text_file_backend.hpp 23 KB

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  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 text_file_backend.hpp
  9. * \author Andrey Semashev
  10. * \date 09.06.2009
  11. *
  12. * The header contains implementation of a text file sink backend.
  13. */
  14. #ifndef BOOST_LOG_SINKS_TEXT_FILE_BACKEND_HPP_INCLUDED_
  15. #define BOOST_LOG_SINKS_TEXT_FILE_BACKEND_HPP_INCLUDED_
  16. #include <ios>
  17. #include <string>
  18. #include <ostream>
  19. #include <boost/limits.hpp>
  20. #include <boost/cstdint.hpp>
  21. #include <boost/smart_ptr/shared_ptr.hpp>
  22. #include <boost/date_time/date_defs.hpp>
  23. #include <boost/date_time/special_defs.hpp>
  24. #include <boost/date_time/gregorian/greg_day.hpp>
  25. #include <boost/date_time/posix_time/posix_time_types.hpp>
  26. #include <boost/filesystem/path.hpp>
  27. #include <boost/log/keywords/max_size.hpp>
  28. #include <boost/log/keywords/max_files.hpp>
  29. #include <boost/log/keywords/min_free_space.hpp>
  30. #include <boost/log/keywords/target.hpp>
  31. #include <boost/log/keywords/target_file_name.hpp>
  32. #include <boost/log/keywords/file_name.hpp>
  33. #include <boost/log/keywords/open_mode.hpp>
  34. #include <boost/log/keywords/auto_flush.hpp>
  35. #include <boost/log/keywords/rotation_size.hpp>
  36. #include <boost/log/keywords/time_based_rotation.hpp>
  37. #include <boost/log/keywords/enable_final_rotation.hpp>
  38. #include <boost/log/detail/config.hpp>
  39. #include <boost/log/detail/light_function.hpp>
  40. #include <boost/log/detail/parameter_tools.hpp>
  41. #include <boost/log/sinks/basic_sink_backend.hpp>
  42. #include <boost/log/sinks/frontend_requirements.hpp>
  43. #include <boost/log/detail/header.hpp>
  44. #ifdef BOOST_HAS_PRAGMA_ONCE
  45. #pragma once
  46. #endif
  47. namespace boost {
  48. BOOST_LOG_OPEN_NAMESPACE
  49. namespace sinks {
  50. namespace file {
  51. //! The enumeration of the stored files scan methods
  52. enum scan_method
  53. {
  54. no_scan, //!< Don't scan for stored files
  55. scan_matching, //!< Scan for files with names matching the specified mask
  56. scan_all //!< Scan for all files in the directory
  57. };
  58. /*!
  59. * \brief Base class for file collectors
  60. *
  61. * All file collectors, supported by file sink backends, should inherit this class.
  62. */
  63. struct BOOST_LOG_NO_VTABLE collector
  64. {
  65. /*!
  66. * Default constructor
  67. */
  68. BOOST_DEFAULTED_FUNCTION(collector(), {})
  69. /*!
  70. * Virtual destructor
  71. */
  72. virtual ~collector() {}
  73. /*!
  74. * The function stores the specified file in the storage. May lead to an older file
  75. * deletion and a long file moving.
  76. *
  77. * \param src_path The name of the file to be stored
  78. */
  79. virtual void store_file(filesystem::path const& src_path) = 0;
  80. /*!
  81. * Scans the target directory for the files that have already been stored. The found
  82. * files are added to the collector in order to be tracked and erased, if needed.
  83. *
  84. * The function may scan the directory in two ways: it will either consider every
  85. * file in the directory a log file, or will only consider files with names that
  86. * match the specified pattern. The pattern may contain the following placeholders:
  87. *
  88. * \li %y, %Y, %m, %d - date components, in Boost.DateTime meaning.
  89. * \li %H, %M, %S, %f - time components, in Boost.DateTime meaning.
