Remove redis.Client type from asynq package API

asynq.go

@@ -4,10 +4,12 @@
 
 package asynq
 
-/*
-TODOs:
-- [P0] Go docs
-*/
+import (
+	"crypto/tls"
+	"fmt"
+
+	"github.com/go-redis/redis/v7"
+)
 
 // Task represents a task to be performed.
 type Task struct {
@@ -28,3 +30,109 @@ func NewTask(typename string, payload map[string]interface{}) *Task {
 		Payload: Payload{payload},
 	}
 }
+
+// RedisConnOpt is a discriminated union of redis-client-option types.
+//
+// RedisConnOpt represents a sum of following types:
+// RedisClientOpt | *RedisClientOpt | RedisFailoverClientOpt | *RedisFailoverClientOpt
+type RedisConnOpt interface{}
+
+// RedisClientOpt is used to specify redis client options to connect
+// to a redis server running as a stand alone instance.
+type RedisClientOpt struct {
+	// Network type to use, either tcp or unix.
+	// Default is tcp.
+	Network string
+
+	// Redis server address in the format 'host:port'.
+	Addr string
+
+	// Redis server password.
+	Password string
+
+	// Redis DB to select after connecting to the server.
+	// See: https://redis.io/commands/select.
+	DB int
+
+	// Maximum number of socket connections.
+	// Default is 10 connections per every CPU as reported by runtime.NumCPU.
+	PoolSize int
+
+	// TLS Config used to connect to the server.
+	// TLS will be negotiated only if this field is set.
+	TLSConfig *tls.Config
+}
+
+// RedisFailoverClientOpt is used to specify redis failover client.
+type RedisFailoverClientOpt struct {
+	// Redis master name that monitored by sentinels.
+	MasterName string
+
+	// Addresses of sentinels in the form "host:port".
+	// Use at least three sentinels to avoid problems described in
+	// https://redis.io/topics/sentinel.
+	SentinelAddrs []string
+
+	// Redis sentinel password.
+	SentinelPassword string
+
+	// Redis server password.
+	Password string
+
+	// Redis DB to select after connecting to the server.
+	// See: https://redis.io/commands/select.
+	DB int
+
+	// Maximum number of socket connections.
+	// Default is 10 connections per every CPU as reported by runtime.NumCPU.
+	PoolSize int
+
+	// TLS Config used to connect to the server.
+	// TLS will be negotiated only if this field is set.
+	TLSConfig *tls.Config
+}
+
+func createRedisClient(r RedisConnOpt) *redis.Client {
+	switch r := r.(type) {
+	case *RedisClientOpt:
+		return redis.NewClient(&redis.Options{
+			Network:   r.Network,
+			Addr:      r.Addr,
+			Password:  r.Password,
+			DB:        r.DB,
+			PoolSize:  r.PoolSize,
+			TLSConfig: r.TLSConfig,
+		})
+	case RedisClientOpt:
+		return redis.NewClient(&redis.Options{
+			Network:   r.Network,
+			Addr:      r.Addr,
+			Password:  r.Password,
+			DB:        r.DB,
+			PoolSize:  r.PoolSize,
+			TLSConfig: r.TLSConfig,
+		})
+	case *RedisFailoverClientOpt:
+		return redis.NewFailoverClient(&redis.FailoverOptions{
+			MasterName:       r.MasterName,
+			SentinelAddrs:    r.SentinelAddrs,
+			SentinelPassword: r.SentinelPassword,
+			Password:         r.Password,
+			DB:               r.DB,
+			PoolSize:         r.PoolSize,
+			TLSConfig:        r.TLSConfig,
+		})
+	case RedisFailoverClientOpt:
+		return redis.NewFailoverClient(&redis.FailoverOptions{
+			MasterName:       r.MasterName,
+			SentinelAddrs:    r.SentinelAddrs,
+			SentinelPassword: r.SentinelPassword,
+			Password:         r.Password,
+			DB:               r.DB,
+			PoolSize:         r.PoolSize,
+			TLSConfig:        r.TLSConfig,
+		})
+	default:
+		panic(fmt.Sprintf("unexpected type %T for RedisConnOpt", r))
+	}
+}