view tests/test-fastannotate-perfhack.t @ 42377:0546ead39a7e stable

manifest: avoid corruption by dropping removed files with pure (issue5801)

Previously, removed files would simply be marked by overwriting the first byte
with NUL and dropping their entry in `self.position`.  But no effort was made to
ignore them when compacting the dictionary into text form.  This allowed them to
slip into the manifest revision, since the code seems to be trying to minimize
the string operations by copying as large a chunk as possible.  As part of this,
compact() walks the existing text based on entries in the `positions` list, and
consumed everything up to the next position entry.   This typically resulted in
a ValueError complaining about unsorted manifest entries.

Sometimes it seems that files do get dropped in large repos- it seems to
correspond to there being a new entry that would take the same slot.  A much
more trivial problem is that if the only changes were removals, `_compact()`
didn't even run because `__delitem__` doesn't add anything to `self.extradata`.
Now there's an explicit variable to flag this, both to allow `_compact()` to
run, and to avoid searching the manifest in cases where there are no removals.

In practice, this behavior was mostly obscured by the check in fastdelta() which
takes a different path that explicitly drops removed files if there are fewer
than 1000 changes.  However, timeless has a repo where after rebasing tens of
commits, a totally different path[1] is taken that bypasses the change count
check and hits this problem.

[1] https://www.mercurial-scm.org/repo/hg/file/2338bdea4474/mercurial/manifest.py#l1511

  $ cat >> $HGRCPATH << EOF
  > [extensions]
  > fastannotate=
  > [fastannotate]
  > perfhack=1
  > EOF

  $ HGMERGE=true; export HGMERGE

  $ hg init repo
  $ cd repo

a simple merge case

  $ echo 1 > a
  $ hg commit -qAm 'append 1'
  $ echo 2 >> a
  $ hg commit -m 'append 2'
  $ echo 3 >> a
  $ hg commit -m 'append 3'
  $ hg up 1 -q
  $ cat > a << EOF
  > 0
  > 1
  > 2
  > EOF
  $ hg commit -qm 'insert 0'
  $ hg merge 2 -q
  $ echo 4 >> a
  $ hg commit -m merge
  $ hg log -G -T '{rev}: {desc}'
  @    4: merge
  |\
  | o  3: insert 0
  | |
  o |  2: append 3
  |/
  o  1: append 2
  |
  o  0: append 1
  
  $ hg fastannotate a
  3: 0
  0: 1
  1: 2
  2: 3
  4: 4
  $ hg fastannotate -r 0 a
  0: 1
  $ hg fastannotate -r 1 a
  0: 1
  1: 2
  $ hg fastannotate -udnclf a
  test 3 d641cb51f61e Thu Jan 01 00:00:00 1970 +0000 a:1: 0
  test 0 4994017376d3 Thu Jan 01 00:00:00 1970 +0000 a:1: 1
  test 1 e940cb6d9a06 Thu Jan 01 00:00:00 1970 +0000 a:2: 2
  test 2 26162a884ba6 Thu Jan 01 00:00:00 1970 +0000 a:3: 3
  test 4 3ad7bcd2815f Thu Jan 01 00:00:00 1970 +0000 a:5: 4
  $ hg fastannotate --linear a
  3: 0
  0: 1
  1: 2
  4: 3
  4: 4

incrementally updating

  $ hg fastannotate -r 0 a --debug
  fastannotate: a: using fast path (resolved fctx: True)
  0: 1
  $ hg fastannotate -r 0 a --debug --rebuild
  fastannotate: a: 1 new changesets in the main branch
  0: 1
  $ hg fastannotate -r 1 a --debug
  fastannotate: a: 1 new changesets in the main branch
  0: 1
  1: 2
  $ hg fastannotate -r 3 a --debug
  fastannotate: a: 1 new changesets in the main branch
  3: 0
  0: 1
  1: 2
  $ hg fastannotate -r 4 a --debug
  fastannotate: a: 1 new changesets in the main branch
  3: 0
  0: 1
  1: 2
  2: 3
  4: 4
  $ hg fastannotate -r 1 a --debug
  fastannotate: a: using fast path (resolved fctx: True)
  0: 1
  1: 2

rebuild happens automatically if unable to update

  $ hg fastannotate -r 2 a --debug
  fastannotate: a: cache broken and deleted
  fastannotate: a: 3 new changesets in the main branch
  0: 1
  1: 2
  2: 3

config option "fastannotate.mainbranch"

  $ hg fastannotate -r 1 --rebuild --config fastannotate.mainbranch=tip a --debug
  fastannotate: a: 4 new changesets in the main branch
  0: 1
  1: 2
  $ hg fastannotate -r 4 a --debug
  fastannotate: a: using fast path (resolved fctx: True)
  3: 0
  0: 1
  1: 2
  2: 3
  4: 4

rename

  $ hg mv a b
  $ cat > b << EOF
  > 0
  > 11
  > 3
  > 44
  > EOF
  $ hg commit -m b -q
  $ hg fastannotate -ncf --long-hash b
  3 d641cb51f61e331c44654104301f8154d7865c89 a: 0
  5 d44dade239915bc82b91e4556b1257323f8e5824 b: 11
  2 26162a884ba60e8c87bf4e0d6bb8efcc6f711a4e a: 3
  5 d44dade239915bc82b91e4556b1257323f8e5824 b: 44
  $ hg fastannotate -r 26162a884ba60e8c87bf4e0d6bb8efcc6f711a4e a
  0: 1
  1: 2
  2: 3

fastannotate --deleted

  $ hg fastannotate --deleted -nf b
  3 a:  0
  5 b:  11
  0 a: -1
  1 a: -2
  2 a:  3
  5 b:  44
  4 a: -4
  $ hg fastannotate --deleted -r 3 -nf a
  3 a:  0
  0 a:  1
  1 a:  2

file and directories with ".l", ".m" suffixes

  $ cd ..
  $ hg init repo2
  $ cd repo2

  $ mkdir a.l b.m c.lock a.l.hg b.hg
  $ for i in a b c d d.l d.m a.l/a b.m/a c.lock/a a.l.hg/a b.hg/a; do
  >   echo $i > $i
  > done
  $ hg add . -q
  $ hg commit -m init
  $ hg fastannotate a.l/a b.m/a c.lock/a a.l.hg/a b.hg/a d.l d.m a b c d
  0: a
  0: a.l.hg/a
  0: a.l/a
  0: b
  0: b.hg/a
  0: b.m/a
  0: c
  0: c.lock/a
  0: d
  0: d.l
  0: d.m

empty file

  $ touch empty
  $ hg commit -A empty -m empty
  $ hg fastannotate empty