  90. * \li %N - numeric file counter. May also contain width specification
  91. * in printf-compatible form (e.g. %5N). The resulting number will always be zero-filled.
  92. * \li %% - a percent sign
  93. *
  94. * All other placeholders are not supported.
  95. *
  96. * \param method The method of scanning. If \c no_scan is specified, the call has no effect.
  97. * \param pattern The file name pattern if \a method is \c scan_matching. Otherwise the parameter
  98. * is not used.
  99. * \param counter If not \c NULL and \a method is \c scan_matching, the method suggests initial value
  100. * of a file counter that may be used in the file name pattern. The parameter
  101. * is not used otherwise.
  102. * \return The number of found files.
  103. *
  104. * \note In case if \a method is \c scan_matching the effect of this function is highly dependent
  105. * on the \a pattern definition. It is recommended to choose patterns with easily
  106. * distinguished placeholders (i.e. having delimiters between them). Otherwise
  107. * either some files can be mistakenly found or not found, which in turn may lead
  108. * to an incorrect file deletion.
  109. */
  110. virtual uintmax_t scan_for_files(
  111. scan_method method, filesystem::path const& pattern = filesystem::path(), unsigned int* counter = 0) = 0;
  112. BOOST_DELETED_FUNCTION(collector(collector const&))
  113. BOOST_DELETED_FUNCTION(collector& operator= (collector const&))
  114. };
  115. namespace aux {
  116. //! Creates and returns a file collector with the specified parameters
  117. BOOST_LOG_API shared_ptr< collector > make_collector(
  118. filesystem::path const& target_dir,
  119. uintmax_t max_size,
  120. uintmax_t min_free_space,
  121. uintmax_t max_files = (std::numeric_limits< uintmax_t >::max)()
  122. );
  123. template< typename ArgsT >
  124. inline shared_ptr< collector > make_collector(ArgsT const& args)
  125. {
  126. return aux::make_collector(
  127. filesystem::path(args[keywords::target]),
  128. args[keywords::max_size | (std::numeric_limits< uintmax_t >::max)()],
  129. args[keywords::min_free_space | static_cast< uintmax_t >(0)],
  130. args[keywords::max_files | (std::numeric_limits< uintmax_t >::max)()]);
  131. }
  132. } // namespace aux
  133. #ifndef BOOST_LOG_DOXYGEN_PASS
  134. template< typename T1 >
  135. inline shared_ptr< collector > make_collector(T1 const& a1)
  136. {
  137. return aux::make_collector(a1);
  138. }
  139. template< typename T1, typename T2 >
  140. inline shared_ptr< collector > make_collector(T1 const& a1, T2 const& a2)
  141. {
  142. return aux::make_collector((a1, a2));
  143. }
  144. template< typename T1, typename T2, typename T3 >
  145. inline shared_ptr< collector > make_collector(T1 const& a1, T2 const& a2, T3 const& a3)
  146. {
  147. return aux::make_collector((a1, a2, a3));
  148. }
  149. template< typename T1, typename T2, typename T3, typename T4 >
  150. inline shared_ptr< collector > make_collector(T1 const& a1, T2 const& a2, T3 const& a3, T4 const& a4)
  151. {
  152. return aux::make_collector((a1, a2, a3, a4));
  153. }
  154. #else
  155. /*!
  156. * The function creates a file collector for the specified target directory.
  157. * Each target directory is managed by a single file collector, so if
  158. * this function is called several times for the same directory,
  159. * it will return a reference to the same file collector. It is safe
  160. * to use the same collector in different sinks, even in a multithreaded
  161. * application.
  162. *
  163. * One can specify certain restrictions for the stored files, such as
  164. * maximum total size or minimum free space left in the target directory.
  165. * If any of the specified restrictions is not met, the oldest stored file
  166. * is deleted. If the same collector is requested more than once with
  167. * different restrictions, the collector will act according to the most strict
  168. * combination of all specified restrictions.
  169. *
  170. * The following named parameters are supported:
  171. *
  172. * \li \c target - Specifies the target directory for the files being stored in. This parameter
  173. * is mandatory.
