Squashed 'subprojects/boost-sqlite/' content from commit 3378e35

git-subtree-dir: subprojects/boost-sqlite
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diff --git a/include/boost/sqlite/function.hpp b/include/boost/sqlite/function.hpp
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+//
+// Copyright (c) 2022 Klemens Morgenstern (klemens.morgenstern@gmx.net)
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+
+#ifndef BOOST_SQLITE_FUNCTION_HPP
+#define BOOST_SQLITE_FUNCTION_HPP
+
+#include <boost/sqlite/detail/config.hpp>
+#include <boost/sqlite/detail/aggregate_function.hpp>
+#include <boost/sqlite/detail/scalar_function.hpp>
+#include <boost/sqlite/detail/window_function.hpp>
+#include <boost/sqlite/connection.hpp>
+#include <boost/sqlite/result.hpp>
+#include <boost/sqlite/value.hpp>
+#include <boost/sqlite/detail/exception.hpp>
+#include <boost/sqlite/cstring_ref.hpp>
+
+#include <boost/core/span.hpp>
+#include <boost/callable_traits/args.hpp>
+#include <boost/callable_traits/has_void_return.hpp>
+#include <boost/callable_traits/return_type.hpp>
+
+BOOST_SQLITE_BEGIN_NAMESPACE
+
+enum function_flags
+{
+  deterministic  = SQLITE_DETERMINISTIC,
+  directonly     = SQLITE_DIRECTONLY,
+  subtype        = SQLITE_SUBTYPE,
+  innocuous      = SQLITE_INNOCUOUS,
+  result_subtype = SQLITE_RESULT_SUBTYPE,
+#if defined(SQLITE_SELFORDER1)
+  selforder1     = SQLITE_SELFORDER1,
+#else
+  selforder1     = 0
+#endif
+};
+
+
+/** @brief A context that can be passed into scalar functions.
+  @ingroup reference
+
+  @tparam Args The argument that can be stored in the context.
+
+  @code{.cpp}
+  extern sqlite::connection conn;
+
+  sqlite::create_scalar_function(
+    conn, "my_sum",
+    [](sqlite::context<std::size_t> ctx,
+       boost::span<sqlite::value, 1u> args) -> std::size_t
+    {
+        auto value = args[0].get_int();
+        auto p = ctx.get_if<0>();
+        if (p != nullptr) // increment the counter
+            return (*p) += value;
+        else // set the initial value
+            ctx.set<0>(value);
+        return value;
+    });
+  @endcode
+
+*/
+template<typename ... Args>
+struct context
+{
+  template<std::size_t N>
+  using element = mp11::mp_take_c<mp11::mp_list<Args...>, N>;
+
+  /// Set the value in the context at position `Idx`
+  template<std::size_t Idx>
+  void set(element<Idx> value)
+  {
+    sqlite3_set_auxdata(ctx_, Idx, *static_cast<void**>(&value),
+                        new (memory_tag{}) element<Idx>(std::move(value)),
+                        +[](void * ptr)
+                        {
+                          delete_(static_cast<element<Idx> *>(ptr));
+                        });
+  }
+
+  /// Returns the value in the context at position `Idx`. Throws if the value isn't set.
+  template<std::size_t Idx>
+  auto get() -> element<Idx>  &
+  {
+    using type = element<Idx> ;
+    auto p = static_cast<type*>(sqlite3_get_auxdata(ctx_, Idx));
+    if (p == nullptr)
+      detail::throw_invalid_argument("argument not set",
+                                     BOOST_CURRENT_LOCATION);
+    return *p;
+  }
+
+  /// Returns the value in the context at position `Idx`. Returns nullptr .value isn't set.
+  template<std::size_t Idx>
+  auto get_if() -> element<Idx>  *
+  {
+    using type = element<Idx> ;
+    return static_cast<type*>(sqlite3_get_auxdata(ctx_, Idx));
+  }
+
+
+  explicit context(sqlite3_context * ctx) noexcept : ctx_(ctx) {}
+
+  /// Set the result through the context, instead of returning it.
+  template<typename T>
+  auto set_result(T && val)
+#if !defined(BOOST_SQLITE_GENERATING_DOCS)
+    -> decltype(detail::set_result(static_cast<sqlite3_context*>(nullptr), std::forward<T>(val)))
+#endif
+  {
+    detail::set_result(ctx_, std::forward<T>(val));
+  }
+  /// Set the an error through the context, instead of throwing it.
+  void set_error(cstring_ref message, int code = SQLITE_ERROR)
+  {
+    sqlite3_result_error(ctx_, message.c_str(), -1);
+    sqlite3_result_error_code(ctx_, code);
+  }
+  /// Returns the connection of the context.
