move lua db to external file

internal/server/sv1/db_sqlite.go

@@ -0,0 +1,318 @@
+package sv1
+
+import (
+	"database/sql"
+	"fmt"
+	"log/slog"
+	"sync"
+
+	lua "github.com/yuin/gopher-lua"
+)
+
+type DBConnection struct {
+	dbPath    string
+	log       bool
+	logger    *slog.Logger
+	writeChan chan *dbWriteRequest
+	closeChan chan struct{}
+}
+
+type dbWriteRequest struct {
+	query string
+	args  []interface{}
+	resCh chan *dbWriteResult
+}
+
+type dbWriteResult struct {
+	rowsAffected int64
+	err          error
+}
+
+var dbMutexMap = make(map[string]*sync.RWMutex)
+var dbGlobalMutex sync.Mutex
+
+func getDBMutex(dbPath string) *sync.RWMutex {
+	dbGlobalMutex.Lock()
+	defer dbGlobalMutex.Unlock()
+
+	if mtx, ok := dbMutexMap[dbPath]; ok {
+		return mtx
+	}
+
+	mtx := &sync.RWMutex{}
+	dbMutexMap[dbPath] = mtx
+	return mtx
+}
+
+func loadDBMod(llog *slog.Logger) func(*lua.LState) int {
+	llog.Debug("import module db-sqlite")
+	return func(L *lua.LState) int {
+		dbMod := L.NewTable()
+
+		L.SetField(dbMod, "connect", L.NewFunction(func(L *lua.LState) int {
+			dbPath := L.CheckString(1)
+
+			logQueries := false
+			if L.GetTop() >= 2 {
+				opts := L.CheckTable(2)
+				if val := opts.RawGetString("log"); val != lua.LNil {
+					logQueries = lua.LVAsBool(val)
+				}
+			}
+
+			conn := &DBConnection{
+				dbPath:    dbPath,
+				log:       logQueries,
+				logger:    llog,
+				writeChan: make(chan *dbWriteRequest, 100),
+				closeChan: make(chan struct{}),
+			}
+
+			go conn.processWrites()
+
+			ud := L.NewUserData()
+			ud.Value = conn
+			L.SetMetatable(ud, L.GetTypeMetatable("gosally_db"))
+
+			L.Push(ud)
+			return 1
+		}))
+
+		mt := L.NewTypeMetatable("gosally_db")
+		L.SetField(mt, "__index", L.SetFuncs(L.NewTable(), map[string]lua.LGFunction{
+			"exec":  dbExec,
+			"query": dbQuery,
+			"close": dbClose,
+		}))
+
+		L.SetField(dbMod, "__gosally_internal", lua.LString("0"))
+		L.Push(dbMod)
+		return 1
+	}
+}
+
+func (conn *DBConnection) processWrites() {
+	for {
+		select {
+		case req := <-conn.writeChan:
+			mtx := getDBMutex(conn.dbPath)
+			mtx.Lock()
+
+			db, err := sql.Open("sqlite", conn.dbPath+"?_busy_timeout=5000&_journal_mode=WAL&_sync=NORMAL&_cache_size=-10000")
+			if err == nil {
+				_, err = db.Exec("PRAGMA journal_mode=WAL;")
+				if err == nil {
+					res, execErr := db.Exec(req.query, req.args...)
+					if execErr == nil {
+						rows, _ := res.RowsAffected()
+						req.resCh <- &dbWriteResult{rowsAffected: rows}
+					} else {
+						req.resCh <- &dbWriteResult{err: execErr}
+					}
+				}
+				db.Close()
+			}
+
+			if err != nil {
+				req.resCh <- &dbWriteResult{err: err}
+			}
+
+			mtx.Unlock()
+		case <-conn.closeChan:
+			return
+		}
+	}
+}
+
+func dbExec(L *lua.LState) int {
+	ud := L.CheckUserData(1)
+	conn, ok := ud.Value.(*DBConnection)
+	if !ok {
+		L.Push(lua.LNil)
+		L.Push(lua.LString("invalid database connection"))
+		return 2
+	}
+
+	query := L.CheckString(2)
+
+	var args []any
+	if L.GetTop() >= 3 {
+		params := L.CheckTable(3)
+		params.ForEach(func(k lua.LValue, v lua.LValue) {
+			args = append(args, ConvertLuaTypesToGolang(v))
+		})
+	}
+
+	if conn.log {
+		conn.logger.Info("DB Exec",
+			slog.String("query", query),
+			slog.Any("params", args))
+	}
+
+	resCh := make(chan *dbWriteResult, 1)
+	conn.writeChan <- &dbWriteRequest{
+		query: query,
+		args:  args,
+		resCh: resCh,
+	}
+
+	ctx := L.NewTable()
+	L.SetField(ctx, "done", lua.LBool(false))
