package redis import ( "bytes" "fmt" "strconv" "strings" "time" "github.com/go-redis/redis/internal" "github.com/go-redis/redis/internal/pool" "github.com/go-redis/redis/internal/proto" "github.com/go-redis/redis/internal/util" ) type Cmder interface { Name() string Args() []interface{} stringArg(int) string readReply(*pool.Conn) error setErr(error) readTimeout() *time.Duration Err() error fmt.Stringer } func setCmdsErr(cmds []Cmder, e error) { for _, cmd := range cmds { if cmd.Err() == nil { cmd.setErr(e) } } } func firstCmdsErr(cmds []Cmder) error { for _, cmd := range cmds { if err := cmd.Err(); err != nil { return err } } return nil } func writeCmd(cn *pool.Conn, cmds ...Cmder) error { cn.Wb.Reset() for _, cmd := range cmds { if err := cn.Wb.Append(cmd.Args()); err != nil { return err } } _, err := cn.Write(cn.Wb.Bytes()) return err } func cmdString(cmd Cmder, val interface{}) string { var ss []string for _, arg := range cmd.Args() { ss = append(ss, fmt.Sprint(arg)) } s := strings.Join(ss, " ") if err := cmd.Err(); err != nil { return s + ": " + err.Error() } if val != nil { switch vv := val.(type) { case []byte: return s + ": " + string(vv) default: return s + ": " + fmt.Sprint(val) } } return s } func cmdFirstKeyPos(cmd Cmder, info *CommandInfo) int { switch cmd.Name() { case "eval", "evalsha": if cmd.stringArg(2) != "0" { return 3 } return 0 case "publish": return 1 } if info == nil { return 0 } return int(info.FirstKeyPos) } //------------------------------------------------------------------------------ type baseCmd struct { _args []interface{} err error _readTimeout *time.Duration } var _ Cmder = (*Cmd)(nil) func (cmd *baseCmd) Err() error { return cmd.err } func (cmd *baseCmd) Args() []interface{} { return cmd._args } func (cmd *baseCmd) stringArg(pos int) string { if pos < 0 || pos >= len(cmd._args) { return "" } s, _ := cmd._args[pos].(string) return s } func (cmd *baseCmd) Name() string { if len(cmd._args) > 0 { // Cmd name must be lower cased. s := internal.ToLower(cmd.stringArg(0)) cmd._args[0] = s return s } return "" } func (cmd *baseCmd) readTimeout() *time.Duration { return cmd._readTimeout } func (cmd *baseCmd) setReadTimeout(d time.Duration) { cmd._readTimeout = &d } func (cmd *baseCmd) setErr(e error) { cmd.err = e } //------------------------------------------------------------------------------ type Cmd struct { baseCmd val interface{} } func NewCmd(args ...interface{}) *Cmd { return &Cmd{ baseCmd: baseCmd{_args: args}, } } func (cmd *Cmd) Val() interface{} { return cmd.val } func (cmd *Cmd) Result() (interface{}, error) { return cmd.val, cmd.err } func (cmd *Cmd) String() string { return cmdString(cmd, cmd.val) } func (cmd *Cmd) readReply(cn *pool.Conn) error { cmd.val, cmd.err = cn.Rd.ReadReply(sliceParser) if cmd.err != nil { return cmd.err } if b, ok := cmd.val.([]byte); ok { // Bytes must be copied, because underlying memory is reused. cmd.val = string(b) } return nil } //------------------------------------------------------------------------------ type SliceCmd struct { baseCmd val []interface{} } var _ Cmder = (*SliceCmd)(nil) func NewSliceCmd(args ...interface{}) *SliceCmd { return &SliceCmd{ baseCmd: baseCmd{_args: args}, } } func (cmd *SliceCmd) Val() []interface{} { return cmd.val } func (cmd *SliceCmd) Result() ([]interface{}, error) { return cmd.val, cmd.err } func (cmd *SliceCmd) String() string { return cmdString(cmd, cmd.val) } func (cmd *SliceCmd) readReply(cn *pool.Conn) error { var v interface{} v, cmd.err = cn.Rd.ReadArrayReply(sliceParser) if cmd.err != nil { return cmd.err } cmd.val = v.([]interface{}) return nil } //------------------------------------------------------------------------------ type StatusCmd struct { baseCmd val string } var _ Cmder = (*StatusCmd)(nil) func NewStatusCmd(args ...interface{}) *StatusCmd { return &StatusCmd{ baseCmd: baseCmd{_args: args}, } } func (cmd *StatusCmd) Val() string { return cmd.val } func (cmd *StatusCmd) Result() (string, error) { return cmd.val, cmd.err } func (cmd *StatusCmd) String() string { return cmdString(cmd, cmd.val) } func (cmd *StatusCmd) readReply(cn *pool.Conn) error { cmd.val, cmd.err = cn.Rd.ReadStringReply() return cmd.err } //------------------------------------------------------------------------------ type IntCmd struct { baseCmd val int64 } var _ Cmder = (*IntCmd)(nil) func NewIntCmd(args ...interface{}) *IntCmd { return &IntCmd{ baseCmd: baseCmd{_args: args}, } } func (cmd *IntCmd) Val() int64 { return cmd.val } func (cmd *IntCmd) Result() (int64, error) { return cmd.val, cmd.err } func (cmd *IntCmd) String() string { return cmdString(cmd, cmd.val) } func (cmd *IntCmd) readReply(cn *pool.Conn) error { cmd.val, cmd.err = cn.Rd.ReadIntReply() return cmd.err } //------------------------------------------------------------------------------ type DurationCmd struct { baseCmd val time.Duration precision time.Duration } var _ Cmder = (*DurationCmd)(nil) func NewDurationCmd(precision time.Duration, args ...interface{}) *DurationCmd { return &DurationCmd{ baseCmd: baseCmd{_args: args}, precision: precision, } } func (cmd *DurationCmd) Val() time.Duration { return cmd.val } func (cmd *DurationCmd) Result() (time.Duration, error) { return cmd.val, cmd.err } func (cmd *DurationCmd) String() string { return cmdString(cmd, cmd.val) } func (cmd *DurationCmd) readReply(cn *pool.Conn) error { var n int64 n, cmd.err = cn.Rd.ReadIntReply() if cmd.err != nil { return cmd.err } cmd.val = time.Duration(n) * cmd.precision return nil } //------------------------------------------------------------------------------ type TimeCmd struct { baseCmd val time.Time } var _ Cmder = (*TimeCmd)(nil) func NewTimeCmd(args ...interface{}) *TimeCmd { return &TimeCmd{ baseCmd: baseCmd{_args: args}, } } func (cmd *TimeCmd) Val() time.Time { return cmd.val } func (cmd *TimeCmd) Result() (time.Time, error) { return cmd.val, cmd.err } func (cmd *TimeCmd) String() string { return cmdString(cmd, cmd.val) } func (cmd *TimeCmd) readReply(cn *pool.Conn) error { var v interface{} v, cmd.err = cn.Rd.ReadArrayReply(timeParser) if cmd.err != nil { return cmd.err } cmd.val = v.(time.Time) return nil } //------------------------------------------------------------------------------ type BoolCmd struct { baseCmd val bool } var _ Cmder = (*BoolCmd)(nil) func NewBoolCmd(args ...interface{}) *BoolCmd { return &BoolCmd{ baseCmd: baseCmd{_args: args}, } } func (cmd *BoolCmd) Val() bool { return cmd.val } func (cmd *BoolCmd) Result() (bool, error) { return cmd.val, cmd.err } func (cmd *BoolCmd) String() string { return cmdString(cmd, cmd.val) } var ok = []byte("OK") func (cmd *BoolCmd) readReply(cn *pool.Conn) error { var v interface{} v, cmd.err = cn.Rd.ReadReply(nil) // `SET key value NX` returns nil when key already exists. But // `SETNX key value` returns bool (0/1). So convert nil to bool. // TODO: is this okay? if cmd.err == Nil { cmd.val = false cmd.err = nil return nil } if cmd.err != nil { return cmd.err } switch v := v.