/usr/include/boost/log/detail
Edit: /usr/include/boost/log/detail/format.hpp (10809B)
/*
* Copyright Andrey Semashev 2007 - 2015.
* 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 format.hpp
* \author Andrey Semashev
* \date 15.11.2012
*
* \brief This header is the Boost.Log library implementation, see the library documentation
* at http://www.boost.org/doc/libs/release/libs/log/doc/html/index.html.
*/
#ifndef BOOST_LOG_DETAIL_FORMAT_HPP_INCLUDED_
#define BOOST_LOG_DETAIL_FORMAT_HPP_INCLUDED_
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#ifdef BOOST_HAS_PRAGMA_ONCE
#pragma once
#endif
namespace boost {
BOOST_LOG_OPEN_NAMESPACE
namespace aux {
//! An element (either literal or placeholder) of the format string
struct format_element
{
//! Argument placeholder number or -1 if it's not a placeholder (i.e. a literal)
int arg_number;
//! If the element describes a constant literal, the starting character and length of the literal
unsigned int literal_start_pos, literal_len;
format_element() : arg_number(0), literal_start_pos(0), literal_len(0)
{
}
static format_element literal(unsigned int start_pos, unsigned int len)
{
format_element el;
el.arg_number = -1;
el.literal_start_pos = start_pos;
el.literal_len = len;
return el;
}
static format_element positional_argument(unsigned int arg_n)
{
format_element el;
el.arg_number = arg_n;
return el;
}
};
//! Parsed format string description
template< typename CharT >
struct format_description
{
BOOST_COPYABLE_AND_MOVABLE_ALT(format_description)
public:
//! Character type
typedef CharT char_type;
//! String type
typedef std::basic_string< char_type > string_type;
//! Array of format element descriptors
typedef std::vector< format_element > format_element_list;
//! Characters of all literal parts of the format string
string_type literal_chars;
//! Format element descriptors
format_element_list format_elements;
BOOST_DEFAULTED_FUNCTION(format_description(), {})
format_description(format_description const& that) : literal_chars(that.literal_chars), format_elements(that.format_elements)
{
}
format_description(BOOST_RV_REF(format_description) that) BOOST_NOEXCEPT
{
literal_chars.swap(that.literal_chars);
format_elements.swap(that.format_elements);
}
format_description& operator= (format_description that) BOOST_NOEXCEPT
{
literal_chars.swap(that.literal_chars);
format_elements.swap(that.format_elements);
return *this;
}
};
//! Parses format string
template< typename CharT >
BOOST_LOG_API format_description< CharT > parse_format(const CharT* begin, const CharT* end);
//! Parses format string
template< typename CharT >
BOOST_FORCEINLINE format_description< CharT > parse_format(const CharT* begin)
{
return parse_format(begin, begin + std::char_traits< CharT >::length(begin));
}
//! Parses format string
template< typename CharT, typename TraitsT, typename AllocatorT >
BOOST_FORCEINLINE format_description< CharT > parse_format(std::basic_string< CharT, TraitsT, AllocatorT > const& fmt)
{
const CharT* begin = fmt.c_str();
return parse_format(begin, begin + fmt.size());
}
//! Formatter object
template< typename CharT >
class basic_format
{
public:
//! Character type
typedef CharT char_type;
//! String type
typedef std::basic_string< char_type > string_type;
//! Stream type
typedef basic_formatting_ostream< char_type > stream_type;
//! Format description type
typedef format_description< char_type > format_description_type;
//! The pump receives arguments and formats them into strings. At destruction the pump composes the final string in the attached stream.
