Fix inefficient SimpleGraph#matching_edge

This method has two issues:
 * it is inefficient when there are many events
 * it tries to match edges that shouldn't be matched

With recursive file resources, many change events can be generated.
The method used to find the good ones is pretty inefficient, allocating
arrays and/or appending to arrays which is a slow operation that can
consume lot of memory.

Still with recursife file resources, the current code tries to match the
events with edges pointing to generated sub-file-resources, which is not
necessary. In fact this all happens because we masquerade the sub-generated
resources with the topmost resource whic itself has auto-required links
to them. There is no reason to send back those events to where they were
generated.

This patch tries to minimize allocations or array appending, it also collect
event names (instead of events themselve) while matching since there are
great chances there are way less events names than events (and we're matchin
by name).

This patch also makes sure we select only edges that don't point back to
the event sources.

Results for matching 1100 events:
 * old code: 22s
 * new code:  0.02s

This patch also helps on the memory consumption side since the GC has
almost no work to perform.

Signed-off-by: Brice Figureau <brice-puppet@daysofwonder.com>

0 files changed, 0 insertions, 0 deletions