FileMetadata::Store
An interface to be implemented by Stores in the FileMetadata framework
Stores are used to store metadata for use or analysis at a later time. Stores can use SQL databases, flat files or XML as storage. Stores are specific to the FileMetadata framework and are not intended for use as stand alone modules.
Stores do not implement any methods to query metadata from stores. It is considered that the use of metadata is application specific and hence is more easily analyzed by the application. It is possible for a Store implementation to implement methods to enable such querying but such methods are beyond the scope of this interface.
This constructor takes a single argument. The argument is a reference to a hash that represents configuration information. The method returns a reference to a new miner object.
The exact format for the configuration hash should be available in the documentation for the specific Store module. This hash is generally used to specify which meta information should be stored and which can be ignored. The hash can also be used to transform the keys in the meta information hashes passed to the store() method into less verbose and application specific forms.
This method stores meta information for later use.
This method does not return any thing.
This method takes one argument - a reference to a hash that contains meta data known for the resource. The hash contains the key 'ID' whose value is a unique string identifier for the resource. It can be assumed that this key is unique for the resource and that information represented by this hash is all that is know for the resource associated with the identifier. The store should replace all existing data on this resource with the information in the hash. The hash also contains another key 'TIMESTAMP' which represents the local time at which this information was extracted as seconds since epoch. It is illegal for either the 'ID' key or the 'TIMESTAMP' key to be absent or undefined.
Other keys in the hash are usually generated by Miners. These keys are prefixed by the name space of the Miner module. For example the FileMetadata::Miner::Stat miner would insert the key 'FileMetadata::Miner::Stat::atime'.
There might be other keys in the hash that do not follow this convention. These keys would have been generated by the application that is using the Store to specify some application specific meta information.
All values in the hash are numbers or strings.
This method deletes all information from the store.
This method does not return anything.
This method does not take any arguments.
This method is called to remove information pertaining to a certain identifier in the store.
This method takes a single argument which is the identifier for a resource. When this method is called, all data in the store associated with the specified 'ID' must be discarded.
This method takes a single argument which is the identifier for a resource.
This method returns the time (as seconds since epoch) when the information associated with the given identifier was stored. Returns undef if the identifier is not known.
This method returns a list of all identifiers that are known to the store.
Errors that occur in stores are unrecoverable by the application. It is hence expected that the store should 'die' when errors occur.
1.0 - This is the first release
Midh Mulpuri midh@enjine.com
This software can be used under the terms of any Open Source Initiative approved license. A list of these licenses are available at the OSI site - http://www.opensource.org/licenses/
To install FileMetadata::Store, copy and paste the appropriate command in to your terminal.
cpanm
cpanm FileMetadata::Store
CPAN shell
perl -MCPAN -e shell install FileMetadata::Store
For more information on module installation, please visit the detailed CPAN module installation guide.