| package redis |
| |
| import ( |
| "context" |
| "crypto/tls" |
| "errors" |
| "fmt" |
| "net" |
| "net/url" |
| "runtime" |
| "strconv" |
| "strings" |
| "time" |
| |
| "github.com/go-redis/redis/v8/internal" |
| "github.com/go-redis/redis/v8/internal/pool" |
| "go.opentelemetry.io/otel/api/trace" |
| "go.opentelemetry.io/otel/label" |
| ) |
| |
| // Limiter is the interface of a rate limiter or a circuit breaker. |
| type Limiter interface { |
| // Allow returns nil if operation is allowed or an error otherwise. |
| // If operation is allowed client must ReportResult of the operation |
| // whether it is a success or a failure. |
| Allow() error |
| // ReportResult reports the result of the previously allowed operation. |
| // nil indicates a success, non-nil error usually indicates a failure. |
| ReportResult(result error) |
| } |
| |
| // Options keeps the settings to setup redis connection. |
| type Options struct { |
| // The network type, either tcp or unix. |
| // Default is tcp. |
| Network string |
| // host:port address. |
| Addr string |
| |
| // Dialer creates new network connection and has priority over |
| // Network and Addr options. |
| Dialer func(ctx context.Context, network, addr string) (net.Conn, error) |
| |
| // Hook that is called when new connection is established. |
| OnConnect func(ctx context.Context, cn *Conn) error |
| |
| // Use the specified Username to authenticate the current connection |
| // with one of the connections defined in the ACL list when connecting |
| // to a Redis 6.0 instance, or greater, that is using the Redis ACL system. |
| Username string |
| // Optional password. Must match the password specified in the |
| // requirepass server configuration option (if connecting to a Redis 5.0 instance, or lower), |
| // or the User Password when connecting to a Redis 6.0 instance, or greater, |
| // that is using the Redis ACL system. |
| Password string |
| |
| // Database to be selected after connecting to the server. |
| DB int |
| |
| // Maximum number of retries before giving up. |
| // Default is 3 retries. |
| MaxRetries int |
| // Minimum backoff between each retry. |
| // Default is 8 milliseconds; -1 disables backoff. |
| MinRetryBackoff time.Duration |
| // Maximum backoff between each retry. |
| // Default is 512 milliseconds; -1 disables backoff. |
| MaxRetryBackoff time.Duration |
| |
| // Dial timeout for establishing new connections. |
| // Default is 5 seconds. |
| DialTimeout time.Duration |
| // Timeout for socket reads. If reached, commands will fail |
| // with a timeout instead of blocking. Use value -1 for no timeout and 0 for default. |
| // Default is 3 seconds. |
| ReadTimeout time.Duration |
| // Timeout for socket writes. If reached, commands will fail |
| // with a timeout instead of blocking. |
| // Default is ReadTimeout. |
| WriteTimeout time.Duration |
| |
| // Maximum number of socket connections. |
| // Default is 10 connections per every CPU as reported by runtime.NumCPU. |
| PoolSize int |
| // Minimum number of idle connections which is useful when establishing |
| // new connection is slow. |
| MinIdleConns int |
| // Connection age at which client retires (closes) the connection. |
| // Default is to not close aged connections. |
| MaxConnAge time.Duration |
| // Amount of time client waits for connection if all connections |
| // are busy before returning an error. |
| // Default is ReadTimeout + 1 second. |
| PoolTimeout time.Duration |
| // Amount of time after which client closes idle connections. |
| // Should be less than server's timeout. |
| // Default is 5 minutes. -1 disables idle timeout check. |
| IdleTimeout time.Duration |
| // Frequency of idle checks made by idle connections reaper. |
| // Default is 1 minute. -1 disables idle connections reaper, |
| // but idle connections are still discarded by the client |
| // if IdleTimeout is set. |
| IdleCheckFrequency time.Duration |
| |
| // Enables read only queries on slave nodes. |
| readOnly bool |
| |
| // TLS Config to use. When set TLS will be negotiated. |
| TLSConfig *tls.Config |
| |
| // Limiter interface used to implemented circuit breaker or rate limiter. |
| Limiter Limiter |
| } |
| |
| func (opt *Options) init() { |
| if opt.Addr == "" { |
| opt.Addr = "localhost:6379" |
| } |
| if opt.Network == "" { |
| if strings.HasPrefix(opt.Addr, "/") { |
| opt.Network = "unix" |
| } else { |
| opt.Network = "tcp" |
| } |
| } |
| if opt.DialTimeout == 0 { |
| opt.DialTimeout = 5 * time.Second |
| } |
| if opt.Dialer == nil { |
| opt.Dialer = func(ctx context.Context, network, addr string) (net.Conn, error) { |
