PickledDB database

Pickled Database

Implement permanent version of orion.core.io.database.ephemeraldb.EphemeralDB.

class orion.core.io.database.pickleddb.PickledDB(host='', timeout=60, *args, **kwargs)

Pickled EphemeralDB to support permanancy and concurrency

This is a very simple and inefficient implementation of a permanent database on disk for Oríon. The data is loaded from disk for every operation, and every operation is protected with a filelock.

Parameters

host: str

File path to save pickled ephemeraldb. Default is {user data dir}/orion/orion_db.pkl ex: $HOME/.local/share/orion/orion_db.pkl

timeout: int

Maximum number of seconds to wait for the lock before raising DatabaseTimeout. Default is 60.

Attributes

is_connected

Return true, always.

Methods

close_connection()	Do nothing
count(collection_name[, query])	Count the number of documents in a collection which match the query.
drop_index(collection_name, name)	Remove index from the database
ensure_index(collection_name, keys[, unique])	Create given indexes if they do not already exist in database.
get_defaults()	Get database arguments needed to create a database instance.
index_information(collection_name)	Return dict of names and sorting order of indexes
initiate_connection()	Do nothing
locked_database([write])	Lock database file during wrapped operation call.
read(collection_name[, query, selection])	Read a collection and return a value according to the query.
read_and_write(collection_name, query, data)	Read a collection's document and update the found document.
remove(collection_name, query)	Delete from a collection document[s] which match the query.
write(collection_name, data[, query])	Write new information to a collection.

close_connection()

Do nothing

count(collection_name, query=None)

Count the number of documents in a collection which match the query.

See also

orion.core.io.database.Database.count() for argument documentation.

drop_index(collection_name, name)

Remove index from the database

ensure_index(collection_name, keys, unique=False)

Create given indexes if they do not already exist in database.

Indexes are only created if unique is True.

classmethod get_defaults()

Get database arguments needed to create a database instance.

See also

orion.core.io.database.Database.get_defaults() for argument documentation.

index_information(collection_name)

Return dict of names and sorting order of indexes

initiate_connection()

Do nothing

property is_connected

Return true, always.

locked_database(write=True)

Lock database file during wrapped operation call.

read(collection_name, query=None, selection=None)

Read a collection and return a value according to the query.

See also

orion.core.io.database.Database.read() for argument documentation.

read_and_write(collection_name, query, data, selection=None)

Read a collection’s document and update the found document.

Returns the updated document, or None if nothing found.

See also

orion.core.io.database.Database.read_and_write() for argument documentation.

remove(collection_name, query)

Delete from a collection document[s] which match the query.

See also

orion.core.io.database.Database.remove() for argument documentation.

write(collection_name, data, query=None)

Write new information to a collection. Perform insert or update.

See also

orion.core.io.database.Database.write() for argument documentation.

orion.core.io.database.pickleddb.find_unpickable_doc(dict_of_dict)

Look for a dictionary that cannot be pickled.

orion.core.io.database.pickleddb.find_unpickable_field(doc)

Look for a field in a dictionary that cannot be pickled