UCommon
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:

Public Member Functions

off_t getCapacity (void)
 Get current file capacity.
 
Error getErrorNumber (void) const
 Return current error id.
 
char * getErrorString (void) const
 Return current error string.
 
bool initial (void)
 This method should be called right after a RandomFile derived object has been created.
 
 operator bool () const
 
bool operator! (void) const
 
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 (char *err)
 Post an extended string error message.
 
Error error (Error errid, char *errstr=NULL)
 Post an error event.
 
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=NULL)
 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 Symbols

(Note that these are not member symbols.)

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.nosp@m.@ost.nosp@m.el.co.nosp@m.m

Portable random disk file access.

Definition at line 392 of file file.h.

Member Function Documentation

◆ error() [1/2]

Error ost::RandomFile::error ( char * err)
inlineprotected

Post an extended string error message.

Returns
errExtended.
Parameters
errerror string.

Definition at line 443 of file file.h.

Here is the call graph for this function:

◆ error() [2/2]

Error ost::RandomFile::error ( Error errid,
char * errstr = NULL )
protected

Post an error event.

Returns
error code.
Parameters
erriderror code.
errstrerror message string.

◆ getCapacity()

off_t ost::RandomFile::getCapacity ( void )

Get current file capacity.

Returns
total file size.

◆ getErrorNumber()

Error ost::RandomFile::getErrorNumber ( void ) const
inline

Return current error id.

Returns
last error identifier set.

Definition at line 531 of file file.h.

◆ getErrorString()

char * ost::RandomFile::getErrorString ( void ) const
inline

Return current error string.

Returns
last error string set.

Definition at line 540 of file file.h.

◆ initial()

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.

◆ initialize()

virtual Attr ost::RandomFile::initialize ( void )
protectedvirtual

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.

◆ restart()

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.

◆ setCompletion()

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

Used to set file completion modes.

Returns
errSuccess if okay.
Parameters
modecompletion mode.
Todo
implement in win32

◆ setError()

void ost::RandomFile::setError ( bool enable)
inlineprotected

Used to enable or disable throwing of exceptions on errors.

Parameters
enabletrue if errors will be thrown.

Definition at line 453 of file file.h.

◆ setTemporary()

void ost::RandomFile::setTemporary ( bool enable)
inlineprotected

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 474 of file file.h.

Field Documentation

◆ access

Access ost::RandomFile::access
protected

Definition at line 402 of file file.h.

◆ count

unsigned ost::RandomFile::count

Definition at line 409 of file file.h.

◆ fd

int ost::RandomFile::fd
protected

Definition at line 400 of file file.h.

◆ immediate

bool ost::RandomFile::immediate

Definition at line 413 of file file.h.

◆ initial

bool ost::RandomFile::initial ( void )

Definition at line 411 of file file.h.

◆ pathname

char* ost::RandomFile::pathname
protected

Definition at line 406 of file file.h.

◆ temp

bool ost::RandomFile::temp

Definition at line 415 of file file.h.

◆ thrown

bool ost::RandomFile::thrown

Definition at line 410 of file file.h.


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