(type) { case int64: cmd.val = v == 1 return nil case []byte: cmd.val = bytes.Equal(v, ok) return nil default: cmd.err = fmt.Errorf("got %T, wanted int64 or string", v) return cmd.err } } //------------------------------------------------------------------------------ type StringCmd struct { baseCmd val []byte } var _ Cmder = (*StringCmd)(nil) func NewStringCmd(args ...interface{}) *StringCmd { return &StringCmd{ baseCmd: baseCmd{_args: args}, } } func (cmd *StringCmd) Val() string { return util.BytesToString(cmd.val) } func (cmd *StringCmd) Result() (string, error) { return cmd.Val(), cmd.err } func (cmd *StringCmd) Bytes() ([]byte, error) { return cmd.val, cmd.err } func (cmd *StringCmd) Int64() (int64, error) { if cmd.err != nil { return 0, cmd.err } return strconv.ParseInt(cmd.Val(), 10, 64) } func (cmd *StringCmd) Uint64() (uint64, error) { if cmd.err != nil { return 0, cmd.err } return strconv.ParseUint(cmd.Val(), 10, 64) } func (cmd *StringCmd) Float64() (float64, error) { if cmd.err != nil { return 0, cmd.err } return strconv.ParseFloat(cmd.Val(), 64) } func (cmd *StringCmd) Scan(val interface{}) error { if cmd.err != nil { return cmd.err } return proto.Scan(cmd.val, val) } func (cmd *StringCmd) String() string { return cmdString(cmd, cmd.val) } func (cmd *StringCmd) readReply(cn *pool.Conn) error { cmd.val, cmd.err = cn.Rd.ReadBytesReply() return cmd.err } //------------------------------------------------------------------------------ type FloatCmd struct { baseCmd val float64 } var _ Cmder = (*FloatCmd)(nil) func NewFloatCmd(args ...interface{}) *FloatCmd { return &FloatCmd{ baseCmd: baseCmd{_args: args}, } } func (cmd *FloatCmd) Val() float64 { return cmd.val } func (cmd *FloatCmd) Result() (float64, error) { return cmd.Val(), cmd.Err() } func (cmd *FloatCmd) String() string { return cmdString(cmd, cmd.val) } func (cmd *FloatCmd) readReply(cn *pool.Conn) error { cmd.val, cmd.err = cn.Rd.ReadFloatReply() return cmd.err } //------------------------------------------------------------------------------ type StringSliceCmd struct { baseCmd val []string } var _ Cmder = (*StringSliceCmd)(nil) func NewStringSliceCmd(args ...interface{}) *StringSliceCmd { return &StringSliceCmd{ baseCmd: baseCmd{_args: args}, } } func (cmd *StringSliceCmd) Val() []string { return cmd.val } func (cmd *StringSliceCmd) Result() ([]string, error) { return cmd.Val(), cmd.Err() } func (cmd *StringSliceCmd) String() string { return cmdString(cmd, cmd.val) } func (cmd *StringSliceCmd) ScanSlice(container interface{}) error { return proto.ScanSlice(cmd.Val(), container) } func (cmd *StringSliceCmd) readReply(cn *pool.Conn) error { var v interface{} v, cmd.err = cn.Rd.ReadArrayReply(stringSliceParser) if cmd.err != nil { return cmd.err } cmd.val = v.([]string) return nil } //------------------------------------------------------------------------------ type BoolSliceCmd struct { baseCmd val []bool } var _ Cmder = (*BoolSliceCmd)(nil) func NewBoolSliceCmd(args ...interface{}) *BoolSliceCmd { return &BoolSliceCmd{ baseCmd: baseCmd{_args: args}, } } func (cmd *BoolSliceCmd) Val() []bool { return cmd.val } func (cmd *BoolSliceCmd) Result() ([]bool, error) { return cmd.val, cmd.err } func (cmd *BoolSliceCmd) String() string { return cmdString(cmd, cmd.val) } func (cmd *BoolSliceCmd) readReply(cn *pool.Conn) error { var v interface{} v, cmd.err = cn.Rd.ReadArrayReply(boolSliceParser) if cmd.err != nil { return cmd.err } cmd.val = v.([]bool) return nil } //------------------------------------------------------------------------------ type StringStringMapCmd struct { baseCmd val map[string]string } var _ Cmder = (*StringStringMapCmd)(nil) func NewStringStringMapCmd(args ...interface{}) *StringStringMapCmd { return &StringStringMapCmd{ baseCmd: baseCmd{_args: args}, } } func (cmd *StringStringMapCmd) Val() map[string]string { return cmd.val } func (cmd *StringStringMapCmd) Result() (map[string]string, error) { return cmd.val, cmd.err } func (cmd *StringStringMapCmd) String() string { return cmdString(cmd, cmd.val) } func (cmd *StringStringMapCmd) readReply(cn *pool.Conn) error { var v interface{} v, cmd.err = cn.Rd.ReadArrayReply(stringStringMapParser) if cmd.err != nil { return cmd.err } cmd.val = v.