Add nicos request via socket as first alternative looking up devices

eos/nicos_interface.py

@@ -2,30 +2,59 @@
 Functions used to directly access information from nicos.
 """
 
+import socket
 import platform
 import logging
 import subprocess
 
-if  platform.node().startswith('amor'):
-    NICOS_CACHE_DIR = '/home/data/nicosdata/cache/'
-    GREP = '/usr/bin/grep "value"'
-else:
-    NICOS_CACHE_DIR = None
+ON_AMOR = platform.node().startswith('amor')
+NICOS_CACHE_DIR = '/home/data/nicosdata/cache/'
+GREP = '/usr/bin/grep "value"'
 
 
 def lookup_nicos_value(key, nicos_key, dtype=float, suffix='', year="2026"):
     # TODO: Implement direct communication to nicos to read the cache
     if nicos_key=='ignore':
         return dtype(0)
-    if NICOS_CACHE_DIR:
+    try:
+        logging.debug(f'     trying socket request for device {nicos_key}')
+        response = nicos_single_request(nicos_key)
+        logging.info(f"     using parameter {nicos_key} from nicos cache via socket")
+        return dtype(response)
+    except Exception as e:
+        logging.debug(f'       socket request failed with {e!r}')
+    if ON_AMOR:
+        logging.debug(f"     trying to extract {nicos_key} from nicos cache files")
+        call = f'{GREP} {NICOS_CACHE_DIR}nicos-{nicos_key}/{year}{suffix}'
         try:
-            logging.info(f"     using parameter {nicos_key} from nicos cache")
-            call = f'{GREP} {NICOS_CACHE_DIR}nicos-{nicos_key}/{year}{suffix}'
             value = str(subprocess.getoutput(call)).split('\t')[-1]
+            logging.info(f"     using parameter {nicos_key} from nicos cache file")
             return dtype(value)
         except Exception:
-            logging.error(f"Couldn't get value from nicos cache {nicos_key}, {call}")
+            logging.error(f"       couldn't get value from nicos cache {nicos_key}, {call}")
             return dtype(0)
     else:
         logging.warning(f"     parameter {key} not found, relpace by zero")
         return dtype(0)
+
+def nicos_single_request(device):
+    sentinel = b'\n'
+    with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
+        s.settimeout(1.0)
+        s.connect(('amor', 14869))
+
+        tosend = f'@nicos/{device}/value?\n'
+
+        # write request
+        # self.log.debug("get_explicit: sending %r", tosend)
+        s.sendall(tosend.encode())
+
+        # read response
+        data = b''
+        while not data.endswith(sentinel):
+            newdata = s.recv(8192)  # blocking read
+            if not newdata:
+                raise IOError('cache closed connection')
+            data += newdata
+        s.shutdown(socket.SHUT_RDWR)
+    return data.decode('utf-8').split('=')[-1]