view tests/test-remotefilelog-bgprefetch.t @ 43198:c16fe77e340a

pathcopies: give up any optimization based on `introrev`

Between 8a0136f69027 and d98fb3f42f33, we sped up the search for the
introduction revision during path copies. However, further checking show that
finding the introduction revision is still expensive and that we are better off
without it. So we simply drop it and only rely on the linkrev optimisation.

I ran `perfpathcopies` on 6989 pair of revision in the pypy
repository (`hg perfhelper-pathcopies`. The result is massively in favor of
dropping this condition. The result of the copy tracing are unchanged.

Attempt to use a smaller changes preserving linkrev usage were unsuccessful, it
can return wrong result. The following changesets broke test-mv-cp-st-diff.t

    -        if not f.isintroducedafter(limit):
    +        if limit >= 0 and f.linkrev() < limit:
                 return None


Here are various numbers (before this changeset/after this changesets)

            source       destination  before      after    saved-time  ratio
worth cases e66f24650daf 695dfb0f493b 1.062843 1.246369 -0.183526 1.172675
            c979853a3b6a 8d60fe293e79 1.036985 1.196414 -0.159429 1.153743
            22349fa2fc33 fbb1c9fd86c0 0.879926 1.038682 -0.158756 1.180420
            682b98f3e672 a4878080a536 0.909952 1.063801 -0.153849 1.169074
            5adabc9b9848 920958a93997 0.993622 1.147452 -0.153830 1.154817
worse  1%   dbfbfcf077e9 aea8f2fd3593 1.016595 1.082999 -0.066404 1.065320
worse  5%   c95f1ced15f2 7d29d5e39734 0.453694 0.471156 -0.017462 1.038488
worse 10%   3e144ed1d5b7 2aef0e942480 0.035140 0.037535 -0.002395 1.068156
worse 25%   321fc60db035 801748ba582a 0.009267 0.009325 -0.000058 1.006259
median      2088ce763fc2 e6991321d78b 0.000665 0.000651 0.000014 0.978947
best 25%    915631a97de6 385b31354be6 0.040743 0.040363 0.000380 0.990673
best 10%    ad495c36a765 19c10384d3e7 0.431658 0.411490 0.020168 0.953278
best  5%    d13ae7d283ae 813c99f810ac 1.141404 1.075346 0.066058 0.942126
best  1%    81593cb4a496 99ae11866969 1.833297 0.063823 1.769474 0.034813
best cases  c3b14617fbd7 743a0fcaa4eb 1101.811740 2.735970 1099.075770 0.002483
            c3b14617fbd7 9ba6ab77fd29 1116.753953 2.800729 1113.953224 0.002508
            058b99d6e81f 57e249b7a3ea 1246.128485 3.042762 1243.085723 0.002442
            9a8c361aab49 0354a250d371 1253.111894 3.085796 1250.026098 0.002463
            442dbbc53c68 3ec1002a818c 1261.786294 3.138607 1258.647687 0.002487


As one can see, the average case is not really impacted. However, the worth case
we get after this changeset are much better than the one we had before it. We
have 30 pairs where improvements are above 10 minutes.

This reflect in the combined time for all pairs
before: 26256s
after:   1300s (-95%)

If we remove these pathological 30 cases, we still see a significant improvements:
before:  1631s
after:   1245s (-24%)

#require no-windows

  $ . "$TESTDIR/remotefilelog-library.sh"
# devel.remotefilelog.ensurestart: reduce race condition with
# waiton{repack/prefetch}
  $ cat >> $HGRCPATH <<EOF
  > [devel]
  > remotefilelog.ensurestart=True
  > EOF

  $ hg init master
  $ cd master
  $ cat >> .hg/hgrc <<EOF
  > [remotefilelog]
  > server=True
  > EOF
  $ echo x > x
  $ echo z > z
  $ hg commit -qAm x
  $ echo x2 > x
  $ echo y > y
  $ hg commit -qAm y
  $ echo w > w
  $ rm z
  $ hg commit -qAm w
  $ hg bookmark foo

  $ cd ..

