Hi Bruce,
On 01/24/2014 06:32 PM, Bruce Hill wrote:
We've been trying to reduce network bandwidth on
CA image transfers by using ROI to reduce the required
data, and just noticed that the default for the caget
command line tool always fetches the full array, even
if NORD is less than NELM.
This happens because caget currently defaults to synchronous
get, and only the -c async option supports dynamic array sizing.
As async vs sync CA is a subtle distinction that doesn't matter for
most of our users, I've added an option to our caget to request
synchronous get and changed the default to async.
I think this could be useful for the broader community,
so here's a patch that does this.
I could accept using an environment variable to control the default
asyn/sync behaviour of the caget/caput tools, but I would be concerned
about breaking existing scripts that call them if we were to change
their behaviour without at least allowing sites to easily switch back to
the old default.
My personal preference would be for the catools programs to take
defaults from environment variables like GNU's GREP_OPTIONS variable.
Then it would be up to you to add something like
export EPICS_CAGET_OPTIONS=-c
to your systems' shell configurations.
Ralph Lange is the maintainer for the catools programs though, so I'm
waiting for a response from him.
