tree 9edd3b0bc999a7677d8e1fd16c2bf1c18fcfd6de
parent 44bf361719b3c1c7c36e4f708097f847cea6ab9c
author Lalit Maganti <lalitm@google.com> 1539679229 +0100
committer Lalit Maganti <lalitm@google.com> 1539679229 +0100

trace_processor: add diff testing for trace processor

Trace processor is notoriously hard to test using unit or integration
tests because of the intermediate steps being closely tied to the code
and being implementation dependent.

Fundamentally, all we really care about is that for a certain set of
traces and queries, we maintain correctness and performance.

This can be done using diff testing where we take a trace and a query
and run the whole end-to-end trace processor over it, comparing the
output to the expected (i.e. correct) output and complaining if that is
not correct.

This CL only addresses the correctness portion. The performance portion
will be tackled in a follow-up.

Bug: 117596113
Change-Id: Idbfe1fc732bea9b3b7a926ef2d99d3c2ac90dc16