Added routines to get only the PVs from snapshot file and to get the data by these PVS. This avoids crashed of too many files open when used often

interface/__init__.py

@@ -1,4 +1,6 @@
 from .snap import getSnap
+from .snap import getSnapPV
+from .snap import getSnapVal
 from .snap import saveSnap
 from .snap import loadSnap
 from .snap import parseSnapShotReqYAML

interface/snap.py

@@ -61,6 +61,24 @@ def getSnap(pvs=None):
             ret[pv]=float(val[i]) 
     return ret
 
+def getSnapPV(pvs=None):
+    if not isinstance(pvs,list):
+        pvs = parseSnapShotReqYAML(pvs)
+    if not pvs:
+        return
+    return [epics.PV(pvname,auto_monitor = False) for pvname in pvs]
+
+
+def getSnapVal(pvs=None):
+    if not pvs:
+        return None
+    ret={}
+    val = [pv.value for pv in pvs]
+    for i,pv in enumerate(pvs):
+        if not val[i] is None:      # filter out None values
+            ret[pv.pvname]=float(val[i]) 
+    return ret
+
 def saveSnap(pvs={},label="", comment = "generated by application",reqfile = "SF_settings.yaml"):
     filename = datetime.datetime.now().strftime('/sf/data/applications/snapshot/SF_settings_%Y%m%d_%H%M%S.snap')
     with open(filename,'w') as fid: