commands: add debugdeltachain command
We have debug commands for displaying overall revlog statistics
(debugrevlog) and for dumping a revlog index (debugindex). As part
of investigating various aspects of revlog behavior and performance,
I found it important to have an understanding of how revlog
delta chains behave in practice.
This patch implements a "debugdeltachain" command. For each revision
in a revlog, it dumps information about the delta chain. Which delta
chain it is part of, length of the delta chain, distance since base
revision, info about base revision, size of the delta chain, etc. The
generic formatting facility is used, which means we can templatize
output and get machine readable output like JSON.
This command has already uncovered some weird history in
mozilla-central I didn't know about. So I think it's valuable.
# Base Revsets to be used with revsetbenchmarks.py script
#
# The goal of this file is to gather a limited amount of revsets that allow a
# good coverage of the internal revsets mechanisms. Revsets included should not
# be selected for their individual implementation, but for what they reveal of
# the internal implementation of smartsets classes (and their interactions).
#
# Use and update this file when you change internal implementation of these
# smartsets classes. Please include a comment explaining what each of your
# addition is testing. Also check if your changes to the smartset class makes
# some of the tests inadequate and replace them with a new one testing the same
# behavior.
#
# If you want to benchmark revsets predicate itself, check 'all-revsets.txt'.
#
# The current content of this file is currently likely not reaching this goal
# entirely, feel free, to audit its content and comment on each revset to
# highlight what internal mechanisms they test.
all()
draft()
::tip
draft() and ::tip
::tip and draft()
0::tip
roots(0::tip)
author(lmoscovicz)
author(mpm)
author(lmoscovicz) or author(mpm)
author(mpm) or author(lmoscovicz)
tip:0
0::
# those two `roots(...)` inputs are close to what phase movement use.
roots((tip~100::) - (tip~100::tip))
roots((0::) - (0::tip))
42:68 and roots(42:tip)
::p1(p1(tip))::
public()
:10000 and public()
draft()
:10000 and draft()
roots((0:tip)::)
(not public() - obsolete())
(_intlist('20000\x0020001')) and merge()
parents(20000)
(20000::) - (20000)
# The one below is used by rebase
(children(ancestor(tip~5, tip)) and ::(tip~5))::