Golang variable.GetSysVar函数代码示例

// GetGlobalSysVar implements GlobalVarAccessor GetGlobalSysVar interface.
func (c *Context) GetGlobalSysVar(ctx context.Context, name string) (string, error) {
	v := variable.GetSysVar(name)
	if v == nil {
		return "", terror.UnknownSystemVar.Gen("unknown sys variable: %s", name)
	}
	return v.Value, nil
}

// SetGlobalSysVar implements GlobalVarAccessor SetGlobalSysVar interface.
func (c *Context) SetGlobalSysVar(ctx context.Context, name string, value string) error {
	v := variable.GetSysVar(name)
	if v == nil {
		return terror.UnknownSystemVar.Gen("unknown sys variable: %s", name)
	}
	v.Value = value
	return nil
}

func (e *SimpleExec) executeSet(s *ast.SetStmt) error {
	sessionVars := variable.GetSessionVars(e.ctx)
	globalVars := variable.GetGlobalVarAccessor(e.ctx)
	for _, v := range s.Variables {
		// Variable is case insensitive, we use lower case.
		if v.Name == ast.SetNames {
			// This is set charset stmt.
			cs := v.Value.GetValue().(string)
			var co string
			if v.ExtendValue != nil {
				co = v.ExtendValue.GetValue().(string)
			}
			err := e.setCharset(cs, co)
			if err != nil {
				return errors.Trace(err)
			}
			continue
		}
		name := strings.ToLower(v.Name)
		if !v.IsSystem {
			// Set user variable.
			value, err := evaluator.Eval(e.ctx, v.Value)
			if err != nil {
				return errors.Trace(err)
			}

			if value.IsNull() {
				delete(sessionVars.Users, name)
			} else {
				svalue, err1 := value.ToString()
				if err1 != nil {
					return errors.Trace(err1)
				}
				sessionVars.Users[name] = fmt.Sprintf("%v", svalue)
			}
			continue
		}

		// Set system variable
		sysVar := variable.GetSysVar(name)
		if sysVar == nil {
			return variable.UnknownSystemVar.Gen("Unknown system variable '%s'", name)
		}
		if sysVar.Scope == variable.ScopeNone {
			return errors.Errorf("Variable '%s' is a read only variable", name)
		}
		if v.IsGlobal {
			// Set global scope system variable.
			if sysVar.Scope&variable.ScopeGlobal == 0 {
				return errors.Errorf("Variable '%s' is a SESSION variable and can't be used with SET GLOBAL", name)
			}
			value, err := evaluator.Eval(e.ctx, v.Value)
			if err != nil {
				return errors.Trace(err)
			}
			if value.IsNull() {
				value.SetString("")
			}
			svalue, err := value.ToString()
			if err != nil {
				return errors.Trace(err)
			}
			err = globalVars.SetGlobalSysVar(e.ctx, name, svalue)
			if err != nil {
				return errors.Trace(err)
			}
		} else {
			// Set session scope system variable.
			if sysVar.Scope&variable.ScopeSession == 0 {
				return errors.Errorf("Variable '%s' is a GLOBAL variable and should be set with SET GLOBAL", name)
			}
			value, err := evaluator.Eval(e.ctx, v.Value)
			if err != nil {
				return errors.Trace(err)
			}
			err = sessionVars.SetSystemVar(name, value)
			if err != nil {
				return errors.Trace(err)
			}
		}
	}
	return nil
}

// Exec implements the stmt.Statement Exec interface.
func (s *SetStmt) Exec(ctx context.Context) (_ rset.Recordset, err error) {
	log.Debug("Set sys/user variables")

	sessionVars := variable.GetSessionVars(ctx)
	globalVars := variable.GetGlobalVarAccessor(ctx)
	for _, v := range s.Variables {
		// Variable is case insensitive, we use lower case.
		name := strings.ToLower(v.Name)
		if !v.IsSystem {
			// User variable.
			value, err := v.getValue(ctx)
			if err != nil {
				return nil, errors.Trace(err)
			}

