1 files changed, 399 insertions, 0 deletions
diff --git a/src/dma/vendor/github.com/go-redis/redis/sentinel.go b/src/dma/vendor/github.com/go-redis/redis/sentinel.go
new file mode 100644
index 00000000..7cbb90bd
--- /dev/null
+++ b/src/dma/vendor/github.com/go-redis/redis/sentinel.go
@@ -0,0 +1,399 @@
+package redis
+
+import (
+	"crypto/tls"
+	"errors"
+	"net"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/go-redis/redis/internal"
+	"github.com/go-redis/redis/internal/pool"
+)
+
+//------------------------------------------------------------------------------
+
+// FailoverOptions are used to configure a failover client and should
+// be passed to NewFailoverClient.
+type FailoverOptions struct {
+	// The master name.
+	MasterName string
+	// A seed list of host:port addresses of sentinel nodes.
+	SentinelAddrs []string
+
+	// Following options are copied from Options struct.
+
+	OnConnect func(*Conn) error
+
+	Password string
+	DB       int
+
+	MaxRetries      int
+	MinRetryBackoff time.Duration
+	MaxRetryBackoff time.Duration
+
+	DialTimeout  time.Duration
+	ReadTimeout  time.Duration
+	WriteTimeout time.Duration
+
+	PoolSize           int
+	MinIdleConns       int
+	MaxConnAge         time.Duration
+	PoolTimeout        time.Duration
+	IdleTimeout        time.Duration
+	IdleCheckFrequency time.Duration
+
+	TLSConfig *tls.Config
+}
+
+func (opt *FailoverOptions) options() *Options {
+	return &Options{
+		Addr: "FailoverClient",
+
+		OnConnect: opt.OnConnect,
+
+		DB:       opt.DB,
+		Password: opt.Password,
+
+		MaxRetries: opt.MaxRetries,
+
+		DialTimeout:  opt.DialTimeout,
+		ReadTimeout:  opt.ReadTimeout,
+		WriteTimeout: opt.WriteTimeout,
+
+		PoolSize:           opt.PoolSize,
+		PoolTimeout:        opt.PoolTimeout,
+		IdleTimeout:        opt.IdleTimeout,
+		IdleCheckFrequency: opt.IdleCheckFrequency,
+
+		TLSConfig: opt.TLSConfig,
+	}
+}
+
+// NewFailoverClient returns a Redis client that uses Redis Sentinel
+// for automatic failover. It's safe for concurrent use by multiple
+// goroutines.
+func NewFailoverClient(failoverOpt *FailoverOptions) *Client {
+	opt := failoverOpt.options()
+	opt.init()
+
+	failover := &sentinelFailover{
+		masterName:    failoverOpt.MasterName,
+		sentinelAddrs: failoverOpt.SentinelAddrs,
+
+		opt: opt,
+	}
+
+	c := Client{
+		baseClient: baseClient{
+			opt:      opt,
+			connPool: failover.Pool(),
+
+			onClose: func() error {
+				return failover.Close()
+			},
+		},
+	}
+	c.baseClient.init()
+	c.cmdable.setProcessor(c.Process)
+
+	return &c
+}
+
+//------------------------------------------------------------------------------
+
+type SentinelClient struct {
+	baseClient
+}
+
+func NewSentinelClient(opt *Options) *SentinelClient {
+	opt.init()
+	c := &SentinelClient{
+		baseClient: baseClient{
+			opt:      opt,
+			connPool: newConnPool(opt),
+		},
+	}
+	c.baseClient.init()
+	return c
+}
+
+func (c *SentinelClient) pubSub() *PubSub {
+	pubsub := &PubSub{
+		opt: c.opt,
+
+		newConn: func(channels []string) (*pool.Conn, error) {
+			return c.newConn()
+		},
+		closeConn: c.connPool.CloseConn,
+	}
+	pubsub.init()
+	return pubsub
+}
+
+// Subscribe subscribes the client to the specified channels.
+// Channels can be omitted to create empty subscription.
