lure/internal/dlcache/dlcache.go

91 lines
2.2 KiB
Go

/*
* LURE - Linux User REpository
* Copyright (C) 2023 Arsen Musayelyan
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package dlcache
import (
"crypto/sha1"
"encoding/hex"
"io"
"os"
"path/filepath"
"go.arsenm.dev/lure/internal/config"
)
// BasePath stores the base path to the download cache
var BasePath = filepath.Join(config.CacheDir, "dl")
// New creates a new directory with the given ID in the cache.
// If a directory with the same ID already exists,
// it will be deleted before creating a new one.
func New(id string) (string, error) {
h, err := hashID(id)
if err != nil {
return "", err
}
itemPath := filepath.Join(BasePath, h)
fi, err := os.Stat(itemPath)
if err == nil || (fi != nil && !fi.IsDir()) {
err = os.RemoveAll(itemPath)
if err != nil {
return "", err
}
}
err = os.MkdirAll(itemPath, 0o755)
if err != nil {
return "", err
}
return itemPath, nil
}
// Get checks if an entry with the given ID
// already exists in the cache, and if so,
// returns the directory and true. If it
// does not exist, it returns an empty string
// and false.
func Get(id string) (string, bool) {
h, err := hashID(id)
if err != nil {
return "", false
}
itemPath := filepath.Join(BasePath, h)
_, err = os.Stat(itemPath)
if err != nil {
return "", false
}
return itemPath, true
}
// hashID hashes the input ID with SHA1
// and returns the hex string of the hashed
// ID.
func hashID(id string) (string, error) {
h := sha1.New()
_, err := io.WriteString(h, id)
if err != nil {
return "", err
}
return hex.EncodeToString(h.Sum(nil)), nil
}