decentral1se
9e9227b420
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continuous-integration/drone/push Build is passing
55 lines
1.4 KiB
Go
55 lines
1.4 KiB
Go
package client
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import (
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"io"
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"net/http"
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"sync/atomic"
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)
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// KeepAliveTransport drains the remaining body from a response
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// so that go will reuse the TCP connections.
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// This is not enabled by default because there are servers where
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// the response never gets closed and that would make the code hang forever.
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// So instead it's provided as a http client middleware that can be used to override
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// any request.
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func KeepAliveTransport(rt http.RoundTripper) http.RoundTripper {
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return &keepAliveTransport{wrapped: rt}
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}
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type keepAliveTransport struct {
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wrapped http.RoundTripper
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}
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func (k *keepAliveTransport) RoundTrip(r *http.Request) (*http.Response, error) {
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resp, err := k.wrapped.RoundTrip(r)
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if err != nil {
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return resp, err
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}
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resp.Body = &drainingReadCloser{rdr: resp.Body}
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return resp, nil
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}
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type drainingReadCloser struct {
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rdr io.ReadCloser
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seenEOF uint32
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}
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func (d *drainingReadCloser) Read(p []byte) (n int, err error) {
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n, err = d.rdr.Read(p)
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if err == io.EOF || n == 0 {
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atomic.StoreUint32(&d.seenEOF, 1)
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}
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return
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}
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func (d *drainingReadCloser) Close() error {
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// drain buffer
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if atomic.LoadUint32(&d.seenEOF) != 1 {
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// If the reader side (a HTTP server) is misbehaving, it still may send
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// some bytes, but the closer ignores them to keep the underling
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// connection open.
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_, _ = io.Copy(io.Discard, d.rdr)
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}
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return d.rdr.Close()
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}
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