+  connection get_connection() const
+  {
+    return connection{sqlite3_context_db_handle(ctx_), false};
+  }
+
+ private:
+  sqlite3_context * ctx_;
+};
+
+
+///@{
+/** @brief create a scalar function
+   @ingroup reference
+
+ @param conn The connection to add the function to.
+ @param name The name of the function
+ @param func The function to be added
+ @param ec The system::error_code
+
+ @throws `system::system_error` when the overload without `ec` is used.
+
+ `func` must take `context<Args...>` as the first and a `span<value, N>` as the second value.
+ If `N` is not `dynamic_extent` it will be used to deduce the number of arguments for the function.
+
+ @par Example
+
+ @code{.cpp}
+  extern sqlite::connection conn;
+
+  sqlite::create_function(
+    conn, "my_sum",
+    [](sqlite::context<std::size_t> ctx,
+       boost::span<sqlite::value, 1u> args) -> std::size_t
+    {
+        auto value = args[0].get_int();
+        auto p = ctx.get_if<0>();
+        if (p != nullptr) // increment the counter
+            return (*p) += value;
+        else // set the initial value
+            ctx.set<0>(value);
+        return value;
+    });
+  @endcode
+
+ */
+template<typename Func>
+auto create_scalar_function(
+    connection & conn,
+    cstring_ref name,
+    Func && func,
+    function_flags flags,
+    system::error_code & ec,
+    error_info & ei)
+#if !defined(BOOST_SQLITE_GENERATING_DOCS)
+    -> typename std::enable_if<
+        std::is_same<
+          decltype(
+              detail::create_scalar_function(
+                  static_cast<sqlite3*>(nullptr), name,
+                  std::declval<Func>(), flags)
+              ), int>::value>::type
+#endif
+{
+    auto res = detail::create_scalar_function(conn.handle(), name,
+                                              std::forward<Func>(func), static_cast<int>(flags));
+    if (res != 0)
+    {
+      BOOST_SQLITE_ASSIGN_EC(ec, res);
+      ei.set_message(sqlite3_errmsg(conn.handle()));
+    }
+}
+
+///@{
+/** @brief create a scalar function
+   @ingroup reference
+
+ @param conn The connection to add the function to.
+ @param name The name of the function
+ @param func The function to be added
+ @param ec The system::error_code
+
+ @throws `system::system_error` when the overload without `ec` is used.
+
+ `func` must take `context<Args...>` as the first and a `span<value, N>` as the second value.
+ If `N` is not `dynamic_extent` it will be used to deduce the number of arguments for the function.
+
+ @par Example
+
+ @code{.cpp}
+  extern sqlite::connection conn;
+
+  sqlite::create_function(
+    conn, "to_upper",
+    [](sqlite::context<> ctx,
+       boost::span<sqlite::value, 1u> args) -> std::string
+    {
+        std::string res;
+        auto txt = val[0].get_text();
+        res.resize(txt.size());
+        std::transform(txt.begin(), txt.end(), res.begin(),
+                       [](char c){return std::toupper(c);});
+        return value;
+    });
+  @endcode
+
+ */
+template<typename Func>
+auto create_scalar_function(
+    connection & conn,
+    cstring_ref name,
+    Func && func,
+    function_flags flags = {})
+    -> typename std::enable_if<
+        std::is_same<
+          decltype(
+              detail::create_scalar_function(
+                  static_cast<sqlite3*>(nullptr), name,
+                  std::declval<Func>(), flags)
+              ), int>::value>::type
+{
+    system::error_code ec;
+    error_info ei;
+    create_scalar_function(conn, name, std::forward<Func>(func), flags, ec, ei);
+    if (ec)
+        detail::throw_error_code(ec, ei);
+}
+///@}
+
+
+///@{
+/** @brief create a aggregate function
+   @ingroup reference
+
+ @param conn The connection to add the function to.
+ @param name The name of the function
+ @param args
+ @param ec The system::error_code
+
+@tparam Func The function to be added
+
+ @throws `system::system_error` when the overload without `ec` is used.
+
+
+ `func` needs to be an object with two functions:
+
+ @code{.cpp}
+ void step(boost::span<sqlite::value, N> args);
+ T final();
+ @endcode
+
+
+
+ An aggregrate function will create a new `Func` for a new `aggregate` from the args tuple and call `step` for every step.
+ When the aggregation is done `final` is called and the result is returned to sqlite.
