By eager loading these associations we can greatly cut down the number
of SQL queries executed when processing documents with lots of
references, especially in cases where there are references belonging to
the same project.
Since these associations are so specific to the reference parsing
process and the permissions checking process that follows it I opted to
include them directly in IssueParser instead of using something like a
scope. Once we have a need for it we can move this code to a scope or
method.
This splits the Markdown rendering and reference extraction phases into
two distinct code bases. The reference extraction phase no longer relies
on the html-pipeline Gem (and any related code) and allows for
extracting of references from multiple HTML nodes in a single pass. This
means that if you want to extract user references from 200 comments you
no longer need to run 200 times N number of queries, instead only a
handful of queries may be needed.