# clone the repo

  $ hgcloneshallow ssh://user@dummy/master shallow --noupdate
  streaming all changes
  2 files to transfer, 776 bytes of data
  transferred 776 bytes in * seconds (*/sec) (glob)
  searching for changes
  no changes found

# Set the prefetchdays config to zero so that all commits are prefetched
# no matter what their creation date is. Also set prefetchdelay config
# to zero so that there is no delay between prefetches.
  $ cd shallow
  $ cat >> .hg/hgrc <<EOF
  > [remotefilelog]
  > prefetchdays=0
  > prefetchdelay=0
  > EOF
  $ cd ..

# prefetch a revision
  $ cd shallow

  $ hg prefetch -r 0
  2 files fetched over 1 fetches - (2 misses, 0.00% hit ratio) over *s (glob)

  $ hg cat -r 0 x
  x

# background prefetch on pull when configured

  $ cat >> .hg/hgrc <<EOF
  > [remotefilelog]
  > pullprefetch=bookmark()
  > backgroundprefetch=True
  > EOF
  $ hg strip tip
  saved backup bundle to $TESTTMP/shallow/.hg/strip-backup/6b4b6f66ef8c-b4b8bdaf-backup.hg (glob)

  $ clearcache
  $ hg pull
  pulling from ssh://user@dummy/master
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  updating bookmark foo
  added 1 changesets with 0 changes to 0 files
  new changesets 6b4b6f66ef8c
  (run 'hg update' to get a working copy)
  prefetching file contents
  $ sleep 0.5
  $ hg debugwaitonprefetch >/dev/null 2>%1
  $ find $CACHEDIR -type f | sort
  $TESTTMP/hgcache/master/11/f6ad8ec52a2984abaafd7c3b516503785c2072/ef95c5376f34698742fe34f315fd82136f8f68c0
  $TESTTMP/hgcache/master/95/cb0bfd2977c761298d9624e4b4d4c72a39974a/076f5e2225b3ff0400b98c92aa6cdf403ee24cca
  $TESTTMP/hgcache/master/af/f024fe4ab0fece4091de044c58c9ae4233383a/bb6ccd5dceaa5e9dc220e0dad65e051b94f69a2c
  $TESTTMP/hgcache/repos

# background prefetch with repack on pull when configured

  $ cat >> .hg/hgrc <<EOF
  > [remotefilelog]
  > backgroundrepack=True
  > EOF
  $ hg strip tip
  saved backup bundle to $TESTTMP/shallow/.hg/strip-backup/6b4b6f66ef8c-b4b8bdaf-backup.hg (glob)

  $ clearcache
  $ hg pull
  pulling from ssh://user@dummy/master
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  updating bookmark foo
  added 1 changesets with 0 changes to 0 files
  new changesets 6b4b6f66ef8c
  (run 'hg update' to get a working copy)
  prefetching file contents
  $ sleep 0.5
  $ hg debugwaitonprefetch >/dev/null 2>%1
  $ sleep 0.5
  $ hg debugwaitonrepack >/dev/null 2>%1
  $ sleep 0.5
  $ find $CACHEDIR -type f | sort
  $TESTTMP/hgcache/master/packs/6e8633deba6e544e5f8edbd7b996d6e31a2c42ae.histidx
  $TESTTMP/hgcache/master/packs/6e8633deba6e544e5f8edbd7b996d6e31a2c42ae.histpack
  $TESTTMP/hgcache/master/packs/8ce5ab3745465ab83bba30a7b9c295e0c8404652.dataidx
  $TESTTMP/hgcache/master/packs/8ce5ab3745465ab83bba30a7b9c295e0c8404652.datapack
  $TESTTMP/hgcache/repos

