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author | Christopher Speller <crspeller@gmail.com> | 2016-10-03 16:03:15 -0400 |
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committer | GitHub <noreply@github.com> | 2016-10-03 16:03:15 -0400 |
commit | 8f91c777559748fa6e857d9fc1f4ae079a532813 (patch) | |
tree | 190f7cef373764a0d47a91045fdb486ee3d6781d /vendor/github.com/miekg/dns/singleinflight.go | |
parent | 5f8e5c401bd96cba9a98b2db02d72f9cbacb0103 (diff) | |
download | chat-8f91c777559748fa6e857d9fc1f4ae079a532813.tar.gz chat-8f91c777559748fa6e857d9fc1f4ae079a532813.tar.bz2 chat-8f91c777559748fa6e857d9fc1f4ae079a532813.zip |
Adding ability to serve TLS directly from Mattermost server (#4119)
Diffstat (limited to 'vendor/github.com/miekg/dns/singleinflight.go')
-rw-r--r-- | vendor/github.com/miekg/dns/singleinflight.go | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/vendor/github.com/miekg/dns/singleinflight.go b/vendor/github.com/miekg/dns/singleinflight.go new file mode 100644 index 000000000..9573c7d0b --- /dev/null +++ b/vendor/github.com/miekg/dns/singleinflight.go @@ -0,0 +1,57 @@ +// Copyright 2013 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. + +// Adapted for dns package usage by Miek Gieben. + +package dns + +import "sync" +import "time" + +// call is an in-flight or completed singleflight.Do call +type call struct { + wg sync.WaitGroup + val *Msg + rtt time.Duration + err error + dups int +} + +// singleflight represents a class of work and forms a namespace in +// which units of work can be executed with duplicate suppression. +type singleflight struct { + sync.Mutex // protects m + m map[string]*call // lazily initialized +} + +// Do executes and returns the results of the given function, making +// sure that only one execution is in-flight for a given key at a +// time. If a duplicate comes in, the duplicate caller waits for the +// original to complete and receives the same results. +// The return value shared indicates whether v was given to multiple callers. +func (g *singleflight) Do(key string, fn func() (*Msg, time.Duration, error)) (v *Msg, rtt time.Duration, err error, shared bool) { + g.Lock() + if g.m == nil { + g.m = make(map[string]*call) + } + if c, ok := g.m[key]; ok { + c.dups++ + g.Unlock() + c.wg.Wait() + return c.val, c.rtt, c.err, true + } + c := new(call) + c.wg.Add(1) + g.m[key] = c + g.Unlock() + + c.val, c.rtt, c.err = fn() + c.wg.Done() + + g.Lock() + delete(g.m, key) + g.Unlock() + + return c.val, c.rtt, c.err, c.dups > 0 +} |