Files
wangjia f3471ae139 feat(server/db): 数据层多库支持(1/4)— 连接分派 + 双方言迁移管线
- config 增 DB_DRIVER(mysql 默认 | sqlite);DSN 对 sqlite 为文件路径
- db.OpenDriver 按驱动分派:sqlite 用 modernc(纯 Go 免 CGO)+ WAL/
  busy_timeout/foreign_keys/_txlock=immediate;mysql 路径不变
- store.Open 分派;mysql 保留 UTC/collation 断言,sqlite 跳过
- 迁移拆 migrations/{mysql,sqlite}/ 双套,embed 双 FS,migrate 按驱动选源
  与 golang-migrate 驱动;修复 m.Close() 误关调用方 *sql.DB 的坑
- cmd/migrate 串入 DB_DRIVER;集成测试 MigrateUp 签名更新
- 新增 SQLite 时间往返 smoke 测试与端到端迁移测试(免 docker)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-06-18 00:01:03 +08:00

105 lines
3.4 KiB
Go

// Package db provides a database connection helper that dispatches on the
// configured driver (MySQL or SQLite). Switching engines is a single env var:
//
// DB_DRIVER=mysql (default) → DB_DSN is a full MySQL DSN
// DB_DRIVER=sqlite → DB_DSN is the SQLite file path (or :memory:)
package db
import (
"database/sql"
"fmt"
"os"
"strings"
"time"
// Register the database drivers with database/sql.
_ "github.com/go-sql-driver/mysql"
_ "modernc.org/sqlite"
)
// Normalize canonicalizes a driver name. Empty → "mysql"; "sqlite3" → "sqlite".
func Normalize(driver string) string {
switch strings.ToLower(strings.TrimSpace(driver)) {
case "", "mysql":
return "mysql"
case "sqlite", "sqlite3":
return "sqlite"
default:
return strings.ToLower(strings.TrimSpace(driver))
}
}
// Driver returns the configured driver from DB_DRIVER (default "mysql").
func Driver() string { return Normalize(os.Getenv("DB_DRIVER")) }
// Open opens a *sql.DB using the driver from DB_DRIVER (default mysql) and pings it.
func Open(dsn string) (*sql.DB, error) { return OpenDriver(Driver(), dsn) }
// OpenDriver opens a *sql.DB for the given driver and DSN, configures the pool,
// and pings. For mysql the DSN must already carry parseTime=true and UTC params
// (see internal/store.Open which builds them); for sqlite the DSN is a file path.
func OpenDriver(driver, dsn string) (*sql.DB, error) {
switch Normalize(driver) {
case "sqlite":
return openSQLite(dsn)
default:
return openMySQL(dsn)
}
}
func openMySQL(dsn string) (*sql.DB, error) {
database, err := sql.Open("mysql", dsn)
if err != nil {
return nil, fmt.Errorf("db.Open: %w", err)
}
database.SetMaxOpenConns(30)
database.SetMaxIdleConns(10)
database.SetConnMaxLifetime(5 * time.Minute)
if err := database.Ping(); err != nil {
database.Close()
return nil, fmt.Errorf("db.Open ping: %w", err)
}
return database, nil
}
func openSQLite(dsn string) (*sql.DB, error) {
database, err := sql.Open("sqlite", sqliteDSN(dsn))
if err != nil {
return nil, fmt.Errorf("db.Open(sqlite): %w", err)
}
// SQLite is a single-writer engine; readers/writers serialize via the
// busy_timeout pragma (set in the DSN). A modest pool is safe under WAL.
database.SetMaxOpenConns(10)
database.SetMaxIdleConns(10)
database.SetConnMaxLifetime(0)
if err := database.Ping(); err != nil {
database.Close()
return nil, fmt.Errorf("db.Open(sqlite) ping: %w", err)
}
return database, nil
}
// sqliteDSN appends the pragmas the server relies on (busy_timeout for write
// contention, foreign_keys enforcement, WAL for file-backed DBs). An empty DSN
// or ":memory:" maps to a shared-cache in-memory DB (so the pool's connections
// see the same database — used by tests).
func sqliteDSN(dsn string) string {
// _txlock=immediate makes every transaction BEGIN IMMEDIATE (acquire the
// write lock up front), giving the pessimistic exclusivity that the MySQL
// "SELECT … FOR UPDATE" paths rely on. busy_timeout lets contended writers
// wait instead of failing with SQLITE_BUSY.
const filePragmas = "_txlock=immediate&_pragma=busy_timeout(5000)&_pragma=foreign_keys(1)&_pragma=journal_mode(WAL)"
const memPragmas = "_txlock=immediate&_pragma=busy_timeout(5000)&_pragma=foreign_keys(1)"
if dsn == "" || dsn == ":memory:" {
return "file::memory:?cache=shared&" + memPragmas
}
sep := "?"
if strings.Contains(dsn, "?") {
sep = "&"
}
return dsn + sep + filePragmas
}