ucommon
Public Member Functions | Protected Member Functions | Protected Attributes | Related Functions
ost::RandomFile Class Reference

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. More...

#include <file.h>

Inheritance diagram for ost::RandomFile:
Inheritance graph
[legend]

Public Member Functions

off_t getCapacity (void)
 Get current file capacity.
Error getErrorNumber (void)
 Return current error id.
char * getErrorString (void)
 Return current error string.
bool initial (void)
 This method should be called right after a RandomFile derived object has been created.
bool operator! (void)
virtual Error restart (void)
 This method is commonly used to close and re-open an existing database.
virtual ~RandomFile ()
 Destroy a random access file or it's derived class.

Protected Member Functions

Error error (Error errid, char *errstr=((void *) 0))
 Post an error event.
Error error (char *err)
 Post an extended string error message.
void final (void)
 Close the file.
virtual Attr initialize (void)
 This method is used to initialize a newly created file as indicated by the "initial" flag.
 RandomFile (const char *name=((void *) 0))
 Create an unopened random access file.
 RandomFile (const RandomFile &rf)
 Default copy constructor.
Error setCompletion (Complete mode)
 Used to set file completion modes.
void setError (bool enable)
 Used to enable or disable throwing of exceptions on errors.
void setTemporary (bool enable)
 Used to set the temporary attribute for the file.

Protected Attributes

Access access
int fd
struct {
   unsigned   count: 16
   bool   immediate: 1
   bool   initial: 1
   bool   temp: 1
   bool   thrown: 1
flags
char * pathname

Related Functions

(Note that these are not member functions.)

bool canAccess (const char *path)
bool canModify (const char *path)
bool isDevice (const char *path)
bool isDir (const char *path)
bool isFile (const char *path)
time_t lastAccessed (const char *path)
time_t lastModified (const char *path)

Detailed Description

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.

Author:
David Sugar <dyfet@ostel.com> Portable random disk file access.

Definition at line 376 of file file.h.


Member Function Documentation

Error ost::RandomFile::error ( Error  errid,
char *  errstr = ((void *) 0) 
) [protected]

Post an error event.

Returns:
error code.
Parameters:
erriderror code.
errstrerror message string.
Error ost::RandomFile::error ( char *  err) [inline, protected]

Post an extended string error message.

Returns:
errExtended.
Parameters:
errerror string.

Definition at line 427 of file file.h.

Here is the call graph for this function:

off_t ost::RandomFile::getCapacity ( void  )

Get current file capacity.

Returns:
total file size.
Error ost::RandomFile::getErrorNumber ( void  ) [inline]

Return current error id.

Returns:
last error identifier set.

Definition at line 512 of file file.h.

char* ost::RandomFile::getErrorString ( void  ) [inline]

Return current error string.

Returns:
last error string set.

Definition at line 520 of file file.h.

bool ost::RandomFile::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.
virtual Attr ost::RandomFile::initialize ( void  ) [protected, virtual]

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 attrInvalid if should be removed.
virtual Error ost::RandomFile::restart ( void  ) [virtual]

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.

Reimplemented in ost::SharedFile.

Error ost::RandomFile::setCompletion ( Complete  mode) [protected]

Used to set file completion modes.

Returns:
errSuccess if okay.
Parameters:
modecompletion mode.
Todo:
implement in win32
void ost::RandomFile::setError ( bool  enable) [inline, protected]

Used to enable or disable throwing of exceptions on errors.

Parameters:
enabletrue if errors will be thrown.

Definition at line 436 of file file.h.

void ost::RandomFile::setTemporary ( bool  enable) [inline, protected]

Used to set the temporary attribute for the file.

Temporary files are automatically deleted when closed.

Parameters:
enabletrue for marking as temporary.

Definition at line 456 of file file.h.


Friends And Related Function Documentation

bool canAccess ( const char *  path) [related]
bool canModify ( const char *  path) [related]
bool isDevice ( const char *  path) [related]
bool isDir ( const char *  path) [related]
bool isFile ( const char *  path) [related]
time_t lastAccessed ( const char *  path) [related]
time_t lastModified ( const char *  path) [related]

The documentation for this class was generated from the following file: