From 973aec43ea54bbf95b64fbcb636403401d1ca60e Mon Sep 17 00:00:00 2001 From: Rutger Broekhoff Date: Fri, 28 Aug 2026 18:03:05 +0200 Subject: Import from e4b104792206ee7ea64bf39c6b7d2c0c230f9d14 --- server/src/sqlite3.cppm | 257 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 257 insertions(+) create mode 100644 server/src/sqlite3.cppm (limited to 'server/src/sqlite3.cppm') diff --git a/server/src/sqlite3.cppm b/server/src/sqlite3.cppm new file mode 100644 index 0000000..f226c6b --- /dev/null +++ b/server/src/sqlite3.cppm @@ -0,0 +1,257 @@ +module; + +#include + +export module routemon:sqlite3; + +import std; +import :util; + +namespace routemon::sqlite3 { + + class mutex_guard { + explicit mutex_guard(::sqlite3_mutex* mut) noexcept : mut_{mut} { + ::sqlite3_mutex_enter(mut_); + } + + friend auto do_guarded(::sqlite3_mutex* mut, std::invocable auto f) -> decltype(f(std::declval())); + + public: + mutex_guard(mutex_guard const&) = delete; + ~mutex_guard() { + ::sqlite3_mutex_leave(mut_); + } + + private: + ::sqlite3_mutex* mut_; + }; + + auto do_guarded(::sqlite3_mutex* mut, std::invocable auto f) -> decltype(f(std::declval())) { + return f(mutex_guard{mut}); + } + + auto do_guarded(::sqlite3* dbc, std::invocable auto f) -> decltype(f(std::declval())) { + return do_guarded(::sqlite3_db_mutex(dbc), f); + } + + class error : public std::exception { + int code_; + std::string message_; + + public: + explicit error(mutex_guard const&, int code, ::sqlite3* dbc) + : code_{code}, message_{::sqlite3_errmsg(dbc)} + {} + + explicit error(int code) + : code_{code}, message_{::sqlite3_errstr(code)} + {} + + [[nodiscard]] auto what() const noexcept -> char const* override { + return message_.c_str(); + } + + [[nodiscard]] auto code() const noexcept -> int { + return code_; + } + }; + + template concept C> + concept optional_of = requires { + typename T::value_type; + requires std::same_as>; + requires C; + }; + + template + concept scannable_prim = + std::same_as || + std::same_as || + std::same_as; + + template + concept scannable = scannable_prim || optional_of; + + class statement { + ::sqlite3_stmt* stmt_; + + public: + explicit statement(::sqlite3_stmt* stmt) : stmt_{stmt} {} + statement(statement const&) = delete; + statement(statement&& s) noexcept { + stmt_ = s.stmt_; + s.stmt_ = nullptr; + } + ~statement() { + ::sqlite3_finalize(stmt_); + } + auto get() -> ::sqlite3_stmt* { + return stmt_; + } + }; + + class row_reader { + statement stmt_; + + explicit row_reader(statement stmt) : stmt_{std::move(stmt)} {} + + friend class connection; + + void scan(int col, std::string& s) { + if (::sqlite3_column_type(stmt_.get(), col) != SQLITE_TEXT) + throw std::invalid_argument{"invalid type for scan"}; + unsigned char const* chs = ::sqlite3_column_text(stmt_.get(), col); + auto size = util::size_from_int(::sqlite3_column_bytes(stmt_.get(), col)); + if (!size.has_value()) + throw std::logic_error{"unexpected negative amount of bytes in column"}; + s = std::string{reinterpret_cast(chs), *size}; + } + + void scan(int col, double& v) { + if (::sqlite3_column_type(stmt_.get(), col) != SQLITE_FLOAT) + throw std::invalid_argument{"invalid type for scan"}; + v = ::sqlite3_column_double(stmt_.get(), col); + } + + void scan(int col, std::int64_t& v) { + if (::sqlite3_column_type(stmt_.get(), col) != SQLITE_INTEGER) + throw std::invalid_argument{"invalid type for scan"}; + v = ::sqlite3_column_int64(stmt_.get(), col); + } + + void scan(int col, optional_of auto& v) { + if (::sqlite3_column_type(stmt_.get(), col) == SQLITE_NULL) { + v.reset(); + } else { + typename std::remove_cvref_t::value_type tmp; + scan(col, tmp); + v = std::move(tmp); + } + } + + public: + auto next() -> bool { + ::sqlite3* dbc = ::sqlite3_db_handle(stmt_.get()); + return do_guarded(dbc, [&](auto const& guard) -> bool { + auto const s = ::sqlite3_step(stmt_.get()); + if (s == SQLITE_ROW) + return true; + if (s == SQLITE_DONE) + return false; + throw error{guard, s, dbc}; + }); + } + + auto scan(scannable auto&... args) -> void { + auto const ncols = util::size_from_int(::sqlite3_data_count(stmt_.get())); + if (!ncols.has_value()) + throw std::logic_error{"got unexpected negative amount of columns"}; + if (sizeof...