[VOL-3860] redis client support in voltha-lib-go
redis client support has been added in this patch. There are two
types client `redis` and `redis-sentinel` to connect a redis instance.
redis-sentinel is required to be able to find the master redis
instance from a redis-sentinel process. See redis-sentinel usage
https://redis.io/topics/sentinel and
https://pkg.go.dev/github.com/go-redis/redis/v8#NewFailoverClient
for more information. If there is no need to have any failover
mechanism then the redis client type is the option to choose.
Change-Id: I997ed92115a9d565df632c6dd8184b9bab77b991
diff --git a/vendor/github.com/go-redis/redis/v8/internal/once.go b/vendor/github.com/go-redis/redis/v8/internal/once.go
new file mode 100644
index 0000000..64f4627
--- /dev/null
+++ b/vendor/github.com/go-redis/redis/v8/internal/once.go
@@ -0,0 +1,60 @@
+/*
+Copyright 2014 The Camlistore Authors
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package internal
+
+import (
+ "sync"
+ "sync/atomic"
+)
+
+// A Once will perform a successful action exactly once.
+//
+// Unlike a sync.Once, this Once's func returns an error
+// and is re-armed on failure.
+type Once struct {
+ m sync.Mutex
+ done uint32
+}
+
+// Do calls the function f if and only if Do has not been invoked
+// without error for this instance of Once. In other words, given
+// var once Once
+// if once.Do(f) is called multiple times, only the first call will
+// invoke f, even if f has a different value in each invocation unless
+// f returns an error. A new instance of Once is required for each
+// function to execute.
+//
+// Do is intended for initialization that must be run exactly once. Since f
+// is niladic, it may be necessary to use a function literal to capture the
+// arguments to a function to be invoked by Do:
+// err := config.once.Do(func() error { return config.init(filename) })
+func (o *Once) Do(f func() error) error {
+ if atomic.LoadUint32(&o.done) == 1 {
+ return nil
+ }
+ // Slow-path.
+ o.m.Lock()
+ defer o.m.Unlock()
+ var err error
+ if o.done == 0 {
+ err = f()
+ if err == nil {
+ atomic.StoreUint32(&o.done, 1)
+ }
+ }
+ return err
+}