Possible -Dhpss improvement

[Andrew Bennetts]

Jonathan Lange wrote:
> How hard would it be to get -Dhpss to show the number of VFS calls
> separately from the total number of HPSS calls? How useful would it
> be?

Not very hard.  Just adjust the hook installed in bzrlib.smart.medium.  The
class to change is_DebugCounter, especially its increment_call_count method.
The params passed to that method include the verb, so you can pretty easily
distinguish VFS calls with that.

> I realize it might be a little late in the piece to suggest this.

For 1.14, yeah :)

The next release is never too far away.  You could make a plugin to do this
too...

We are fairly rapidly getting rid of VFS calls for common push/pull
operations, but there are a fair few cases where we haven't yet gotten rid
of them entirely, so I don't think its too late for this to be useful.

-Andrew.