view tests/test-mq-qrefresh-replace-log-message.t @ 39496:2f9f7889549b

snapshot: introduce an intermediate `_refinedgroups` generator

This method will be used to improve the search for a good snapshot base. To
keep things simpler, we introduce the necessary function before doing any
delta base logic change. The next handful of commits will focus on refactoring
the code to let that new logic land as clearly as possible.

# General Idea

Right now, the search for a good delta base stop whenever we found a good one.
However, when using sparse-revlog, we should probably try a bit harder.

We do significant effort to increase delta re-use by jumping on "unrelated"
delta chains that provide better results. Moving to another chain for a better
result is good, but we have no guarantee we jump at a reasonable point in that
new chain. When we consider over the chains related to the parents, we start
from the higher-level snapshots. This is a way to consider the snapshot closer
to the current revision that has the best chance to produce a small delta. We
do benefit from this walk order when jumping to a better "unrelated" stack.

To counter-balance this, we'll introduce a way to "refine" the result. After a
good delta have been found, we'll keep searching for a better delta, using the
current best one as a starting point.

# Target Setup

The `finddeltainfo` method is responsible for the general search for a good
delta. It requests candidates base from `_candidategroups` and decides which
one are usable.

The `_candidategroups` generator act as a top-level filter, it does not care
about how we pick candidates, it just does basic filtering, excluding
revisions that have been tested already or that are an obvious misfit.

The `_rawgroups` generator is the one with the actual ancestors walking logic,
It does not care about what would do a good delta and what was already tested,
it just issues the initial candidates.

We introduce a new `_refinedgroup` function to bridge the gap between
`_candidategroups` and `_rawgroups`. It delegates the initial iteration logic
and then performing relevant refining of the valid base once found. (This
logic is yet to be added to function)

All these logics are fairly independent and easier to understand when standing
alone, not mixed with each other. It also makes it easy to test and try
different approaches for one of those four layers without affecting the other
ones.

# Technical details

To communicate `finddeltainfo` choice of "current best delta base" to the
`_refinegroup` logic, we plan to use python co-routine feature. The
`_candidategroups` and `_refinegroup` generators will become co-routine. This
will allow `_refinegroup` to detect when a good delta have been found and
triggers various refining steps.

For now, `_candidategroups` will just pass the value down the stack.

After poking at various option, the co-routine appears the best to keep each
layers focus on its duty, without the need to spread implementation details
across layers.

Environment setup for MQ

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "mq=" >> $HGRCPATH
  $ cat >> $HGRCPATH <<EOF
  > [defaults]
  > # explicit date to commit with fixed hashid
  > qnew = -d "0 0"
  > qrefresh = -d "0 0"
  > qfold = -d "0 0"
  > EOF
  $ hg init
  $ hg qinit

Should fail if no patches applied
(this tests also that editor is not invoked if '--edit' is not
specified)

  $ hg qrefresh
  no patches applied
  [1]
  $ hg qrefresh -e
  no patches applied
  [1]
  $ hg qnew -m "First commit message" first-patch
  $ echo aaaa > file
  $ hg add file
  $ HGEDITOR=cat hg qrefresh

Should display 'First commit message'

  $ hg log -l1 --template "{desc}\n"
  First commit message

Testing changing message with -m
(this tests also that '--edit' can be used with '--message', and
that '[committemplate] changeset' definition and commit log specific
template keyword 'extramsg' work well)

  $ cat >> .hg/hgrc <<EOF
  > [committemplate]
  > listupfiles = {file_adds %
  >    "HG: added {file}\n"     }{file_mods %
  >    "HG: changed {file}\n"   }{file_dels %
  >    "HG: removed {file}\n"   }{if(files, "",
  >    "HG: no files changed\n")}
  > 
  > changeset = HG: this is customized commit template
  >     {desc}\n\n
  >     HG: Enter commit message.  Lines beginning with 'HG:' are removed.
  >     HG: {extramsg}
  >     HG: --
  >     HG: user: {author}
  >     HG: branch '{branch}'\n{listupfiles}
  > EOF

  $ echo bbbb > file
  $ HGEDITOR=cat hg qrefresh -m "Second commit message" -e
  HG: this is customized commit template
  Second commit message
  
  
  HG: Enter commit message.  Lines beginning with 'HG:' are removed.
  HG: Leave message empty to use default message.
  HG: --
  HG: user: test
  HG: branch 'default'
  HG: added file

  $ cat >> .hg/hgrc <<EOF
  > # disable customizing for subsequent tests
  > [committemplate]
  > changeset =
  > EOF

Should display 'Second commit message'

  $ hg log -l1 --template "{desc}\n"
  Second commit message

Testing changing message with -l

  $ echo "Third commit message" > logfile
  $ echo " This is the 3rd log message" >> logfile
  $ echo bbbb > file
  $ hg qrefresh -l logfile

Should display 'Third commit message\\\n This is the 3rd log message'

  $ hg log -l1 --template "{desc}\n"
  Third commit message
   This is the 3rd log message

Testing changing message with -l-

  $ hg qnew -m "First commit message" second-patch
  $ echo aaaa > file2
  $ hg add file2
  $ echo bbbb > file2
  $ (echo "Fifth commit message"; echo " This is the 5th log message") | hg qrefresh -l-

Should display 'Fifth commit message\\\n This is the 5th log message'

  $ hg log -l1 --template "{desc}\n"
  Fifth commit message
   This is the 5th log message

Test saving last-message.txt:

  $ cat > $TESTTMP/editor.sh << EOF
  > echo "==== before editing"
  > cat \$1
  > echo "===="
  > (echo; echo "test saving last-message.txt") >> \$1
  > EOF