			if value == nil {
				delete(sessionVars.Users, name)
			} else {
				sessionVars.Users[name] = fmt.Sprintf("%v", value)
			}
			return nil, nil
		}
		sysVar := variable.GetSysVar(name)
		if sysVar == nil {
			return nil, variable.UnknownSystemVar.Gen("Unknown system variable '%s'", name)
		}
		if sysVar.Scope == variable.ScopeNone {
			return nil, errors.Errorf("Variable '%s' is a read only variable", name)
		}
		if v.IsGlobal {
			if sysVar.Scope&variable.ScopeGlobal > 0 {
				value, err := v.getValue(ctx)
				if err != nil {
					return nil, errors.Trace(err)
				}
				if value == nil {
					value = ""
				}
				svalue, err := types.ToString(value)
				if err != nil {
					return nil, errors.Trace(err)
				}
				err = globalVars.SetGlobalSysVar(ctx, name, svalue)
				return nil, errors.Trace(err)
			}
			return nil, errors.Errorf("Variable '%s' is a SESSION variable and can't be used with SET GLOBAL", name)
		}
		if sysVar.Scope&variable.ScopeSession > 0 {
			if value, err := v.getValue(ctx); err != nil {
				return nil, errors.Trace(err)
			} else if value == nil {
				sessionVars.Systems[name] = ""
			} else {
				sessionVars.Systems[name] = fmt.Sprintf("%v", value)
			}
			return nil, nil
		}
		return nil, errors.Errorf("Variable '%s' is a GLOBAL variable and should be set with SET GLOBAL", name)
	}

	return nil, nil
}

func (e *SetExecutor) executeSet() error {
	sessionVars := e.ctx.GetSessionVars()
	for _, v := range e.vars {
		// Variable is case insensitive, we use lower case.
		if v.Name == ast.SetNames {
			// This is set charset stmt.
			cs := v.Expr.(*expression.Constant).Value.GetString()
			var co string
			if v.ExtendValue != nil {
				co = v.ExtendValue.Value.GetString()
			}
			err := e.setCharset(cs, co)
			if err != nil {
				return errors.Trace(err)
			}
			continue
		}
		name := strings.ToLower(v.Name)
		if !v.IsSystem {
			// Set user variable.
			value, err := v.Expr.Eval(nil, e.ctx)
			if err != nil {
				return errors.Trace(err)
			}

			if value.IsNull() {
				delete(sessionVars.Users, name)
			} else {
				svalue, err1 := value.ToString()
				if err1 != nil {
					return errors.Trace(err1)
				}
				sessionVars.Users[name] = fmt.Sprintf("%v", svalue)
			}
			continue
		}

		// Set system variable
		sysVar := variable.GetSysVar(name)
		if sysVar == nil {
			return variable.UnknownSystemVar.GenByArgs(name)
		}
		if sysVar.Scope == variable.ScopeNone {
			return errors.Errorf("Variable '%s' is a read only variable", name)
		}
		if v.IsGlobal {
			// Set global scope system variable.
			if sysVar.Scope&variable.ScopeGlobal == 0 {
				return errors.Errorf("Variable '%s' is a SESSION variable and can't be used with SET GLOBAL", name)
			}
			value, err := e.getVarValue(v, sysVar)
			if err != nil {
				return errors.Trace(err)
			}
			if value.IsNull() {
				value.SetString("")
			}
			svalue, err := value.ToString()
			if err != nil {
				return errors.Trace(err)
			}
			err = sessionVars.GlobalVarsAccessor.SetGlobalSysVar(name, svalue)
			if err != nil {
				return errors.Trace(err)
			}
		} else {
			// Set session scope system variable.
			if sysVar.Scope&variable.ScopeSession == 0 {
				return errors.Errorf("Variable '%s' is a GLOBAL variable and should be set with SET GLOBAL", name)
			}
			value, err := e.getVarValue(v, nil)
			if err != nil {
				return errors.Trace(err)
			}
			err = varsutil.SetSystemVar(sessionVars, name, value)
			if err != nil {
				return errors.Trace(err)
			}
			e.loadSnapshotInfoSchemaIfNeeded(name)
			log.Infof("[%d] set system variable %s = %s", sessionVars.ConnectionID, name, value.GetString())
		}
	}
	return nil
}

