tests/test-contrib-perf.t

log: add -L/--line-range option to follow file history by line range

We add an experimental -L/--line-range option to 'hg log' taking file patterns
along with a line range using the (new) FILE,FROMLINE-TOLINE syntax where FILE
may be a pattern (matching exactly one file). The resulting history is similar
to what the "followlines" revset except that, if --patch is specified,
only diff hunks within specified line range are shown.

Basically, this brings the CLI on par with what currently only exists in hgweb
through line selection in "file" and "annotate" views resulting in a file log
with filtered patch to only display followed line range.

The option may be specified multiple times and can be combined with --rev and
regular file patterns to further restrict revisions. Usage of this option
requires --follow; revisions are shown in descending order and renames are
followed. Only the --graph option is currently not supported.

The UI is the result of a consensus from review feedback at:

  https://www.mercurial-scm.org/pipermail/mercurial-devel/2017-October/106749.html


The implementation spreads between commands.log() and cmdutil module.
In commands.log(), the main loop may now use a "hunksfilter" factory (similar
to "filematcher") that, for a given "rev", produces a filtering function
for diff hunks for a given file context object.
The logic to build revisions from -L/--line-range options lives in
cmdutil.getloglinerangerevs() which produces "revs", "filematcher" and
"hunksfilter" information. Revisions obtained by following files' line range
are filtered if they do not match the revset specified by --rev option. If
regular FILE arguments are passed along with -L options, both filematchers are
combined into a new matcher.

.. feature::

   Add an experimental -L/--line-range FILE,FROMLINE-TOLINE option to 'hg log'
   command to follow the history of files by line range. In combination with
   -p/--patch option, only diff hunks within specified line range will be
   displayed. Feedback, especially on UX aspects, is welcome.

#require test-repo

Set vars:

  $ . "$TESTDIR/helpers-testrepo.sh"
  $ CONTRIBDIR="$TESTDIR/../contrib"

Prepare repo:

  $ hg init

  $ echo this is file a > a
  $ hg add a
  $ hg commit -m first

  $ echo adding to file a >> a
  $ hg commit -m second

  $ echo adding more to file a >> a
  $ hg commit -m third

  $ hg up -r 0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo merge-this >> a
  $ hg commit -m merge-able
  created new head

  $ hg up -r 2
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

perfstatus

  $ cat >> $HGRCPATH << EOF
  > [extensions]
  > perfstatusext=$CONTRIBDIR/perf.py
  > [perf]
  > presleep=0
  > stub=on
  > parentscount=1
  > EOF
  $ hg help perfstatusext
  perfstatusext extension - helper extension to measure performance
  
  list of commands:
  
   perfaddremove
                 (no help text available)
   perfancestors
                 (no help text available)
   perfancestorset
                 (no help text available)
   perfannotate  (no help text available)
   perfbdiff     benchmark a bdiff between revisions
   perfbookmarks
                 benchmark parsing bookmarks from disk to memory
   perfbranchmap
                 benchmark the update of a branchmap
   perfcca       (no help text available)
   perfchangegroupchangelog
                 Benchmark producing a changelog group for a changegroup.
   perfchangeset
                 (no help text available)
   perfctxfiles  (no help text available)
   perfdiffwd    Profile diff of working directory changes
   perfdirfoldmap
                 (no help text available)
   perfdirs      (no help text available)
   perfdirstate  (no help text available)
   perfdirstatedirs
                 (no help text available)
   perfdirstatefoldmap
                 (no help text available)
   perfdirstatewrite
                 (no help text available)
   perffncacheencode
                 (no help text available)
   perffncacheload
                 (no help text available)
   perffncachewrite
                 (no help text available)
   perfheads     (no help text available)
   perfindex     (no help text available)
   perfloadmarkers
                 benchmark the time to parse the on-disk markers for a repo
   perflog       (no help text available)
   perflookup    (no help text available)
   perflrucachedict
                 (no help text available)
   perfmanifest  (no help text available)
   perfmergecalculate
                 (no help text available)
   perfmoonwalk  benchmark walking the changelog backwards
   perfnodelookup
                 (no help text available)
   perfparents   (no help text available)
   perfpathcopies
                 (no help text available)
   perfphases    benchmark phasesets computation
   perfrawfiles  (no help text available)
   perfrevlogchunks
                 Benchmark operations on revlog chunks.
   perfrevlogindex
                 Benchmark operations against a revlog index.
   perfrevlogrevision
                 Benchmark obtaining a revlog revision.
   perfrevlogrevisions
                 Benchmark reading a series of revisions from a revlog.
   perfrevrange  (no help text available)
   perfrevset    benchmark the execution time of a revset
   perfstartup   (no help text available)
   perfstatus    (no help text available)
   perftags      (no help text available)
   perftemplating
                 (no help text available)
   perfvolatilesets
                 benchmark the computation of various volatile set
   perfwalk      (no help text available)
   perfwrite     microbenchmark ui.write
  
  (use 'hg help -v perfstatusext' to show built-in aliases and global options)
  $ hg perfaddremove
  $ hg perfancestors
  $ hg perfancestorset 2
  $ hg perfannotate a
  $ hg perfbdiff -c 1
  $ hg perfbdiff --alldata 1
  $ hg perfbookmarks
  $ hg perfbranchmap
  $ hg perfcca
  $ hg perfchangegroupchangelog
  $ hg perfchangeset 2
  $ hg perfctxfiles 2
  $ hg perfdiffwd
  $ hg perfdirfoldmap
  $ hg perfdirs
  $ hg perfdirstate
  $ hg perfdirstatedirs
  $ hg perfdirstatefoldmap
  $ hg perfdirstatewrite
  $ hg perffncacheencode
  $ hg perffncacheload
  $ hg perffncachewrite
  $ hg perfheads
  $ hg perfindex
  $ hg perfloadmarkers
  $ hg perflog
  $ hg perflookup 2
  $ hg perflrucache
  $ hg perfmanifest 2
  $ hg perfmergecalculate -r 3
  $ hg perfmoonwalk
  $ hg perfnodelookup 2
  $ hg perfpathcopies 1 2
  $ hg perfrawfiles 2
  $ hg perfrevlogindex -c
  $ hg perfrevlogrevisions .hg/store/data/a.i
  $ hg perfrevlogrevision -m 0
  $ hg perfrevlogchunks -c
  $ hg perfrevrange
  $ hg perfrevset 'all()'
  $ hg perfstartup
  $ hg perfstatus
  $ hg perftags
  $ hg perftemplating
  $ hg perfvolatilesets
  $ hg perfwalk
  $ hg perfparents

Check perf.py for historical portability

  $ cd "$TESTDIR/.."

  $ (testrepohg files -r 1.2 glob:mercurial/*.c glob:mercurial/*.py;
  >  testrepohg files -r tip glob:mercurial/*.c glob:mercurial/*.py) |
  > "$TESTDIR"/check-perf-code.py contrib/perf.py