view tests/test-rebase-mq-skip.t @ 38781:0a57945aaf7f

manifest: persist the manifestfulltext cache

Reconstructing the manifest from the revlog takes time, so much so that there
already is a LRU cache to avoid having to load a manifest multiple times.

This patch persists that LRU cache in the .hg/cache directory, so we can re-use
this cache across hg commands. Commit benchmark (run on Macos 10.13 on a
2017-model Macbook Pro with Core i7 2.9GHz and flash drive), testing without
and with patch run 5 times, baseline is r2a227782e754:

* committing to an existing file, against the mozilla-central repository.
  Baseline real time average 1.9692, with patch 1.3786.

A new debugcommand "hg debugmanifestfulltextcache" lets you inspect the cache,
clear it, or add specific manifest nodeids to it. When calling
repo.updatecaches(), the manifest(s) for the working copy parents are added to
the cache.

The hg perfmanifest command has an additional --clear-disk switch to clear this
cache when testing manifest loading performance.

Using this command to test performance on the firefox repository for revision
f947d902ed91, whose manifest has a delta chain length of 60540, we see:

$ hg perfmanifest f947d902ed91 --clear-disk
! wall 0.972253 comb 0.970000 user 0.850000 sys 0.120000 (best of 10)
$ hg debugmanifestfulltextcache -a `hg log --debug -r f947d902ed91 | grep manifest | cut -d: -f3`
Cache contains 1 manifest entries, in order of most to least recent:
id: 0294517df4aad07c70701db43bc7ff24c3ce7dbc, size 25.6 MB
Total cache data size 25.6 MB, on-disk 0 bytes
$ hg perfmanifest f947d902ed91
! wall 0.036748 comb 0.040000 user 0.020000 sys 0.020000 (best of 100)

Worst-case scenario: a manifest text loaded from a single delta; in the firefox
repository manifest node 9a1246ff762e is the chain base for the manifest
attached to revision f947d902ed91. Loading this from a full cache file is just
as fast as without the cache; the extra node ids ensure a big full cache:

$ for node in 9a1246ff762e 1a1922c14a3e 54a31d11a36a 0294517df4aa; do
>   hgd debugmanifestfulltextcache -a $node > /dev/null
> done
$ hgd perfmanifest -m 9a1246ff762e
! wall 0.077513 comb 0.080000 user 0.030000 sys 0.050000 (best of 100)
$ hgd perfmanifest -m 9a1246ff762e --clear-disk
! wall 0.078547 comb 0.080000 user 0.070000 sys 0.010000 (best of 100)

This emulates the effects of an hg pull --rebase in which the remote repo
already has one local mq patch

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > rebase=
  > mq=
  > 
  > [phases]
  > publish=False
  > 
  > [alias]
  > tglog = log -G --template "{rev}: {node|short} '{desc}' tags: {tags}\n"
  > EOF


