Configuring the Goblin
App Object¶
The Goblin
object generally supports the same
configuration options as
Cluster
. Please see the
driver docs for a complete list of configuration parameters.
The Goblin
object should be created using the
open
classmethod, and configuration can
be passed as keyword arguments, or loaded from a config file:
>>> import asyncio
>>> from goblin import Goblin
>>> loop = asyncio.get_event_loop()
>>> app = loop.run_until_complete(Goblin.open(loop))
>>> app.config_from_file('config.yml')
Contents of config.yml:
scheme: 'ws'
hosts: ['localhost']
port': 8182
ssl_certfile: ''
ssl_keyfile: ''
ssl_password: ''
username: ''
password: ''
response_timeout: null
max_conns: 4
min_conns: 1
max_times_acquired: 16
max_inflight: 64
message_serializer: 'goblin.driver.GraphSONMessageSerializer'
Special Goblin
App Configuration¶
Goblin
supports two additional configuration
keyword parameters: aliases and get_hashable_id.
aliases¶
aliases as stated in the TinkerPop docs: are “a map of key/value pairs that
allow globally bound Graph and TraversalSource objects to be aliased to
different variable names for purposes of the current request”. Setting the
aliases on the Goblin
object provides a default
for this value to be passed on each request.
get_hashable_id¶
get_hashable_id is a callable that translates a graph id into a hash
that can be used to map graph elements in the
Session
element cache. In many cases,
it is not necessary to provide a value for this keyword argument. For example,
TinkerGraph assigns integer IDs that work perfectly for this purpose. However,
other provider implementations, such as DSE, use more complex data structures
to represent element IDs. In this case, the application developer must provide a
hashing function. For example, the following recipe takes an id map and uses
its values to produces a hashable id:
>>> def get_id_hash(dict):
... hashes = map(hash, dict.items())
... id_hash = functools.reduce(operator.xor, hashes, 0)
... return id_hash
Look for provider specific Goblin
libraries in the near
future!