[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/pool/pool_sticky.go b/vendor/github.com/go-redis/redis/v8/internal/pool/pool_sticky.go
new file mode 100644
index 0000000..c3e7e7c
--- /dev/null
+++ b/vendor/github.com/go-redis/redis/v8/internal/pool/pool_sticky.go
@@ -0,0 +1,202 @@
+package pool
+
+import (
+ "context"
+ "errors"
+ "fmt"
+ "sync/atomic"
+)
+
+const (
+ stateDefault = 0
+ stateInited = 1
+ stateClosed = 2
+)
+
+type BadConnError struct {
+ wrapped error
+}
+
+var _ error = (*BadConnError)(nil)
+
+func (e BadConnError) Error() string {
+ s := "redis: Conn is in a bad state"
+ if e.wrapped != nil {
+ s += ": " + e.wrapped.Error()
+ }
+ return s
+}
+
+func (e BadConnError) Unwrap() error {
+ return e.wrapped
+}
+
+//------------------------------------------------------------------------------
+
+type StickyConnPool struct {
+ pool Pooler
+ shared int32 // atomic
+
+ state uint32 // atomic
+ ch chan *Conn
+
+ _badConnError atomic.Value
+}
+
+var _ Pooler = (*StickyConnPool)(nil)
+
+func NewStickyConnPool(pool Pooler) *StickyConnPool {
+ p, ok := pool.(*StickyConnPool)
+ if !ok {
+ p = &StickyConnPool{
+ pool: pool,
+ ch: make(chan *Conn, 1),
+ }
+ }
+ atomic.AddInt32(&p.shared, 1)
+ return p
+}
+
+func (p *StickyConnPool) NewConn(ctx context.Context) (*Conn, error) {
+ return p.pool.NewConn(ctx)
+}
+
+func (p *StickyConnPool) CloseConn(cn *Conn) error {
+ return p.pool.CloseConn(cn)
+}
+
+func (p *StickyConnPool) Get(ctx context.Context) (*Conn, error) {
+ // In worst case this races with Close which is not a very common operation.
+ for i := 0; i < 1000; i++ {
+ switch atomic.LoadUint32(&p.state) {
+ case stateDefault:
+ cn, err := p.pool.Get(ctx)
+ if err != nil {
+ return nil, err
+ }
+ if atomic.CompareAndSwapUint32(&p.state, stateDefault, stateInited) {
+ return cn, nil
+ }
+ p.pool.Remove(ctx, cn, ErrClosed)
+ case stateInited:
+ if err := p.badConnError(); err != nil {
+ return nil, err
+ }
+ cn, ok := <-p.ch
+ if !ok {
+ return nil, ErrClosed
+ }
+ return cn, nil
+ case stateClosed:
+ return nil, ErrClosed
+ default:
+ panic("not reached")
+ }
+ }
+ return nil, fmt.Errorf("redis: StickyConnPool.Get: infinite loop")
+}
+
+func (p *StickyConnPool) Put(ctx context.Context, cn *Conn) {
+ defer func() {
+ if recover() != nil {
+ p.freeConn(ctx, cn)
+ }
+ }()
+ p.ch <- cn
+}
+
+func (p *StickyConnPool) freeConn(ctx context.Context, cn *Conn) {
+ if err := p.badConnError(); err != nil {
+ p.pool.Remove(ctx, cn, err)
+ } else {
+ p.pool.Put(ctx, cn)
+ }
+}
+
+func (p *StickyConnPool) Remove(ctx context.Context, cn *Conn, reason error) {
+ defer func() {
+ if recover() != nil {
+ p.pool.Remove(ctx, cn, ErrClosed)
+ }
+ }()
+ p._badConnError.Store(BadConnError{wrapped: reason})
+ p.ch <- cn
+}
+
+func (p *StickyConnPool) Close() error {
+ if shared := atomic.AddInt32(&p.shared, -1); shared > 0 {
+ return nil
+ }
+
+ for i := 0; i < 1000; i++ {
+ state := atomic.LoadUint32(&p.state)
+ if state == stateClosed {
+ return ErrClosed
+ }
+ if atomic.CompareAndSwapUint32(&p.state, state, stateClosed) {
+ close(p.ch)
+ cn, ok := <-p.ch
+ if ok {
+ p.freeConn(context.TODO(), cn)
+ }
+ return nil
+ }
+ }
+
+ return errors.New("redis: StickyConnPool.Close: infinite loop")
+}
+
+func (p *StickyConnPool) Reset(ctx context.Context) error {
+ if p.badConnError() == nil {
+ return nil
+ }
+
+ select {
+ case cn, ok := <-p.ch:
+ if !ok {
+ return ErrClosed
+ }
+ p.pool.Remove(ctx, cn, ErrClosed)
+ p._badConnError.Store(BadConnError{wrapped: nil})
+ default:
+ return errors.New("redis: StickyConnPool does not have a Conn")
+ }
+
+ if !atomic.CompareAndSwapUint32(&p.state, stateInited, stateDefault) {
+ state := atomic.LoadUint32(&p.state)
+ return fmt.Errorf("redis: invalid StickyConnPool state: %d", state)
+ }
+
+ return nil
+}
+
+func (p *StickyConnPool) badConnError() error {
+ if v := p._badConnError.Load(); v != nil {
+ err := v.(BadConnError)
+ if err.wrapped != nil {
+ return err
+ }
+ }
+ return nil
+}
+
+func (p *StickyConnPool) Len() int {
+ switch atomic.LoadUint32(&p.state) {
+ case stateDefault:
+ return 0
+ case stateInited:
+ return 1
+ case stateClosed:
+ return 0
+ default:
+ panic("not reached")
+ }
+}
+
+func (p *StickyConnPool) IdleLen() int {
+ return len(p.ch)
+}
+
+func (p *StickyConnPool) Stats() *Stats {
+ return &Stats{}
+}