123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561 |
- /*
- * Copyright Andrey Semashev 2016.
- * 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)
- */
- /*!
- * \file formatters/max_size_decorator.hpp
- * \author Andrey Semashev
- * \date 06.07.2016
- *
- * The header contains implementation of a string length limiting decorator.
- */
- #ifndef BOOST_LOG_EXPRESSIONS_FORMATTERS_MAX_SIZE_DECORATOR_HPP_INCLUDED_
- #define BOOST_LOG_EXPRESSIONS_FORMATTERS_MAX_SIZE_DECORATOR_HPP_INCLUDED_
- #include <cstddef>
- #include <string>
- #include <boost/assert.hpp>
- #include <boost/mpl/bool.hpp>
- #include <boost/move/core.hpp>
- #include <boost/move/utility_core.hpp>
- #include <boost/core/addressof.hpp>
- #include <boost/phoenix/core/actor.hpp>
- #include <boost/phoenix/core/meta_grammar.hpp>
- #include <boost/phoenix/core/terminal_fwd.hpp>
- #include <boost/phoenix/core/is_nullary.hpp>
- #include <boost/phoenix/core/environment.hpp>
- #include <boost/phoenix/support/vector.hpp>
- #include <boost/fusion/sequence/intrinsic/at_c.hpp>
- #include <boost/type_traits/remove_cv.hpp>
- #include <boost/type_traits/remove_reference.hpp>
- #include <boost/log/detail/config.hpp>
- #include <boost/log/detail/custom_terminal_spec.hpp>
- #include <boost/log/utility/formatting_ostream.hpp>
- #include <boost/log/detail/header.hpp>
- #ifdef BOOST_HAS_PRAGMA_ONCE
- #pragma once
- #endif
- namespace boost {
- BOOST_LOG_OPEN_NAMESPACE
- namespace expressions {
- namespace aux {
- //! String size limiting decorator stream output terminal
- template< typename LeftT, typename SubactorT, typename CharT >
- class max_size_decorator_output_terminal
- {
- private:
- //! Self type
- typedef max_size_decorator_output_terminal< LeftT, SubactorT, CharT > this_type;
- public:
- #ifndef BOOST_LOG_DOXYGEN_PASS
- //! Internal typedef for type categorization
- typedef void _is_boost_log_terminal;
- #endif
- //! Character type
- typedef CharT char_type;
- //! String type
- typedef std::basic_string< char_type > string_type;
- //! String size type
- typedef std::size_t size_type;
- //! Adopted actor type
- typedef SubactorT subactor_type;
- //! Result type definition
- template< typename >
- struct result;
- template< typename ThisT, typename ContextT >
- struct result< ThisT(ContextT) >
- {
- typedef typename remove_cv< typename remove_reference< ContextT >::type >::type context_type;
- typedef typename phoenix::evaluator::impl<
- typename LeftT::proto_base_expr&,
- context_type,
- phoenix::unused
- >::result_type type;
- };
- private:
- //! Left argument actor
- LeftT m_left;
- //! Adopted formatter actor
- subactor_type m_subactor;
- //! Max size of the formatted string produced by the adopted formatter
- size_type m_max_size;
- //! Overflow marker
- string_type m_overflow_marker;
- public:
- /*!
- * Initializing constructor. Creates decorator of the \a fmt formatter with the specified \a decorations.
- */
- max_size_decorator_output_terminal(LeftT const& left, subactor_type const& sub, size_type max_size, string_type const& overflow_marker = string_type()) :
- m_left(left), m_subactor(sub), m_max_size(max_size), m_overflow_marker(overflow_marker)
- {
- BOOST_ASSERT(overflow_marker.size() <= max_size);
- }
- /*!
- * Copy constructor
- */
- max_size_decorator_output_terminal(max_size_decorator_output_terminal const& that) :
- m_left(that.m_left), m_subactor(that.m_subactor), m_max_size(that.m_max_size), m_overflow_marker(that.m_overflow_marker)
- {
- }
- /*!
