[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/iterator.go b/vendor/github.com/go-redis/redis/v8/iterator.go
new file mode 100644
index 0000000..2f8bc2b
--- /dev/null
+++ b/vendor/github.com/go-redis/redis/v8/iterator.go
@@ -0,0 +1,77 @@
+package redis
+
+import (
+ "context"
+ "sync"
+)
+
+// ScanIterator is used to incrementally iterate over a collection of elements.
+// It's safe for concurrent use by multiple goroutines.
+type ScanIterator struct {
+ mu sync.Mutex // protects Scanner and pos
+ cmd *ScanCmd
+ pos int
+}
+
+// Err returns the last iterator error, if any.
+func (it *ScanIterator) Err() error {
+ it.mu.Lock()
+ err := it.cmd.Err()
+ it.mu.Unlock()
+ return err
+}
+
+// Next advances the cursor and returns true if more values can be read.
+func (it *ScanIterator) Next(ctx context.Context) bool {
+ it.mu.Lock()
+ defer it.mu.Unlock()
+
+ // Instantly return on errors.
+ if it.cmd.Err() != nil {
+ return false
+ }
+
+ // Advance cursor, check if we are still within range.
+ if it.pos < len(it.cmd.page) {
+ it.pos++
+ return true
+ }
+
+ for {
+ // Return if there is no more data to fetch.
+ if it.cmd.cursor == 0 {
+ return false
+ }
+
+ // Fetch next page.
+ switch it.cmd.args[0] {
+ case "scan", "qscan":
+ it.cmd.args[1] = it.cmd.cursor
+ default:
+ it.cmd.args[2] = it.cmd.cursor
+ }
+
+ err := it.cmd.process(ctx, it.cmd)
+ if err != nil {
+ return false
+ }
+
+ it.pos = 1
+
+ // Redis can occasionally return empty page.
+ if len(it.cmd.page) > 0 {
+ return true
+ }
+ }
+}
+
+// Val returns the key/field at the current cursor position.
+func (it *ScanIterator) Val() string {
+ var v string
+ it.mu.Lock()
+ if it.cmd.Err() == nil && it.pos > 0 && it.pos <= len(it.cmd.page) {
+ v = it.cmd.page[it.pos-1]
+ }
+ it.mu.Unlock()
+ return v
+}