view tests/test-mq-qpush-exact.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.

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "mq=" >> $HGRCPATH

make a test repository that looks like this:

o    2:28bc7b1afd6a
|
| @  1:d7fe2034f71b
|/
o    0/62ecad8b70e5

  $ hg init r0
  $ cd r0
  $ touch f0
  $ hg ci -m0 -Aq
  $ touch f1
  $ hg ci -m1 -Aq

  $ hg update 0 -q
  $ touch f2
  $ hg ci -m2 -Aq
  $ hg update 1 -q

make some patches with a parent: 1:d7fe2034f71b -> p0 -> p1

  $ echo cp0 >> fp0
  $ hg add fp0
  $ hg ci -m p0 -d "0 0"
  $ hg export -r. > p0
  $ hg strip -qn .
  $ hg qimport p0
  adding p0 to series file
  $ hg qpush
  applying p0
  now at: p0

  $ echo cp1 >> fp1
  $ hg add fp1
  $ hg qnew p1 -d "0 0"

  $ hg qpop -aq
  patch queue now empty

qpush --exact when at the parent

  $ hg update 1 -q
  $ hg qpush -e
  applying p0
  now at: p0
  $ hg parents -qr qbase
  1:d7fe2034f71b
  $ hg qpop -aq
  patch queue now empty

  $ hg qpush -e p0
  applying p0
  now at: p0
  $ hg parents -qr qbase
  1:d7fe2034f71b
  $ hg qpop -aq
  patch queue now empty

  $ hg qpush -e p1
  applying p0
  applying p1
  now at: p1
  $ hg parents -qr qbase
  1:d7fe2034f71b
  $ hg qpop -aq
  patch queue now empty

qpush --exact when at another rev

  $ hg update 0 -q
  $ hg qpush -e
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  applying p0
  now at: p0
  $ hg parents -qr qbase
  1:d7fe2034f71b
  $ hg qpop -aq
  patch queue now empty

  $ hg update 0 -q
  $ hg qpush -e p0
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  applying p0
  now at: p0
  $ hg parents -qr qbase
  1:d7fe2034f71b
  $ hg qpop -aq
  patch queue now empty

  $ hg update 0 -q
  $ hg qpush -e p1
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  applying p0
  applying p1
  now at: p1
  $ hg parents -qr qbase
  1:d7fe2034f71b
  $ hg qpop -aq
  patch queue now empty

  $ hg update 0 -q
  $ hg qpush -ea
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  applying p0
  applying p1
  now at: p1
  $ hg parents -qr qbase
  1:d7fe2034f71b
  $ hg qpop -aq
  patch queue now empty

qpush --exact while crossing branches

  $ hg update 2 -q
  $ hg qpush -e
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  applying p0
  now at: p0
  $ hg parents -qr qbase
  1:d7fe2034f71b
  $ hg qpop -aq
  patch queue now empty

  $ hg update 2 -q
  $ hg qpush -e p0
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  applying p0
  now at: p0
  $ hg parents -qr qbase
  1:d7fe2034f71b
  $ hg qpop -aq
  patch queue now empty

  $ hg update 2 -q
  $ hg qpush -e p1
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  applying p0
  applying p1
  now at: p1
  $ hg parents -qr qbase
  1:d7fe2034f71b
  $ hg qpop -aq
  patch queue now empty

  $ hg update 2 -q
  $ hg qpush -ea
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  applying p0
  applying p1
  now at: p1
  $ hg parents -qr qbase
  1:d7fe2034f71b
  $ hg qpop -aq
  patch queue now empty

qpush --exact --force with changes to an unpatched file

  $ hg update 1 -q
  $ echo c0 >> f0
  $ hg qpush -e
  abort: local changes found
  [255]
  $ hg qpush -ef
  applying p0
  now at: p0
  $ cat f0
  c0
  $ rm f0
  $ touch f0
  $ hg qpop -aq
  patch queue now empty

  $ hg update 1 -q
  $ echo c0 >> f0
  $ hg qpush -e p1
  abort: local changes found
  [255]
  $ hg qpush -e p1 -f
  applying p0
  applying p1
  now at: p1
  $ cat f0
  c0
  $ rm f0
  $ touch f0
  $ hg qpop -aq
  patch queue now empty

qpush --exact --force with changes to a patched file

  $ hg update 1 -q
  $ echo cp0-bad >> fp0
  $ hg add fp0
  $ hg qpush -e
  abort: local changes found
  [255]
  $ hg qpush -ef
  applying p0
  file fp0 already exists
  1 out of 1 hunks FAILED -- saving rejects to file fp0.rej
  patch failed, unable to continue (try -v)
  patch failed, rejects left in working directory
  errors during apply, please fix and qrefresh p0
  [2]
  $ cat fp0
  cp0-bad
  $ cat fp0.rej
  --- fp0
  +++ fp0
  @@ -0,0 +1,1 @@
  +cp0
  $ hg qpop -aqf
  patch queue now empty
  $ rm fp0
  $ rm fp0.rej

  $ hg update 1 -q
  $ echo cp1-bad >> fp1
  $ hg add fp1
  $ hg qpush -e p1
  abort: local changes found
  [255]
  $ hg qpush -e p1 -f
  applying p0
  applying p1
  file fp1 already exists
  1 out of 1 hunks FAILED -- saving rejects to file fp1.rej
  patch failed, unable to continue (try -v)
  patch failed, rejects left in working directory
  errors during apply, please fix and qrefresh p1
  [2]
  $ cat fp1
  cp1-bad
  $ cat fp1.rej
  --- fp1
  +++ fp1
  @@ -0,0 +1,1 @@
  +cp1
  $ hg qpop -aqf
  patch queue now empty
  $ hg forget fp1
  $ rm fp1
  $ rm fp1.rej

qpush --exact when already at a patch

  $ hg update 1
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg qpush -e p0
  applying p0
  now at: p0
  $ hg qpush -e p1
  abort: cannot push --exact with applied patches
  [255]
  $ hg qpop -aq
  patch queue now empty

qpush --exact --move should fail

  $ hg qpush -e --move p1
  abort: cannot use --exact and --move together
  [255]

qpush --exact a patch without a parent recorded

  $ hg qpush -q
  now at: p0
  $ grep -v '# Parent' .hg/patches/p0 > p0.new
  $ mv p0.new .hg/patches/p0
  $ hg qpop -aq
  patch queue now empty
  $ hg qpush -e
  abort: p0 does not have a parent recorded
  [255]
  $ hg qpush -e p0
  abort: p0 does not have a parent recorded
  [255]
  $ hg qpush -e p1
  abort: p0 does not have a parent recorded
  [255]
  $ hg qpush -ea
  abort: p0 does not have a parent recorded
  [255]

  $ cd ..