// Exec implements the stmt.Statement Exec interface.
func (s *SetStmt) Exec(ctx context.Context) (_ rset.Recordset, err error) {
	log.Debug("Set sys/user variables")

	sessionVars := variable.GetSessionVars(ctx)

	for _, v := range s.Variables {
		// Variable is case insensitive, we use lower case.
		name := strings.ToLower(v.Name)
		if !v.IsSystem {
			// User variable.
			value, err := v.getValue(ctx)
			if err != nil {
				return nil, errors.Trace(err)
			}

			if value == nil {
				delete(sessionVars.Users, name)
			} else {
				sessionVars.Users[name] = fmt.Sprintf("%v", value)
			}
			return nil, nil
		}

		// TODO: should get global sys var from db.
		sysVar := variable.GetSysVar(name)
		if sysVar == nil {
			return nil, errors.Errorf("Unknown system variable '%s'", name)
		}
		if sysVar.Scope == variable.ScopeNone {
			return nil, errors.Errorf("Variable '%s' is a read only variable", name)
		}

		if v.IsGlobal {
			if sysVar.Scope&variable.ScopeGlobal > 0 {
				value, err := v.getValue(ctx)
				if err != nil {
					return nil, errors.Trace(err)
				}
				if value == nil {
					sysVar.Value = ""
				} else {
					// TODO: set global variables in db, now we only change memory global sys var map.
					// TODO: check sys variable type if possible.
					sysVar.Value = fmt.Sprintf("%v", value)
				}
				return nil, nil
			}
			return nil, errors.Errorf("Variable '%s' is a SESSION variable and can't be used with SET GLOBAL", name)
		}
		if sysVar.Scope&variable.ScopeSession > 0 {
			if value, err := v.getValue(ctx); err != nil {
				return nil, errors.Trace(err)
			} else if value == nil {
				sysVar.Value = ""
			} else {
				// TODO: check sys variable type if possible.
				sessionVars.Systems[name] = fmt.Sprintf("%v", value)
			}
			return nil, nil
		}
		return nil, errors.Errorf("Variable '%s' is a GLOBAL variable and should be set with SET GLOBAL", name)
	}

	return nil, nil
}

func (e *SimpleExec) executeSet(s *ast.SetStmt) error {
	sessionVars := variable.GetSessionVars(e.ctx)
	globalVars := variable.GetGlobalVarAccessor(e.ctx)
	for _, v := range s.Variables {
		// Variable is case insensitive, we use lower case.
		name := strings.ToLower(v.Name)
		if !v.IsSystem {
			// Set user variable.
			value, err := evaluator.Eval(e.ctx, v.Value)
			if err != nil {
				return errors.Trace(err)
			}

			if value == nil {
				delete(sessionVars.Users, name)
			} else {
				sessionVars.Users[name] = fmt.Sprintf("%v", value)
			}
			continue
		}

		// Set system variable
		sysVar := variable.GetSysVar(name)
		if sysVar == nil {
			return variable.UnknownSystemVar.Gen("Unknown system variable '%s'", name)
		}
		if sysVar.Scope == variable.ScopeNone {
			return errors.Errorf("Variable '%s' is a read only variable", name)
		}
		if v.IsGlobal {
			// Set global scope system variable.
			if sysVar.Scope&variable.ScopeGlobal == 0 {
				return errors.Errorf("Variable '%s' is a SESSION variable and can't be used with SET GLOBAL", name)
			}
			value, err := evaluator.Eval(e.ctx, v.Value)
			if err != nil {
				return errors.Trace(err)
			}
			if value == nil {
				value = ""
			}
			svalue, err := types.ToString(value)
			if err != nil {
				return errors.Trace(err)
			}
			err = globalVars.SetGlobalSysVar(e.ctx, name, svalue)
			if err != nil {
				return errors.Trace(err)
			}
		} else {
			// Set session scope system variable.
			if sysVar.Scope&variable.ScopeSession == 0 {
				return errors.Errorf("Variable '%s' is a GLOBAL variable and should be set with SET GLOBAL", name)
			}
			if value, err := evaluator.Eval(e.ctx, v.Value); err != nil {
				return errors.Trace(err)
			} else if value == nil {
				sessionVars.Systems[name] = ""
			} else {
				sessionVars.Systems[name] = fmt.Sprintf("%v", value)
			}
		}
	}
	return nil
}