make function for AD prime plugin

[prjemian]

This is a common pattern:

from .. import iconfig
from apstools.devices import AD_plugin_primed
from apstools.devices import AD_prime_plugin2

if iconfig.get("ALLOW_AREA_DETECTOR_WARMUP", False):
    # WORKAROUND
    # Even with `lazy_open=1`, ophyd checks if the area
    # detector HDF5 plugin has been primed.  We might
    # need to prime it.  Here's ophyd's test:
    # if np.array(adsimdet.hdf1.array_size.get()).sum() == 0:
    #     logger.info(f"Priming {adsimdet.hdf1.name} ...")
    #     adsimdet.hdf1.warmup()
    #     logger.info(f"Enabling {adsimdet.image.name} plugin ...")
    #     adsimdet.image.enable.put("Enable")
    if not AD_plugin_primed(adsimdet.hdf1):
        AD_prime_plugin2(adsimdet.hdf1)

Make it into a function.

[prjemian]

such as this definition:

from apstools.devices import AD_plugin_primed
from apstools.devices import AD_prime_plugin2

def ensure_AD_plugin_primed(plugin, allow_warmup=False):
    """
    Ensure the AD plugin is warmed up, if allowed.

    This is a workaround for a check in area_detector_handlers which
    found a mismatch in the description of the image array parameters
    (size, number of bits, & color mode) between the cam and the plugin.

    Even with ``lazy_open=1``, ophyd (via area_detector_handlers) checks
    if the area detector HDF5 plugin has been _primed_.

    We might need to prime it.  Here's ophyd's test (which is not sufficient)::

        if np.array(plugin.array_size.get()).sum() == 0:
            logger.info(f"Priming {plugin.name} ...")
            plugin.warmup()
    """
    if allow_warmup:
        if not AD_plugin_primed(plugin):
            logger.info(f"Priming {plugin.name} ...")
            AD_prime_plugin2(plugin)

then replace the original call with this new one:

from .. import iconfig
from apstools.devices import ensure_AD_plugin_primed

ensure_AD_plugin_primed(adsimdet.hdf1, iconfig.get("ALLOW_AREA_DETECTOR_WARMUP", False))

[MarkRivers]

Even with lazy_open=1, ophyd (via area_detector_handlers) checks if the area detector HDF5 plugin has been primed.

Can't this be fixed in ophyd?

[prjemian]

Fixing this problem in ophyd would involve removing the if ... clause from the HDF5Plugin's stage() method:

    def stage(self):
        if np.array(self.array_size.get()).sum() == 0:
            raise UnprimedPlugin(
                f"The plugin {self.dotted_name} on the "
                f"area detector with name {self.root.name} "
                f"has not been primed."
            )
        return super().stage()

There must be other code (called by the bluesky RunEngine) which reports the image array parameters in the descriptor documents. In the case of a lazy_open=1 plugin configuration, this other code must be refactored to wait for the first image before creating the associated descriptor document.