  174. * \li \c max_size - Specifies the maximum total size, in bytes, of stored files that the collector
  175. * will try not to exceed. If the size exceeds this threshold the oldest file(s) is
  176. * deleted to free space. Note that the threshold may be exceeded if the size of
  177. * individual files exceed the \c max_size value. The threshold is not maintained,
  178. * if not specified.
  179. * \li \c min_free_space - Specifies the minimum free space, in bytes, in the target directory that
  180. * the collector tries to maintain. If the threshold is exceeded, the oldest
  181. * file(s) is deleted to free space. The threshold is not maintained, if not
  182. * specified.
  183. * \li \c max_files - Specifies the maximum number of log files stored. If the number of files exceeds
  184. * this threshold, the oldest file(s) is deleted to free space. The threshhold is
  185. * not maintained if not specified.
  186. *
  187. * \return The file collector.
  188. */
  189. template< typename... ArgsT >
  190. shared_ptr< collector > make_collector(ArgsT... const& args);
  191. #endif // BOOST_LOG_DOXYGEN_PASS
  192. /*!
  193. * The class represents the time point of log file rotation. One can specify one of three
  194. * types of time point based rotation:
  195. *
  196. * \li rotation takes place every day, at the specified time
  197. * \li rotation takes place on the specified day of every week, at the specified time
  198. * \li rotation takes place on the specified day of every month, at the specified time
  199. *
  200. * The time points are considered to be local time.
  201. */
  202. class rotation_at_time_point
  203. {
  204. public:
  205. typedef bool result_type;
  206. private:
  207. enum day_kind
  208. {
  209. not_specified,
  210. weekday,
  211. monthday
  212. };
  213. day_kind m_DayKind : 2;
  214. unsigned char m_Day : 6;
  215. unsigned char m_Hour, m_Minute, m_Second;
  216. mutable posix_time::ptime m_Previous;
  217. public:
  218. /*!
  219. * Creates a rotation time point of every day at the specified time
  220. *
  221. * \param hour The rotation hour, should be within 0 and 23
  222. * \param minute The rotation minute, should be within 0 and 59
  223. * \param second The rotation second, should be within 0 and 59
  224. */
  225. BOOST_LOG_API explicit rotation_at_time_point(unsigned char hour, unsigned char minute, unsigned char second);
  226. /*!
  227. * Creates a rotation time point of each specified weekday at the specified time
  228. *
  229. * \param wday The weekday of the rotation
  230. * \param hour The rotation hour, should be within 0 and 23
  231. * \param minute The rotation minute, should be within 0 and 59
  232. * \param second The rotation second, should be within 0 and 59
  233. */
  234. BOOST_LOG_API explicit rotation_at_time_point(
  235. date_time::weekdays wday,
  236. unsigned char hour = 0,
  237. unsigned char minute = 0,
  238. unsigned char second = 0);
  239. /*!
  240. * Creates a rotation time point of each specified day of month at the specified time
  241. *
  242. * \param mday The monthday of the rotation, should be within 1 and 31
  243. * \param hour The rotation hour, should be within 0 and 23
  244. * \param minute The rotation minute, should be within 0 and 59
  245. * \param second The rotation second, should be within 0 and 59
  246. */
  247. BOOST_LOG_API explicit rotation_at_time_point(
  248. gregorian::greg_day mday,
  249. unsigned char hour = 0,
  250. unsigned char minute = 0,
  251. unsigned char second = 0);
  252. /*!
  253. * Checks if it's time to rotate the file
  254. */
  255. BOOST_LOG_API bool operator() () const;
  256. };
  257. /*!
  258. * The class represents the time interval of log file rotation. The log file will be rotated
  259. * after the specified time interval has passed.
  260. */
  261. class rotation_at_time_interval
  262. {
  263. public:
  264. typedef bool result_type;
  265. private:
  266. posix_time::time_duration m_Interval;
  267. mutable posix_time::ptime m_Previous;
  268. public:
  269. /*!