# background prefetch with repack on update when wcprevset configured

  $ clearcache
  $ hg up -r 0
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  2 files fetched over 1 fetches - (2 misses, 0.00% hit ratio) over *s (glob)
  $ find $CACHEDIR -type f | sort
  $TESTTMP/hgcache/master/11/f6ad8ec52a2984abaafd7c3b516503785c2072/1406e74118627694268417491f018a4a883152f0
  $TESTTMP/hgcache/master/39/5df8f7c51f007019cb30201c49e884b46b92fa/69a1b67522704ec122181c0890bd16e9d3e7516a
  $TESTTMP/hgcache/repos

  $ hg up -r 1
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  2 files fetched over 2 fetches - (2 misses, 0.00% hit ratio) over *s (glob)

  $ cat >> .hg/hgrc <<EOF
  > [remotefilelog]
  > bgprefetchrevs=.::
  > EOF

  $ clearcache
  $ hg up -r 0
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  * files fetched over * fetches - (* misses, 0.00% hit ratio) over *s (glob)
  $ sleep 1
  $ hg debugwaitonprefetch >/dev/null 2>%1
  $ sleep 1
  $ hg debugwaitonrepack >/dev/null 2>%1
  $ sleep 1
  $ find $CACHEDIR -type f | sort
  $TESTTMP/hgcache/master/packs/8f1443d44e57fec96f72fb2412e01d2818767ef2.histidx
  $TESTTMP/hgcache/master/packs/8f1443d44e57fec96f72fb2412e01d2818767ef2.histpack
  $TESTTMP/hgcache/master/packs/f4d50848e0b465e9bfd2875f213044c06cfd7407.dataidx
  $TESTTMP/hgcache/master/packs/f4d50848e0b465e9bfd2875f213044c06cfd7407.datapack
  $TESTTMP/hgcache/repos

# Ensure that file 'w' was prefetched - it was not part of the update operation and therefore
# could only be downloaded by the background prefetch

  $ hg debugdatapack `ls -ct $TESTTMP/hgcache/master/packs/*.datapack | head -n 1`
  $TESTTMP/hgcache/master/packs/f4d50848e0b465e9bfd2875f213044c06cfd7407:
  w:
  Node          Delta Base    Delta Length  Blob Size
  bb6ccd5dceaa  000000000000  2             2
  
  Total:                      2             2         (0.0% bigger)
  x:
  Node          Delta Base    Delta Length  Blob Size
  ef95c5376f34  000000000000  3             3
  1406e7411862  ef95c5376f34  14            2
  
  Total:                      17            5         (240.0% bigger)
  y:
  Node          Delta Base    Delta Length  Blob Size
  076f5e2225b3  000000000000  2             2
  
  Total:                      2             2         (0.0% bigger)
  z:
  Node          Delta Base    Delta Length  Blob Size
  69a1b6752270  000000000000  2             2
  
  Total:                      2             2         (0.0% bigger)

# background prefetch with repack on commit when wcprevset configured

  $ cat >> .hg/hgrc <<EOF
  > [remotefilelog]
  > bgprefetchrevs=0::
  > EOF

  $ clearcache
  $ find $CACHEDIR -type f | sort
  $ echo b > b
  $ hg commit -qAm b
  * files fetched over 1 fetches - (* misses, 0.00% hit ratio) over *s (glob)
  $ hg bookmark temporary
  $ sleep 1
  $ hg debugwaitonprefetch >/dev/null 2>%1
  $ sleep 1
  $ hg debugwaitonrepack >/dev/null 2>%1
  $ sleep 1
  $ find $CACHEDIR -type f | sort
  $TESTTMP/hgcache/master/packs/8f1443d44e57fec96f72fb2412e01d2818767ef2.histidx
  $TESTTMP/hgcache/master/packs/8f1443d44e57fec96f72fb2412e01d2818767ef2.histpack
  $TESTTMP/hgcache/master/packs/f4d50848e0b465e9bfd2875f213044c06cfd7407.dataidx
  $TESTTMP/hgcache/master/packs/f4d50848e0b465e9bfd2875f213044c06cfd7407.datapack
  $TESTTMP/hgcache/repos

