src/gromacs/utility/messagestringcollector.h

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  35 /*! \libinternal \file
  36  * \brief
  37  * Declares ::gmx::MessageStringCollector.
  38  *
  39  * \author Teemu Murtola <teemu.murtola@gmail.com>
  40  * \inlibraryapi
  41  * \ingroup module_utility
  42  */
  43 #ifndef GMX_UTILITY_MESSAGESTRINGCOLLECTOR_H
  44 #define GMX_UTILITY_MESSAGESTRINGCOLLECTOR_H
  45
  46 #include <string>
  47
  48 #include "gromacs/utility/classhelpers.h"
  49
  50 namespace gmx
  51 {
  52
  53 /*! \libinternal \brief
  54  * Helper class for collecting message strings, optionally with context.
  55  *
  56  * After strings have been collected, they can be formatted into one long
  57  * string for, e.g., printing out or for including in an exception.
  58  *
  59  * \inlibraryapi
  60  * \ingroup module_utility
  61  */
  62 class MessageStringCollector
  63 {
  64     public:
  65         MessageStringCollector();
  66         ~MessageStringCollector();
  67
  68         /*! \brief
  69          * Starts a context for messages.
  70          *
  71          * \param[in] name  Short description of the context.
  72          *
  73          * \see finishContext()
  74          * \see MessageStringContext
  75          */
  76         void startContext(const char *name);
  77         /*! \brief
  78          * Convenience wrapper for startContext(const char *).
  79          */
  80         void startContext(const std::string &name)
  81         { startContext(name.c_str()); }
  82         /*! \brief
  83          * Adds a new message.
  84          */
  85         void append(const char *message)
  86         { append(std::string(message)); }
  87         /*! \brief
  88          * Adds a new message.
  89          */
  90         void append(const std::string &message);
  91         /*! \brief
  92          * Ends a context started with startContext().
  93          *
  94          * \see MessageStringContext
  95          */
  96         void finishContext();
  97         /*! \brief
  98          * Clears all collected messages.
  99          */
 100         void clear();
 101
 102         /*! \brief
 103          * Returns true if any messages have been added.
 104          *
 105          * \returns true if append() has been called at least once.
 106          *
 107          * The return value is identical to `toString().empty()`.
 108          * Calls to startContext() or finishContext() only do not cause this
 109          * function to return true.
 110          */
 111         bool isEmpty() const;
 112         /*! \brief
 113          * Returns all collected messages as one string.
 114          */
 115         std::string toString() const;
 116
 117     private:
 118         class Impl;
 119
 120         PrivateImplPointer<Impl> impl_;
 121 };
 122
 123 /*! \libinternal \brief
 124  * Convenience class for creating a message context.
 125  *
 126  * This class provides a RAII-style interface to the
 127  * MessageStringCollector::startContext() and
 128  * MessageStringCollector::finishContext() methods: finishContext() is called
 129  * upon destruction of the object.  This avoids the need to call
 130  * MessageStringCollector::finishContext() on every possible exit point.
 131  *
 132  * Example usage:
 133  * \code
 134    bool function(::gmx::MessageStringCollector *errors)
 135    {
 136        ::gmx::MessageStringContext errcontext(errors, "In function()");
 137        bool bOk = function2(errors);
 138        bOk = function3(errors) && bOk;
 139        // <more processing>
 140        return bOk;
 141    }
 142    \endcode
 143  *
 144  * \see MessageStringCollector
 145  * \inlibraryapi
 146  * \ingroup module_utility
 147  */
 148 class MessageStringContext
 149 {
 150     public:
 151         /*! \brief
 152          * Adds a context for the given object.
 153          */
 154         MessageStringContext(MessageStringCollector *collector, const char *name)
 155             : collector_(*collector)
 156         {
 157             collector_.startContext(name);
 158         }
 159         /*! \brief
 160          * Adds a context for the given object.
 161          */
 162         MessageStringContext(MessageStringCollector *collector,
 163                              const std::string      &name)
 164             : collector_(*collector)
 165         {
 166             collector_.startContext(name);
 167         }
 168         /*! \brief
 169          * Calls MessageStringCollector::finishContext() on the wrapped object.
 170          */
 171         ~MessageStringContext()
 172         {
 173             collector_.finishContext();
 174         }
 175
 176     private:
 177         //! The wrapped object.
 178         MessageStringCollector &collector_;
 179
 180         GMX_DISALLOW_COPY_AND_ASSIGN(MessageStringContext);
 181 };
 182
 183 } // namespace gmx
 184
 185 #endif