ZLMediaKit/3rdpart/sqlite3pp/sqlite3ppext.h

233 lines
7.1 KiB
C++

// sqlite3ppext.h
//
// The MIT License
//
// Copyright (c) 2015 Wongoo Lee (iwongu at gmail dot com)
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
#ifndef SQLITE3PPEXT_H
#define SQLITE3PPEXT_H
#include <cstddef>
#include <map>
#include <memory>
#include <tuple>
#include <type_traits>
#include <utility>
#include "sqlite3pp.h"
namespace sqlite3pp
{
namespace
{
template<size_t N>
struct Apply {
template<typename F, typename T, typename... A>
static inline auto apply(F&& f, T&& t, A&&... a)
-> decltype(Apply<N-1>::apply(std::forward<F>(f),
std::forward<T>(t),
std::get<N-1>(std::forward<T>(t)),
std::forward<A>(a)...))
{
return Apply<N-1>::apply(std::forward<F>(f),
std::forward<T>(t),
std::get<N-1>(std::forward<T>(t)),
std::forward<A>(a)...);
}
};
template<>
struct Apply<0> {
template<typename F, typename T, typename... A>
static inline auto apply(F&& f, T&&, A&&... a)
-> decltype(std::forward<F>(f)(std::forward<A>(a)...))
{
return std::forward<F>(f)(std::forward<A>(a)...);
}
};
template<typename F, typename T>
inline auto apply(F&& f, T&& t)
-> decltype(Apply<std::tuple_size<typename std::decay<T>::type>::value>::apply(std::forward<F>(f), std::forward<T>(t)))
{
return Apply<std::tuple_size<typename std::decay<T>::type>::value>::apply(
std::forward<F>(f), std::forward<T>(t));
}
}
namespace ext
{
database borrow(sqlite3* pdb);
class context : noncopyable
{
public:
explicit context(sqlite3_context* ctx, int nargs = 0, sqlite3_value** values = nullptr);
int args_count() const;
int args_bytes(int idx) const;
int args_type(int idx) const;
template <class T> T get(int idx) const {
return get(idx, T());
}
void result(int value);
void result(double value);
void result(long long int value);
void result(std::string const& value);
void result(char const* value, bool fcopy);
void result(void const* value, int n, bool fcopy);
void result();
void result(null_type);
void result_copy(int idx);
void result_error(char const* msg);
void* aggregate_data(int size);
int aggregate_count();
template <class... Ts>
std::tuple<Ts...> to_tuple() {
return to_tuple_impl(0, *this, std::tuple<Ts...>());
}
private:
int get(int idx, int) const;
double get(int idx, double) const;
long long int get(int idx, long long int) const;
char const* get(int idx, char const*) const;
std::string get(int idx, std::string) const;
void const* get(int idx, void const*) const;
template<class H, class... Ts>
static inline std::tuple<H, Ts...> to_tuple_impl(int index, const context& c, std::tuple<H, Ts...>&&)
{
auto h = std::make_tuple(c.context::get<H>(index));
return std::tuple_cat(h, to_tuple_impl(++index, c, std::tuple<Ts...>()));
}
static inline std::tuple<> to_tuple_impl(int /*index*/, const context& /*c*/, std::tuple<>&&)
{
return std::tuple<>();
}
private:
sqlite3_context* ctx_;
int nargs_;
sqlite3_value** values_;
};
namespace
{
template <class R, class... Ps>
void functionx_impl(sqlite3_context* ctx, int nargs, sqlite3_value** values)
{
context c(ctx, nargs, values);
auto f = static_cast<std::function<R (Ps...)>*>(sqlite3_user_data(ctx));
c.result(apply(*f, c.to_tuple<Ps...>()));
}
}
class function : noncopyable
{
public:
using function_handler = std::function<void (context&)>;
using pfunction_base = std::shared_ptr<void>;
explicit function(database& db);
int create(char const* name, function_handler h, int nargs = 0);
template <class F> int create(char const* name, std::function<F> h) {
fh_[name] = std::shared_ptr<void>(new std::function<F>(h));
return create_function_impl<F>()(db_, fh_[name].get(), name);
}
private:
template<class R, class... Ps>
struct create_function_impl;
template<class R, class... Ps>
struct create_function_impl<R (Ps...)>
{
int operator()(sqlite3* db, void* fh, char const* name) {
return sqlite3_create_function(db, name, sizeof...(Ps), SQLITE_UTF8, fh,
functionx_impl<R, Ps...>,
0, 0);
}
};
private:
sqlite3* db_;
std::map<std::string, pfunction_base> fh_;
};
namespace
{
template <class T, class... Ps>
void stepx_impl(sqlite3_context* ctx, int nargs, sqlite3_value** values)
{
context c(ctx, nargs, values);
T* t = static_cast<T*>(c.aggregate_data(sizeof(T)));
if (c.aggregate_count() == 1) new (t) T;
apply([](T* tt, Ps... ps){tt->step(ps...);},
std::tuple_cat(std::make_tuple(t), c.to_tuple<Ps...>()));
}
template <class T>
void finishN_impl(sqlite3_context* ctx)
{
context c(ctx);
T* t = static_cast<T*>(c.aggregate_data(sizeof(T)));
c.result(t->finish());
t->~T();
}
}
class aggregate : noncopyable
{
public:
using function_handler = std::function<void (context&)>;
using pfunction_base = std::shared_ptr<void>;
explicit aggregate(database& db);
int create(char const* name, function_handler s, function_handler f, int nargs = 1);
template <class T, class... Ps>
int create(char const* name) {
return sqlite3_create_function(db_, name, sizeof...(Ps), SQLITE_UTF8, 0, 0, stepx_impl<T, Ps...>, finishN_impl<T>);
}
private:
sqlite3* db_;
std::map<std::string, std::pair<pfunction_base, pfunction_base> > ah_;
};
} // namespace ext
} // namespace sqlite3pp
#endif