Added -f and --follow option to pav log command.

[smehta99]

Usage: pav log -f/--follow <log_type> <test_id>

example: pav log -f build 72

[Paul-Ferrell]

You also need to make a unit test for this. I would:

• Add a 'FOLLOW_TEST' class variable, defaulted to false.
• Exit the follow loop after successfully reading data when FOLLOW_TEST is true.
• In the unit test:
  • Set the follow sleep time to really short (0.1)
  • Set FOLLOW_TEST to True
  • Create a pav test that prints some stuff in test test run and run it.
  • Grab the log command, and use the silence() method on it.
  • Use threading to background the call to the log.run method.
  • Wait 0.2 seconds
  • Append something to the log.
  • Wait for the log.run thread to finish.
  • Check that the thing you appended is in the command output.

Let's work on this in the Pavilion meeting today as a group.

[smehta99]

There is a bug where where build hash log doesn't change from the previous run and ends up not finding the new hash. I will fix it when I return.