(map[string]string) return nil } //------------------------------------------------------------------------------ type StringIntMapCmd struct { baseCmd val map[string]int64 } var _ Cmder = (*StringIntMapCmd)(nil) func NewStringIntMapCmd(args ...interface{}) *StringIntMapCmd { return &StringIntMapCmd{ baseCmd: baseCmd{_args: args}, } } func (cmd *StringIntMapCmd) Val() map[string]int64 { return cmd.val } func (cmd *StringIntMapCmd) Result() (map[string]int64, error) { return cmd.val, cmd.err } func (cmd *StringIntMapCmd) String() string { return cmdString(cmd, cmd.val) } func (cmd *StringIntMapCmd) readReply(cn *pool.Conn) error { var v interface{} v, cmd.err = cn.Rd.ReadArrayReply(stringIntMapParser) if cmd.err != nil { return cmd.err } cmd.val = v.(map[string]int64) return nil } //------------------------------------------------------------------------------ type StringStructMapCmd struct { baseCmd val map[string]struct{} } var _ Cmder = (*StringStructMapCmd)(nil) func NewStringStructMapCmd(args ...interface{}) *StringStructMapCmd { return &StringStructMapCmd{ baseCmd: baseCmd{_args: args}, } } func (cmd *StringStructMapCmd) Val() map[string]struct{} { return cmd.val } func (cmd *StringStructMapCmd) Result() (map[string]struct{}, error) { return cmd.val, cmd.err } func (cmd *StringStructMapCmd) String() string { return cmdString(cmd, cmd.val) } func (cmd *StringStructMapCmd) readReply(cn *pool.Conn) error { var v interface{} v, cmd.err = cn.Rd.ReadArrayReply(stringStructMapParser) if cmd.err != nil { return cmd.err } cmd.val = v.(map[string]struct{}) return nil } //------------------------------------------------------------------------------ type XStream struct { Stream string Messages []*XMessage } type XMessage struct { ID string Values map[string]interface{} } //------------------------------------------------------------------------------ type XStreamSliceCmd struct { baseCmd val []*XStream } var _ Cmder = (*XStreamSliceCmd)(nil) func NewXStreamSliceCmd(args ...interface{}) *XStreamSliceCmd { return &XStreamSliceCmd{ baseCmd: baseCmd{_args: args}, } } func (cmd *XStreamSliceCmd) Val() []*XStream { return cmd.val } func (cmd *XStreamSliceCmd) Result() ([]*XStream, error) { return cmd.val, cmd.err } func (cmd *XStreamSliceCmd) String() string { return cmdString(cmd, cmd.val) } func (cmd *XStreamSliceCmd) readReply(cn *pool.Conn) error { var v interface{} v, cmd.err = cn.Rd.ReadArrayReply(xStreamSliceParser) if cmd.err != nil { return cmd.err } cmd.val = v.([]*XStream) return nil } // Implements proto.MultiBulkParse func xStreamSliceParser(rd *proto.Reader, n int64) (interface{}, error) { xx := make([]*XStream, n) for i := int64(0); i < n; i++ { v, err := rd.ReadArrayReply(xStreamParser) if err != nil { return nil, err } xx[i] = v.(*XStream) } return xx, nil } // Implements proto.MultiBulkParse func xStreamParser(rd *proto.Reader, n int64) (interface{}, error) { if n != 2 { return nil, fmt.Errorf("got %d, wanted 2", n) } stream, err := rd.ReadStringReply() if err != nil { return nil, err } v, err := rd.ReadArrayReply(xMessageSliceParser) if err != nil { return nil, err } return &XStream{ Stream: stream, Messages: v.([]*XMessage), }, nil } //------------------------------------------------------------------------------ type XMessageSliceCmd struct { baseCmd val []*XMessage } var _ Cmder = (*XMessageSliceCmd)(nil) func NewXMessageSliceCmd(args ...interface{}) *XMessageSliceCmd { return &XMessageSliceCmd{ baseCmd: baseCmd{_args: args}, } } func (cmd *XMessageSliceCmd) Val() []*XMessage { return cmd.val } func (cmd *XMessageSliceCmd) Result() ([]*XMessage, error) { return cmd.val, cmd.err } func (cmd *XMessageSliceCmd) String() string { return cmdString(cmd, cmd.val) } func (cmd *XMessageSliceCmd) readReply(cn *pool.Conn) error { var v interface{} v, cmd.err = cn.Rd.ReadArrayReply(xMessageSliceParser) if cmd.err != nil { return cmd.err } cmd.val = v.