src/gromacs/utility/loggerbuilder.h

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  35 /*! \libinternal \file
  36  * \brief
  37  * Declares functionality for initializing logging.
  38  *
  39  * See \ref page_logging for an overview of the functionality.
  40  *
  41  * \inlibraryapi
  42  * \ingroup module_utility
  43  */
  44 #ifndef GMX_UTILITY_LOGGERBUILDER_H
  45 #define GMX_UTILITY_LOGGERBUILDER_H
  46
  47 #include <memory>
  48 #include <string>
  49
  50 #include "gromacs/utility/classhelpers.h"
  51 #include "gromacs/utility/logger.h"
  52
  53 namespace gmx
  54 {
  55
  56 class TextOutputStream;
  57
  58 class LoggerFormatterBuilder;
  59 class LoggerOwner;
  60
  61 /*! \libinternal \brief
  62  * Initializes loggers.
  63  *
  64  * This class provides methods for specifying logging targets for a logger and
  65  * building the logger after all targets have been specified.  Having this
  66  * separate from the logger allows using different internal data structures
  67  * during initialization and operation, and simplifies the responsibilities of
  68  * the involved classes.
  69  *
  70  * \ingroup module_utility
  71  */
  72 class LoggerBuilder
  73 {
  74 public:
  75     LoggerBuilder();
  76     ~LoggerBuilder();
  77
  78     /*! \brief
  79      * Adds a stream to which log output is written.
  80      *
  81      * All output at level \p level or above it is written to \p stream.
  82      * The caller is responsible of closing and freeing \p stream once the
  83      * logger is discarded.
  84      */
  85     void addTargetStream(MDLogger::LogLevel level, TextOutputStream* stream);
  86     /*! \brief
  87      * Adds a file to which log output is written.
  88      *
  89      * All output at level \p level or above it is written to \p fp.
  90      * The caller is responsible of closing \p fp once the logger is
  91      * discarded.
  92      */
  93     void addTargetFile(MDLogger::LogLevel level, FILE* fp);
  94
  95     /*! \brief
  96      * Builds the logger with the targets set for this builder.
  97      *
  98      * After this function has been called, the builder can (and should) be
  99      * discarded.
 100      */
 101     LoggerOwner build();
 102
 103 private:
 104     class Impl;
 105
 106     PrivateImplPointer<Impl> impl_;
 107 };
 108
 109 /*! \libinternal \brief
 110  * Manages memory for a logger built with LoggerBuilder.
 111  *
 112  * This class is responsible of managing all memory allocated by LoggerBuilder
 113  * that is needed for operation of the actual logger.  Also the actual logger
 114  * instance is owned by this class.  This allows keeping the actual logger simple
 115  * and streamlined.
 116  *
 117  * This class supports move construction and assignment, which allows
 118  * initializing it on the stack and assigning a new instance if the targets
 119  * need to be changed.
 120  *
 121  * \ingroup module_utility
 122  */
 123 class LoggerOwner
 124 {
 125 public:
 126     //! Move-constructs the owner.
 127     LoggerOwner(LoggerOwner&& other) noexcept;
 128     ~LoggerOwner();
 129
 130     //! Move-assings the owner.
 131     LoggerOwner& operator=(LoggerOwner&& other) noexcept;
 132
 133     //! Returns the logger for writing the logs.
 134     const MDLogger& logger() const { return *logger_; }
 135
 136 private:
 137     class Impl;
 138
 139     LoggerOwner(std::unique_ptr<Impl> impl);
 140
 141     PrivateImplPointer<Impl> impl_;
 142     const MDLogger*          logger_;
 143
 144     friend class LoggerBuilder;
 145 };
 146
 147 } // namespace gmx
 148
 149 #endif