  $ hg init a
  $ cd a
  $ hg qinit -c

  $ echo c1 > c1
  $ hg add c1
  $ hg ci -m C1

  $ echo r1 > r1
  $ hg add r1
  $ hg ci -m R1

  $ hg up -q 0

  $ hg qnew p0.patch -d '1 0'
  $ echo p0 > p0
  $ hg add p0
  $ hg qref -m P0

  $ hg qnew p1.patch -d '2 0'
  $ echo p1 > p1
  $ hg add p1
  $ hg qref -m P1

  $ hg export qtip > p1.patch

  $ hg up -q -C 1

  $ hg import p1.patch
  applying p1.patch

  $ rm p1.patch

  $ hg up -q -C qtip

  $ hg rebase -v
  rebasing 2:13a46ce44f60 "P0" (p0.patch qbase)
  resolving manifests
  removing p0
  getting r1
  resolving manifests
  getting p0
  committing files:
  p0
  committing manifest
  committing changelog
  rebasing 3:148775c71080 "P1" (p1.patch qtip)
  resolving manifests
  note: rebase of 3:148775c71080 created no changes to commit
  rebase merging completed
  updating mq patch p0.patch to 5:9ecc820b1737
  $TESTTMP/a/.hg/patches/p0.patch
  2 changesets found
  uncompressed size of bundle content:
       348 (changelog)
       324 (manifests)
       129  p0
       129  p1
  saved backup bundle to $TESTTMP/a/.hg/strip-backup/13a46ce44f60-5da6ecfb-rebase.hg
  2 changesets found
  uncompressed size of bundle content:
       403 (changelog)
       324 (manifests)
       129  p0
       129  p1
  adding branch
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 2 files
  rebase completed
  1 revisions have been skipped

  $ hg tglog
  @  3: 9ecc820b1737 'P0' tags: p0.patch qbase qtip tip
  |
  o  2: 869d8b134a27 'P1' tags: qparent
  |
  o  1: da108f2755df 'R1' tags:
  |
  o  0: cd320d50b341 'C1' tags:
  
  $ cd ..


  $ hg init b
  $ cd b
  $ hg qinit -c

  $ for i in r0 r1 r2 r3 r4 r5 r6;
  > do
  >     echo $i > $i
  >     hg ci -Am $i
  > done
  adding r0
  adding r1
  adding r2
  adding r3
  adding r4
  adding r5
  adding r6

  $ hg qimport -r 1:tip

  $ hg up -q 0

  $ for i in r1 r3 r7 r8;
  > do
  >     echo $i > $i
  >     hg ci -Am branch2-$i
  > done
  adding r1
  created new head
  adding r3
  adding r7
  adding r8

  $ echo somethingelse > r4
  $ hg ci -Am branch2-r4
  adding r4

  $ echo r6 > r6
  $ hg ci -Am branch2-r6
  adding r6

  $ hg up -q qtip

  $ HGMERGE=internal:fail hg rebase
  rebasing 1:b4bffa6e4776 "r1" (qbase r1)
  note: rebase of 1:b4bffa6e4776 created no changes to commit
  rebasing 2:c0fd129beb01 "r2" (r2)
  rebasing 3:6ff5b8feed8e "r3" (r3)
  note: rebase of 3:6ff5b8feed8e created no changes to commit
  rebasing 4:094320fec554 "r4" (r4)
  unresolved conflicts (see hg resolve, then hg rebase --continue)
  [1]

  $ HGMERGE=internal:local hg resolve --all
  (no more unresolved files)
  continue: hg rebase --continue

  $ hg rebase --continue
  already rebased 1:b4bffa6e4776 "r1" (qbase r1) as 057f55ff8f44
  already rebased 2:c0fd129beb01 "r2" (r2) as 1660ab13ce9a
  already rebased 3:6ff5b8feed8e "r3" (r3) as 1660ab13ce9a
  rebasing 4:094320fec554 "r4" (r4)
  note: rebase of 4:094320fec554 created no changes to commit
  rebasing 5:681a378595ba "r5" (r5)
  rebasing 6:512a1f24768b "r6" (qtip r6)
  note: rebase of 6:512a1f24768b created no changes to commit
  saved backup bundle to $TESTTMP/b/.hg/strip-backup/b4bffa6e4776-b9bfb84d-rebase.hg

  $ hg tglog
  @  8: 0b9735ce8f0a 'r5' tags: qtip r5 tip
  |
  o  7: 1660ab13ce9a 'r2' tags: qbase r2
  |
  o  6: 057f55ff8f44 'branch2-r6' tags: qparent
  |
  o  5: 1d7287f8deb1 'branch2-r4' tags:
  |
  o  4: 3c10b9db2bd5 'branch2-r8' tags:
  |
  o  3: b684023158dc 'branch2-r7' tags:
  |
  o  2: d817754b1251 'branch2-r3' tags:
  |
  o  1: 0621a206f8a4 'branch2-r1' tags:
  |
  o  0: 222799e2f90b 'r0' tags:
  

  $ cd ..