([]*XMessage) return nil } // Implements proto.MultiBulkParse func xMessageSliceParser(rd *proto.Reader, n int64) (interface{}, error) { msgs := make([]*XMessage, n) for i := int64(0); i < n; i++ { v, err := rd.ReadArrayReply(xMessageParser) if err != nil { return nil, err } msgs[i] = v.(*XMessage) } return msgs, nil } // Implements proto.MultiBulkParse func xMessageParser(rd *proto.Reader, n int64) (interface{}, error) { id, err := rd.ReadStringReply() if err != nil { return nil, err } v, err := rd.ReadArrayReply(xKeyValueParser) if err != nil { return nil, err } return &XMessage{ ID: id, Values: v.(map[string]interface{}), }, nil } // Implements proto.MultiBulkParse func xKeyValueParser(rd *proto.Reader, n int64) (interface{}, error) { values := make(map[string]interface{}, n) for i := int64(0); i < n; i += 2 { key, err := rd.ReadStringReply() if err != nil { return nil, err } value, err := rd.ReadStringReply() if err != nil { return nil, err } values[key] = value } return values, nil } //------------------------------------------------------------------------------ type ZSliceCmd struct { baseCmd val []Z } var _ Cmder = (*ZSliceCmd)(nil) func NewZSliceCmd(args ...interface{}) *ZSliceCmd { return &ZSliceCmd{ baseCmd: baseCmd{_args: args}, } } func (cmd *ZSliceCmd) Val() []Z { return cmd.val } func (cmd *ZSliceCmd) Result() ([]Z, error) { return cmd.val, cmd.err } func (cmd *ZSliceCmd) String() string { return cmdString(cmd, cmd.val) } func (cmd *ZSliceCmd) readReply(cn *pool.Conn) error { var v interface{} v, cmd.err = cn.Rd.ReadArrayReply(zSliceParser) if cmd.err != nil { return cmd.err } cmd.val = v.([]Z) return nil } //------------------------------------------------------------------------------ type ScanCmd struct { baseCmd page []string cursor uint64 process func(cmd Cmder) error } var _ Cmder = (*ScanCmd)(nil) func NewScanCmd(process func(cmd Cmder) error, args ...interface{}) *ScanCmd { return &ScanCmd{ baseCmd: baseCmd{_args: args}, process: process, } } func (cmd *ScanCmd) Val() (keys []string, cursor uint64) { return cmd.page, cmd.cursor } func (cmd *ScanCmd) Result() (keys []string, cursor uint64, err error) { return cmd.page, cmd.cursor, cmd.err } func (cmd *ScanCmd) String() string { return cmdString(cmd, cmd.page) } func (cmd *ScanCmd) readReply(cn *pool.Conn) error { cmd.page, cmd.cursor, cmd.err = cn.Rd.ReadScanReply() return cmd.err } // Iterator creates a new ScanIterator. func (cmd *ScanCmd) Iterator() *ScanIterator { return &ScanIterator{ cmd: cmd, } } //------------------------------------------------------------------------------ type ClusterNode struct { Id string Addr string } type ClusterSlot struct { Start int End int Nodes []ClusterNode } type ClusterSlotsCmd struct { baseCmd val []ClusterSlot } var _ Cmder = (*ClusterSlotsCmd)(nil) func NewClusterSlotsCmd(args ...interface{}) *ClusterSlotsCmd { return &ClusterSlotsCmd{ baseCmd: baseCmd{_args: args}, } } func (cmd *ClusterSlotsCmd) Val() []ClusterSlot { return cmd.val } func (cmd *ClusterSlotsCmd) Result() ([]ClusterSlot, error) { return cmd.Val(), cmd.Err() } func (cmd *ClusterSlotsCmd) String() string { return cmdString(cmd, cmd.val) } func (cmd *ClusterSlotsCmd) readReply(cn *pool.Conn) error { var v interface{} v, cmd.err = cn.Rd.ReadArrayReply(clusterSlotsParser) if cmd.err != nil { return cmd.err } cmd.val = v.