view tests/test-pull-pull-corruption.t @ 24735:07200e3332a1

tags: extract .hgtags filenodes cache to a standalone file Resolution of .hgtags filenodes values has historically been a performance pain point for large repositories, where reading individual manifests can take over 100ms. Multiplied by hundreds or even thousands of heads and resolving .hgtags filenodes becomes a performance issue. This patch establishes a standalone cache file holding the .hgtags filenodes for each changeset. After this patch, the .hgtags filenode for any particular changeset should only have to be computed once during the lifetime of the repository. The introduced hgtagsfnodes1 cache file is modeled after the rev branch cache: the cache is effectively an array of entries consisting of a changeset fragment and the filenode for a revision. The file grows in proportion to the length of the repository (24 bytes per changeset) and is truncated when the repository is stripped. The file is not written unless tag info is requested and tags have changed since last time. This patch partially addresses issue4550. Future patches will split the "tags" cache file into per-filter files and will refactor the cache format to not capture the .hgtags fnodes, as these are now stored in the hgtagsfnodes1 cache. This patch is capable of standing alone. We should not have to wait on the tags cache filter split and format refactor for this patch to land.
author Gregory Szorc <gregory.szorc@gmail.com>
date Wed, 15 Apr 2015 17:42:38 -0400
parents f2719b387380
children eb586ed5d8ce
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Corrupt an hg repo with two pulls.
create one repo with a long history

  $ hg init source1
  $ cd source1
  $ touch foo
  $ hg add foo
  $ for i in 1 2 3 4 5 6 7 8 9 10; do
  >     echo $i >> foo
  >     hg ci -m $i
  > done
  $ cd ..

create one repo with a shorter history

  $ hg clone -r 0 source1 source2
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd source2
  $ echo a >> foo
  $ hg ci -m a
  $ cd ..

create a third repo to pull both other repos into it

  $ hg init corrupted
  $ cd corrupted

use a hook to make the second pull start while the first one is still running

  $ echo '[hooks]' >> .hg/hgrc
  $ echo 'prechangegroup = sleep 5' >> .hg/hgrc

start a pull...

  $ hg pull ../source1 > pull.out 2>&1 &

... and start another pull before the first one has finished

  $ sleep 1
  $ hg pull ../source2 2>/dev/null
  pulling from ../source2
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files (+1 heads)
  (run 'hg heads' to see heads, 'hg merge' to merge)
  $ cat pull.out
  pulling from ../source1
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 10 changesets with 10 changes to 1 files
  (run 'hg update' to get a working copy)

see the result

  $ wait
  $ hg verify
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  1 files, 11 changesets, 11 total revisions

  $ cd ..