  270. * Creates a rotation time interval of the specified duration
  271. *
  272. * \param interval The interval of the rotation, should be no less than 1 second
  273. */
  274. explicit rotation_at_time_interval(posix_time::time_duration const& interval) :
  275. m_Interval(interval)
  276. {
  277. BOOST_ASSERT(!interval.is_special());
  278. BOOST_ASSERT(interval.total_seconds() > 0);
  279. }
  280. /*!
  281. * Checks if it's time to rotate the file
  282. */
  283. BOOST_LOG_API bool operator() () const;
  284. };
  285. } // namespace file
  286. /*!
  287. * \brief An implementation of a text file logging sink backend
  288. *
  289. * The sink backend puts formatted log records to a text file.
  290. * The sink supports file rotation and advanced file control, such as
  291. * size and file count restriction.
  292. */
  293. class text_file_backend :
  294. public basic_formatted_sink_backend<
  295. char,
  296. combine_requirements< synchronized_feeding, flushing >::type
  297. >
  298. {
  299. //! Base type
  300. typedef basic_formatted_sink_backend<
  301. char,
  302. combine_requirements< synchronized_feeding, flushing >::type
  303. > base_type;
  304. public:
  305. //! Character type
  306. typedef base_type::char_type char_type;
  307. //! String type to be used as a message text holder
  308. typedef base_type::string_type string_type;
  309. //! Stream type
  310. typedef std::basic_ostream< char_type > stream_type;
  311. //! File open handler
  312. typedef boost::log::aux::light_function< void (stream_type&) > open_handler_type;
  313. //! File close handler
  314. typedef boost::log::aux::light_function< void (stream_type&) > close_handler_type;
  315. //! Predicate that defines the time-based condition for file rotation
  316. typedef boost::log::aux::light_function< bool () > time_based_rotation_predicate;
  317. private:
  318. //! \cond
  319. struct implementation;
  320. implementation* m_pImpl;
  321. //! \endcond
  322. public:
  323. /*!
  324. * Default constructor. The constructed sink backend uses default values of all the parameters.
  325. */
  326. BOOST_LOG_API text_file_backend();
  327. /*!
  328. * Constructor. Creates a sink backend with the specified named parameters.
  329. * The following named parameters are supported:
  330. *
  331. * \li \c file_name - Specifies the active file name pattern where logs are actually written to. The pattern may
  332. * contain directory and file name portions, but only the file name may contain
  333. * placeholders. The backend supports Boost.DateTime placeholders for injecting
  334. * current time and date into the file name. Also, an additional %N placeholder is
  335. * supported, it will be replaced with an integral increasing file counter. The placeholder
  336. * may also contain width specification in the printf-compatible form (e.g. %5N). The
  337. * printed file counter will always be zero-filled. If \c file_name is not specified,
  338. * pattern "%5N.log" will be used.
  339. * \li \c target_file_name - Specifies the target file name pattern to use to rename the log file on rotation,
  340. * before passing it to the file collector. The pattern may contain the same
  341. * placeholders as the \c file_name parameter. By default, no renaming is done,
  342. * i.e. the written log file keeps its name according to \c file_name.
  343. * \li \c open_mode - File open mode. The mode should be presented in form of mask compatible to
  344. * <tt>std::ios_base::openmode</tt>. If not specified, <tt>trunc | out</tt> will be used.
  345. * \li \c rotation_size - Specifies the approximate size, in characters written, of the temporary file
  346. * upon which the file is passed to the file collector. Note the size does
  347. * not count any possible character conversions that may take place during
  348. * writing to the file. If not specified, the file won't be rotated upon reaching
  349. * any size.
  350. * \li \c time_based_rotation - Specifies the predicate for time-based file rotation.
  351. * No time-based file rotations will be performed, if not specified.
  352. * \li \c enable_final_rotation - Specifies a flag, whether or not perform log file rotation on
  353. * sink backend destruction. By default, is \c true.