class pump;
friend class pump;
private:
//! Formatting params for a single placeholder in the format string
struct formatting_params
{
//! Formatting element index in the format description
unsigned int element_idx;
//! Formatting result
string_type target;
formatting_params() : element_idx(~0u) {}
};
typedef std::vector< formatting_params > formatting_params_list;
private:
//! Format string description
format_description_type m_format;
//! Formatting parameters for all placeholders
formatting_params_list m_formatting_params;
//! Current formatting position
unsigned int m_current_idx;
public:
//! Initializing constructor
explicit basic_format(string_type const& fmt) : m_format(aux::parse_format(fmt)), m_current_idx(0)
{
init_params();
}
//! Initializing constructor
explicit basic_format(const char_type* fmt) : m_format(aux::parse_format(fmt)), m_current_idx(0)
{
init_params();
}
//! Clears all formatted strings and resets the current formatting position
void clear() BOOST_NOEXCEPT
{
for (typename formatting_params_list::iterator it = m_formatting_params.begin(), end = m_formatting_params.end(); it != end; ++it)
{
it->target.clear();
}
m_current_idx = 0;
}
//! Creates a pump that will receive all format arguments and put the formatted string into the stream
pump make_pump(stream_type& strm)
{
// Flush the stream beforehand so that the pump can safely switch the stream storage string
strm.flush();
return pump(*this, strm);
}
//! Composes the final string from the formatted pieces
string_type str() const
{
string_type result;
compose(result);
return BOOST_LOG_NRVO_RESULT(result);
}
private:
//! Initializes the formatting params
void init_params()
{
typename format_description_type::format_element_list::const_iterator it = m_format.format_elements.begin(), end = m_format.format_elements.end();
for (; it != end; ++it)
{
if (it->arg_number >= 0)
{
if (static_cast< unsigned int >(it->arg_number) >= m_formatting_params.size())
m_formatting_params.resize(it->arg_number + 1);
m_formatting_params[it->arg_number].element_idx = static_cast< unsigned int >(it - m_format.format_elements.begin());
}
}
}
//! Composes the final string from the formatted pieces
template< typename T >
void compose(T& str) const
{
typename format_description_type::format_element_list::const_iterator it = m_format.format_elements.begin(), end = m_format.format_elements.end();
for (; it != end; ++it)
{
if (it->arg_number >= 0)
{
// This is a placeholder
string_type const& target = m_formatting_params[it->arg_number].target;
str.append(target.data(), target.size());
}
else
{
// This is a literal
const char_type* p = m_format.literal_chars.c_str() + it->literal_start_pos;
str.append(p, it->literal_len);
}
}
}
};
//! The pump receives arguments and formats them into strings. At destruction the pump composes the final string in the attached stream.
template< typename CharT >
class basic_format< CharT >::pump
{
BOOST_MOVABLE_BUT_NOT_COPYABLE(pump)
private:
//! The guard temporarily replaces storage string in the specified stream
struct scoped_storage
{
scoped_storage(stream_type& strm, string_type& storage) : m_stream(strm), m_storage_state_backup(strm.rdbuf()->get_storage_state())
{
strm.attach(storage);
}
~scoped_storage()
{
m_stream.rdbuf()->set_storage_state(m_storage_state_backup);
}
private:
stream_type& m_stream;
typename stream_type::streambuf_type::storage_state m_storage_state_backup;
};
private:
//! Reference to the owner
basic_format* m_owner;
//! Reference to the stream
stream_type* m_stream;
//! Unhandled exception count
const unsigned int m_exception_count;
public:
//! Initializing constructor
pump(basic_format& owner, stream_type& strm) BOOST_NOEXCEPT : m_owner(&owner), m_stream(&strm), m_exception_count(boost::core::uncaught_exceptions())
{
}
//! Move constructor
pump(BOOST_RV_REF(pump) that) BOOST_NOEXCEPT : m_owner(that.m_owner), m_stream(that.m_stream), m_exception_count(that.m_exception_count)
{
that.m_owner = NULL;
that.m_stream = NULL;
}
//! Destructor
~pump() BOOST_NOEXCEPT_IF(false)
{
if (m_owner)
{
// Whether or not the destructor is called because of an exception, the format object has to be cleared
boost::log::aux::cleanup_guard< basic_format< char_type > > cleanup1(*m_owner);
BOOST_ASSERT(m_stream != NULL);
if (m_exception_count >= boost::core::uncaught_exceptions())
{
// Compose the final string in the stream buffer
m_stream->flush();
m_owner->compose(*m_stream->rdbuf());
}
}
}
/*!
* Puts an argument to the formatter. Note the pump has to be returned by value and not by reference in order this to
* work with Boost.Phoenix expressions. Otherwise the pump that is returned from \c basic_format::make_pump is
* destroyed after the first call to \c operator%, and the returned reference becomes dangling.
*/
template< typename T >
pump operator% (T const& val)
{
BOOST_ASSERT_MSG(m_owner != NULL && m_stream != NULL, "Boost.Log: This basic_format::pump has already been moved from");
if (m_owner->m_current_idx < m_owner->m_formatting_params.size())
{
scoped_storage storage_guard(*m_stream, m_owner->m_formatting_params[m_owner->m_current_idx].target);
*m_stream << val;
m_stream->flush();
++m_owner->m_current_idx;
}
return boost::move(*this);
}
};
} // namespace aux
BOOST_LOG_CLOSE_NAMESPACE // namespace log
} // namespace boost
#include
#endif // BOOST_LOG_DETAIL_FORMAT_HPP_INCLUDED_