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archiver-appliance / epicsarchiverap

This is an implementation of an archiver for EPICS control systems that aims to archive millions of PVs.
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Add number of samples to MetaInfo #124

Closed slacmshankar closed 2 years ago

slacmshankar commented 2 years ago

When looking at the Python module that defines policy, I can see the following function:

def determinePolicy(pv_info): """Return the policy to apply for the given PV

pv_info is a dict with the information computed by the engine about the PV.
It includes:
    - dbrtype -- The ArchDBRType of the PV
    - eventRate -- The sampled event rate in events per second.
    - storageRate -- The sampled storage in bytes per seconds.
    - aliasName -- The value of the .NAME field for aliases
    - policyName -- If the user has overridden the policy when requesting archiving, this is the name of the policy

The Python dictionary "pv_info" has several keys but none of them tells the programmer what is the number of data points of the PV to be archived. Do you know if such a key (of the dictionary) exists or should we just calculate/extrapolate this number based on the "eventRate" and "storageRate" keys?

slacmshankar commented 2 years ago

Fixed. The number of samples is now available as eventCount