tests/test-subrepo-missing.t

cborutil: change buffering strategy

Profiling revealed that we were spending a lot of time on the
line that was concatenating the old buffer with the incoming data
when attempting to decode long byte strings, such as manifest
revisions.

Essentially, we were feeding N chunks of size len(X) << len(Y) into
decode() and continuously allocating a new, larger buffer to hold
the undecoded input. This created substantial memory churn and
slowed down execution.

Changing the code to aggregate pending chunks in a list until we
have enough data to fully decode the next atom makes things much
more efficient.

I don't have exact data, but I recall the old code spending >1s
on manifest fulltexts from the mozilla-unified repo. The new code
doesn't significantly appear in profile output.

Differential Revision: https://phab.mercurial-scm.org/D4854

  $ hg init repo
  $ cd repo
  $ hg init subrepo
  $ echo a > subrepo/a
  $ hg -R subrepo ci -Am adda
  adding a
  $ echo 'subrepo = subrepo' > .hgsub
  $ hg ci -Am addsubrepo
  adding .hgsub
  $ echo b > subrepo/b
  $ hg -R subrepo ci -Am addb
  adding b
  $ hg ci -m updatedsub

ignore blanklines in .hgsubstate

  >>> open('.hgsubstate', 'wb').write(b'\n\n   \t \n   \n') and None
  $ hg st --subrepos
  M .hgsubstate
  $ hg revert -qC .hgsubstate

abort more gracefully on .hgsubstate parsing error

  $ cp .hgsubstate .hgsubstate.old
  >>> open('.hgsubstate', 'wb').write(b'\ninvalid') and None
  $ hg st --subrepos --cwd $TESTTMP -R $TESTTMP/repo
  abort: invalid subrepository revision specifier in 'repo/.hgsubstate' line 2
  [255]
  $ mv .hgsubstate.old .hgsubstate

delete .hgsub and revert it

  $ rm .hgsub
  $ hg revert .hgsub
  warning: subrepo spec file '.hgsub' not found
  warning: subrepo spec file '.hgsub' not found

delete .hgsubstate and revert it

  $ rm .hgsubstate
  $ hg revert .hgsubstate

delete .hgsub and update

  $ rm .hgsub
  $ hg up 0 --cwd $TESTTMP -R $TESTTMP/repo
  warning: subrepo spec file 'repo/.hgsub' not found
  warning: subrepo spec file 'repo/.hgsub' not found
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg st
  warning: subrepo spec file '.hgsub' not found
  ! .hgsub
  $ ls subrepo
  a

delete .hgsubstate and update

  $ hg up -C
  warning: subrepo spec file '.hgsub' not found
  warning: subrepo spec file '.hgsub' not found
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm .hgsubstate
  $ hg up 0
  other [destination] changed .hgsubstate which local [working copy] deleted
  use (c)hanged version or leave (d)eleted? c
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg st
  $ ls subrepo
  a

Enable obsolete

  $ cat >> $HGRCPATH << EOF
  > [ui]
  > logtemplate= {rev}:{node|short} {desc|firstline}
  > [phases]
  > publish=False
  > [experimental]
  > evolution.createmarkers=True
  > EOF

check that we can update parent repo with missing (amended) subrepo revision

  $ hg up --repository subrepo -r tip
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg ci -m "updated subrepo to tip"
  created new head
  $ cd subrepo
  $ hg update -r tip
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo foo > a
  $ hg commit --amend -m "addb (amended)"
  $ cd ..
  $ hg update --clean .
  revision 102a90ea7b4a in subrepository "subrepo" is hidden
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

check that --hidden is propagated to the subrepo

  $ hg -R subrepo up tip
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg ci -m 'commit with amended subrepo'
  $ echo bar > subrepo/a
  $ hg -R subrepo ci --amend -m "amend a (again)"
  $ hg --hidden cat subrepo/a
  foo

verify will warn if locked-in subrepo revisions are hidden or missing

  $ hg ci -m "amended subrepo (again)"
  $ hg --config extensions.strip= --hidden strip -R subrepo -qr 'tip' --config devel.strip-obsmarkers=no
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 5 changesets with 5 changes to 2 files
  checking subrepo links
  subrepo 'subrepo' is hidden in revision a66de08943b6
  subrepo 'subrepo' is hidden in revision 674d05939c1e
  subrepo 'subrepo' not found in revision a7d05d9055a4

verifying shouldn't init a new subrepo if the reference doesn't exist

  $ mv subrepo b
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 5 changesets with 5 changes to 2 files
  checking subrepo links
  0: repository $TESTTMP/repo/subrepo not found
  1: repository $TESTTMP/repo/subrepo not found
  3: repository $TESTTMP/repo/subrepo not found
  4: repository $TESTTMP/repo/subrepo not found
  $ ls
  b
  $ mv b subrepo

  $ cd ..