[tor-bugs] #17755 [CollecTor]: Add @type annotation to each Torperf measurement

[Tor Bug Tracker & Wiki]

#17755: Add @type annotation to each Torperf measurement
---------------------------+-----------------
     Reporter:  karsten    |      Owner:
         Type:  defect     |     Status:  new
     Priority:  Medium     |  Milestone:
    Component:  CollecTor  |    Version:
     Severity:  Normal     |   Keywords:
Actual Points:             |  Parent ID:
       Points:             |    Sponsor:
---------------------------+-----------------
 According to the format description on the CollecTor website: "A Torperf
 results file contains a single line per Torperf run with key=value pairs.
 Such a result line is sufficient to learn about 1) the Tor and Torperf
 configuration, 2) measurement results, and 3) additional information that
 might help explain the results."

 The Torperf Measurement Result files that CollecTor provides all start
 with a `@type torperf 1.0` annotation, followed by one or more measurement
 lines.  However, the correct way to do it is to include a `@type torperf
 1.0` annotation for each contained measurement.

 The main reason is that each measurement is a descriptor in the sense that
 it describes what Torperf recorded for a single measurement.  The fact
 that two or more such measurements end up in the same file is mostly
 random and only happens because it makes measurement results easier to
 handle.  But the measurements that are contained in a file are not
 necessarily related, as it would be okay to just throw in all measurements
 from a given day or even month into a single file.  The line is the
 descriptor, not the file, and that's why each line deserves its own
 `@type` annotation.  This would be more obvious if measurements were to
 span multiple lines, but that doesn't mean that we can optimize the
 annotation away in the single-line case.

 A possible reason against making this change is file size.  I tested
 adding these annotations to the November 2015 tarball.  The uncompressed
 tarball grew from 25904640 to 26491904 bytes (+2.3%), the compressed
 tarball grew from 2629336 to 2641308 bytes (+0.5%).  This seems not crazy.

 I'll post a simple branch that adds more @type annotations later today,
 and I'll replace existing tarballs with files that contain one such
 annotation per included line.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/17755>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online