+
+	var result lua.LValue = lua.LNil
+	var errorMsg lua.LValue = lua.LNil
+
+	L.SetField(ctx, "wait", L.NewFunction(func(lL *lua.LState) int {
+		res := <-resCh
+		L.SetField(ctx, "done", lua.LBool(true))
+
+		if res.err != nil {
+			errorMsg = lua.LString(res.err.Error())
+			result = lua.LNil
+		} else {
+			result = lua.LNumber(res.rowsAffected)
+			errorMsg = lua.LNil
+		}
+
+		if res.err != nil {
+			lL.Push(lua.LNil)
+			lL.Push(lua.LString(res.err.Error()))
+			return 2
+		}
+		lL.Push(lua.LNumber(res.rowsAffected))
+		lL.Push(lua.LNil)
+		return 2
+	}))
+
+	L.SetField(ctx, "check", L.NewFunction(func(lL *lua.LState) int {
+		select {
+		case res := <-resCh:
+			lL.SetField(ctx, "done", lua.LBool(true))
+			if res.err != nil {
+				errorMsg = lua.LString(res.err.Error())
+				result = lua.LNil
+				lL.Push(lua.LNil)
+				lL.Push(lua.LString(res.err.Error()))
+				return 2
+			} else {
+				result = lua.LNumber(res.rowsAffected)
+				errorMsg = lua.LNil
+				lL.Push(lua.LNumber(res.rowsAffected))
+				lL.Push(lua.LNil)
+				return 2
+			}
+		default:
+			lL.Push(result)
+			lL.Push(errorMsg)
+			return 2
+		}
+	}))
+
+	L.Push(ctx)
+	L.Push(lua.LNil)
+	return 2
+}
+
+func dbQuery(L *lua.LState) int {
+	ud := L.CheckUserData(1)
+	conn, ok := ud.Value.(*DBConnection)
+	if !ok {
+		L.Push(lua.LNil)
+		L.Push(lua.LString("invalid database connection"))
+		return 2
+	}
+
+	query := L.CheckString(2)
+
+	var args []any
+	if L.GetTop() >= 3 {
+		params := L.CheckTable(3)
+		params.ForEach(func(k lua.LValue, v lua.LValue) {
+			args = append(args, ConvertLuaTypesToGolang(v))
+		})
+	}
+
+	if conn.log {
+		conn.logger.Info("DB Query",
+			slog.String("query", query),
+			slog.Any("params", args))
+	}
+
+	mtx := getDBMutex(conn.dbPath)
+	mtx.RLock()
+	defer mtx.RUnlock()
+
+	db, err := sql.Open("sqlite", conn.dbPath+"?_busy_timeout=5000&_journal_mode=WAL&_sync=NORMAL&_cache_size=-10000")
+	if err != nil {
+		L.Push(lua.LNil)
+		L.Push(lua.LString(err.Error()))
+		return 2
+	}
+	defer db.Close()
+
+	rows, err := db.Query(query, args...)
+	if err != nil {
+		L.Push(lua.LNil)
+		L.Push(lua.LString(fmt.Sprintf("query failed: %v", err)))
+		return 2
+	}
+	defer rows.Close()
+
+	columns, err := rows.Columns()
+	if err != nil {
+		L.Push(lua.LNil)
+		L.Push(lua.LString(fmt.Sprintf("get columns failed: %v", err)))
+		return 2
+	}
+
+	result := L.NewTable()
+	colCount := len(columns)
+	values := make([]any, colCount)
+	valuePtrs := make([]any, colCount)
+
+	for rows.Next() {
+		for i := range columns {
+			valuePtrs[i] = &values[i]
+		}
+
+		if err := rows.Scan(valuePtrs...); err != nil {
+			L.Push(lua.LNil)
+			L.Push(lua.LString(fmt.Sprintf("scan failed: %v", err)))
+			return 2
+		}
+
+		rowTable := L.NewTable()
+		for i, col := range columns {
+			val := values[i]
+			if val == nil {
+				L.SetField(rowTable, col, lua.LNil)
+			} else {
+				L.SetField(rowTable, col, ConvertGolangTypesToLua(L, val))
+			}
+		}
+		result.Append(rowTable)
+	}
+
+	if err := rows.Err(); err != nil {
+		L.Push(lua.LNil)
+		L.Push(lua.LString(fmt.Sprintf("rows iteration failed: %v", err)))
+		return 2
+	}
+
+	L.Push(result)
+	return 1
+}
+
+func dbClose(L *lua.LState) int {
+	ud := L.CheckUserData(1)
+	conn, ok := ud.Value.(*DBConnection)
+	if !ok {
+		L.Push(lua.LFalse)
+		L.Push(lua.LString("invalid database connection"))
+		return 2
+	}
+
+	close(conn.closeChan)
+	L.Push(lua.LTrue)
+	return 1
+}