- * Invokation operator
- */
- template< typename ContextT >
- typename result< this_type(ContextT const&) >::type operator() (ContextT const& ctx)
- {
- // Flush the stream and keep the current write position in the target string
- typedef typename result< this_type(ContextT const&) >::type result_type;
- result_type strm = phoenix::eval(m_left, ctx);
- strm.flush();
- if (!strm.rdbuf()->storage_overflow())
- {
- const size_type old_max_size = strm.rdbuf()->max_size();
- const size_type start_pos = strm.rdbuf()->storage()->size(), max_size_left = strm.rdbuf()->storage()->max_size() - start_pos;
- strm.rdbuf()->max_size(start_pos + (m_max_size <= max_size_left ? m_max_size : max_size_left));
- try
- {
- // Invoke the adopted formatter
- phoenix::eval(m_subactor, ctx);
- // Flush the buffered characters and apply decorations
- strm.flush();
- if (strm.rdbuf()->storage_overflow())
- {
- if (!m_overflow_marker.empty())
- {
- // Free up space for the overflow marker
- strm.rdbuf()->max_size(strm.rdbuf()->max_size() - m_overflow_marker.size());
- // Append the marker
- strm.rdbuf()->max_size(strm.rdbuf()->storage()->max_size());
- strm.rdbuf()->storage_overflow(false);
- strm.rdbuf()->append(m_overflow_marker.data(), m_overflow_marker.size());
- }
- else
- {
- strm.rdbuf()->storage_overflow(false);
- }
- }
- // Restore the original size limit
- strm.rdbuf()->max_size(old_max_size);
- }
- catch (...)
- {
- strm.rdbuf()->storage_overflow(false);
- strm.rdbuf()->max_size(old_max_size);
- throw;
- }
- }
- return strm;
- }
- /*!
- * Invokation operator
- */
- template< typename ContextT >
- typename result< const this_type(ContextT const&) >::type operator() (ContextT const& ctx) const
- {
- // Flush the stream and keep the current write position in the target string
- typedef typename result< const this_type(ContextT const&) >::type result_type;
- result_type strm = phoenix::eval(m_left, ctx);
- strm.flush();
- if (!strm.rdbuf()->storage_overflow())
- {
- const size_type old_max_size = strm.rdbuf()->max_size();
- const size_type start_pos = strm.rdbuf()->storage()->size(), max_size_left = strm.rdbuf()->storage()->max_size() - start_pos;
- strm.rdbuf()->max_size(start_pos + (m_max_size <= max_size_left ? m_max_size : max_size_left));
- try
- {
- // Invoke the adopted formatter
- phoenix::eval(m_subactor, ctx);
- // Flush the buffered characters and apply decorations
- strm.flush();
- if (strm.rdbuf()->storage_overflow())
- {
- if (!m_overflow_marker.empty())
- {
- // Free up space for the overflow marker
- strm.rdbuf()->max_size(strm.rdbuf()->max_size() - m_overflow_marker.size());
- // Append the marker
- strm.rdbuf()->max_size(strm.rdbuf()->storage()->max_size());
- strm.rdbuf()->storage_overflow(false);
- strm.rdbuf()->append(m_overflow_marker.data(), m_overflow_marker.size());
- }
- else
- {
- strm.rdbuf()->storage_overflow(false);
- }
- }
- // Restore the original size limit
- strm.rdbuf()->max_size(old_max_size);
- }
- catch (...)
- {
- strm.rdbuf()->storage_overflow(false);
- strm.rdbuf()->max_size(old_max_size);
- throw;
- }
- }
- return strm;
- }
- BOOST_DELETED_FUNCTION(max_size_decorator_output_terminal())
- };
- } // namespace aux
- /*!
- * String size limiting decorator terminal class. This formatter allows to limit the maximum total length
- * of the strings generated by other formatters.
- *
- * The \c max_size_decorator_terminal class aggregates the formatter being decorated, the maximum string length
- * it can produce and an optional truncation marker string, which will be put at the end of the output if the limit is exceeded. Note that
- * the marker length is included in the limit and as such must not exceed it.
- * The \c max_size_decorator_terminal class is a formatter itself, so it can be used to construct
- * more complex formatters, including nesting decorators.
- */
- template< typename SubactorT, typename CharT >
- class max_size_decorator_terminal
- {
- private:
- //! Self type
- typedef max_size_decorator_terminal< SubactorT, CharT > this_type;
- public:
- #ifndef BOOST_LOG_DOXYGEN_PASS
- //! Internal typedef for type categorization
- typedef void _is_boost_log_terminal;
- #endif
- //! Character type
- typedef CharT char_type;
- //! String type
- typedef std::basic_string< char_type > string_type;
- //! String size type
- typedef std::size_t size_type;
- //! Stream type
- typedef basic_formatting_ostream< char_type > stream_type;
- //! Adopted actor type
- typedef SubactorT subactor_type;
- //! Result type definition
- typedef string_type result_type;
- private:
- //! Adopted formatter actor
- subactor_type m_subactor;
- //! Max size of the formatted string produced by the adopted formatter
- size_type m_max_size;
- //! Overflow marker
- string_type m_overflow_marker;
- public:
- /*!
- * Initializing constructor.
- */
- max_size_decorator_terminal(subactor_type const& sub, size_type max_size, string_type const& overflow_marker = string_type()) :
- m_subactor(sub), m_max_size(max_size), m_overflow_marker(overflow_marker)
- {
- BOOST_ASSERT(overflow_marker.size() <= max_size);
- }
- /*!