+func (c *SentinelClient) Subscribe(channels ...string) *PubSub {
+	pubsub := c.pubSub()
+	if len(channels) > 0 {
+		_ = pubsub.Subscribe(channels...)
+	}
+	return pubsub
+}
+
+// PSubscribe subscribes the client to the given patterns.
+// Patterns can be omitted to create empty subscription.
+func (c *SentinelClient) PSubscribe(channels ...string) *PubSub {
+	pubsub := c.pubSub()
+	if len(channels) > 0 {
+		_ = pubsub.PSubscribe(channels...)
+	}
+	return pubsub
+}
+
+func (c *SentinelClient) GetMasterAddrByName(name string) *StringSliceCmd {
+	cmd := NewStringSliceCmd("sentinel", "get-master-addr-by-name", name)
+	c.Process(cmd)
+	return cmd
+}
+
+func (c *SentinelClient) Sentinels(name string) *SliceCmd {
+	cmd := NewSliceCmd("sentinel", "sentinels", name)
+	c.Process(cmd)
+	return cmd
+}
+
+// Failover forces a failover as if the master was not reachable, and without
+// asking for agreement to other Sentinels.
+func (c *SentinelClient) Failover(name string) *StatusCmd {
+	cmd := NewStatusCmd("sentinel", "failover", name)
+	c.Process(cmd)
+	return cmd
+}
+
+// Reset resets all the masters with matching name. The pattern argument is a
+// glob-style pattern. The reset process clears any previous state in a master
+// (including a failover in progress), and removes every slave and sentinel
+// already discovered and associated with the master.
+func (c *SentinelClient) Reset(pattern string) *IntCmd {
+	cmd := NewIntCmd("sentinel", "reset", pattern)
+	c.Process(cmd)
+	return cmd
+}
+
+type sentinelFailover struct {
+	sentinelAddrs []string
+
+	opt *Options
+
+	pool     *pool.ConnPool
+	poolOnce sync.Once
+
+	mu          sync.RWMutex
+	masterName  string
+	_masterAddr string
+	sentinel    *SentinelClient
+	pubsub      *PubSub
+}
+
+func (c *sentinelFailover) Close() error {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	if c.sentinel != nil {
+		return c.closeSentinel()
+	}
+	return nil
+}
+
+func (c *sentinelFailover) Pool() *pool.ConnPool {
+	c.poolOnce.Do(func() {
+		c.opt.Dialer = c.dial
+		c.pool = newConnPool(c.opt)
+	})
+	return c.pool
+}
+
+func (c *sentinelFailover) dial() (net.Conn, error) {
+	addr, err := c.MasterAddr()
+	if err != nil {
+		return nil, err
+	}
+	return net.DialTimeout("tcp", addr, c.opt.DialTimeout)
+}
+
+func (c *sentinelFailover) MasterAddr() (string, error) {
+	addr, err := c.masterAddr()
+	if err != nil {
+		return "", err
+	}
+	c.switchMaster(addr)
+	return addr, nil
+}
+
+func (c *sentinelFailover) masterAddr() (string, error) {
+	addr := c.getMasterAddr()
+	if addr != "" {
+		return addr, nil
+	}
+
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	for i, sentinelAddr := range c.sentinelAddrs {
+		sentinel := NewSentinelClient(&Options{
+			Addr: sentinelAddr,
+
+			MaxRetries: c.opt.MaxRetries,
+
+			DialTimeout:  c.opt.DialTimeout,
+			ReadTimeout:  c.opt.ReadTimeout,
+			WriteTimeout: c.opt.WriteTimeout,
+
+			PoolSize:           c.opt.PoolSize,
+			PoolTimeout:        c.opt.PoolTimeout,
+			IdleTimeout:        c.opt.IdleTimeout,
+			IdleCheckFrequency: c.opt.IdleCheckFrequency,
+
+			TLSConfig: c.opt.TLSConfig,
+		})
+
+		masterAddr, err := sentinel.GetMasterAddrByName(c.masterName).Result()
+		if err != nil {
+			internal.Logf("sentinel: GetMasterAddrByName master=%q failed: %s",
+				c.masterName, err)
+			_ = sentinel.Close()
+			continue
+		}
+
+		// Push working sentinel to the top.
