roulette/cmd/cache.go

140 lines
2.4 KiB
Go

/*
Copyright © 2023 Seednode <seednode@seedno.de>
*/
package cmd
import (
"encoding/gob"
"net/http"
"os"
"sync"
"github.com/julienschmidt/httprouter"
"github.com/klauspost/compress/zstd"
"seedno.de/seednode/roulette/types"
)
type fileCache struct {
mutex sync.RWMutex
list []string
}
func (cache *fileCache) List() []string {
cache.mutex.RLock()
val := cache.list
cache.mutex.RUnlock()
return val
}
func (cache *fileCache) remove(path string) {
cache.mutex.RLock()
tempIndex := make([]string, len(cache.list))
copy(tempIndex, cache.list)
cache.mutex.RUnlock()
var position int
for k, v := range tempIndex {
if path == v {
position = k
break
}
}
tempIndex[position] = tempIndex[len(tempIndex)-1]
cache.mutex.Lock()
cache.list = make([]string, len(tempIndex)-1)
copy(cache.list, tempIndex[:len(tempIndex)-1])
cache.mutex.Unlock()
}
func (cache *fileCache) set(val []string) {
cache.mutex.Lock()
cache.list = val
cache.mutex.Unlock()
}
func (cache *fileCache) generate(args []string, formats *types.Types) {
cache.mutex.Lock()
cache.list = []string{}
cache.mutex.Unlock()
fileList(args, &filters{}, "", cache, formats)
if Cache && CacheFile != "" {
cache.Export(CacheFile)
}
}
func (cache *fileCache) isEmpty() bool {
cache.mutex.RLock()
length := len(cache.list)
cache.mutex.RUnlock()
return length == 0
}
func (cache *fileCache) Export(path string) error {
file, err := os.OpenFile(path, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0600)
if err != nil {
return err
}
defer file.Close()
z, err := zstd.NewWriter(file)
if err != nil {
return err
}
defer z.Close()
enc := gob.NewEncoder(z)
cache.mutex.RLock()
enc.Encode(&cache.list)
cache.mutex.RUnlock()
return nil
}
func (cache *fileCache) Import(path string) error {
file, err := os.OpenFile(path, os.O_RDONLY, 0600)
if err != nil {
return err
}
defer file.Close()
z, err := zstd.NewReader(file)
if err != nil {
return err
}
defer z.Close()
dec := gob.NewDecoder(z)
cache.mutex.Lock()
err = dec.Decode(&cache.list)
cache.mutex.Unlock()
if err != nil {
return err
}
return nil
}
func serveCacheClear(args []string, cache *fileCache, formats *types.Types) httprouter.Handle {
return func(w http.ResponseWriter, r *http.Request, p httprouter.Params) {
cache.generate(args, formats)
w.Header().Set("Content-Type", "text/plain")
w.Write([]byte("Ok"))
}
}