X-Git-Url: http://g0dil.de/git?a=blobdiff_plain;f=Utils%2FException.hh;h=a99171002e92780f2da8ba37682174da9ad6f517;hb=498e46942326c504b30ebdbb5e4d9be1b48d2b5f;hp=67435ba5f403b2f9c538db65dcc9390f7eb0eba4;hpb=85ab07d100a382467a42e19d741d403a7a96c951;p=senf.git

diff --git a/Utils/Exception.hh b/Utils/Exception.hh
index 67435ba..a991710 100644
--- a/Utils/Exception.hh
+++ b/Utils/Exception.hh
@@ -29,6 +29,8 @@
 // Custom includes
 #include <exception>
 #include <string>
+#include <boost/preprocessor/repeat.hpp>
+#include <boost/preprocessor/cat.hpp>
 
 //#include "Exception.mpp"
 ///////////////////////////////hh.p////////////////////////////////////////
@@ -37,46 +39,108 @@ namespace senf {
 
     /** \brief Exception handling standard UNIX errors (errno)
 
-        This exception is thrown to signal generic errno failuers.
+        This exception is thrown to signal generic \c errno failures. In addition to the \c errno
+        number (the code()), this class manages optional origin information. This parameter should
+        be provided to further describe, in what context the exception was created.
 
-        \todo make where and err accessors and make the member vars private
+        This exception should not be used directly. Instead the derived class ErrnoException should
+        be thrown via one of the senf::throwErrno() helpers.
 
-        \idea Add a template class derived from SystemException which
-        takes the error number as a numeric argument. This allows
-        catching specific errno conditions: ErrnoException<EPIPE> etc.
-
-        \idea Add a generic error thrower which takes the origin
-        string and errno value as an argument and will throw a
-        corresponding template class instance. This would just be a
-        big switch statement containing all possible errno values,
-        probably created using some makro metaprogramming.
+        \see ErrnoException
      */
     class SystemException : public std::exception
     {
     public:
-        explicit SystemException(int err); ///< SystemException without error lokus info
-                                        /**< \param[in] err errror number (the errno value) */
-        SystemException(char const * where, int err); ///< SystemException with error lokus info
+        SystemException();              ///< SystemException without error location infor
+                                        /**< The error code is taken from the current value of the
+                                             global \c errno variable  */
+
+        explicit SystemException(int code); ///< SystemException without error location info
+                                        /**< \param[in] code error number (the \c errno value) */
+
+        explicit SystemException(char const * where); ///< SystemException with error location info
+                                        /**< The error code is taken from the current value of the
+                                             global \c errno variable 
+                                             \param[in] where description of error origin */
+
+        SystemException(char const * where, int code); ///< SystemException with error location info 
                                         /**< \param[in] where description of error origin
-                                             \param[in] err error number (the errno value) */
+                                             \param[in] code error number (the \c errno value) */
 
         virtual char const * what() const throw(); ///< Return verbose error description
 
-        char const * where; ///< Error origin
-        int err; ///< Error number
+        char const * where() const;     ///< Error origin
+        int code() const;               ///< Error code (\c errno number)
+        char const * description() const; ///< Error description (strerror() value)
+
+        bool anyOf(int c0, int c1=0, int c2=0, int c3=0, int c4=0, int c5=0, 
+                   int c6=0, int c7=0, int c8=0, int c9=0);
+                                        ///< \c true, if code() is one of \a c0 ... \a c9
 
         virtual ~SystemException() throw();
+
     private:
         void init();
+
+        char const * const where_;
+        int const code_;                // This must be const to make the derived ErrnoException
+                                        // class a valid derived class.
         std::string buffer_;
     };
 
+    /** \brief Error specific system exception
+
+        This template restricts the generic SystemException to a specific, compile-time constant
+        error number \p Code. This allows a specific \c errno number to be cached explicitly.
+
+        This exception is normally thrown via one of the senf::throwErrno() helpers. These helpers
+        take the numeric \c errno value (either from the \c errno variable or from their
+        argument) and will throw the corresponding ErrnoException:
+        \code
+        if ((fd = ::open(filename, O_RDWR)) < 0)
+             senf::throwErrno("open()");
+        \endcode
+     */
+    template <int Code>
+    class ErrnoException : public SystemException
+    {
+    public:
+        static int const fixed_code = Code;
+
+        ErrnoException();               ///< ErrnoException without error location information
+        explicit ErrnoException(char const * where);
+                                        ///< ErrnoException with error location information
+    };
+
+    
+    /** \brief Throw ErrnoException based on current \c errno value
+        \related ErrnoException
+     */
+    void throwErrno();
+
+    /** \brief Throw ErrnoException based on current \c errno value (with location info)
+        \related ErrnoException
+     */
+    void throwErrno(char const * where);
+
+    /** \brief Throw ErrnoException based on given \c errno value
+        \related ErrnoException
+     */
+    void throwErrno(int code);
+
+    /** \brief Throw ErrnoException based on given \c errno value (with location info)
+        \related ErrnoException
+     */
+    void throwErrno(char const * where, int code);
+
+    enum NoThrow_t { nothrow };
+
 }
 
 ///////////////////////////////hh.e////////////////////////////////////////
 #include "Exception.cci"
 //#include "Exception.ct"
-//#include "Exception.cti"
+#include "Exception.cti"
 #endif
 
 
@@ -86,4 +150,6 @@ namespace senf {
 // c-file-style: "senf"
 // indent-tabs-mode: nil
 // ispell-local-dictionary: "american"
+// compile-command: "scons -u test"
+// comment-column: 40
 // End: