Files
storage/sqlite3/sqlite3.go
2020-10-31 11:18:29 -04:00

120 lines
2.4 KiB
Go

package sqlite3
import (
"database/sql"
"fmt"
"time"
"github.com/gofiber/utils"
)
// Storage interface that is implemented by storage providers
type Storage struct {
db *sql.DB
gcInterval time.Duration
selectQuery string
insertQuery string
deleteQuery string
clearQuery string
gcQuery string
}
var (
migrateQuery = `
CREATE TABLE IF NOT EXISTS %s (
id VARCHAR(64) PRIMARY KEY NOT NULL DEFAULT '',
key TEXT NOT NULL,
data TEXT NOT NULL,
exp BIGINT NOT NULL
);
`
)
// New creates a new storage
func New(config ...Config) *Storage {
// Set default config
cfg := ConfigDefault
// Override config if provided
if len(config) > 0 {
cfg = configDefault(config[0])
}
// Create storage
store := &Storage{
gcInterval: cfg.GCInterval,
selectQuery: fmt.Sprintf(`SELECT data, exp FROM %s WHERE key=?;`, cfg.TableName),
insertQuery: fmt.Sprintf("INSERT INTO %s (key, data, exp) VALUES (?,?,?)", cfg.TableName),
deleteQuery: fmt.Sprintf("DELETE FROM %s WHERE key=?", cfg.TableName),
clearQuery: fmt.Sprintf("DELETE FROM %s;", cfg.TableName),
gcQuery: fmt.Sprintf("DELETE FROM %s WHERE exp <= ?", cfg.TableName),
}
// Create db
db, err := sql.Open("sqlite3", cfg.TableName)
if err != nil {
panic(err)
}
store.db = db
// Migrate db
_, err = store.db.Exec(fmt.Sprintf(migrateQuery, cfg.TableName))
if err != nil {
panic(err)
}
// Start garbage collector
go store.gc()
return store
}
// Get value by key
func (s *Storage) Get(key string) ([]byte, error) {
row := s.db.QueryRow(s.selectQuery, key)
// Add db response to data
var (
data = []byte{}
exp int64 = 0
)
if err := row.Scan(&data, &exp); err != nil {
return nil, err
}
// If the expiration time has already passed, then return nil
if time.Now().After(time.Unix(exp, 0)) {
return nil, nil
}
return data, nil
}
// Set key with value
func (s *Storage) Set(key string, val []byte, exp time.Duration) error {
_, err := s.db.Exec(s.insertQuery, key, utils.GetString(val), time.Now().Add(exp).Unix())
return err
}
// Delete entry by key
func (s *Storage) Delete(key string) error {
_, err := s.db.Exec(s.deleteQuery, key)
return err
}
// Clear all entries, including unexpired
func (s *Storage) Clear() error {
_, err := s.db.Exec(s.clearQuery)
return err
}
// GC deletes all expired entries
func (s *Storage) gc() {
tick := time.NewTicker(s.gcInterval)
for {
<-tick.C
s.db.Exec(s.gcQuery)
}
}