([]ClusterSlot) return nil } //------------------------------------------------------------------------------ // GeoLocation is used with GeoAdd to add geospatial location. type GeoLocation struct { Name string Longitude, Latitude, Dist float64 GeoHash int64 } // GeoRadiusQuery is used with GeoRadius to query geospatial index. type GeoRadiusQuery struct { Radius float64 // Can be m, km, ft, or mi. Default is km. Unit string WithCoord bool WithDist bool WithGeoHash bool Count int // Can be ASC or DESC. Default is no sort order. Sort string Store string StoreDist string } type GeoLocationCmd struct { baseCmd q *GeoRadiusQuery locations []GeoLocation } var _ Cmder = (*GeoLocationCmd)(nil) func NewGeoLocationCmd(q *GeoRadiusQuery, args ...interface{}) *GeoLocationCmd { args = append(args, q.Radius) if q.Unit != "" { args = append(args, q.Unit) } else { args = append(args, "km") } if q.WithCoord { args = append(args, "withcoord") } if q.WithDist { args = append(args, "withdist") } if q.WithGeoHash { args = append(args, "withhash") } if q.Count > 0 { args = append(args, "count", q.Count) } if q.Sort != "" { args = append(args, q.Sort) } if q.Store != "" { args = append(args, "store") args = append(args, q.Store) } if q.StoreDist != "" { args = append(args, "storedist") args = append(args, q.StoreDist) } return &GeoLocationCmd{ baseCmd: baseCmd{_args: args}, q: q, } } func (cmd *GeoLocationCmd) Val() []GeoLocation { return cmd.locations } func (cmd *GeoLocationCmd) Result() ([]GeoLocation, error) { return cmd.locations, cmd.err } func (cmd *GeoLocationCmd) String() string { return cmdString(cmd, cmd.locations) } func (cmd *GeoLocationCmd) readReply(cn *pool.Conn) error { var v interface{} v, cmd.err = cn.Rd.ReadArrayReply(newGeoLocationSliceParser(cmd.q)) if cmd.err != nil { return cmd.err } cmd.locations = v.([]GeoLocation) return nil } //------------------------------------------------------------------------------ type GeoPos struct { Longitude, Latitude float64 } type GeoPosCmd struct { baseCmd positions []*GeoPos } var _ Cmder = (*GeoPosCmd)(nil) func NewGeoPosCmd(args ...interface{}) *GeoPosCmd { return &GeoPosCmd{ baseCmd: baseCmd{_args: args}, } } func (cmd *GeoPosCmd) Val() []*GeoPos { return cmd.positions } func (cmd *GeoPosCmd) Result() ([]*GeoPos, error) { return cmd.Val(), cmd.Err() } func (cmd *GeoPosCmd) String() string { return cmdString(cmd, cmd.positions) } func (cmd *GeoPosCmd) readReply(cn *pool.Conn) error { var v interface{} v, cmd.err = cn.Rd.ReadArrayReply(geoPosSliceParser) if cmd.err != nil { return cmd.err } cmd.positions = v.([]*GeoPos) return nil } //------------------------------------------------------------------------------ type CommandInfo struct { Name string Arity int8 Flags []string FirstKeyPos int8 LastKeyPos int8 StepCount int8 ReadOnly bool } type CommandsInfoCmd struct { baseCmd val map[string]*CommandInfo } var _ Cmder = (*CommandsInfoCmd)(nil) func NewCommandsInfoCmd(args ...interface{}) *CommandsInfoCmd { return &CommandsInfoCmd{ baseCmd: baseCmd{_args: args}, } } func (cmd *CommandsInfoCmd) Val() map[string]*CommandInfo { return cmd.val } func (cmd *CommandsInfoCmd) Result() (map[string]*CommandInfo, error) { return cmd.Val(), cmd.Err() } func (cmd *CommandsInfoCmd) String() string { return cmdString(cmd, cmd.val) } func (cmd *CommandsInfoCmd) readReply(cn *pool.Conn) error { var v interface{} v, cmd.err = cn.Rd.ReadArrayReply(commandInfoSliceParser) if cmd.err != nil { return cmd.err } cmd.val = v.(map[string]*CommandInfo) return nil } //------------------------------------------------------------------------------ type cmdsInfoCache struct { fn func() (map[string]*CommandInfo, error) once internal.Once cmds map[string]*CommandInfo } func newCmdsInfoCache(fn func() (map[string]*CommandInfo, error)) *cmdsInfoCache { return &cmdsInfoCache{ fn: fn, } } func (c *cmdsInfoCache) Get() (map[string]*CommandInfo, error) { err := c.once.Do(func() error { cmds, err := c.fn() if err != nil { return err } c.cmds = cmds return nil }) return c.cmds, err }