Public Member Functions¶

MappedFile (const char *fname, Access mode)
Open a file for mapping. MappedFile (const char *fname, Access mode, size_t size)
Create if not exists, and map a file of specified size into memory. MappedFile (const char *fname, pos_t offset, size_t size, Access mode)
Map a portion or all of a specified file in the specified shared memory access mode. virtual ~MappedFile ()
Release a mapped section of memory associated with a file. void sync (void)
Synchronize the contents of the mapped portion of memory with the disk file and wait for completion. void sync (caddr_t address, size_t len)
Synchronize a segment of memory mapped from a segment fetch. void update (size_t offset=0, size_t len=0)
Map a portion of the memory mapped from the file back to the file and do not wait for completion. void update (caddr_t address, size_t len)
Update a mapped region back to disk as specified by address and length. void release (caddr_t address, size_t len)
Release (unmap) a memory segment. caddr_t fetch (size_t offset=0)
Fetch a pointer to an offset within the memory mapped portion of the disk file. caddr_t fetch (off_t pos, size_t len)
Fetch and map a portion of a disk file to a logical memory block. bool lock (void)
Lock the currently mapped portion of a file. void unlock (void)
Unlock a locked mapped portion of a file. size_t pageAligned (size_t size)
Compute map size to aligned page boundry.

Additional Inherited Members¶

ost::MappedFile::MappedFile (const char * fname, Access mode)¶

Open a file for mapping. More than one segment of a file may be mapped into separate regions of memory.

Parameters

ost::MappedFile::MappedFile (const char * fname, Access mode, size_t size)¶

Create if not exists, and map a file of specified size into memory.

Parameters

ost::MappedFile::MappedFile (const char * fname, pos_t offset, size_t size, Access mode)¶

Map a portion or all of a specified file in the specified shared memory access mode. Valid mapping modes include mappedRead, mappedWrite, and mappedReadWrite.

Parameters

virtual ost::MappedFile::~MappedFile () [virtual]¶

Release a mapped section of memory associated with a file. The mapped area is updated back to disk.

caddr_t ost::MappedFile::fetch (off_t pos, size_t len)¶

Fetch and map a portion of a disk file to a logical memory block.

Returns

Parameters

caddr_t ost::MappedFile::fetch (size_t offset = 0) [inline]¶

Fetch a pointer to an offset within the memory mapped portion of the disk file. This really is used for convience of matching operations between Update and Fetch, as one could simply have accessed the base pointer where the file was mapped directly.

Parameters

bool ost::MappedFile::lock (void)¶

Lock the currently mapped portion of a file.

Returns

size_t ost::MappedFile::pageAligned (size_t size)¶

Compute map size to aligned page boundry.

Parameters

Returns

void ost::MappedFile::release (caddr_t address, size_t len)¶

Release (unmap) a memory segment.

Parameters

void ost::MappedFile::sync (caddr_t address, size_t len)¶

Synchronize a segment of memory mapped from a segment fetch.

Parameters

void ost::MappedFile::sync (void)¶

Synchronize the contents of the mapped portion of memory with the disk file and wait for completion. This assures the memory mapped from the file is written back.

void ost::MappedFile::unlock (void)¶

Unlock a locked mapped portion of a file.

void ost::MappedFile::update (caddr_t address, size_t len)¶

Update a mapped region back to disk as specified by address and length.

Parameters

void ost::MappedFile::update (size_t offset = 0, size_t len = 0)¶

Map a portion of the memory mapped from the file back to the file and do not wait for completion. This is useful when mapping a database file and updating a single record.

Parameters