This is a cache system written by Golang and base on red black tree.
You can simply use this project to build a buffer/cache system for your own project or just use the red black tree to do some other interesting things.
This project is based on GoLLRB which was written by Petar Maymounkov.
Thanks for the great work of him and you can follow him on Twitter @maymounkov!
The origin project GoLLRB seems have slept for a long time and will no longer to be maintained, so I think
it's better to open a new repo and keep it fresh.
If anyone has any objections, please let me know.
With a healthy Go language installed, simply run go get github.com/HuKeping/cache
package main
import (
"fmt"
"github.com/HuKeping/cache"
)
func Print(item cache.Item, buffer *cache.LLRB) bool {
i, ok := item.(cache.Int)
if !ok {
return false
}
fmt.Println(int(i))
return true
}
func main() {
buffer := cache.New()
buffer.Add(cache.Int(1), cache.MOD_NOREPLACE)
buffer.Add(cache.Int(2), cache.MOD_NOREPLACE)
buffer.Add(cache.Int(3), cache.MOD_NOREPLACE)
buffer.Add(cache.Int(4), cache.MOD_NOREPLACE)
buffer.DeleteMin()
buffer.Delete(cache.Int(4))
buffer.AscendGreaterOrEqual(buffer.Min(), Print)
}
package main
import (
"fmt"
"github.com/HuKeping/cache"
)
func Print(item cache.Item, buffer *cache.LLRB) bool {
i, ok := item.(cache.String)
if !ok {
return false
}
fmt.Println(cache.String(i))
return true
}
func main() {
buffer := cache.New()
// For now it is not ordered.
order := []cache.String{
"ab", "aba", "abc", "a", "aa", "aaa", "b", "a-", "a!",
}
for _, i := range order {
buffer.Add(cache.String(i), cache.MOD_REPLACE)
}
// We expect to get `ab`, `aba` and `abc`, otherwise something wrong happened.
buffer.AscendRange(cache.String("ab"), cache.String("ac"), Print)
}
package main
import (
"fmt"
"github.com/HuKeping/cache"
"time"
)
type Var struct {
Expiry time.Time `json:"expiry,omitempty"`
ID string `json:"id",omitempty`
}
// We will order the node by `Time`
func (x Var) Less(than cache.Item) bool {
return x.Expiry.Before(than.(Var).Expiry)
}
func PrintVar(item cache.Item, buffer *cache.LLRB) bool {
i, ok := item.(Var)
if !ok {
return false
}
if i.Expiry.Before(time.Now()) {
fmt.Printf("Item expired and to be deleted : %v\n", i)
buffer.Delete(i)
}
return true
}
func main() {
buffer := cache.New()
var1 := Var{
Expiry: time.Now().Add(time.Second * 10),
ID: "var1",
}
var2 := Var{
Expiry: time.Now().Add(time.Second * 20),
ID: "var2",
}
var3 := Var{
Expiry: time.Now().Add(time.Second * 30),
ID: "var3",
}
var4 := Var{
Expiry: time.Now().Add(time.Second * 40),
ID: "var4",
}
var5 := Var{
Expiry: time.Now().Add(time.Second * 50),
ID: "var5",
}
buffer.Add(var1, cache.MOD_REPLACE)
buffer.Add(var2, cache.MOD_REPLACE)
buffer.Add(var3, cache.MOD_REPLACE)
buffer.Add(var4, cache.MOD_REPLACE)
buffer.Add(var5, cache.MOD_REPLACE)
go func() {
for {
time.Sleep(time.Second * 10)
fmt.Printf("[VAR] Refreshing begin ...\n")
buffer.AscendGreaterOrEqual(buffer.Min(), PrintVar)
fmt.Printf("[VAR] Refreshing end...\n\n")
}
}()
time.Sleep(time.Minute)
}