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The purpose of this class is to define a base class for low level random file access that is portable between Win32 and Posix systems. This class is a foundation both for optimized thread shared and traditional locked file access that is commonly used to build database services, rather than the standard C++ streaming file classes.
RandomFile () |
Create an unopened random access file.
RandomFile (const RandomFile &rf) |
Default copy constructor.
fileerror_t Error (fileerror_t errid, char *errstr = NULL) |
Post an error event.
Parameters:
error | code. |
error | message string. |
Returns: error code.
inline fileerror_t Error (char *errstr) |
Post an extended string error message.
Parameters:
error | string. |
Returns: FILE_EXTENDED_ERROR.
inline void setError (bool enable) |
Used to enable or disable throwing of exceptions on errors.
Parameters:
true | if errors will be thrown. |
fileerror_t setCompletion (filecomplete_t mode) |
Used to set file completion modes.
Parameters:
completion | mode. |
Returns: FILE_SUCCESS if okay.
inline void setTemporary (bool enable) |
Used to set the temporary attribute for the file. Temporary files are automatically deleted when closed.
Parameters:
true | for marking as temporary. |
fileattr_t Initialize (void) |
This method is used to initialize a newly created file as indicated by the "initial" flag. This method also returns the file access permissions that should be associated with the file. This method should never be called directly, but is instead used to impliment the "Initial" method. Typically one would use this to build an empty database shell when a previously empty database file is created.
Returns: access, or FILE_ATTR_INVALID if should be removed.
void Final (void) |
Close the file.
~RandomFile () |
Destroy a random access file or it's derived class.
bool Initial (void) |
This method should be called right after a RandomFile derived object has been created. This method will invoke initialize if the object is newly created, and set file access permissions appropriately.
Returns: true if file had to be initialized.
off_t getCapacity (void) |
Get current file capacity.
Returns: total file size.
fileerror_t Restart (void) |
This method is commonly used to close and re-open an existing database. This may be used when the database has been unlinked and an external process provides a new one to use.
inline fileerror_t getErrorNumber (void) |
Return current error id.
Returns: last error identifier set.
inline char * getErrorString (void) |
Return current error string.
Returns: last error string set.