/
disk.go
52 lines (44 loc) · 1.2 KB
/
disk.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
package persistent
import (
"context"
"database/sql"
"os"
"path"
_ "github.com/mattn/go-sqlite3"
)
type disk struct {
db *sql.DB
}
// NewDisk returns object storage backed by an on-disk database stored at `loc`.
func NewDisk(loc string) (ObjectStorage, error) {
if err := os.MkdirAll(path.Dir(loc), 0744); err != nil {
return nil, err
}
db, err := sql.Open("sqlite3", loc)
if err != nil {
return nil, err
}
_, err = db.Exec("CREATE TABLE IF NOT EXISTS db (key text not null primary key, val bytea)")
if err != nil {
return nil, err
}
return &disk{db}, nil
}
func (d *disk) Get(ctx context.Context, key string) ([]byte, error) {
var data []byte
err := d.db.QueryRowContext(ctx, "SELECT val FROM db WHERE key = ?", key).Scan(&data)
if err == sql.ErrNoRows {
return nil, ErrObjectNotFound
} else if err != nil {
return nil, err
}
return data, nil
}
func (d *disk) Set(ctx context.Context, key string, data []byte, _ DataType) error {
_, err := d.db.ExecContext(ctx, "INSERT OR REPLACE INTO db (key, val) VALUES (?, ?)", key, data)
return err
}
func (d *disk) Delete(ctx context.Context, key string) error {
_, err := d.db.ExecContext(ctx, "DELETE FROM db WHERE key = ?", key)
return err
}