- * Copy constructor
- */
- max_size_decorator_terminal(max_size_decorator_terminal const& that) :
- m_subactor(that.m_subactor), m_max_size(that.m_max_size), m_overflow_marker(that.m_overflow_marker)
- {
- }
- /*!
- * \returns Adopted subactor
- */
- subactor_type const& get_subactor() const
- {
- return m_subactor;
- }
- /*!
- * \returns Max string size limit
- */
- size_type get_max_size() const
- {
- return m_max_size;
- }
- /*!
- * \returns Max string size limit
- */
- string_type const& get_overflow_marker() const
- {
- return m_overflow_marker;
- }
- /*!
- * Invokation operator
- */
- template< typename ContextT >
- result_type operator() (ContextT const& ctx)
- {
- string_type str;
- stream_type strm(str);
- strm.rdbuf()->max_size(m_max_size);
- // Invoke the adopted formatter
- typedef phoenix::vector3<
- subactor_type*,
- typename fusion::result_of::at_c<
- typename remove_cv<
- typename remove_reference<
- typename phoenix::result_of::env< ContextT const& >::type
- >::type
- >::type::args_type,
- 0
- >::type,
- stream_type&
- > env_type;
- env_type env = { boost::addressof(m_subactor), fusion::at_c< 0 >(phoenix::env(ctx).args()), strm };
- phoenix::eval(m_subactor, phoenix::make_context(env, phoenix::actions(ctx)));
- // Flush the buffered characters and see of overflow happened
- strm.flush();
- if (strm.rdbuf()->storage_overflow() && !m_overflow_marker.empty())
- {
- strm.rdbuf()->max_size(strm.rdbuf()->max_size() - m_overflow_marker.size());
- strm.rdbuf()->max_size(str.max_size());
- strm.rdbuf()->storage_overflow(false);
- strm.rdbuf()->append(m_overflow_marker.data(), m_overflow_marker.size());
- strm.flush();
- }
- return BOOST_LOG_NRVO_RESULT(str);
- }
- /*!
- * Invokation operator
- */
- template< typename ContextT >
- result_type operator() (ContextT const& ctx) const
- {
- string_type str;
- stream_type strm(str);
- strm.rdbuf()->max_size(m_max_size);
- // Invoke the adopted formatter
- typedef phoenix::vector3<
- const subactor_type*,
- typename fusion::result_of::at_c<
- typename remove_cv<
- typename remove_reference<
- typename phoenix::result_of::env< ContextT const& >::type
- >::type
- >::type::args_type,
- 0
- >::type,
- stream_type&
- > env_type;
- env_type env = { boost::addressof(m_subactor), fusion::at_c< 0 >(phoenix::env(ctx).args()), strm };
- phoenix::eval(m_subactor, phoenix::make_context(env, phoenix::actions(ctx)));
- // Flush the buffered characters and see of overflow happened
- strm.flush();
- if (strm.rdbuf()->storage_overflow())
- {
- strm.rdbuf()->max_size(strm.rdbuf()->max_size() - m_overflow_marker.size());
- strm.rdbuf()->max_size(str.max_size());
- strm.rdbuf()->storage_overflow(false);
- strm.rdbuf()->append(m_overflow_marker.data(), m_overflow_marker.size());
- strm.flush();
- }
- return BOOST_LOG_NRVO_RESULT(str);
- }
- BOOST_DELETED_FUNCTION(max_size_decorator_terminal())
- };
- /*!
