view tests/test-subrepo-relative-path.t @ 44363:f7459da77f23

nodemap: introduce an option to use mmap to read the nodemap mapping

The performance and memory benefit is much greater if we don't have to copy all
the data in memory for each information. So we introduce an option (on by
default) to read the data using mmap.

This changeset is the last one definition the API for index support nodemap
data. (they have to be able to use the mmaping).

Below are some benchmark comparing the best we currently have in 5.3 with the
final step of this series (using the persistent nodemap implementation in
Rust). The benchmark run `hg perfindex` with various revset and the following
variants:

Before:

 * do not use the persistent nodemap
 * use the CPython implementation of the index for nodemap
 * use mmapping of the changelog index

After:

 * use the MixedIndex Rust code, with the NodeTree object for nodemap access
   (still in review)
 * use the persistent nodemap data from disk
 * access the persistent nodemap data through mmap
 * use mmapping of the changelog index

The persistent nodemap greatly speed up  most operation on very large
repositories. Some of the previously very fast lookup end up a bit slower because
the persistent nodemap has to be setup. However the absolute slowdown is very
small and won't matters in the big picture.

Here are some numbers (in seconds) for the reference copy of mozilla-try:

Revset            Before   After     abs-change speedup

-10000:           0.004622 0.005532   0.000910  ×   0.83
-10:              0.000050 0.000132   0.000082  ×   0.37
tip               0.000052 0.000085   0.000033  ×   0.61
0 + (-10000:)     0.028222 0.005337  -0.022885  ×   5.29
0                 0.023521 0.000084  -0.023437  × 280.01
(-10000:) + 0     0.235539 0.005308  -0.230231  ×  44.37
(-10:) + :9       0.232883 0.000180  -0.232703  ×1293.79
(-10000:) + (:99) 0.238735 0.005358  -0.233377  ×  44.55
:99 + (-10000:)   0.317942 0.005593  -0.312349  ×  56.84
:9 + (-10:)       0.313372 0.000179  -0.313193  ×1750.68
:9                0.316450 0.000143  -0.316307  ×2212.93


On smaller repositories, the cost of nodemap related operation is not as big, so
the win is much more modest. Yet it helps shaving a handful of millisecond here
and there.

Here are some numbers (in seconds) for the reference copy of mercurial:

Revset            Before   After     abs-change speedup
-10:              0.000065 0.000097   0.000032  × 0.67
tip               0.000063 0.000078   0.000015  × 0.80
0                 0.000561 0.000079  -0.000482  × 7.10
-10000:           0.004609 0.003648  -0.000961  × 1.26
0 + (-10000:)     0.005023 0.003715  -0.001307  × 1.35
(-10:) + :9       0.002187 0.000108  -0.002079  ×20.25
(-10000:) + 0     0.006252 0.003716  -0.002536  × 1.68
(-10000:) + (:99) 0.006367 0.003707  -0.002660  × 1.71
:9 + (-10:)       0.003846 0.000110  -0.003736  ×34.96
:9                0.003854 0.000099  -0.003755  ×38.92
:99 + (-10000:)   0.007644 0.003778  -0.003866  × 2.02

Differential Revision: https://phab.mercurial-scm.org/D7894

Preparing the subrepository 'sub'

  $ hg init sub
  $ echo sub > sub/sub
  $ hg add -R sub
  adding sub/sub
  $ hg commit -R sub -m "sub import"

Preparing the 'main' repo which depends on the subrepo 'sub'

  $ hg init main
  $ echo main > main/main
  $ echo "sub = ../sub" > main/.hgsub
  $ hg clone sub main/sub
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg add -R main
  adding main/.hgsub
  adding main/main
  $ hg commit -R main -m "main import"

Cleaning both repositories, just as a clone -U

  $ hg up -C -R sub null
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg up -C -R main null
  0 files updated, 0 files merged, 3 files removed, 0 files unresolved
  $ rm -rf main/sub

hide outer repo
  $ hg init

Serving them both using hgweb

  $ printf '[paths]\n/main = main\nsub = sub\n' > webdir.conf
  $ hg serve --webdir-conf webdir.conf -a localhost -p $HGPORT \
  >    -A /dev/null -E /dev/null --pid-file hg.pid -d
  $ cat hg.pid >> $DAEMON_PIDS

Clone main from hgweb

  $ hg clone "http://user:pass@localhost:$HGPORT/main" cloned
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 3 changes to 3 files
  new changesets fdfeeb3e979e
  updating to branch default
  cloning subrepo sub from http://user@localhost:$HGPORT/sub
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets 863c1745b441
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved

Ensure that subrepos pay attention to default:pushurl

  $ cat > cloned/.hg/hgrc << EOF
  > [paths]
  > default:pushurl = http://user:pass@localhost:$HGPORT/main
  > EOF

  $ hg -R cloned out -S --config paths.default=bogus://invalid
  comparing with http://user:***@localhost:$HGPORT/main
  searching for changes
  no changes found
  comparing with http://user:***@localhost:$HGPORT/sub
  searching for changes
  no changes found
  [1]

TODO: Figure out why, if the password is left out of the default:pushurl URL,
this says "no changes made to subrepo sub since last push".  It looks like from
the original clone command above, the password is getting stripped off, not
just masked out, and that would make the hashed URL different.

  $ hg -R cloned push --config paths.default=bogus://invalid
  pushing to http://user:***@localhost:$HGPORT/main
  pushing subrepo sub to http://user:***@localhost:$HGPORT/sub
  searching for changes
  no changes found
  searching for changes
  no changes found
  abort: HTTP Error 403: ssl required
  [255]

Checking cloned repo ids

  $ hg id -R cloned
  fdfeeb3e979e tip
  $ hg id -R cloned/sub
  863c1745b441 tip

subrepo debug for 'main' clone

  $ hg debugsub -R cloned
  path sub
   source   ../sub
   revision 863c1745b441bd97a8c4a096e87793073f4fb215

Test sharing with a remote URL reference

  $ hg init absolute_subrepo
  $ cd absolute_subrepo
  $ echo foo > foo.txt
  $ hg ci -Am 'initial commit'
  adding foo.txt
  $ echo "sub = http://localhost:$HGPORT/sub" > .hgsub
  $ hg ci -Am 'add absolute subrepo'
  adding .hgsub
  $ cd ..

Clone pooling works for local clones with a remote subrepo reference.  The
subrepo is cloned to the pool and shared from there, so that all clones will
share the same subrepo.

  $ hg --config extensions.share= --config share.pool=$TESTTMP/pool \
  >    clone absolute_subrepo cloned_from_abs
  (sharing from new pooled repository 8d6a2f1e993b34b6557de0042cfe825ae12a8dae)
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 3 changes to 3 files
  new changesets 8d6a2f1e993b:* (glob)
  searching for changes
  no changes found
  updating working directory
  cloning subrepo sub from http://localhost:$HGPORT/sub
  (sharing from new pooled repository 863c1745b441bd97a8c4a096e87793073f4fb215)
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets 863c1745b441
  searching for changes
  no changes found
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved

Vanilla sharing with a subrepo remote path reference will clone the subrepo.
Each share of these top level repos will end up with independent subrepo copies
(potentially leaving the shared parent with dangling cset references).

  $ hg --config extensions.share= share absolute_subrepo shared_from_abs
  updating working directory
  cloning subrepo sub from http://localhost:$HGPORT/sub
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets 863c1745b441
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg --config extensions.share= share -U absolute_subrepo shared_from_abs2
  $ hg -R shared_from_abs2 update -r tip
  cloning subrepo sub from http://localhost:$HGPORT/sub
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets 863c1745b441
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved

A parent repo without its subrepo available locally can be shared if the
subrepo is referenced by absolute path.

  $ hg clone -U absolute_subrepo cloned_null_from_abs
  $ hg --config extensions.share= share cloned_null_from_abs shared_from_null_abs
  updating working directory
  cloning subrepo sub from http://localhost:$HGPORT/sub
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets 863c1745b441
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ killdaemons.py

subrepo paths with ssh urls

  $ hg clone -e "\"$PYTHON\" \"$TESTDIR/dummyssh\"" ssh://user@dummy/cloned sshclone
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 3 changes to 3 files
  new changesets fdfeeb3e979e
  updating to branch default
  cloning subrepo sub from ssh://user@dummy/sub
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 1 changes to 1 files
  new changesets 863c1745b441
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved

  $ hg -R sshclone push -e "\"$PYTHON\" \"$TESTDIR/dummyssh\"" ssh://user@dummy/`pwd`/cloned
  pushing to ssh://user@dummy/$TESTTMP/cloned
  pushing subrepo sub to ssh://user@dummy/$TESTTMP/sub
  searching for changes
  no changes found
  searching for changes
  no changes found
  [1]

  $ cat dummylog
  Got arguments 1:user@dummy 2:hg -R cloned serve --stdio
  Got arguments 1:user@dummy 2:hg -R sub serve --stdio
  Got arguments 1:user@dummy 2:hg -R $TESTTMP/cloned serve --stdio
  Got arguments 1:user@dummy 2:hg -R $TESTTMP/sub serve --stdio