Documentation
¶
Index ¶
Examples ¶
Constants ¶
This section is empty.
Variables ¶
var ( // ErrNotFound is an error returned when the key is not found. ErrNotFound = errors.New("memo: not found") // ErrInvalidExpiration represents an invalid expiration error. ErrInvalidExpiration = errors.New("memo: invalid expiration") )
Functions ¶
This section is empty.
Types ¶
type Clock ¶
type Clock interface {
// Now returns the current time in nanoseconds.
Now() int64
}
A Clock represents the passage of time, it can provide the current time in nanoseconds, which could be a relative value, not an absolute value.
type GetOption ¶
type GetOption func(*getOptions)
GetOption specifies the option when getting a value from the memo.
func GetWithExpiration ¶
GetWithExpiration provides an expiration option when getting a value from the memo.
func GetWithLoader ¶
GetWithLoader provides a loader option when getting a value from the memo.
type Loader ¶
A Loader returns the value of the key.
Example ¶
package main
import (
"fmt"
"reflect"
"github.com/dploop/golib/memo"
)
func main() {
fmt.Println("Scene: default loader only")
m := memo.New(memo.WithLoader(length))
fmt.Println(m.Get("x"))
fmt.Println(m.Get(233))
fmt.Println("Scene: get loader only")
m = memo.New()
fmt.Println(m.Get("x", memo.GetWithLoader(length)))
fmt.Println(m.Get(233, memo.GetWithLoader(length)))
fmt.Println("Scene: get loader overwrites default loader")
m = memo.New(memo.WithLoader(length))
fmt.Println(m.Get("x", memo.GetWithLoader(doubleLength)))
}
func length(k memo.Key) (memo.Value, error) {
switch v := reflect.ValueOf(k); v.Kind() {
case reflect.Array, reflect.Slice, reflect.String, reflect.Map, reflect.Chan:
return v.Len(), nil
default:
return nil, &reflect.ValueError{Method: "reflect.Value.Len", Kind: v.Kind()}
}
}
func doubleLength(k memo.Key) (memo.Value, error) {
switch v := reflect.ValueOf(k); v.Kind() {
case reflect.Array, reflect.Slice, reflect.String, reflect.Map, reflect.Chan:
return 2 * v.Len(), nil
default:
return nil, &reflect.ValueError{Method: "reflect.Value.Len", Kind: v.Kind()}
}
}
Output: Scene: default loader only 1 <nil> <nil> reflect: call of reflect.Value.Len on int Value Scene: get loader only 1 <nil> <nil> reflect: call of reflect.Value.Len on int Value Scene: get loader overwrites default loader 2 <nil>
type Memo ¶
type Memo struct {
// contains filtered or unexported fields
}
Memo is an in-memory k-v storage, which supports concurrently get/set/delete k-v pairs. The most special place is that it can load value if not found, and can set an expiration time.
type Option ¶
type Option func(*options)
Option specifies the option when creating a new memo.
func WithExpiration ¶
WithExpiration provides an expiration option when creating a new memo.
func WithLoader ¶
WithLoader provides a loader option when creating a new memo.
type SetOption ¶
type SetOption func(*setOptions)
SetOption specifies the option when setting a value to the memo.
func SetWithExpiration ¶
SetWithExpiration provides an expiration option when setting a value to the memo.
Source Files