nspyre.data.server

The nspyre data server transports arbitrary python objects over a TCP/IP socket to a set of local or remote network clients, and keeps those objects up to date as they are modified. For each data set on the data server, there is a single data DataSource, and a set of data DataSink. The source pushes data to the data server and each of the sinks pops data from the data server.

Objects are serialized by the source then pushed to the server. Each sink receives a copy of the serialized objects, then deserializes them locally. If the user makes use of “Streaming” objects such as the StreamingList, the source will only serialize the operations that have been performed on the streaming object since the last serialization. The sink can then reconstruct the pushed data using a local copy of the last version of the object, and the diff received from the data server. This is more efficient when data sets start becoming larger and serialization performance is a bottleneck.

The data server can be started using the command-line interface, e.g.:

$ nspyre-dataserv -p 12345

Module Contents

Classes

DataServer

The server has a set of DataSet objects. Each has 1 data source, and any number of

Attributes

DATASERV_PORT

Default port to host the data server on.

nspyre.data.server.DATASERV_PORT = 30101

Default port to host the data server on.

class nspyre.data.server.DataServer(port=DATASERV_PORT)

The server has a set of DataSet objects. Each has 1 data source, and any number of data sinks. Pickled object data from the source is received on its socket, then transferred to the FIFO of every sink. The pickle is then sent out on the sink’s socket. E.g.:

self.datasets = {

'dataset1' : _DataSet(
socket (source) ----------> FIFO ------> socket (sink 1)
                   |
                    ------> FIFO ------> socket (sink 2)
),

'dataset2' : _DataSet(
socket (source) ----------> FIFO ------> socket (sink 1)
                   |
                    ------> FIFO ------> socket (sink 2)
                   |
                    ------> FIFO ------> socket (sink 3)
                   |
                    ------> FIFO ------> socket (sink 4)
),

... }

Parameters:

port (int) – TCP/IP port of the data server

serve_forever()

Run the asyncio event loop - ayncio requires this be run in the main thread if processes are to be spawned from the event loop. See https://docs.python.org/3/library/asyncio-dev.html.

stop()

Stop the asyncio event loop.