Remove obsolete examples and improve the lcls example

dev-environment.yml

@@ -11,7 +11,7 @@ dependencies:
   - bokeh
   - click
   - pyyaml
-  - lume-model>=1.4
+  - lume-model>=2.0.0
   - nose>=1.1.2
   - pip:
     - p4p

environment.yml

@@ -11,7 +11,7 @@ dependencies:
   - bokeh
   - click
   - pyyaml
-  - lume-model>=1.4
+  - lume-model>=2.0.0
   - nose>=1.1.2
   - pip:
     - p4p

examples/common/p4p_server.py

@@ -0,0 +1,63 @@
+
+import p4p
+import threading
+import math
+import random
+import time
+import yaml
+import argparse
+import os
+from p4p.nt import NTScalar
+from p4p.server import Server
+from p4p.server.thread import SharedPV
+from typing import Dict
+from threading import Thread
+
+class SimpleSimServer():
+
+    def __init__(self, config: dict):
+        """
+        Create a new simple simulated server.
+        This pretty must just serves some PVs and gives them a random value
+
+        Configuration dictionary:
+        {
+            "mypv": { "value": 1, "range": 3, "type": "d" }
+        }
+        """
+        self.config = config
+        self.pvs = {
+            x: SharedPV(
+                initial=c['value'],
+                nt=NTScalar('d' if 'type' not in c else c['value'])
+            )
+            for x, c in config.items()
+        }
+        self.running = True
+        self.server = Server([self.pvs])
+        self.thread = Thread(target=self._thread_proc)
+        self.thread.start()
+
+    def update_env(self):
+        """Update the process's environment with config items generated by p4p"""
+        conf = self.server.conf()
+        for k, v in conf.items():
+            os.environ[k] = v
+
+    def stop(self):
+        """Stop the simulated server"""
+        self.running = False
+        self.thread.join()
+        self.server.stop()
+
+    def _thread_proc(self):
+        while self.running:
+            for k, v in self.config.items():
+                range = self.config[k].get('range', 1)
+                self.pvs[k].post(
+                    random.uniform(
+                        self.config[k]['value'] + range / 2,
+                        self.config[k]['value'] - range / 2,
+                    )
+                )
+            time.sleep(0.1)

examples/lcls/README.md

@@ -1,21 +1,18 @@
 # LCLS Model + Client
 
-Provided you're connected to the SLAC network via VPN, this demo will monitor LCLS pvs, execute summation of those PV values on value change, serve an output pv, and display the results in a Bokeh-based web app.
+This example demonstrates a summation of klystron amplitude PVs and serves the result over PVA.
 
+The example may be run with real PV data from the accelerator, or standalone with dummy simulated values.
 
-Open two terminal windows. Activate a Python environment with an updated `lume-epics` installation. Set the channel access address list in each:
-```
-$ export EPICS_CA_ADDR_LIST={LCLS_PROD_HOST}:{CA_SERVER_PORT}
+To run in standalone mode:
+```bash
+$ cd examples
+$ python3 -m lcls.server --standalone
 ```
 
-## Server
-In the first window, run:
-```
-python examples/lcls/server.py
-```
-
-## Client
-In the second window, run:
-```
-bokeh serve examples/lcls/client.py --show
+If you're on the SLAC network, configure the EPICS environment to point to the production gateway, and then run:
+```bash
+$ source $EPICS_SETUP/envSet_prodOnDev.bash
+$ cd examples
+$ python3 -m lcls.server
 ```

examples/lcls/server.py

@@ -1,10 +1,13 @@
 import numpy as np
+import yaml
+import argparse
 from lume_model.base import LUMEBaseModel
 from lume_model.utils import variables_from_yaml
 from lume_epics.utils import config_from_yaml
 from lume_epics.epics_server import Server
-from pathlib import Path
+from common.p4p_server import SimpleSimServer
 
+from pathlib import Path
 
 class AmplSummationModel(LUMEBaseModel):
     def __init__(self):
@@ -22,6 +25,17 @@ def _evaluate(self, input_dict: dict) -> dict:
 
 
 if __name__ == "__main__":
+    parser = argparse.ArgumentParser()
+    parser.add_argument('--standalone', action='store_true', help='Spins up an internal EPICS PVA server to simulate the PVs used by this test')
+    args = parser.parse_args()
+
+    # Spin up P4P server if requested
+    if args.standalone:
+        with open(Path(__file__).parent / "sim_config.yml") as fp:
+            config = yaml.safe_load(fp)
+        sim_server = SimpleSimServer(config)
+        sim_server.update_env()
+
     # load epics configuration
     epics_path = Path(__file__).parent / "epics_config.yml"
     epics_config = config_from_yaml(Path(__file__).parent / "epics_config.yml")
@@ -32,3 +46,6 @@ def _evaluate(self, input_dict: dict) -> dict:
     )
     # monitor = False does not loop in main thread
     server.start(monitor=True)
+
+    if sim_server:
+        sim_server.stop()

examples/lcls/sim_config.yml

@@ -0,0 +1,19 @@
+KLYS:LI24:11:AMPL:
+  value: 51.123
+  range: 2
+
+KLYS:LI24:21:AMPL:
+  value: 24.0234
+  range: 2
+
+KLYS:LI24:31:AMPL:
+  value: 56.4697
+  range: 2
+
+KLYS:LI24:41:AMPL:
+  value: 55.2002
+  range: 2
+
+KLYS:LI24:51:AMPL:
+  value: 57.666
+  range: 2