python: Add search functions to pystats groups

This change adds three functions, a `children` function which will
iterate through all of the children of group based (optionally) on some
predicate. Then, it implements a `find` function and a `find_re`
function using the `children` function.

The `find` function allows users to match statistics or groups
within a group. For instance, you might want to find all of the groups
within the system which have the name "cpu{i}". This is useful for
aggregate statistic values across multiple components.

Example:
total_instruuctions = sum([cpu.exec_context.thread_0.numInsts.value
                           for cpu in simstat.system.find('cpu')])

The find function matches based on substring. If the name given the find
function is a substring of the stat name or the group name the
stat/group will be returned.

The `find_re` function is the same as find, but matches a regular
expression instead of a simple substring match.

Change-Id: I31c2a029d8a6b1d97225ab4efa34a4d13147ea32
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/41603
Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu>
Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
1 file changed