| // Copyright 2016 The Go Authors. All rights reserved. | |
| // Use of this source code is governed by a BSD-style | |
| // license that can be found in the LICENSE file. | |
| // Package nettrace contains internal hooks for tracing activity in | |
| // the net package. This package is purely internal for use by the | |
| // net/http/httptrace package and has no stable API exposed to end | |
| // users. | |
| package nettrace | |
| // TraceKey is a context.Context Value key. Its associated value should | |
| // be a *Trace struct. | |
| type TraceKey struct{} | |
| // LookupIPAltResolverKey is a context.Context Value key used by tests to | |
| // specify an alternate resolver func. | |
| // It is not exposed to outsider users. (But see issue 12503) | |
| // The value should be the same type as lookupIP: | |
| // | |
| // func lookupIP(ctx context.Context, host string) ([]IPAddr, error) | |
| type LookupIPAltResolverKey struct{} | |
| // Trace contains a set of hooks for tracing events within | |
| // the net package. Any specific hook may be nil. | |
| type Trace struct { | |
| // DNSStart is called with the hostname of a DNS lookup | |
| // before it begins. | |
| DNSStart func(name string) | |
| // DNSDone is called after a DNS lookup completes (or fails). | |
| // The coalesced parameter is whether singleflight de-duped | |
| // the call. The addrs are of type net.IPAddr but can't | |
| // actually be for circular dependency reasons. | |
| DNSDone func(netIPs []any, coalesced bool, err error) | |
| // ConnectStart is called before a Dial, excluding Dials made | |
| // during DNS lookups. In the case of DualStack (Happy Eyeballs) | |
| // dialing, this may be called multiple times, from multiple | |
| // goroutines. | |
| ConnectStart func(network, addr string) | |
| // ConnectDone is called after a Dial with the results, excluding | |
| // Dials made during DNS lookups. It may also be called multiple | |
| // times, like ConnectStart. | |
| ConnectDone func(network, addr string, err error) | |
| } | |