the `SendAGETRequestHandler` which will send a request.
self.multiplexer.createStreamChannel(promise: nil, requestStreamInitializer)
}
}
要完成它,让我们设置客户端的通道管道:
let bootstrap = ClientBootstrap(group: group)
.channelInitializer { channel in
let myEventLoop = channel.eventLoop
let sslHandler = try! OpenSSLClientHandler(context: sslContext, serverHostname: hostname)
let http2Parser = HTTP2Parser(mode: .client)
let http2Multiplexer = HTTP2StreamMultiplexer { (channel, streamID) -> EventLoopFuture<Void> in
return myEventLoop.newSucceededFuture(result: ())
}
return channel.pipeline.addHandlers([sslHandler,
http2Parser,
http2Multiplexer,
CreateRequestStreamHandler(multiplexer: http2Multiplexer,
responseReceivedPromise: responseReceivedPromise),
CollectErrorsAndCloseStreamHandler(responseReceivedPromise: responseReceivedPromise)],
first: false).map {
}
}
let bootstrap=ClientBootstrap(组:组)
/// Fires off a GET request when our stream is active and collects all response parts into a promise.
///
/// - warning: This will read the whole response into memory and delivers it into a promise.
final class SendAGETRequestHandler: ChannelInboundHandler {
typealias InboundIn = HTTPClientResponsePart
typealias OutboundOut = HTTPClientRequestPart
private let responseReceivedPromise: EventLoopPromise<[HTTPClientResponsePart]>
private var responsePartAccumulator: [HTTPClientResponsePart] = []
init(responseReceivedPromise: EventLoopPromise<[HTTPClientResponsePart]>) {
self.responseReceivedPromise = responseReceivedPromise
}
func channelActive(ctx: ChannelHandlerContext) {
assert(ctx.channel.parent!.isActive)
var reqHead = HTTPRequestHead(version: .init(major: 2, minor: 0), method: .GET, uri: "/")
reqHead.headers.add(name: "Host", value: hostname)
ctx.write(self.wrapOutboundOut(.head(reqHead)), promise: nil)
ctx.writeAndFlush(self.wrapOutboundOut(.end(nil)), promise: nil)
}
func channelRead(ctx: ChannelHandlerContext, data: NIOAny) {
let resPart = self.unwrapInboundIn(data)
self.responsePartAccumulator.append(resPart)
if case .end = resPart {
self.responseReceivedPromise.succeed(result: self.responsePartAccumulator)
}
}
}
let bootstrap = ClientBootstrap(group: group)
.channelInitializer { channel in
let myEventLoop = channel.eventLoop
let sslHandler = try! OpenSSLClientHandler(context: sslContext, serverHostname: hostname)
let http2Parser = HTTP2Parser(mode: .client)
let http2Multiplexer = HTTP2StreamMultiplexer { (channel, streamID) -> EventLoopFuture<Void> in
return myEventLoop.newSucceededFuture(result: ())
}
return channel.pipeline.addHandlers([sslHandler,
http2Parser,
http2Multiplexer,
CreateRequestStreamHandler(multiplexer: http2Multiplexer,
responseReceivedPromise: responseReceivedPromise),
CollectErrorsAndCloseStreamHandler(responseReceivedPromise: responseReceivedPromise)],
first: false).map {
}
}