93 lines
1.4 KiB
Go
93 lines
1.4 KiB
Go
package kv
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import (
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"errors"
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"io/ioutil"
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"os"
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"path/filepath"
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"strings"
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"sync"
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)
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var (
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errInvalidKey = errors.New("invalid key")
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errNoSuchKey = errors.New("no such key")
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)
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type Database struct {
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data map[string][]byte
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basedir string
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m sync.RWMutex
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}
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func NewDatabse(basedir string) (db *Database, err error) {
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err = os.Mkdir(basedir, 0755)
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if err != nil && !os.IsExist(err) {
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return
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}
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return &Database{
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data: make(map[string][]byte),
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basedir: basedir,
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}, nil
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}
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func (db *Database) Set(key string, val []byte) (err error) {
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if len(key) < 1 {
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return errInvalidKey
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}
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db.m.Lock()
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defer func() {
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if err != nil {
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delete(db.data, key)
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}
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db.m.Unlock()
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}()
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db.data[key] = val
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err = ioutil.WriteFile(filepath.Join(db.basedir, key), val, 0644)
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return
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}
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func (db *Database) Get(key string) (val []byte, err error) {
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if len(key) < 1 {
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return nil, errInvalidKey
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}
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db.m.RLock()
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defer db.m.RUnlock()
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data, ok := db.data[key]
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if !ok {
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data, err = ioutil.ReadFile(filepath.Join(db.basedir, key))
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if err != nil {
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err = errNoSuchKey
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return nil, err
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}
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db.data[key] = data
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}
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val = make([]byte, len(data))
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copy(val, data)
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return
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}
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func (db *Database) Remove(key string) {
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if len(key) < 1 || strings.ContainsRune(key, os.PathSeparator) {
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return
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}
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db.m.Lock()
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defer db.m.Unlock()
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delete(db.data, key)
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os.Remove(filepath.Join(db.basedir, key))
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return
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}
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