  354. * \li \c auto_flush - Specifies a flag, whether or not to automatically flush the file after each
  355. * written log record. By default, is \c false.
  356. *
  357. * \note Read the caution note regarding file name pattern in the <tt>sinks::file::collector::scan_for_files</tt>
  358. * documentation.
  359. */
  360. #ifndef BOOST_LOG_DOXYGEN_PASS
  361. BOOST_LOG_PARAMETRIZED_CONSTRUCTORS_CALL(text_file_backend, construct)
  362. #else
  363. template< typename... ArgsT >
  364. explicit text_file_backend(ArgsT... const& args);
  365. #endif
  366. /*!
  367. * Destructor
  368. */
  369. BOOST_LOG_API ~text_file_backend();
  370. /*!
  371. * The method sets the active file name wildcard for the files being written. The wildcard supports
  372. * date and time injection into the file name.
  373. *
  374. * \param pattern The name pattern for the file being written.
  375. */
  376. template< typename PathT >
  377. void set_file_name_pattern(PathT const& pattern)
  378. {
  379. set_file_name_pattern_internal(filesystem::path(pattern));
  380. }
  381. /*!
  382. * The method sets the target file name wildcard for the files being rotated. The wildcard supports
  383. * date and time injection into the file name.
  384. *
  385. * This pattern will be used when the log file is being rotated, to rename the just written
  386. * log file (which has the name according to the pattern in the \c file_name constructor parameter or
  387. * set by a call to \c set_file_name_pattern), just before passing the file to the file collector.
  388. *
  389. * \param pattern The name pattern for the file being rotated.
  390. */
  391. template< typename PathT >
  392. void set_target_file_name_pattern(PathT const& pattern)
  393. {
  394. set_target_file_name_pattern_internal(filesystem::path(pattern));
  395. }
  396. /*!
  397. * The method sets the file open mode
  398. *
  399. * \param mode File open mode
  400. */
  401. BOOST_LOG_API void set_open_mode(std::ios_base::openmode mode);
  402. /*!
  403. * The method sets the log file collector function. The function is called
  404. * on file rotation and is being passed the written file name.
  405. *
  406. * \param collector The file collector function object
  407. */
  408. BOOST_LOG_API void set_file_collector(shared_ptr< file::collector > const& collector);
  409. /*!
  410. * The method sets file opening handler. The handler will be called every time
  411. * the backend opens a new temporary file. The handler may write a header to the
  412. * opened file in order to maintain file validity.
  413. *
  414. * \param handler The file open handler function object
  415. */
  416. BOOST_LOG_API void set_open_handler(open_handler_type const& handler);
  417. /*!
  418. * The method sets file closing handler. The handler will be called every time
  419. * the backend closes a temporary file. The handler may write a footer to the
  420. * opened file in order to maintain file validity.
  421. *
  422. * \param handler The file close handler function object
  423. */
  424. BOOST_LOG_API void set_close_handler(close_handler_type const& handler);
  425. /*!
  426. * The method sets maximum file size. When the size is reached, file rotation is performed.
  427. *
  428. * \note The size does not count any possible character translations that may happen in
  429. * the underlying API. This may result in greater actual sizes of the written files.
  430. *
  431. * \param size The maximum file size, in characters.
  432. */
  433. BOOST_LOG_API void set_rotation_size(uintmax_t size);
  434. /*!
  435. * The method sets the predicate that defines the time-based condition for file rotation.
  436. *
  437. * \note The rotation always occurs on writing a log record, so the rotation is
  438. * not strictly bound to the specified condition.
  439. *
  440. * \param predicate The predicate that defines the time-based condition for file rotation.
  441. * If empty, no time-based rotation will take place.
  442. */
  443. BOOST_LOG_API void set_time_based_rotation(time_based_rotation_predicate const& predicate);
  444. /*!
  445. * The method allows to enable or disable log file rotation on sink destruction.
