Implementations

Graphs

class ruruki.graphs.Graph

In-memory graph database.

See IGraph for doco.

class ruruki.graphs.PersistentGraph(path, auto_create=True)

Persistent Graph database storing data to a file system.

See IGraph for doco.

Note

Verices and Edges ID’s are retained when the path is loaded.

Warning

Use this persistent graph if performance is not important. There is a performance hit due to the extra disk I/O overhead when doing many writing/updating operations.

path
   |_ vertices
   |     |_ constraints.json (file)
   |     |_ label
   |     |     |_ 0
   |     |        |_ properties.json (file)
   |     |        |_ in-edges
   |     |        |     |_ 0 -> ../../../../edges/label/0 (symlink)
   |     |        |_ out-edges
   |     |              |_
   |     |
   |     |_ label
   |     |    |_ 1
   |     |         |_ properties.json (file)
   |     |          |_ in-edges
   |     |          |     |_
   |     |          |_ out-edges
   |     |                |_ 0 -> ../../../../edges/label/0 (symlink)
   |
   |_ edges
         |_ label
               |
               |_0
                 |_ properties.json (file)
                 |_ head
                 |   |_ 0 -> ../../../vertices/0 (symlink)
                 |_ tail
                     |_ 1 -> ../../../vertices/1 (symlink)
Parameters:
  • path (str) – Path to ruruki graph data on disk.
  • auto_create (bool) – If True, then missing vertices or edges directories will be created.
Raises:

DatabasePathLocked – If the path is already locked by another persistence graph instance.

Entities

class ruruki.entities.EntitySet(entities=None)

EntitySet used for storing, filtering, and iterating over IEntity objects.

Note

See IEntitySet for documenation.

Parameters:entities (Iterable of IEntity) – Entities being added to the set.
clear()

This is slow (creates N new iterators!) but effective.

discard(entity)

Remove a entity from the current set.

Parameters:entity (IEntity) – Entity to be removed from the set.
Raises:KeyError – KeyError is raised if the entity being discared does not exists in the set.
isdisjoint(other)

Return True if two sets have a null intersection.

pop()

Return the popped value. Raise KeyError if empty.

class ruruki.entities.Entity(label=None, **kwargs)

Base class for containing the common methods used for the other entities like vertices and edges.

Note

See IEntity for doco.

Note

The properties can be accessed as if they are attributes directly by prepending prop__ to the key.

>>> e = Entity("Entity", name="Example")
>>> e.prop__name
'Example'
Parameters:
  • label – IEntity label.
  • kwargs (str`=value or :class:`dict) – Additional properties for the IEntity.
class ruruki.entities.Vertex(label=None, **kwargs)

Vertex/Node is the representation of a entity. It can be anything and contains properties for additional information.

Note

See IVertex for doco.

Note

The properties can be accessed as if they are attributes directly by prepending prop__ to the key.

>>> v = Vertex("Person", name="Foo")
>>> v.prop__name
'Foo'
Parameters:
  • label – IEntity label.
  • kwargs (str`=value or :class:`dict) – Additional properties for the IEntity.
class ruruki.entities.PersistentVertex(*args, **kwargs)

Persistent Vertex behaves exactly the same as a Vertex but has an additional path attribute which is the disk location.

class ruruki.entities.Edge(head, label, tail, **kwargs)

Edge/Relationship is the representation of a relationship between two entities. A edge has properties for additional information.

Note

See IEdge for doco.

Note

The properties can be accessed as if they are attributes directly by prepending prop__ to the key.

>>> v1 = Vertex("Person", name="Foo")
>>> v2 = Vertex("Person", name="Bar")
>>> e = Edge(v1, "knows", v2, since="school")
>>> e.prop__since
'school'
Parameters:
class ruruki.entities.PersistentEdge(*args, **kwargs)

Persistent Edge behaves exactly the same as a Edge but has an additional path attribute which is the disk location.

Locks

class ruruki.locks.Lock

Base locking class.

See ILock for doco.

locked

Return the status of the lock.

Returns:True if the lock is acquired.
Return type:bool
class ruruki.locks.FileLock(filename)

File based locking.

Parameters:filename (str) – Filename to create a lock on.
locked

Return the status of the lock.

Returns:True if the lock is acquired.
Return type:bool
class ruruki.locks.DirectoryLock(path)

Directory based locking.

Parameters:path (str) – Path that you are locking.
locked

Return the status of the lock.

Returns:True if the lock is acquired.
Return type:bool

Parsers

Cypher parser

ruruki.parsers.cypher_parser.parse(query_string)