ENH: More updates to the read_databroker.swift example

hackathon/databroker/README.md

@@ -0,0 +1,40 @@
+# Swift/t + DataBroker
+
+This set of files demonstrates how to access a DataBroker from swift.
+
+## Environment
+
+To run this demo you need:
+
+ - a Python 3.6 with requirements.txt installed
+ - a Python interpreter embedded in swift/t with swift-requirements.txt installed
+ - a running local mongodb server
+
+You can create a conda environment, which takes care of all the steps (except the
+last one):
+
+```
+conda env create -f conda-env.yml
+```
+
+The mongodb server can be installed as follows:
+
+```
+sudo apt update && sudo apt install mongodb-server
+```
+
+## Execution
+
+To run this:
+
+ - copy local.yml to `~/.config/databroker/local.yml` (or someplace
+   else on the search path, see
+   https://nsls-ii.github.io/databroker/configuration.html#search-path)
+ - then in 3 different sessions run the following:
+   - **1st**: `conda activate swift-t` and `bluesky-0MQ-proxy 2000 2001`
+   - **2nd**: `conda activate swift-t` and `swift-t -n <number-of-cores> -l read_databroker.swift`
+   - **3rd**: `conda activate swift-t` and `ipython`, and then in the IPython
+     session run `%run -i gen_data.py` to generate some synthetic data by
+     RunEngine, which will be published to the 0MQ proxy. In the 2nd
+     session you should see a bunch of events printed to the screen, meaning
+     the swift/t received the events from the proxy.

hackathon/databroker/conda-env.yml

@@ -0,0 +1,13 @@
+name: swift-t
+channels:
+  - lightsource2-tag
+  - defaults
+dependencies:
+  - bluesky
+  - databroker
+  - ipython
+  - numpy
+  - ophyd
+  - pymongo
+  - python=3.6
+  - swift-t

hackathon/databroker/gen_data.py

@@ -2,11 +2,14 @@
 import bluesky.plans as bp
 from bluesky import RunEngine
 from bluesky.callbacks.zmq import Publisher
+from bluesky.callbacks.best_effort import BestEffortCallback
 from ophyd.sim import motor, det
 
 db = databroker.Broker.named('local')
+bec = BestEffortCallback()
 RE = RunEngine()
 RE.subscribe(db.insert)
+RE.subscribe(bec)
 
 pub = Publisher('localhost:2000', RE=RE)
 

hackathon/databroker/read_databroker.swift

@@ -21,12 +21,9 @@ deserializer = pickle.loads
 address = ('localhost', 2001)
 
 _context = zmq.Context()
-print(f'=== _context: {_context}')
 _socket = _context.socket(zmq.SUB)
-print(f'=== _socket: {_socket}')
 
 url = "tcp://%s:%d" % address
-print(f'=== _url: {url}')
 _socket.connect(url)
 print('connect')
 
@@ -40,7 +37,7 @@ def _poll(_socket, deserializer, DocumentNames):
         hostname = hostname.decode()
         name = name.decode()
         doc = deserializer(doc)
-        yield (DocumentNames[name], doc)
+        yield (name, doc)
 
 doc_gen = _poll(_socket, deserializer, DocumentNames)
 ----,
@@ -68,15 +65,12 @@ except StopIteration:
 {
   result = python_persist(
 ----
-import time
-time.sleep(1)
-ev = %s
-print(type(ev))
+name, doc = %s
 ----
 % inp
          ,
 ----
-f"{ev['seq_num']} {ev['uid']}: {ev['data']}"
+name
 ----
                   );
 
@@ -87,7 +81,7 @@ global const int MAX = 1000;
 process()
 {
   for (int i = 0, boolean stop = false;
-       i < MAX && !stop;
+       !stop;
        i = i+1, stop = end_of_data)
   {
     line = get_event();