DBM::Deep::Storage::File(3)

NAME
DBM::Deep::Storage::File - mediate low-level interaction with storage mechanism

PURPOSE
This is an internal-use-only object for DBM::Deep. It mediates the low-level interaction with the storage mechanism.

Currently, the only storage mechanism supported is the file system.

OVERVIEW
This class provides an abstraction to the storage mechanism so that the Engine (the only class that uses this class) doesn't have to worry about that.

METHODS

  new( \%args )

  open()
This method opens the filehandle for the filename in " file ".

There is no return value.

  close()
If the filehandle is opened, this will close it.

There is no return value.

  size()
This will return the size of the DB. If file_offset is set, this will take that into account.

NOTE: This function isn't used internally anywhere.

  set_inode()
This will set the inode value of the underlying file object.

This is only needed to handle some obscure Win32 bugs. It really shouldn't be needed outside this object.

There is no return value.

  print_at( $offset, @data )
This takes an offset and some data to print.

$offset will be used to seek into the file. If file_offset is set, it will be used as the zero location. If it is undefined, no seeking will occur. Then, @data will be printed to the current location.

There is no return value.

If writing to the file would make the file too big for the "pack_size" that is a fatal error.

  read_at( $offset, $length )
This takes an optional offset and a length.

$offset , if defined, will be used to seek into the file. If file_offset is set, it will be used as the zero location. If it is undefined, no seeking will occur. Then, $length bytes will be read from the current location.

The data read will be returned.

  DESTROY
When the ::Storage::File object goes out of scope, it will be closed.

  request_space( $size )
This takes a size and adds that much space to the DBM.

This returns the offset for the new location.

  copy_stats( $target_filename )
This will take the stats for the current filehandle and apply them to $target_filename . The stats copied are:

•   Onwer UID and GID

•   Permissions