+
+ @par Example
+
+ @code{.cpp}
+  extern sqlite::connection conn;
+
+  struct aggregate_func
+  {
+      aggregate_func(std::size_t init) : counter(init) {}
+      std::size_t counter;
+      void step(, boost::span<sqlite::value, 1u> val)
+      {
+        counter += val[0].get_text().size();
+      }
+
+      std::size_t final()
+      {
+        return counter;
+      }
+  };
+
+  sqlite::create_function<aggregate_func>(
+    conn, "char_counter", std::make_tuple(42));
+
+  @endcode
+
+ */
+template<typename Func, typename Args = std::tuple<>>
+void create_aggregate_function(
+    connection & conn,
+    cstring_ref name,
+    Args && args,
+    function_flags flags,
+    system::error_code & ec,
+    error_info & ei)
+{
+    using func_type = typename std::decay<Func>::type;
+    auto res = detail::create_aggregate_function<Func>(
+        conn.handle(), name, std::forward<Args>(args), static_cast<int>(flags),
+        callable_traits::has_void_return<decltype(&func_type::step)>{}
+        );
+    if (res != 0)
+    {
+        BOOST_SQLITE_ASSIGN_EC(ec, res);
+        ei.set_message(sqlite3_errmsg(conn.handle()));
+    }
+}
+
+template<typename Func, typename Args = std::tuple<>>
+void create_aggregate_function(
+    connection & conn,
+    cstring_ref name,
+    Args && args= {},
+    function_flags flags = {})
+{
+    system::error_code ec;
+    error_info ei;
+    create_aggregate_function<Func>(conn, name, std::forward<Args>(args), flags, ec, ei);
+    if (ec)
+        detail::throw_error_code(ec, ei);
+}
+///@}
+
+#if SQLITE_VERSION_NUMBER >= 3025000
+
+///@{
+/** @brief create a aggregate window function
+   @ingroup reference
+
+ @param conn The connection to add the function to.
+ @param name The name of the function
+ @param args The arguments to construct Func from.
+ @param ec The system::error_code
+
+@tparam Func The function to be added
+
+ @throws `system::system_error` when the overload without `ec` is used.
+
+ `func` needs to be an object with three functions:
+
+ @code{.cpp}
+ void step(boost::span<sqlite::value, N> args);
+ void inverse(boost::span<sqlite::value, N> args);
+ T final();
+ @endcode
+
+ `State` can be any type and will get deduced together with `N`.
+ An aggregrate function will create a new `State` for a new `aggregate` and call `step` for every step.
+ When an element is removed from the window `inverse` is called.
+ When the aggregation is done `final` is called and the result is returned to sqlite.
+
+ @par Example
+
+ @code{.cpp}
+  extern sqlite::connection conn;
+
+  struct window_func
+  {
+      std::size_t counter;
+      void step(boost::span<sqlite::value, 1u> val)
+      {
+        counter += val[0].get_text().size();
+      }
+      void inverse(boost::span<sqlite::value, 1u> val)
+      {
+        counter -= val[0].get_text().size();
+      }
+
+      std::size_t final()
+      {
+        return counter;
+      }
+  };
+
+  sqlite::create_function(
+    conn, "win_char_counter",
+    aggregate_func{});
+  @endcode
+ */
+template<typename Func, typename Args = std::tuple<>>
+void create_window_function(
+    connection & conn,
+    cstring_ref name,
+    Args && args,
+    function_flags flags,
+    system::error_code & ec)
+{
+    using func_type = typename std::decay<Func>::type;
+    auto res = detail::create_window_function<Func>(
+            conn.handle(), name, std::forward<Args>(args), static_cast<int>(flags),
+            callable_traits::has_void_return<decltype(&func_type::step)>{});
+    if (res != 0)
+        BOOST_SQLITE_ASSIGN_EC(ec, res);
+}
+
+template<typename Func, typename Args = std::tuple<>>
+void create_window_function(
+    connection & conn,
+    cstring_ref name,
+    Args && args = {},
+    function_flags flags = {})
+{
+    system::error_code ec;
+    create_window_function<Func>(conn, name, std::forward<Args>(args), flags, ec);
+    if (ec)
+        detail::throw_error_code(ec);
+}
+
+///@}
+
+///@{
+/// Delete function
+
+inline void delete_function(connection & conn, cstring_ref name, int argc, system::error_code &ec)
+{
+  auto res = sqlite3_create_function_v2(conn.handle(), name.c_str(), argc, 0, nullptr, nullptr, nullptr, nullptr, nullptr);
+  if (res != 0)
+    BOOST_SQLITE_ASSIGN_EC(ec, res);
+
+}
+
+inline void delete_function(connection & conn, cstring_ref name, int argc = -1)
+{
+  system::error_code ec;
+  delete_function(conn, name, argc, ec);
+  if (ec)
+    detail::throw_error_code(ec);
+}
+
+///@}
+#endif
+
+BOOST_SQLITE_END_NAMESPACE
+
+#endif //BOOST_SQLITE_FUNCTION_HPP