view tests/test-fastannotate-protocol.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 >> $HGRCPATH << EOF
  > [ui]
  > ssh = "$PYTHON" "$TESTDIR/dummyssh"
  > [extensions]
  > fastannotate=
  > [fastannotate]
  > mainbranch=@
  > EOF

  $ HGMERGE=true; export HGMERGE

setup the server repo

  $ hg init repo-server
  $ cd repo-server
  $ cat >> .hg/hgrc << EOF
  > [fastannotate]
  > server=1
  > EOF
  $ for i in 1 2 3 4; do
  >   echo $i >> a
  >   hg commit -A -m $i a
  > done
  $ [ -d .hg/fastannotate ]
  [1]
  $ hg bookmark @
  $ cd ..

setup the local repo

  $ hg clone 'ssh://user@dummy/repo-server' repo-local -q
  $ cd repo-local
  $ cat >> .hg/hgrc << EOF
  > [fastannotate]
  > client=1
  > clientfetchthreshold=0
  > EOF
  $ [ -d .hg/fastannotate ]
  [1]
  $ hg fastannotate a --debug
  running * (glob)
  sending hello command
  sending between command
  remote: * (glob) (?)
  remote: capabilities: * (glob)
  remote: * (glob) (?)
  sending protocaps command
  fastannotate: requesting 1 files
  sending getannotate command
  fastannotate: writing 112 bytes to fastannotate/default/a.l
  fastannotate: writing 94 bytes to fastannotate/default/a.m
  fastannotate: a: using fast path (resolved fctx: True)
  0: 1
  1: 2
  2: 3
  3: 4

the cache could be reused and no download is necessary

  $ hg fastannotate a --debug
  fastannotate: a: using fast path (resolved fctx: True)
  0: 1
  1: 2
  2: 3
  3: 4

if the client agrees where the head of the master branch is, no re-download
happens even if the client has more commits

  $ echo 5 >> a
  $ hg commit -m 5
  $ hg bookmark -r 3 @ -f
  $ hg fastannotate a --debug
  0: 1
  1: 2
  2: 3
  3: 4
  4: 5

if the client has a different "@" (head of the master branch) and "@" is ahead
of the server, the server can detect things are unchanged and does not return
full contents (not that there is no "writing ... to fastannotate"), but the
client can also build things up on its own (causing diverge)

  $ hg bookmark -r 4 @ -f
  $ hg fastannotate a --debug
  running * (glob)
  sending hello command
  sending between command
  remote: * (glob) (?)
  remote: capabilities: * (glob)
  remote: * (glob) (?)
  sending protocaps command
  fastannotate: requesting 1 files
  sending getannotate command
  fastannotate: a: 1 new changesets in the main branch
  0: 1
  1: 2
  2: 3
  3: 4
  4: 5

if the client has a different "@" which is behind the server. no download is
necessary

  $ hg fastannotate a --debug --config fastannotate.mainbranch=2
  fastannotate: a: using fast path (resolved fctx: True)
  0: 1
  1: 2
  2: 3
  3: 4
  4: 5

define fastannotate on-disk paths

  $ p1=.hg/fastannotate/default
  $ p2=../repo-server/.hg/fastannotate/default

revert bookmark change so the client is behind the server

  $ hg bookmark -r 2 @ -f

in the "fctx" mode with the "annotate" command, the client also downloads the
cache. but not in the (default) "fastannotate" mode.

  $ rm $p1/a.l $p1/a.m
  $ hg annotate a --debug | grep 'fastannotate: writing'
  [1]
  $ hg annotate a --config fastannotate.modes=fctx --debug | grep 'fastannotate: writing' | sort
  fastannotate: writing 112 bytes to fastannotate/default/a.l
  fastannotate: writing 94 bytes to fastannotate/default/a.m

the fastannotate cache (built server-side, downloaded client-side) in two repos
have the same content (because the client downloads from the server)

  $ diff $p1/a.l $p2/a.l
  $ diff $p1/a.m $p2/a.m

in the "fctx" mode, the client could also build the cache locally

  $ hg annotate a --config fastannotate.modes=fctx --debug --config fastannotate.mainbranch=4 | grep fastannotate
  fastannotate: requesting 1 files
  fastannotate: a: 1 new changesets in the main branch

the server would rebuild broken cache automatically

  $ cp $p2/a.m $p2/a.m.bak
  $ echo BROKEN1 > $p1/a.m
  $ echo BROKEN2 > $p2/a.m
  $ hg fastannotate a --debug | grep 'fastannotate: writing' | sort
  fastannotate: writing 112 bytes to fastannotate/default/a.l
  fastannotate: writing 94 bytes to fastannotate/default/a.m
  $ diff $p1/a.m $p2/a.m
  $ diff $p2/a.m $p2/a.m.bak

use the "debugbuildannotatecache" command to build annotate cache

  $ rm -rf $p1 $p2
  $ hg --cwd ../repo-server debugbuildannotatecache a --debug
  fastannotate: a: 4 new changesets in the main branch
  $ hg --cwd ../repo-local debugbuildannotatecache a --debug
  running * (glob)
  sending hello command
  sending between command
  remote: * (glob) (?)
  remote: capabilities: * (glob)
  remote: * (glob) (?)
  sending protocaps command
  fastannotate: requesting 1 files
  sending getannotate command
  fastannotate: writing * (glob)
  fastannotate: writing * (glob)
  $ diff $p1/a.l $p2/a.l
  $ diff $p1/a.m $p2/a.m

with the clientfetchthreshold config option, the client can build up the cache
without downloading from the server

  $ rm -rf $p1
  $ hg fastannotate a --debug --config fastannotate.clientfetchthreshold=10
  fastannotate: a: 3 new changesets in the main branch
  0: 1
  1: 2
  2: 3
  3: 4
  4: 5

if the fastannotate directory is not writable, the fctx mode still works

  $ rm -rf $p1
  $ touch $p1
  $ hg annotate a --debug --traceback --config fastannotate.modes=fctx
  fastannotate: a: cache broken and deleted
  fastannotate: prefetch failed: * (glob)
  fastannotate: a: cache broken and deleted
  fastannotate: falling back to the vanilla annotate: * (glob)
  0: 1
  1: 2
  2: 3
  3: 4
  4: 5

with serverbuildondemand=False, the server will not build anything

  $ cat >> ../repo-server/.hg/hgrc <<EOF
  > [fastannotate]
  > serverbuildondemand=False
  > EOF
  $ rm -rf $p1 $p2
  $ hg fastannotate a --debug | grep 'fastannotate: writing'
  [1]