status-go/vendor/github.com/anacrolix/missinggo/httptoo/inproc_roundtrip.go

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2022-03-10 09:44:48 +00:00
package httptoo
import (
"context"
"io"
"net/http"
"sync"
"github.com/anacrolix/missinggo"
)
type responseWriter struct {
mu sync.Mutex
r http.Response
headerWritten missinggo.Event
bodyWriter io.WriteCloser
bodyClosed missinggo.SynchronizedEvent
}
var _ interface {
http.ResponseWriter
// We're able to emulate this easily enough.
http.CloseNotifier
} = &responseWriter{}
// Use Request.Context.Done instead.
func (me *responseWriter) CloseNotify() <-chan bool {
ret := make(chan bool, 1)
go func() {
<-me.bodyClosed.C()
ret <- true
}()
return ret
}
func (me *responseWriter) Header() http.Header {
if me.r.Header == nil {
me.r.Header = make(http.Header)
}
return me.r.Header
}
func (me *responseWriter) Write(b []byte) (int, error) {
me.mu.Lock()
if !me.headerWritten.IsSet() {
me.writeHeader(200)
}
me.mu.Unlock()
return me.bodyWriter.Write(b)
}
func (me *responseWriter) WriteHeader(status int) {
me.mu.Lock()
me.writeHeader(status)
me.mu.Unlock()
}
func (me *responseWriter) writeHeader(status int) {
if me.headerWritten.IsSet() {
return
}
me.r.StatusCode = status
me.headerWritten.Set()
}
func (me *responseWriter) runHandler(h http.Handler, req *http.Request) {
var pr *io.PipeReader
pr, me.bodyWriter = io.Pipe()
me.r.Body = struct {
io.Reader
io.Closer
}{pr, eventCloser{pr, &me.bodyClosed}}
// Shouldn't be writing to the response after the handler returns.
defer me.bodyWriter.Close()
// Send a 200 if nothing was written yet.
defer me.WriteHeader(200)
// Wrap the context in the given Request with one that closes when either
// the handler returns, or the response body is closed.
ctx, cancel := context.WithCancel(req.Context())
defer cancel()
go func() {
<-me.bodyClosed.C()
cancel()
}()
h.ServeHTTP(me, req.WithContext(ctx))
}
type eventCloser struct {
c io.Closer
closed *missinggo.SynchronizedEvent
}
func (me eventCloser) Close() (err error) {
err = me.c.Close()
me.closed.Set()
return
}
func RoundTripHandler(req *http.Request, h http.Handler) (*http.Response, error) {
rw := responseWriter{}
go rw.runHandler(h, req)
<-rw.headerWritten.LockedChan(&rw.mu)
return &rw.r, nil
}
type InProcRoundTripper struct {
Handler http.Handler
}
func (me *InProcRoundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
return RoundTripHandler(req, me.Handler)
}