// Copyright 2018 Daniel Parker // Distributed under the Boost license, Version 1.0. // (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) // See https://github.com/danielaparker/jsoncons for latest version #ifndef JSONCONS_BSON_BSON_CURSOR_HPP #define JSONCONS_BSON_BSON_CURSOR_HPP #include <memory> // std::allocator #include <string> #include <vector> #include <stdexcept> #include <system_error> #include <ios> #include <istream> // std::basic_istream #include <jsoncons/byte_string.hpp> #include <jsoncons/config/jsoncons_config.hpp> #include <jsoncons/json_visitor.hpp> #include <jsoncons/json_exception.hpp> #include <jsoncons/staj_cursor.hpp> #include <jsoncons/source.hpp> #include <jsoncons_ext/bson/bson_parser.hpp> namespace jsoncons { namespace bson { template<class Source=jsoncons::binary_stream_source,class Allocator=std::allocator<char>> class basic_bson_cursor : public basic_staj_cursor<char>, private virtual ser_context { using super_type = basic_staj_cursor<char>; public: using source_type = Source; using char_type = char; using allocator_type = Allocator; private: basic_bson_parser<Source,Allocator> parser_; basic_staj_visitor<char_type> cursor_visitor_; bool eof_; // Noncopyable and nonmoveable basic_bson_cursor(const basic_bson_cursor&) = delete; basic_bson_cursor& operator=(const basic_bson_cursor&) = delete; public: using string_view_type = string_view; template <class Sourceable> basic_bson_cursor(Sourceable&& source, const bson_decode_options& options = bson_decode_options(), const Allocator& alloc = Allocator()) : parser_(std::forward<Sourceable>(source), options, alloc), cursor_visitor_(accept_all), eof_(false) { if (!done()) { next(); } } // Constructors that set parse error codes template <class Sourceable> basic_bson_cursor(Sourceable&& source, std::error_code& ec) : basic_bson_cursor(std::allocator_arg, Allocator(), std::forward<Sourceable>(source), bson_decode_options(), ec) { } template <class Sourceable> basic_bson_cursor(Sourceable&& source, const bson_decode_options& options, std::error_code& ec) : basic_bson_cursor(std::allocator_arg, Allocator(), std::forward<Sourceable>(source), options, ec) { } template <class Sourceable> basic_bson_cursor(std::allocator_arg_t, const Allocator& alloc, Sourceable&& source, const bson_decode_options& options, std::error_code& ec) : parser_(std::forward<Sourceable>(source), options, alloc), cursor_visitor_(accept_all), eof_(false) { if (!done()) { next(ec); } } void reset() { parser_.reset(); cursor_visitor_.reset(); eof_ = false; if (!done()) { next(); } } template <class Sourceable> void reset(Sourceable&& source) { parser_.reset(std::forward<Sourceable>(source)); cursor_visitor_.reset(); eof_ = false; if (!done()) { next(); } } void reset(std::error_code& ec) { parser_.reset(); cursor_visitor_.reset(); eof_ = false; if (!done()) { next(ec); } } template <class Sourceable> void reset(Sourceable&& source, std::error_code& ec) { parser_.reset(std::forward<Sourceable>(source)); cursor_visitor_.reset(); eof_ = false; if (!done()) { next(ec); } } bool done() const override { return parser_.done(); } void array_expected(std::error_code& ec) override { if (cursor_visitor_.event().event_type() == staj_event_type::begin_object) { parser_.array_expected(cursor_visitor_, ec); } else { super_type::array_expected(ec); } } const staj_event& current() const override { return cursor_visitor_.event(); } void read_to(basic_json_visitor<char_type>& visitor) override { std::error_code ec; read_to(visitor, ec); if (ec) { JSONCONS_THROW(ser_error(ec,parser_.line(),parser_.column())); } } void read_to(basic_json_visitor<char_type>& visitor, std::error_code& ec) override { if (staj_to_saj_event(cursor_visitor_.event(), visitor, *this, ec)) { read_next(visitor, ec); } } void next() override { std::error_code ec; next(ec); if (ec) { JSONCONS_THROW(ser_error(ec,parser_.line(),parser_.column())); } } void next(std::error_code& ec) override { read_next(ec); } const ser_context& context() const override { return *this; } bool eof() const { return eof_; } std::size_t line() const override { return parser_.line(); } std::size_t column() const override { return parser_.column(); } friend staj_filter_view operator|(basic_bson_cursor& cursor, std::function<bool(const staj_event&, const ser_context&)> pred) { return staj_filter_view(cursor, pred); } #if !defined(JSONCONS_NO_DEPRECATED) template <class Sourceable> JSONCONS_DEPRECATED_MSG("Instead, use pipe syntax for filter") basic_bson_cursor(Sourceable&& source, std::function<bool(const staj_event&, const ser_context&)> filter, std::error_code& ec) : basic_bson_cursor(std::allocator_arg, Allocator(), std::forward<Sourceable>(source), filter, ec) { } template <class Sourceable> JSONCONS_DEPRECATED_MSG("Instead, use pipe syntax for filter") basic_bson_cursor(Sourceable&& source, std::function<bool(const staj_event&, const ser_context&)> filter, const bson_decode_options& options = bson_decode_options(), const Allocator& alloc = Allocator()) : parser_(std::forward<Sourceable>(source), options, alloc), cursor_visitor_(filter), eof_(false) { if (!done()) { next(); } } template <class Sourceable> JSONCONS_DEPRECATED_MSG("Instead, use pipe syntax for filter") basic_bson_cursor(std::allocator_arg_t, const Allocator& alloc, Sourceable&& source, std::function<bool(const staj_event&, const ser_context&)> filter, std::error_code& ec) : parser_(std::forward<Sourceable>(source),alloc), cursor_visitor_(filter), eof_(false) { if (!done()) { next(ec); } } JSONCONS_DEPRECATED_MSG("Instead, use read_to(basic_json_visitor<char_type>&)") void read(basic_json_visitor<char_type>& visitor) { read_to(visitor); } JSONCONS_DEPRECATED_MSG("Instead, use read_to(basic_json_visitor<char_type>&, std::error_code&)") void read(basic_json_visitor<char_type>& visitor, std::error_code& ec) { read_to(visitor, ec); } #endif private: static bool accept_all(const staj_event&, const ser_context&) { return true; } void read_next(std::error_code& ec) { parser_.restart(); while (!parser_.stopped()) { parser_.parse(cursor_visitor_, ec); if (ec) return; } } void read_next(basic_json_visitor<char_type>& visitor, std::error_code& ec) { parser_.restart(); while (!parser_.stopped()) { parser_.parse(visitor, ec); if (ec) return; } } }; using bson_stream_cursor = basic_bson_cursor<jsoncons::binary_stream_source>; using bson_bytes_cursor = basic_bson_cursor<jsoncons::bytes_source>; } // namespace bson } // namespace jsoncons #endif