bindings/go: Add error propagation from bindings lib

bindings/go/stmt.go

@@ -13,29 +13,39 @@ type limboStmt struct {
 	mu  sync.Mutex
 	ctx uintptr
 	sql string
+	err error
 }
 
 func newStmt(ctx uintptr, sql string) *limboStmt {
 	return &limboStmt{
 		ctx: uintptr(ctx),
 		sql: sql,
+		err: nil,
 	}
 }
 
 func (ls *limboStmt) NumInput() int {
 	ls.mu.Lock()
 	defer ls.mu.Unlock()
-	return int(stmtParamCount(ls.ctx))
+	res := int(stmtParamCount(ls.ctx))
+	if res < 0 {
+		// set the error from rust
+		_ = ls.getError()
+	}
+	return res
 }
 
 func (ls *limboStmt) Close() error {
 	ls.mu.Lock()
-	res := closeStmt(ls.ctx)
-	ls.mu.Unlock()
+	defer ls.mu.Unlock()
+	if ls.ctx == 0 {
+		return nil
+	}
+	res := stmtClose(ls.ctx)
+	ls.ctx = 0
 	if ResultCode(res) != Ok {
 		return fmt.Errorf("error closing statement: %s", ResultCode(res).String())
 	}
-	ls.ctx = 0
 	return nil
 }
 
@@ -52,8 +62,8 @@ func (ls *limboStmt) Exec(args []driver.Value) (driver.Result, error) {
 	}
 	var changes uint64
 	ls.mu.Lock()
+	defer ls.mu.Unlock()
 	rc := stmtExec(ls.ctx, argPtr, argCount, uintptr(unsafe.Pointer(&changes)))
-	ls.mu.Unlock()
 	switch ResultCode(rc) {
 	case Ok, Done:
 		return driver.RowsAffected(changes), nil
@@ -66,7 +76,7 @@ func (ls *limboStmt) Exec(args []driver.Value) (driver.Result, error) {
 	case Invalid:
 		return nil, errors.New("invalid statement")
 	default:
-		return nil, fmt.Errorf("unexpected status: %d", rc)
+		return nil, ls.getError()
 	}
 }
 
@@ -81,10 +91,10 @@ func (ls *limboStmt) Query(args []driver.Value) (driver.Rows, error) {
 		argPtr = uintptr(unsafe.Pointer(&queryArgs[0]))
 	}
 	ls.mu.Lock()
+	defer ls.mu.Unlock()
 	rowsPtr := stmtQuery(ls.ctx, argPtr, uint64(len(queryArgs)))
-	ls.mu.Unlock()
 	if rowsPtr == 0 {
-		return nil, fmt.Errorf("query failed for: %q", ls.sql)
+		return nil, ls.getError()
 	}
 	return newRows(rowsPtr), nil
 }
@@ -96,27 +106,26 @@ func (ls *limboStmt) ExecContext(ctx context.Context, query string, args []drive
 	if err != nil {
 		return nil, err
 	}
+	ls.mu.Lock()
 	select {
 	case <-ctx.Done():
+		ls.mu.Unlock()
 		return nil, ctx.Err()
 	default:
-	}
-	var changes uint64
-	ls.mu.Lock()
-	res := stmtExec(ls.ctx, argArray, uint64(len(args)), uintptr(unsafe.Pointer(&changes)))
-	ls.mu.Unlock()
-	switch ResultCode(res) {
-	case Ok, Done:
-		changes := uint64(changes)
-		return driver.RowsAffected(changes), nil
-	case Error:
-		return nil, errors.New("error executing statement")
-	case Busy:
-		return nil, errors.New("busy")
-	case Interrupt:
-		return nil, errors.New("interrupted")
-	default:
-		return nil, fmt.Errorf("unexpected status: %d", res)
+		var changes uint64
+		defer ls.mu.Unlock()
+		res := stmtExec(ls.ctx, argArray, uint64(len(args)), uintptr(unsafe.Pointer(&changes)))
+		switch ResultCode(res) {
+		case Ok, Done:
+			changes := uint64(changes)
+			return driver.RowsAffected(changes), nil
+		case Busy:
+			return nil, errors.New("Database is Busy")
+		case Interrupt:
+			return nil, errors.New("Interrupted")
+		default:
+			return nil, ls.getError()
+		}
 	}
 }
 
@@ -130,16 +139,38 @@ func (ls *limboStmt) QueryContext(ctx context.Context, args []driver.NamedValue)
 	if len(queryArgs) > 0 {
 		argsPtr = uintptr(unsafe.Pointer(&queryArgs[0]))
 	}
+	ls.mu.Lock()
 	select {
 	case <-ctx.Done():
+		ls.mu.Unlock()
 		return nil, ctx.Err()
 	default:
+		defer ls.mu.Unlock()
+		rowsPtr := stmtQuery(ls.ctx, argsPtr, uint64(len(queryArgs)))
+		if rowsPtr == 0 {
+			return nil, ls.getError()
+		}
+		return newRows(rowsPtr), nil
 	}
-	ls.mu.Lock()
-	rowsPtr := stmtQuery(ls.ctx, argsPtr, uint64(len(queryArgs)))
-	ls.mu.Unlock()
-	if rowsPtr == 0 {
-		return nil, fmt.Errorf("query failed for: %q", ls.sql)
-	}
-	return newRows(rowsPtr), nil
+}
+
+func (ls *limboStmt) Err() error {
+	if ls.err == nil {
+		ls.mu.Lock()
+		defer ls.mu.Unlock()
+		ls.getError()
+	}
+	return ls.err
+}
+
+// mutex should always be locked when calling - always called after FFI
+func (ls *limboStmt) getError() error {
+	err := stmtGetError(ls.ctx)
+	if err == 0 {
+		return nil
+	}
+	defer freeCString(err)
+	cpy := fmt.Sprintf("%s", GoString(err))
+	ls.err = errors.New(cpy)
+	return ls.err
 }