  446. *
  447. * By default the sink backend will rotate the log file, if it's been written to, on
  448. * destruction.
  449. *
  450. * \param enable The flag indicates whether the final rotation should be performed.
  451. */
  452. BOOST_LOG_API void enable_final_rotation(bool enable);
  453. /*!
  454. * Sets the flag to automatically flush write buffers of the file being written after each log record.
  455. *
  456. * \param enable The flag indicates whether the automatic buffer flush should be performed.
  457. */
  458. BOOST_LOG_API void auto_flush(bool enable = true);
  459. /*!
  460. * \return The name of the currently open log file. If no file is open, returns an empty path.
  461. */
  462. BOOST_LOG_API filesystem::path get_current_file_name() const;
  463. /*!
  464. * Performs scanning of the target directory for log files that may have been left from
  465. * previous runs of the application. The found files are considered by the file collector
  466. * as if they were rotated.
  467. *
  468. * The file scan can be performed in two ways: either all files in the target directory will
  469. * be considered as log files, or only those files that satisfy the target file name pattern.
  470. * See documentation on <tt>sinks::file::collector::scan_for_files</tt> for more information.
  471. *
  472. * \pre File collector and the proper file name pattern have already been set.
  473. *
  474. * \param method File scanning method
  475. * \param update_counter If \c true and \a method is \c scan_matching, the method attempts
  476. * to update the internal file counter according to the found files. The counter
  477. * is unaffected otherwise.
  478. * \return The number of files found.
  479. *
  480. * \note The method essentially delegates to the same-named function of the file collector.
  481. */
  482. BOOST_LOG_API uintmax_t scan_for_files(
  483. file::scan_method method = file::scan_matching, bool update_counter = true);
  484. /*!
  485. * The method writes the message to the sink
  486. */
  487. BOOST_LOG_API void consume(record_view const& rec, string_type const& formatted_message);
  488. /*!
  489. * The method flushes the currently open log file
  490. */
  491. BOOST_LOG_API void flush();
  492. /*!
  493. * The method rotates the file
  494. */
  495. BOOST_LOG_API void rotate_file();
  496. private:
  497. #ifndef BOOST_LOG_DOXYGEN_PASS
  498. //! Constructor implementation
  499. template< typename ArgsT >
  500. void construct(ArgsT const& args)
  501. {
  502. construct(
  503. filesystem::path(args[keywords::file_name | filesystem::path()]),
  504. filesystem::path(args[keywords::target_file_name | filesystem::path()]),
  505. args[keywords::open_mode | (std::ios_base::trunc | std::ios_base::out)],
  506. args[keywords::rotation_size | (std::numeric_limits< uintmax_t >::max)()],
  507. args[keywords::time_based_rotation | time_based_rotation_predicate()],
  508. args[keywords::auto_flush | false],
  509. args[keywords::enable_final_rotation | true]);
  510. }
  511. //! Constructor implementation
  512. BOOST_LOG_API void construct(
  513. filesystem::path const& pattern,
  514. filesystem::path const& target_file_name,
  515. std::ios_base::openmode mode,
  516. uintmax_t rotation_size,
  517. time_based_rotation_predicate const& time_based_rotation,
  518. bool auto_flush,
  519. bool enable_final_rotation);
  520. //! The method sets file name pattern
  521. BOOST_LOG_API void set_file_name_pattern_internal(filesystem::path const& pattern);
  522. //! The method sets target file name pattern
  523. BOOST_LOG_API void set_target_file_name_pattern_internal(filesystem::path const& pattern);
  524. //! Closes the currently open file
  525. void close_file();
  526. #endif // BOOST_LOG_DOXYGEN_PASS
  527. };
  528. } // namespace sinks
  529. BOOST_LOG_CLOSE_NAMESPACE // namespace log
  530. } // namespace boost
  531. #include <boost/log/detail/footer.hpp>
  532. #endif // BOOST_LOG_SINKS_TEXT_FILE_BACKEND_HPP_INCLUDED_