- * Character decorator actor
- */
- template< typename SubactorT, typename CharT, template< typename > class ActorT = phoenix::actor >
- class max_size_decorator_actor :
- public ActorT< max_size_decorator_terminal< SubactorT, CharT > >
- {
- public:
- //! Base terminal type
- typedef max_size_decorator_terminal< SubactorT, CharT > terminal_type;
- //! Character type
- typedef typename terminal_type::char_type char_type;
- //! Base actor type
- typedef ActorT< terminal_type > base_type;
- public:
- //! Initializing constructor
- explicit max_size_decorator_actor(base_type const& act) : base_type(act)
- {
- }
- //! Returns reference to the terminal
- terminal_type const& get_terminal() const
- {
- return this->proto_expr_.child0;
- }
- };
- #ifndef BOOST_LOG_DOXYGEN_PASS
- #define BOOST_LOG_AUX_OVERLOAD(left_ref, right_ref)\
- template< typename LeftExprT, typename SubactorT, typename CharT, template< typename > class ActorT >\
- BOOST_FORCEINLINE phoenix::actor< aux::max_size_decorator_output_terminal< phoenix::actor< LeftExprT >, SubactorT, CharT > >\
- operator<< (phoenix::actor< LeftExprT > left_ref left, max_size_decorator_actor< SubactorT, CharT, ActorT > right_ref right)\
- {\
- typedef aux::max_size_decorator_output_terminal< phoenix::actor< LeftExprT >, SubactorT, CharT > terminal_type;\
- phoenix::actor< terminal_type > actor = {{ terminal_type(left, right.get_terminal().get_subactor(), right.get_terminal().get_max_size(), right.get_terminal().get_overflow_marker()) }};\
- return actor;\
- }
- #include <boost/log/detail/generate_overloads.hpp>
- #undef BOOST_LOG_AUX_OVERLOAD
- #endif // BOOST_LOG_DOXYGEN_PASS
- namespace aux {
- template< typename CharT >
- class max_size_decorator_gen
- {
- private:
- typedef CharT char_type;
- typedef std::basic_string< char_type > string_type;
- typedef std::size_t size_type;
- private:
- size_type m_max_size;
- string_type m_overflow_marker;
- public:
- explicit max_size_decorator_gen(size_type max_size, string_type const& overflow_marker = string_type()) :
- m_max_size(max_size), m_overflow_marker(overflow_marker)
- {
- BOOST_ASSERT(overflow_marker.size() <= max_size);
- }
- template< typename SubactorT >
- BOOST_FORCEINLINE max_size_decorator_actor< SubactorT, char_type > operator[] (SubactorT const& subactor) const
- {
- typedef max_size_decorator_actor< SubactorT, char_type > result_type;
- typedef typename result_type::terminal_type terminal_type;
- typename result_type::base_type act = {{ terminal_type(subactor, m_max_size, m_overflow_marker) }};
- return result_type(act);
- }
- };
- } // namespace aux
- /*!
- * The function returns a decorator generator object. The generator provides <tt>operator[]</tt> that can be used
- * to construct the actual decorator.
- *
- * \param max_size The maximum number of characters (i.e. string element objects) that the decorated formatter can produce.
- */
- template< typename CharT >
- BOOST_FORCEINLINE aux::max_size_decorator_gen< CharT > max_size_decor(std::size_t max_size)
- {
- return aux::max_size_decorator_gen< CharT >(max_size);
- }
- /*!
- * The function returns a decorator generator object. The generator provides <tt>operator[]</tt> that can be used
- * to construct the actual decorator.
- *
- * \param max_size The maximum number of characters (i.e. string element objects) that the decorated formatter can produce.
- * \param overflow_marker The marker string which is appended to the output if the \a max_size limit is exceeded. Must be
- * a non-null pointer to a zero-terminated string.
- *
- * \pre The \a overflow_marker length must not exceed the \a max_size limit.
- */
- template< typename CharT >
- BOOST_FORCEINLINE aux::max_size_decorator_gen< CharT > max_size_decor(std::size_t max_size, const CharT* overflow_marker)
- {
- return aux::max_size_decorator_gen< CharT >(max_size, overflow_marker);
- }
- /*!
- * The function returns a decorator generator object. The generator provides <tt>operator[]</tt> that can be used
- * to construct the actual decorator.
- *
- * \param max_size The maximum number of characters (i.e. string element objects) that the decorated formatter can produce.
- * \param overflow_marker The marker string which is appended to the output if the \a max_size limit is exceeded.
- *
- * \pre The \a overflow_marker length must not exceed the \a max_size limit.
- */
- template< typename CharT >
- BOOST_FORCEINLINE aux::max_size_decorator_gen< CharT > max_size_decor(std::size_t max_size, std::basic_string< CharT > const& overflow_marker)
- {
- return aux::max_size_decorator_gen< CharT >(max_size, overflow_marker);
- }
- } // namespace expressions
- BOOST_LOG_CLOSE_NAMESPACE // namespace log
- #ifndef BOOST_LOG_DOXYGEN_PASS
- namespace phoenix {
- namespace result_of {
- template< typename SubactorT, typename CharT >
- struct is_nullary< custom_terminal< boost::log::expressions::max_size_decorator_terminal< SubactorT, CharT > > > :
- public mpl::false_
- {
- };
- template< typename LeftT, typename SubactorT, typename CharT >
- struct is_nullary< custom_terminal< boost::log::expressions::aux::max_size_decorator_output_terminal< LeftT, SubactorT, CharT > > > :
- public mpl::false_
- {
- };
- } // namespace result_of
- } // namespace phoenix
- #endif
- } // namespace boost
- #include <boost/log/detail/footer.hpp>
- #endif // BOOST_LOG_EXPRESSIONS_FORMATTERS_MAX_SIZE_DECORATOR_HPP_INCLUDED_
|