| netDialer := &net.Dialer{ |
| Timeout: opt.DialTimeout, |
| KeepAlive: 5 * time.Minute, |
| } |
| if opt.TLSConfig == nil { |
| return netDialer.DialContext(ctx, network, addr) |
| } |
| return tls.DialWithDialer(netDialer, network, addr, opt.TLSConfig) |
| } |
| } |
| if opt.PoolSize == 0 { |
| opt.PoolSize = 10 * runtime.NumCPU() |
| } |
| switch opt.ReadTimeout { |
| case -1: |
| opt.ReadTimeout = 0 |
| case 0: |
| opt.ReadTimeout = 3 * time.Second |
| } |
| switch opt.WriteTimeout { |
| case -1: |
| opt.WriteTimeout = 0 |
| case 0: |
| opt.WriteTimeout = opt.ReadTimeout |
| } |
| if opt.PoolTimeout == 0 { |
| opt.PoolTimeout = opt.ReadTimeout + time.Second |
| } |
| if opt.IdleTimeout == 0 { |
| opt.IdleTimeout = 5 * time.Minute |
| } |
| if opt.IdleCheckFrequency == 0 { |
| opt.IdleCheckFrequency = time.Minute |
| } |
| |
| if opt.MaxRetries == -1 { |
| opt.MaxRetries = 0 |
| } else if opt.MaxRetries == 0 { |
| opt.MaxRetries = 3 |
| } |
| switch opt.MinRetryBackoff { |
| case -1: |
| opt.MinRetryBackoff = 0 |
| case 0: |
| opt.MinRetryBackoff = 8 * time.Millisecond |
| } |
| switch opt.MaxRetryBackoff { |
| case -1: |
| opt.MaxRetryBackoff = 0 |
| case 0: |
| opt.MaxRetryBackoff = 512 * time.Millisecond |
| } |
| } |
| |
| func (opt *Options) clone() *Options { |
| clone := *opt |
| return &clone |
| } |
| |
| // ParseURL parses an URL into Options that can be used to connect to Redis. |
| // Scheme is required. |
| // There are two connection types: by tcp socket and by unix socket. |
| // Tcp connection: |
| // redis://<user>:<password>@<host>:<port>/<db_number> |
| // Unix connection: |
| // unix://<user>:<password>@</path/to/redis.sock>?db=<db_number> |
| func ParseURL(redisURL string) (*Options, error) { |
| u, err := url.Parse(redisURL) |
| if err != nil { |
| return nil, err |
| } |
| |
| switch u.Scheme { |
| case "redis", "rediss": |
| return setupTCPConn(u) |
| case "unix": |
| return setupUnixConn(u) |
| default: |
| return nil, fmt.Errorf("redis: invalid URL scheme: %s", u.Scheme) |
| } |
| } |
| |
| func setupTCPConn(u *url.URL) (*Options, error) { |
| o := &Options{Network: "tcp"} |
| |
| o.Username, o.Password = getUserPassword(u) |
| |
| if len(u.Query()) > 0 { |
| return nil, errors.New("redis: no options supported") |
| } |
| |
| h, p, err := net.SplitHostPort(u.Host) |
| if err != nil { |
| h = u.Host |
| } |
| if h == "" { |
| h = "localhost" |
| } |
| if p == "" { |
| p = "6379" |
| } |
| o.Addr = net.JoinHostPort(h, p) |
| |
| f := strings.FieldsFunc(u.Path, func(r rune) bool { |
| return r == '/' |
| }) |
| switch len(f) { |
| case 0: |
| o.DB = 0 |
| case 1: |
| if o.DB, err = strconv.Atoi(f[0]); err != nil { |
| return nil, fmt.Errorf("redis: invalid database number: %q", f[0]) |
| } |
| default: |
| return nil, fmt.Errorf("redis: invalid URL path: %s", u.Path) |
| } |
| |
| if u.Scheme == "rediss" { |
| o.TLSConfig = &tls.Config{ServerName: h} |
| } |
| |
| return o, nil |
| } |
| |
| func setupUnixConn(u *url.URL) (*Options, error) { |
| o := &Options{ |
| Network: "unix", |
| } |
| |
| if strings.TrimSpace(u.Path) == "" { // path is required with unix connection |
| return nil, errors.New("redis: empty unix socket path") |
| } |
| o.Addr = u.Path |
| |
| o.Username, o.Password = getUserPassword(u) |
| |
| dbStr := u.Query().Get("db") |
| if dbStr == "" { |
| return o, nil // if database is not set, connect to 0 db. |
| } |
| |
| db, err := strconv.Atoi(dbStr) |
| if err != nil { |
| return nil, fmt.Errorf("redis: invalid database number: %s", err) |
| } |
| o.DB = db |
| |
| return o, nil |
| } |
| |
| func getUserPassword(u *url.URL) (string, string) { |
| var user, password string |
| if u.User != nil { |
| user = u.User.Username() |
| if p, ok := u.User.Password(); ok { |
| password = p |
| } |
| } |
| return user, password |
| } |
| |
| func newConnPool(opt *Options) *pool.ConnPool { |
| return pool.NewConnPool(&pool.Options{ |
| Dialer: func(ctx context.Context) (net.Conn, error) { |
| var conn net.Conn |
| err := internal.WithSpan(ctx, "redis.dial", func(ctx context.Context, span trace.Span) error { |
| span.SetAttributes( |
| label.String("db.connection_string", opt.Addr), |
| ) |
| |
| var err error |
| conn, err = opt.Dialer(ctx, opt.Network, opt.Addr) |
| if err != nil { |
| _ = internal.RecordError(ctx, err) |
| } |
| return err |
| }) |
| return conn, err |
| }, |
| PoolSize: opt.PoolSize, |
| MinIdleConns: opt.MinIdleConns, |
| MaxConnAge: opt.MaxConnAge, |
| PoolTimeout: opt.PoolTimeout, |
| IdleTimeout: opt.IdleTimeout, |
| IdleCheckFrequency: opt.IdleCheckFrequency, |
| }) |
| } |