1 /*
2 * Copyright Andrey Semashev 2007 - 2015.
3 * Distributed under the Boost Software License, Version 1.0.
4 * (See accompanying file LICENSE_1_0.txt or copy at
5 * http://www.boost.org/LICENSE_1_0.txt)
6 */
7 /*!
8 * \file formatter_parser.hpp
9 * \author Andrey Semashev
10 * \date 07.04.2008
11 *
12 * The header contains definition of a formatter parser function, along with facilities to
13 * add support for custom formatters.
14 */
15
16 #ifndef BOOST_LOG_UTILITY_SETUP_FORMATTER_PARSER_HPP_INCLUDED_
17 #define BOOST_LOG_UTILITY_SETUP_FORMATTER_PARSER_HPP_INCLUDED_
18
19 #include <iosfwd>
20 #include <map>
21 #include <string>
22 #include <boost/smart_ptr/shared_ptr.hpp>
23 #include <boost/smart_ptr/make_shared_object.hpp>
24 #include <boost/core/enable_if.hpp>
25 #include <boost/type_traits/is_base_and_derived.hpp>
26 #include <boost/log/detail/setup_config.hpp>
27 #include <boost/log/attributes/attribute_name.hpp>
28 #include <boost/log/core/record.hpp>
29 #include <boost/log/expressions/formatter.hpp>
30 #include <boost/log/expressions/attr.hpp>
31 #include <boost/log/expressions/formatters/stream.hpp>
32 #include <boost/log/detail/header.hpp>
33
34 #ifdef BOOST_HAS_PRAGMA_ONCE
35 #pragma once
36 #endif
37
38 namespace boost {
39
40 BOOST_LOG_OPEN_NAMESPACE
41
42 /*!
43 * Formatter factory base interface.
44 */
45 template< typename CharT >
46 struct formatter_factory
47 {
48 //! Character type
49 typedef CharT char_type;
50 //! String type
51 typedef std::basic_string< char_type > string_type;
52 //! The formatter function object
53 typedef basic_formatter< char_type > formatter_type;
54 /*!
55 * Type of the map of formatter factory arguments [argument name -> argument value].
56 * This type of maps will be passed to formatter factories on attempt to create a formatter.
57 */
58 typedef std::map< string_type, string_type > args_map;
59
60 /*!
61 * Default constructor
62 */
formatter_factoryboost::formatter_factory63 BOOST_DEFAULTED_FUNCTION(formatter_factory(), {})
64
65 /*!
66 * Virtual destructor
67 */
68 virtual ~formatter_factory() {}
69
70 /*!
71 * The function creates a formatter for the specified attribute.
72 *
73 * \param name Attribute name
74 * \param args Formatter arguments
75 */
76 virtual formatter_type create_formatter(attribute_name const& name, args_map const& args) = 0;
77
78 BOOST_DELETED_FUNCTION(formatter_factory(formatter_factory const&))
79 BOOST_DELETED_FUNCTION(formatter_factory& operator= (formatter_factory const&))
80 };
81
82 /*!
83 * Base class for formatter factories. This class provides default implementation of formatter expressions for
84 * types supporting stream output. The factory does not take into account any additional parameters that may be specified.
85 */
86 template< typename CharT, typename AttributeValueT >
87 class basic_formatter_factory :
88 public formatter_factory< CharT >
89 {
90 private:
91 typedef formatter_factory< CharT > base_type;
92
93 public:
94 //! Attribute value type
95 typedef AttributeValueT value_type;
96 // Type imports from the base class
97 typedef typename base_type::formatter_type formatter_type;
98 typedef typename base_type::args_map args_map;
99
100 /*!
101 * The function creates a formatter for the specified attribute.
102 *
103 * \param name Attribute name
104 * \param args Formatter arguments
105 */
create_formatter(attribute_name const & name,args_map const & args)106 formatter_type create_formatter(attribute_name const& name, args_map const& args)
107 {
108 return formatter_type(expressions::stream << expressions::attr< value_type >(name));
109 }
110 };
111
112 /*!
113 * \brief The function registers a user-defined formatter factory
114 *
115 * The function registers a user-defined formatter factory. The registered factory function will be
116 * called when the formatter parser detects the specified attribute name in the formatter string.
117 *
118 * \pre <tt>!!attr_name && !!factory</tt>.