# Ensure that file 'w' was prefetched - it was not part of the commit operation and therefore
# could only be downloaded by the background prefetch

  $ hg debugdatapack `ls -ct $TESTTMP/hgcache/master/packs/*.datapack | head -n 1`
  $TESTTMP/hgcache/master/packs/f4d50848e0b465e9bfd2875f213044c06cfd7407:
  w:
  Node          Delta Base    Delta Length  Blob Size
  bb6ccd5dceaa  000000000000  2             2
  
  Total:                      2             2         (0.0% bigger)
  x:
  Node          Delta Base    Delta Length  Blob Size
  ef95c5376f34  000000000000  3             3
  1406e7411862  ef95c5376f34  14            2
  
  Total:                      17            5         (240.0% bigger)
  y:
  Node          Delta Base    Delta Length  Blob Size
  076f5e2225b3  000000000000  2             2
  
  Total:                      2             2         (0.0% bigger)
  z:
  Node          Delta Base    Delta Length  Blob Size
  69a1b6752270  000000000000  2             2
  
  Total:                      2             2         (0.0% bigger)

# background prefetch with repack on rebase when wcprevset configured

  $ hg up -r 2
  3 files updated, 0 files merged, 3 files removed, 0 files unresolved
  (leaving bookmark temporary)
  $ clearcache
  $ find $CACHEDIR -type f | sort
  $ hg rebase -s temporary -d foo
  rebasing 3:58147a5b5242 "b" (temporary tip)
  saved backup bundle to $TESTTMP/shallow/.hg/strip-backup/58147a5b5242-c3678817-rebase.hg
  3 files fetched over 1 fetches - (3 misses, 0.00% hit ratio) over *s (glob)
  $ sleep 1
  $ hg debugwaitonprefetch >/dev/null 2>%1
  $ sleep 1
  $ hg debugwaitonrepack >/dev/null 2>%1
  $ sleep 1

# Ensure that file 'y' was prefetched - it was not part of the rebase operation and therefore
# could only be downloaded by the background prefetch

  $ hg debugdatapack `ls -ct $TESTTMP/hgcache/master/packs/*.datapack | head -n 1`
  $TESTTMP/hgcache/master/packs/f4d50848e0b465e9bfd2875f213044c06cfd7407:
  w:
  Node          Delta Base    Delta Length  Blob Size
  bb6ccd5dceaa  000000000000  2             2
  
  Total:                      2             2         (0.0% bigger)
  x:
  Node          Delta Base    Delta Length  Blob Size
  ef95c5376f34  000000000000  3             3
  1406e7411862  ef95c5376f34  14            2
  
  Total:                      17            5         (240.0% bigger)
  y:
  Node          Delta Base    Delta Length  Blob Size
  076f5e2225b3  000000000000  2             2
  
  Total:                      2             2         (0.0% bigger)
  z:
  Node          Delta Base    Delta Length  Blob Size
  69a1b6752270  000000000000  2             2
  
  Total:                      2             2         (0.0% bigger)

# Check that foregound prefetch with no arguments blocks until background prefetches finish

  $ hg up -r 3
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ clearcache
  $ hg prefetch --repack
  waiting for lock on prefetching in $TESTTMP/shallow held by process * on host * (glob) (?)
  got lock after * seconds (glob) (?)
  (running background incremental repack)
  * files fetched over 1 fetches - (* misses, 0.00% hit ratio) over *s (glob) (?)

