DBM::Deep::Engine::FilUser Contributed Perl DocumentDBM::Deep::Engine::File(3)NAMEDBM::Deep::Engine::FilePURPOSE
This is the engine for use with DBM::Deep::Storage::File.
EXTERNAL METHODSnew()
This takes a set of args. These args are described in the documentation
for "new" in DBM::Deep.
INTERNAL METHODS
The following methods are internal-use-only to DBM::Deep::Engine::File.
read_txn_slots()
This takes no arguments.
This will return an array with a 1 or 0 in each slot. Each spot
represents one available transaction. If the slot is 1, that
transaction is taken. If it is 0, the transaction is available.
write_txn_slots( @slots )
This takes an array of 1's and 0's. This array represents the
transaction slots returned by "read_txn_slots()". In other words, the
following is true:
@x = read_txn_slots( write_txn_slots( @x ) );
(With the obviously missing object referents added back in.)
get_running_txn_ids()
This takes no arguments.
This will return an array of taken transaction IDs. This wraps
"read_txn_slots()".
get_txn_staleness_counter( $trans_id )
This will return the staleness counter for the given transaction ID.
Please see "STALENESS" in DBM::Deep::Engine for more information.
inc_txn_staleness_counter( $trans_id )
This will increment the staleness counter for the given transaction ID.
Please see "STALENESS" in DBM::Deep::Engine for more information.
get_entries()
This takes no arguments.
This returns a list of all the sectors that have been modified by this
transaction.
add_entry( $trans_id, $location )
This takes a transaction ID and a file location and marks the sector at
that location as having been modified by the transaction identified by
$trans_id.
This returns nothing.
NOTE: Unlike all the other _entries() methods, there are several cases
where "$trans_id != $self->trans_id" for this method.
reindex_entry( $old_loc, $new_loc )
This takes two locations (old and new, respectively). If a location
that has been modified by this transaction is subsequently reindexed
due to a bucketlist overflowing, then the entries hash needs to be made
aware of this change.
This returns nothing.
clear_entries()
This takes no arguments. It will clear the entries list for the running
transaction.
This returns nothing.
_write_file_header()
This writes the file header for a new file. This will write the various
settings that set how the file is interpreted.
_read_file_header()
This reads the file header from an existing file. This will read the
various settings that set how the file is interpreted.
_apply_digest( @stuff )
This will apply the digest methd (default to Digest::MD5::md5) to the
arguments passed in and return the result.
_add_free_blist_sector( $offset, $size )
_add_free_data_sector( $offset, $size )
_add_free_index_sector( $offset, $size )
These methods are all wrappers around _add_free_sector(), providing the
proper chain offset ($multiple) for the sector type.
_add_free_sector( $multiple, $offset, $size )
_add_free_sector() takes the offset into the chains location, the
offset of the sector, and the size of that sector. It will mark the
sector as a free sector and put it into the list of sectors that are
free of this type for use later.
This returns nothing.
NOTE: $size is unused?
_request_blist_sector( $size )
_request_data_sector( $size )
_request_index_sector( $size )
These methods are all wrappers around _request_sector(), providing the
proper chain offset ($multiple) for the sector type.
_request_sector( $multiple $size )
This takes the offset into the chains location and the size of that
sector.
This returns the object with the sector. If there is an available free
sector of that type, then it will be reused. If there isn't one, then a
new one will be allocated.
ACCESSORS
The following are readonly attributes.
· byte_size
· hash_size
· hash_chars
· num_txns
· max_buckets
· blank_md5
· data_sector_size
· txn_bitfield_len
The following are read/write attributes.
· trans_id / set_trans_id( $new_id )
· trans_loc / set_trans_loc( $new_loc )
· chains_loc / set_chains_loc( $new_loc )
_dump_file()
This method takes no arguments. It's used to print out a textual
representation of the DBM::Deep DB file. It assumes the file is not-
corrupted.
perl v5.14.1 2011-07-15 DBM::Deep::Engine::File(3)
