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import "net/http/httptrace"
概述
索引
示例
httptrace包提供跟踪HTTP客户端请求中的事件的机制。
package mainimport ("fmt""log""net/http""net/http/httptrace")func main() { req, _ := http.NewRequest("GET", "http://example.com", nil) trace := &httptrace.ClientTrace{ GotConn: func(connInfo httptrace.GotConnInfo) { fmt.Printf("Got Conn: %+v\n", connInfo)}, DNSDone: func(dnsInfo httptrace.DNSDoneInfo) { fmt.Printf("DNS Info: %+v\n", dnsInfo)},} req = req.WithContext(httptrace.WithClientTrace(req.Context(), trace)) _, err := http.DefaultTransport.RoundTrip(req)if err != nil { log.Fatal(err)}}
func WithClientTrace(ctx context.Context, trace *ClientTrace) context.Context
type ClientTrace
func ContextClientTrace(ctx context.Context) *ClientTrace
type DNSDoneInfo
type DNSStartInfo
type GotConnInfo
type WroteRequestInfo
包
trace.go
func WithClientTrace(ctx context.Context, trace *ClientTrace) context.Context
WithClientTrace根据提供的父ctx返回一个新的上下文。除了使用ctx注册的任何以前的挂钩外,使用返回的上下文创建的HTTP客户端请求将使用提供的跟踪挂钩。在提供的轨迹中定义的任何钩子将首先被调用。
ClientTrace是一组挂钩,可以在传出的HTTP请求的各个阶段运行。任何特定的钩子可能是零。函数可以从不同的goroutine同时调用,有些可能在请求完成或失败后调用。
ClientTrace当前在单次往返过程中跟踪单个HTTP请求和响应,并且没有跨越一系列重定向请求的挂钩。
type ClientTrace struct { // GetConn is called before a connection is created or // retrieved from an idle pool. The hostPort is the // "host:port" of the target or proxy. GetConn is called even // if there's already an idle cached connection available. GetConn func(hostPort string) // GotConn is called after a successful connection is // obtained. There is no hook for failure to obtain a // connection; instead, use the error from // Transport.RoundTrip. GotConn func(GotConnInfo) // PutIdleConn is called when the connection is returned to // the idle pool. If err is nil, the connection was // successfully returned to the idle pool. If err is non-nil, // it describes why not. PutIdleConn is not called if // connection reuse is disabled via Transport.DisableKeepAlives. // PutIdleConn is called before the caller's Response.Body.Close // call returns. // For HTTP/2, this hook is not currently used. PutIdleConn func(err error) // GotFirstResponseByte is called when the first byte of the response // headers is available. GotFirstResponseByte func() // Got100Continue is called if the server replies with a "100 // Continue" response. Got100Continue func() // DNSStart is called when a DNS lookup begins. DNSStart func(DNSStartInfo) // DNSDone is called when a DNS lookup ends. DNSDone func(DNSDoneInfo) // ConnectStart is called when a new connection's Dial begins. // If net.Dialer.DualStack (IPv6 "Happy Eyeballs") support is // enabled, this may be called multiple times. ConnectStart func(network, addr string) // ConnectDone is called when a new connection's Dial // completes. The provided err indicates whether the // connection completedly successfully. // If net.Dialer.DualStack ("Happy Eyeballs") support is // enabled, this may be called multiple times. ConnectDone func(network, addr string, err error) // TLSHandshakeStart is called when the TLS handshake is started. When // connecting to a HTTPS site via a HTTP proxy, the handshake happens after // the CONNECT request is processed by the proxy. TLSHandshakeStart func() // TLSHandshakeDone is called after the TLS handshake with either the // successful handshake's connection state, or a non-nil error on handshake // failure. TLSHandshakeDone func(tls.ConnectionState, error) // WroteHeaders is called after the Transport has written // the request headers. WroteHeaders func() // Wait100Continue is called if the Request specified // "Expected: 100-continue" and the Transport has written the // request headers but is waiting for "100 Continue" from the // server before writing the request body. Wait100Continue func() // WroteRequest is called with the result of writing the // request and any body. It may be called multiple times // in the case of retried requests. WroteRequest func(WroteRequestInfo)}
func ContextClientTrace(ctx context.Context) *ClientTrace
ContextClientTrace返回与提供的上下文关联的ClientTrace。如果没有,则返回零。
DNSDoneInfo包含有关DNS查找结果的信息。
type DNSDoneInfo struct { // Addrs are the IPv4 and/or IPv6 addresses found in the DNS // lookup. The contents of the slice should not be mutated. Addrs []net.IPAddr // Err is any error that occurred during the DNS lookup. Err error // Coalesced is whether the Addrs were shared with another // caller who was doing the same DNS lookup concurrently. Coalesced bool}
DNSStartInfo包含有关DNS请求的信息。
type DNSStartInfo struct { Host string}
GotConnInfo是ClientTrace.GotConn函数的参数,并包含有关获取的连接的信息。
type GotConnInfo struct { // Conn is the connection that was obtained. It is owned by // the http.Transport and should not be read, written or // closed by users of ClientTrace. Conn net.Conn // Reused is whether this connection has been previously // used for another HTTP request. Reused bool // WasIdle is whether this connection was obtained from an // idle pool. WasIdle bool // IdleTime reports how long the connection was previously // idle, if WasIdle is true. IdleTime time.Duration}
WroteRequestInfo包含提供给WroteRequest钩子的信息。
type WroteRequestInfo struct { // Err is any error encountered while writing the Request. Err error}