119 *
120 * \param attr_name Attribute name
121 * \param factory Pointer to the formatter factory
122 */
123 template< typename CharT >
124 BOOST_LOG_SETUP_API void register_formatter_factory(
125 attribute_name const& attr_name, shared_ptr< formatter_factory< CharT > > const& factory);
126
127 /*!
128 * \brief The function registers a user-defined formatter factory
129 *
130 * The function registers a user-defined formatter factory. The registered factory function will be
131 * called when the formatter parser detects the specified attribute name in the formatter string.
132 *
133 * \pre <tt>!!attr_name && !!factory</tt>.
134 *
135 * \param attr_name Attribute name
136 * \param factory Pointer to the formatter factory
137 */
138 template< typename FactoryT >
139 inline typename boost::enable_if_c<
140 is_base_and_derived< formatter_factory< typename FactoryT::char_type >, FactoryT >::value
register_formatter_factory(attribute_name const & attr_name,shared_ptr<FactoryT> const & factory)141 >::type register_formatter_factory(attribute_name const& attr_name, shared_ptr< FactoryT > const& factory)
142 {
143 typedef formatter_factory< typename FactoryT::char_type > factory_base;
144 register_formatter_factory(attr_name, boost::static_pointer_cast< factory_base >(factory));
145 }
146
147 /*!
148 * \brief The function registers a simple formatter factory
149 *
150 * The function registers a simple formatter factory. The registered factory will generate formatters
151 * that will be equivalent to the <tt>log::expressions::attr</tt> formatter (i.e. that will use the
152 * native \c operator<< to format the attribute value). The factory does not use any arguments from the format string,
153 * if specified.
154 *
155 * \pre <tt>!!attr_name</tt>.
156 *
157 * \param attr_name Attribute name
158 */
159 template< typename AttributeValueT, typename CharT >
register_simple_formatter_factory(attribute_name const & attr_name)160 inline void register_simple_formatter_factory(attribute_name const& attr_name)
161 {
162 shared_ptr< formatter_factory< CharT > > factory =
163 boost::make_shared< basic_formatter_factory< CharT, AttributeValueT > >();
164 register_formatter_factory(attr_name, factory);
165 }
166
167 /*!
168 * The function parses a formatter from the sequence of characters
169 *
170 * \pre <tt>begin <= end</tt>, both pointers must not be NULL
171 * \param begin Pointer to the first character of the sequence
172 * \param end Pointer to the after-the-last character of the sequence
173 * \return The parsed formatter.
174 *
175 * \b Throws: An <tt>std::exception</tt>-based exception, if a formatter cannot be recognized in the character sequence.
176 */
177 template< typename CharT >
178 BOOST_LOG_SETUP_API basic_formatter< CharT > parse_formatter(const CharT* begin, const CharT* end);
179
180 /*!
181 * The function parses a formatter from the string
182 *
183 * \param str A string that contains format description
184 * \return The parsed formatter.
185 *
186 * \b Throws: An <tt>std::exception</tt>-based exception, if a formatter cannot be recognized in the character sequence.
187 */
188 template< typename CharT, typename TraitsT, typename AllocatorT >
parse_formatter(std::basic_string<CharT,TraitsT,AllocatorT> const & str)189 inline basic_formatter< CharT > parse_formatter(std::basic_string< CharT, TraitsT, AllocatorT > const& str)
190 {
191 const CharT* p = str.c_str();
192 return parse_formatter(p, p + str.size());
193 }
194
195 /*!
196 * The function parses a formatter from the string
197 *
198 * \pre <tt>str != NULL</tt>, <tt>str</tt> points to a zero-terminated string
199 * \param str A string that contains format description.
200 * \return The parsed formatter.
201 *
202 * \b Throws: An <tt>std::exception</tt>-based exception, if a formatter cannot be recognized in the character sequence.
203 */
204 template< typename CharT >
parse_formatter(const CharT * str)205 inline basic_formatter< CharT > parse_formatter(const CharT* str)
206 {
207 return parse_formatter(str, str + std::char_traits< CharT >::length(str));
208 }
209
210 BOOST_LOG_CLOSE_NAMESPACE // namespace log
211
212 } // namespace boost
213
214 #include <boost/log/detail/footer.hpp>
215
216 #endif // BOOST_LOG_UTILITY_SETUP_FORMATTER_PARSER_HPP_INCLUDED_
217