polardbxengine/plugin/x/client/validator/value_validator.h

115 lines
3.6 KiB
C++

/*
* Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2.0,
* as published by the Free Software Foundation.
*
* This program is also distributed with certain software (including
* but not limited to OpenSSL) that is licensed under separate terms,
* as designated in a particular file or component or in included license
* documentation. The authors of MySQL hereby grant you an additional
* permission to link the program and your derivative works with the
* separately licensed software that they have included with MySQL.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License, version 2.0, for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef PLUGIN_X_CLIENT_VALIDATOR_VALUE_VALIDATOR_H_
#define PLUGIN_X_CLIENT_VALIDATOR_VALUE_VALIDATOR_H_
#include <string>
#include "my_dbug.h"
#include "plugin/x/client/mysqlxclient/xargument.h"
#include "plugin/x/client/validator/validator.h"
#include "plugin/x/client/visitor/default_visitor.h"
namespace xcl {
/**
Validator with storage and value casting
`Validator` uses 'void *context' to pass the information
where to store the data, this class goes one step further
it tries to call one of following methods for value-type
stored in Argument_value:
* visit_integer
* visit_bool
* visit_object
* visit_array
* visit_string
which final class should overwrite and use 'get_ctxt' method
to store the value. User can overwrite only one of those methods
in case when he used a type validator for Base_type, for example:
```
struct My_ctxt {
bool my_is_interactive;
...
};
class My_client_interactive_validator:
public Value_validator<My_ctxt, Bool_validator> {
...
void visit_bool(const bool value) override {
get_ctxt()->my_is_interactive = value;
}
}
```
*/
template <typename Context, typename Base_type>
class Value_validator : public Base_type, public Default_visitor {
public:
Context *get_ctxt() { return m_ctxt; }
void set_ctxt(void *ctxt) { m_ctxt = reinterpret_cast<Context *>(ctxt); }
protected:
void visit_integer(const int64_t value) override {
assert(Argument_type::k_integer == Base_type::get_type() &&
"Derived overwrote wrong type");
}
void visit_bool(const bool value) override {
assert(Argument_type::k_bool == Base_type::get_type() &&
"Derived overwrote wrong type");
}
void visit_object(const Argument_object &value) override {
assert(Argument_type::k_null == Base_type::get_type() &&
"Derived overwrote wrong type");
}
void visit_array(const Argument_array &value) override {
assert(Argument_type::k_array == Base_type::get_type() &&
"Derived overwrote wrong type");
}
void visit_string(const std::string &value) override {
assert(Argument_type::k_string == Base_type::get_type() &&
"Derived overwrote wrong type");
}
private:
void store(void *context, const Argument_value &value) override {
DBUG_TRACE;
set_ctxt(context);
value.accept(this);
}
Context *m_ctxt;
};
} // namespace xcl
#endif // PLUGIN_X_CLIENT_VALIDATOR_VALUE_VALIDATOR_H_