wiki/block.go
2022-05-26 21:17:51 +02:00

93 lines
2.2 KiB
Go

/*
* Wiki - A wiki with editor
* Copyright (c) 2021-2021 Peter Stuifzand
*
* 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 main
import (
"encoding/json"
"fmt"
"os"
"path/filepath"
)
type BlockRepository interface {
Save(id string, block Block) error
Load(id string) (Block, error)
}
type blockSaveMessage struct {
id string
block Block
}
type blockRepo struct {
dirname string
saveC chan blockSaveMessage
errC chan error
}
func saveBlock(dirname, id string, block Block) error {
f, err := os.OpenFile(filepath.Join(dirname, BlocksDirectory, id), os.O_CREATE|os.O_WRONLY|os.O_TRUNC, 0644)
if err != nil {
return err
}
defer f.Close()
enc := json.NewEncoder(f)
enc.SetIndent("", " ")
err = enc.Encode(&block)
if err != nil {
return err
}
return nil
}
func NewBlockRepo(dirname string) BlockRepository {
saveC := make(chan blockSaveMessage, 1)
errC := make(chan error)
go func() {
for msg := range saveC {
err := saveBlock(dirname, msg.id, msg.block)
errC <- err
}
}()
return &blockRepo{
dirname: dirname,
saveC: saveC,
errC: errC,
}
}
func (br *blockRepo) Save(id string, block Block) error {
br.saveC <- blockSaveMessage{id, block}
err := <-br.errC
return err
}
func (br *blockRepo) Load(id string) (Block, error) {
f, err := os.Open(filepath.Join(br.dirname, BlocksDirectory, id))
if err != nil {
return Block{}, fmt.Errorf("%q: %w", id, BlockNotFound)
}
defer f.Close()
var block Block
err = json.NewDecoder(f).Decode(&block)
if err != nil {
return Block{}, fmt.Errorf("%q: %w", id, err)
}
return block, nil
}