[Bug 48035] New: Speed up the new failures detection

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=48035

Bug ID: 48035
           Summary: Speed up the new failures detection
           Product: Wine-Testbot
           Version: unspecified
          Hardware: x86
                OS: Linux
            Status: NEW
          Severity: normal
          Priority: P2
         Component: unknown
          Assignee: [e-mail]
          Reporter: [e-mail]
      Distribution: ---

When a task completes the TestBot distinguishes new failures from preexisting
ones by comparing the task's report to the latest WineTest report. Any failure
present in the task's report which is not present in the WineTest report is
new.

This means parsing both reports to extract the errors and diffing them. This
needs to be done whenever we need the list of new failures which is:
* When sending a notification to the developer when a wine-patches job
completes.
* On the JobDetails page.

But the WineTest reports are pretty big (~600KB on Windows, ~1.5MB on Wine)
which translates into non negligible processing time. For instance on my
development environment loading the JobDetails page for a job with 1 Windows
report and 8 Wine reports takes about 0.2 s without the reference WineTest
reports, but close to 2 s when they are present.

So it would help to only store the WineTest failures instead of the full report
(optimisation a in bug 47998). This would cut down not only on the amount of
data to read, but also on the required parsing. Testing this in the same
development environment indicates this could bring the JobDetails processing
time down to about 0.3 s.