Add datapoint_count attribute to devices.

__init__.py

from Products.ZenUtils.Utils import monkeypatch
from ZODB.transact import transact


def get_datapoint_count(device):
    '''
    Return the total number of monitored datapoints on device.
    '''
    if not device.monitorDevice():
        return 0

    total = 0

    for template in device.getRRDTemplates():
        for datasource in template.datasources():
            if datasource.enabled:
                total += datasource.datapoints.countObjects()

    for component in device.getMonitoredComponents():
        for template in device.getRRDTemplates():
            for datasource in template.datasources():
                if datasource.enabled:
                    total += datasource.datapoints.countObjects()

    return total


@transact
def update_datapoint_count(device, datapoint_count):
    '''
    Update device.datapoint_count in a retrying transaction.
    '''
    device.datapoint_count = datapoint_count


@monkeypatch('Products.ZenModel.Device.Device')
def setLastChange(self, value=None):
    '''
    Set the changed datetime for this device.

    Patch: Update device's datapoint_count if necessary.

    @param value: secs since the epoch, default is now
    @type value: float
    @permission: ZEN_CHANGE_DEVICE
    '''
    # original is injected by the @monkeypatch decorator.
    original(self, value=value)

    # This will only occur one the patched setSnmpLastCollection has run
    # at least once, and when the device's model changes in some way.
    if hasattr(self, 'datapoint_count'):
        datapoint_count = get_datapoint_count(self)
        if self.datapoint_count != datapoint_count:
            update_datapoint_count(self, datapoint_count)


@monkeypatch('Products.ZenModel.Device.Device')
def setSnmpLastCollection(self, value=None):
    '''
    Set the last time snmp collection occurred.

    Patch: Initialize and set device's datapoint_count if necessary.

    @param value: secs since the epoch, default is now
    @type value: float
    @permission: ZEN_CHANGE_DEVICE
    '''
    # original is injected by the @monkeypatch decorator.
    original(self, value=value)

    # This should only occur once for devices that were added to Zenoss
    # after this monkeypatch was installed.
    if not hasattr(self, 'datapoint_count'):
        update_datapoint_count(self, get_datapoint_count(self))