Files
NixMsg/internal/store/migrate.go
T

153 lines
3.8 KiB
Go

package store
import (
"database/sql"
"embed"
"fmt"
"io/fs"
"os"
"path/filepath"
"sort"
"strconv"
"strings"
"time"
)
//go:embed migrations/*.sql
var migrationFS embed.FS
// Migrate 应用尚未执行的嵌入迁移。
// 若 dbExisted 为 true(调用 Open/Migrate 前已有 nixmsg.db)且存在未应用版本,
// 先 VACUUM INTO <data_dir>/backup/pre-migrate-<时间>.db,再迁移。
// 任一版本失败则返回错误,调用方不得继续带半新半旧库提供服务。
func Migrate(db *sql.DB, dataDir string, dbExisted bool) error {
if _, err := db.Exec(`
CREATE TABLE IF NOT EXISTS schema_migrations (
version INTEGER PRIMARY KEY,
applied_at INTEGER NOT NULL
)`); err != nil {
return fmt.Errorf("ensure schema_migrations: %w", err)
}
pending, err := pendingMigrations(db)
if err != nil {
return err
}
if len(pending) == 0 {
return nil
}
if dbExisted {
if err := backupBeforeMigrate(db, dataDir); err != nil {
return err
}
}
for _, m := range pending {
if err := applyMigration(db, m); err != nil {
return err
}
}
return nil
}
type migrationFile struct {
version int
name string
body string
}
func pendingMigrations(db *sql.DB) ([]migrationFile, error) {
entries, err := fs.ReadDir(migrationFS, "migrations")
if err != nil {
return nil, fmt.Errorf("read migrations: %w", err)
}
var names []string
for _, e := range entries {
if e.IsDir() || !strings.HasSuffix(e.Name(), ".sql") {
continue
}
names = append(names, e.Name())
}
sort.Strings(names)
var pending []migrationFile
for _, name := range names {
version, err := parseMigrationVersion(name)
if err != nil {
return nil, err
}
var exists int
err = db.QueryRow(`SELECT 1 FROM schema_migrations WHERE version = ?`, version).Scan(&exists)
if err == nil {
continue
}
if err != sql.ErrNoRows {
return nil, fmt.Errorf("check migration %d: %w", version, err)
}
body, err := migrationFS.ReadFile("migrations/" + name)
if err != nil {
return nil, fmt.Errorf("read migration %s: %w", name, err)
}
pending = append(pending, migrationFile{
version: version,
name: name,
body: strings.TrimSpace(string(body)),
})
}
return pending, nil
}
func backupBeforeMigrate(db *sql.DB, dataDir string) error {
backupDir := filepath.Join(dataDir, "backup")
if err := os.MkdirAll(backupDir, 0o755); err != nil {
return fmt.Errorf("mkdir backup: %w", err)
}
stamp := time.Now().UTC().Format("20060102T150405")
backupPath := filepath.Join(backupDir, "pre-migrate-"+stamp+".db")
// SQLite VACUUM INTO 需要字面量路径;统一用斜杠,并对单引号转义。
quoted := strings.ReplaceAll(filepath.ToSlash(backupPath), "'", "''")
if _, err := db.Exec("VACUUM INTO '" + quoted + "'"); err != nil {
return fmt.Errorf("vacuum into backup %s: %w", backupPath, err)
}
return nil
}
func applyMigration(db *sql.DB, m migrationFile) error {
tx, err := db.Begin()
if err != nil {
return fmt.Errorf("begin migration %d: %w", m.version, err)
}
if m.body != "" {
if _, err := tx.Exec(m.body); err != nil {
_ = tx.Rollback()
return fmt.Errorf("apply migration %d (%s): %w", m.version, m.name, err)
}
}
if _, err := tx.Exec(
`INSERT INTO schema_migrations(version, applied_at) VALUES(?, ?)`,
m.version,
time.Now().UnixMilli(),
); err != nil {
_ = tx.Rollback()
return fmt.Errorf("record migration %d: %w", m.version, err)
}
if err := tx.Commit(); err != nil {
return fmt.Errorf("commit migration %d: %w", m.version, err)
}
return nil
}
func parseMigrationVersion(name string) (int, error) {
base := strings.TrimSuffix(name, ".sql")
parts := strings.SplitN(base, "_", 2)
if len(parts) < 1 {
return 0, fmt.Errorf("invalid migration name: %s", name)
}
v, err := strconv.Atoi(parts[0])
if err != nil {
return 0, fmt.Errorf("invalid migration version in %s: %w", name, err)
}
return v, nil
}