(args) > *ncols) + throw std::invalid_argument{"more scanning arguments provided than columns in result set"}; + auto col = 0; (..., scan(col++, args)); + } + + auto scan_single(scannable auto&... args) -> void { + if (!next()) + throw std::logic_error{"no row in result set"}; + scan(args...); + if (next()) { + throw std::logic_error{"more than one row in result set"}; + } + } + }; + + class binder { + statement& stmt_; + + explicit binder(statement& stmt) : stmt_{stmt} {} + + friend class connection; + + public: + auto text(std::string const& param_name, std::string_view str) -> void { + int const i = ::sqlite3_bind_parameter_index(stmt_.get(), param_name.c_str()); + if (i == 0) + throw std::invalid_argument{std::format("bind: no parameter with name {} found", param_name)}; + auto str_size = util::int_from_size(str.size()); + if (!str_size.has_value()) + throw std::invalid_argument{"bind: provided text is too long"}; + if (auto s = ::sqlite3_bind_text(stmt_.get(), i, str.data(), *str_size, SQLITE_TRANSIENT); s != SQLITE_OK) { + throw error{s}; + } + } + + static auto noop(binder&) -> void {} + }; + + export class connection { + ::sqlite3* dbc_; + ::sqlite3_mutex* mut_; + + explicit connection(::sqlite3* dbc) : dbc_{dbc}, mut_{::sqlite3_db_mutex(dbc)} {} + + friend auto open(std::string const& filename) -> connection; + + public: + connection(connection const&) = delete; + connection(connection&& c) noexcept { + dbc_ = c.dbc_; + mut_ = c.mut_; + c.dbc_ = nullptr; + c.mut_ = nullptr; + } + + [[nodiscard]] auto query(std::string const& sql, std::function const& bf = binder::noop) -> row_reader { + ::sqlite3_stmt* pstmt = nullptr; + char const* sql_tail = nullptr; + auto sql_size = util::int_from_size(sql.size()); + if (!sql_size.has_value() || *sql_size >= std::numeric_limits::max() - 1) + throw std::invalid_argument{"provided input text too large"}; + do_guarded(mut_, [&](auto const& guard) -> void { + if (auto s = ::sqlite3_prepare_v2(dbc_, sql.data(), *sql_size + 1, &pstmt, &sql_tail); s != SQLITE_OK) { + if (pstmt != nullptr) { + // Use contract_assert when having a compiler with contracts available + ::sqlite3_finalize(pstmt); + throw std::logic_error{"expected stmt to be null after failed preparation"}; + } + throw error{guard, s, dbc_}; + } + }); + if (!pstmt) + throw std::invalid_argument{"provided input text contains no SQL"}; + auto stmt = statement{pstmt}; + if (sql_tail && std::strlen(sql_tail) > 0) + throw std::invalid_argument{"provided input text contains more than one SQL statement"}; + auto b = binder{stmt}; bf(b); + return row_reader{std::move(stmt)}; + } + + auto exec(std::string const& sql, std::function const& bf = binder::noop) -> void { + auto reader = query(sql, bf); + while (reader.next()); + } + + ~connection() { + std::ignore = ::sqlite3_close(std::exchange(dbc_, nullptr)); + } + }; + + export auto open(std::string const& filename) -> connection { + ::sqlite3* dbc = nullptr; + auto s = ::sqlite3_open_v2(filename.c_str(), &dbc, + SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE | + SQLITE_OPEN_FULLMUTEX | SQLITE_OPEN_EXRESCODE, + nullptr); + if (s != SQLITE_OK) { + if (dbc) { + do_guarded(dbc, [&](auto const& guard) -> void { + throw error{guard, s, dbc}; + }); + } else { + throw error{s}; + } + } + return connection{dbc}; + } + +} // namespace routemon::sqlite3 -- cgit v1.3