  $ sleep 0.5
  $ hg debugwaitonrepack >/dev/null 2>%1
  $ sleep 0.5

  $ find $CACHEDIR -type f | sort
  $TESTTMP/hgcache/master/packs/8f1443d44e57fec96f72fb2412e01d2818767ef2.histidx
  $TESTTMP/hgcache/master/packs/8f1443d44e57fec96f72fb2412e01d2818767ef2.histpack
  $TESTTMP/hgcache/master/packs/f4d50848e0b465e9bfd2875f213044c06cfd7407.dataidx
  $TESTTMP/hgcache/master/packs/f4d50848e0b465e9bfd2875f213044c06cfd7407.datapack
  $TESTTMP/hgcache/repos

# Ensure that files were prefetched
  $ hg debugdatapack `ls -ct $TESTTMP/hgcache/master/packs/*.datapack | head -n 1`
  $TESTTMP/hgcache/master/packs/f4d50848e0b465e9bfd2875f213044c06cfd7407:
  w:
  Node          Delta Base    Delta Length  Blob Size
  bb6ccd5dceaa  000000000000  2             2
  
  Total:                      2             2         (0.0% bigger)
  x:
  Node          Delta Base    Delta Length  Blob Size
  ef95c5376f34  000000000000  3             3
  1406e7411862  ef95c5376f34  14            2
  
  Total:                      17            5         (240.0% bigger)
  y:
  Node          Delta Base    Delta Length  Blob Size
  076f5e2225b3  000000000000  2             2
  
  Total:                      2             2         (0.0% bigger)
  z:
  Node          Delta Base    Delta Length  Blob Size
  69a1b6752270  000000000000  2             2
  
  Total:                      2             2         (0.0% bigger)

# Check that foreground prefetch fetches revs specified by '. + draft() + bgprefetchrevs + pullprefetch'

  $ clearcache
  $ hg prefetch --repack
  waiting for lock on prefetching in $TESTTMP/shallow held by process * on host * (glob) (?)
  got lock after * seconds (glob) (?)
  (running background incremental repack)
  * files fetched over 1 fetches - (* misses, 0.00% hit ratio) over *s (glob) (?)
  $ sleep 0.5
  $ hg debugwaitonrepack >/dev/null 2>%1
  $ sleep 0.5

  $ find $CACHEDIR -type f | sort
  $TESTTMP/hgcache/master/packs/8f1443d44e57fec96f72fb2412e01d2818767ef2.histidx
  $TESTTMP/hgcache/master/packs/8f1443d44e57fec96f72fb2412e01d2818767ef2.histpack
  $TESTTMP/hgcache/master/packs/f4d50848e0b465e9bfd2875f213044c06cfd7407.dataidx
  $TESTTMP/hgcache/master/packs/f4d50848e0b465e9bfd2875f213044c06cfd7407.datapack
  $TESTTMP/hgcache/repos

# Ensure that files were prefetched
  $ hg debugdatapack `ls -ct $TESTTMP/hgcache/master/packs/*.datapack | head -n 1`
  $TESTTMP/hgcache/master/packs/f4d50848e0b465e9bfd2875f213044c06cfd7407:
  w:
  Node          Delta Base    Delta Length  Blob Size
  bb6ccd5dceaa  000000000000  2             2
  
  Total:                      2             2         (0.0% bigger)
  x:
  Node          Delta Base    Delta Length  Blob Size
  ef95c5376f34  000000000000  3             3
  1406e7411862  ef95c5376f34  14            2
  
  Total:                      17            5         (240.0% bigger)
  y:
  Node          Delta Base    Delta Length  Blob Size
  076f5e2225b3  000000000000  2             2
  
  Total:                      2             2         (0.0% bigger)
  z:
  Node          Delta Base    Delta Length  Blob Size
  69a1b6752270  000000000000  2             2
  
  Total:                      2             2         (0.0% bigger)

# Test that if data was prefetched and repacked we dont need to prefetch it again
# It ensures that Mercurial looks not only in loose files but in packs as well

  $ hg prefetch --repack
  (running background incremental repack)