  $ cat > $TESTTMP/commitfailure.py <<EOF
  > from mercurial import error
  > def reposetup(ui, repo):
  >     class commitfailure(repo.__class__):
  >         def commit(self, *args, **kwargs):
  >             raise error.Abort(b'emulating unexpected abort')
  >     repo.__class__ = commitfailure
  > EOF

  $ cat >> .hg/hgrc <<EOF
  > [extensions]
  > # this failure occurs before editor invocation
  > commitfailure = $TESTTMP/commitfailure.py
  > EOF

  $ hg qapplied
  first-patch
  second-patch
  $ hg tip --template "{files}\n"
  file2

(test that editor is not invoked before transaction starting)

  $ rm -f .hg/last-message.txt
  $ HGEDITOR="sh $TESTTMP/editor.sh" hg qrefresh -e
  qrefresh interrupted while patch was popped! (revert --all, qpush to recover)
  abort: emulating unexpected abort
  [255]
  $ test -f .hg/last-message.txt
  [1]

(reset applied patches and directory status)

  $ cat >> .hg/hgrc <<EOF
  > [extensions]
  > commitfailure = !
  > EOF

  $ hg qapplied
  first-patch
  $ hg status -A file2
  ? file2
  $ rm file2
  $ hg qpush -q second-patch
  now at: second-patch

(test that editor is invoked and commit message is saved into
"last-message.txt")

  $ cat >> .hg/hgrc <<EOF
  > [hooks]
  > # this failure occurs after editor invocation
  > pretxncommit.unexpectedabort = false
  > EOF

  $ rm -f .hg/last-message.txt
  $ hg status --rev "second-patch^1" -arm
  A file2
  $ HGEDITOR="sh $TESTTMP/editor.sh" hg qrefresh -e
  ==== before editing
  Fifth commit message
   This is the 5th log message
  
  
  HG: Enter commit message.  Lines beginning with 'HG:' are removed.
  HG: Leave message empty to use default message.
  HG: --
  HG: user: test
  HG: branch 'default'
  HG: added file2
  ====
  note: commit message saved in .hg/last-message.txt
  transaction abort!
  rollback completed
  qrefresh interrupted while patch was popped! (revert --all, qpush to recover)
  abort: pretxncommit.unexpectedabort hook exited with status 1
  [255]
  $ cat .hg/last-message.txt
  Fifth commit message
   This is the 5th log message
  
  
  
  test saving last-message.txt

Test visibility of in-memory dirstate changes outside transaction to
external process

  $ cat > $TESTTMP/checkvisibility.sh <<EOF
  > echo "===="
  > hg parents --template "{rev}:{node|short}\n"
  > hg status -arm
  > echo "===="
  > EOF

== test visibility to external editor

  $ hg update -C -q first-patch
  $ rm -f file2
  $ hg qpush -q second-patch --config hooks.pretxncommit.unexpectedabort=
  now at: second-patch
  $ echo bbbb >> file2

  $ sh "$TESTTMP/checkvisibility.sh"
  ====
  1:e30108269082
  M file2
  ====

  $ HGEDITOR="sh \"$TESTTMP/checkvisibility.sh\"" hg qrefresh -e
  ====
  0:25e397dabed2
  A file2
  ====
  note: commit message saved in .hg/last-message.txt
  transaction abort!
  rollback completed
  qrefresh interrupted while patch was popped! (revert --all, qpush to recover)
  abort: pretxncommit.unexpectedabort hook exited with status 1
  [255]

(rebuilding at failure of qrefresh bases on rev #0, and it causes
dropping status of "file2")

  $ sh "$TESTTMP/checkvisibility.sh"
  ====
  0:25e397dabed2
  ====

== test visibility to precommit external hook

  $ hg update -C -q
  $ rm -f file2
  $ hg qpush -q second-patch --config hooks.pretxncommit.unexpectedabort=
  now at: second-patch
  $ echo bbbb >> file2

  $ cat >> .hg/hgrc <<EOF
  > [hooks]
  > precommit.checkvisibility = sh "$TESTTMP/checkvisibility.sh"
  > EOF

  $ sh "$TESTTMP/checkvisibility.sh"
  ====
  1:e30108269082
  M file2
  ====

  $ hg qrefresh
  ====
  0:25e397dabed2
  A file2
  ====
  transaction abort!
  rollback completed
  qrefresh interrupted while patch was popped! (revert --all, qpush to recover)
  abort: pretxncommit.unexpectedabort hook exited with status 1
  [255]

  $ sh "$TESTTMP/checkvisibility.sh"
  ====
  0:25e397dabed2
  ====

  $ cat >> .hg/hgrc <<EOF
  > [hooks]
  > precommit.checkvisibility =
  > EOF

== test visibility to pretxncommit external hook

  $ hg update -C -q
  $ rm -f file2
  $ hg qpush -q second-patch --config hooks.pretxncommit.unexpectedabort=
  now at: second-patch
  $ echo bbbb >> file2

  $ cat >> .hg/hgrc <<EOF
  > [hooks]
  > pretxncommit.checkvisibility = sh "$TESTTMP/checkvisibility.sh"
  > # make checkvisibility run before unexpectedabort
  > priority.pretxncommit.checkvisibility = 10
  > EOF

  $ sh "$TESTTMP/checkvisibility.sh"
  ====
  1:e30108269082
  M file2
  ====

  $ hg qrefresh
  ====
  0:25e397dabed2
  A file2
  ====
  transaction abort!
  rollback completed
  qrefresh interrupted while patch was popped! (revert --all, qpush to recover)
  abort: pretxncommit.unexpectedabort hook exited with status 1
  [255]

  $ sh "$TESTTMP/checkvisibility.sh"
  ====
  0:25e397dabed2
  ====

  $ cat >> .hg/hgrc <<EOF
  > [hooks]
  > pretxncommit.checkvisibility =
  > EOF