+		c.sentinelAddrs[0], c.sentinelAddrs[i] = c.sentinelAddrs[i], c.sentinelAddrs[0]
+		c.setSentinel(sentinel)
+
+		addr := net.JoinHostPort(masterAddr[0], masterAddr[1])
+		return addr, nil
+	}
+
+	return "", errors.New("redis: all sentinels are unreachable")
+}
+
+func (c *sentinelFailover) getMasterAddr() string {
+	c.mu.RLock()
+	sentinel := c.sentinel
+	c.mu.RUnlock()
+
+	if sentinel == nil {
+		return ""
+	}
+
+	addr, err := sentinel.GetMasterAddrByName(c.masterName).Result()
+	if err != nil {
+		internal.Logf("sentinel: GetMasterAddrByName name=%q failed: %s",
+			c.masterName, err)
+		c.mu.Lock()
+		if c.sentinel == sentinel {
+			c.closeSentinel()
+		}
+		c.mu.Unlock()
+		return ""
+	}
+
+	return net.JoinHostPort(addr[0], addr[1])
+}
+
+func (c *sentinelFailover) switchMaster(addr string) {
+	c.mu.RLock()
+	masterAddr := c._masterAddr
+	c.mu.RUnlock()
+	if masterAddr == addr {
+		return
+	}
+
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	internal.Logf("sentinel: new master=%q addr=%q",
+		c.masterName, addr)
+	_ = c.Pool().Filter(func(cn *pool.Conn) bool {
+		return cn.RemoteAddr().String() != addr
+	})
+	c._masterAddr = addr
+}
+
+func (c *sentinelFailover) setSentinel(sentinel *SentinelClient) {
+	c.discoverSentinels(sentinel)
+	c.sentinel = sentinel
+
+	c.pubsub = sentinel.Subscribe("+switch-master")
+	go c.listen(c.pubsub)
+}
+
+func (c *sentinelFailover) closeSentinel() error {
+	var firstErr error
+
+	err := c.pubsub.Close()
+	if err != nil && firstErr == err {
+		firstErr = err
+	}
+	c.pubsub = nil
+
+	err = c.sentinel.Close()
+	if err != nil && firstErr == err {
+		firstErr = err
+	}
+	c.sentinel = nil
+
+	return firstErr
+}
+
+func (c *sentinelFailover) discoverSentinels(sentinel *SentinelClient) {
+	sentinels, err := sentinel.Sentinels(c.masterName).Result()
+	if err != nil {
+		internal.Logf("sentinel: Sentinels master=%q failed: %s", c.masterName, err)
+		return
+	}
+	for _, sentinel := range sentinels {
+		vals := sentinel.([]interface{})
+		for i := 0; i < len(vals); i += 2 {
+			key := vals[i].(string)
+			if key == "name" {
+				sentinelAddr := vals[i+1].(string)
+				if !contains(c.sentinelAddrs, sentinelAddr) {
+					internal.Logf("sentinel: discovered new sentinel=%q for master=%q",
+						sentinelAddr, c.masterName)
+					c.sentinelAddrs = append(c.sentinelAddrs, sentinelAddr)
+				}
+			}
+		}
+	}
+}
+
+func (c *sentinelFailover) listen(pubsub *PubSub) {
+	ch := pubsub.Channel()
+	for {
+		msg, ok := <-ch
+		if !ok {
+			break
+		}
+
+		switch msg.Channel {
+		case "+switch-master":
+			parts := strings.Split(msg.Payload, " ")
+			if parts[0] != c.masterName {
+				internal.Logf("sentinel: ignore addr for master=%q", parts[0])
+				continue
+			}
+			addr := net.JoinHostPort(parts[3], parts[4])
+			c.switchMaster(addr)
+		}
+	}
+}
+
+func contains(slice []string, str string) bool {
+	for _, s := range slice {
+		if s == str {
+			return true
+		}
+	}
+	return false
+}