view tests/test-narrow-share.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

#testcases flat tree

  $ . "$TESTDIR/narrow-library.sh"

#if tree
  $ cat << EOF >> $HGRCPATH
  > [experimental]
  > treemanifest = 1
  > EOF
#endif

  $ cat << EOF >> $HGRCPATH
  > [extensions]
  > share =
  > EOF

  $ hg init remote
  $ cd remote
  $ for x in `$TESTDIR/seq.py 0 10`
  > do
  >   mkdir d$x
  >   echo $x > d$x/f
  >   hg add d$x/f
  >   hg commit -m "add d$x/f"
  > done
  $ cd ..

  $ hg clone --narrow ssh://user@dummy/remote main -q \
  > --include d1 --include d3 --include d5 --include d7

Ignore file called "ignored"
  $ echo ignored > main/.hgignore

  $ hg share main share
  updating working directory
  4 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg -R share tracked
  I path:d1
  I path:d3
  I path:d5
  I path:d7
  $ hg -R share files
  share/d1/f
  share/d3/f
  share/d5/f
  share/d7/f

Narrow the share and check that the main repo's working copy gets updated

# Make sure the files that are supposed to be known-clean get their timestamps set in the dirstate
  $ sleep 2
  $ hg -R main st
  $ hg -R main debugdirstate --no-dates
  n 644          2 set                 d1/f
  n 644          2 set                 d3/f
  n 644          2 set                 d5/f
  n 644          2 set                 d7/f
# Make d3/f dirty
  $ echo x >> main/d3/f
  $ echo y >> main/d3/g
  $ touch main/d3/ignored
  $ touch main/d3/untracked
  $ hg add main/d3/g
  $ hg -R main st
  M d3/f
  A d3/g
  ? d3/untracked
# Make d5/f not match the dirstate timestamp even though it's clean
  $ sleep 2
  $ hg -R main st
  M d3/f
  A d3/g
  ? d3/untracked
  $ hg -R main debugdirstate --no-dates
  n 644          2 set                 d1/f
  n 644          2 set                 d3/f
  a   0         -1 unset               d3/g
  n 644          2 set                 d5/f
  n 644          2 set                 d7/f
  $ touch main/d5/f
  $ hg -R share tracked --removeinclude d1 --removeinclude d3 --removeinclude d5
  comparing with ssh://user@dummy/remote
  searching for changes
  looking for local changes to affected paths
  deleting data/d1/f.i
  deleting data/d3/f.i
  deleting data/d5/f.i
  deleting meta/d1/00manifest.i (tree !)
  deleting meta/d3/00manifest.i (tree !)
  deleting meta/d5/00manifest.i (tree !)
  $ hg -R main tracked
  I path:d7
  $ hg -R main files
  abort: working copy's narrowspec is stale
  (run 'hg tracked --update-working-copy')
  [255]
  $ hg -R main tracked --update-working-copy
  not deleting possibly dirty file d3/f
  not deleting possibly dirty file d3/g
  not deleting possibly dirty file d5/f
  not deleting unknown file d3/untracked
  not deleting ignored file d3/ignored
# d1/f, d3/f, d3/g and d5/f should no longer be reported
  $ hg -R main files
  main/d7/f
# d1/f should no longer be there, d3/f should be since it was dirty, d3/g should be there since
# it was added, and d5/f should be since we couldn't be sure it was clean
  $ find main/d* -type f | sort
  main/d3/f
  main/d3/g
  main/d3/ignored
  main/d3/untracked
  main/d5/f
  main/d7/f

Widen the share and check that the main repo's working copy gets updated

  $ hg -R share tracked --addinclude d1 --addinclude d3 -q
  $ hg -R share tracked
  I path:d1
  I path:d3
  I path:d7
  $ hg -R share files
  share/d1/f
  share/d3/f
  share/d7/f
  $ hg -R main tracked
  I path:d1
  I path:d3
  I path:d7
  $ hg -R main files
  abort: working copy's narrowspec is stale
  (run 'hg tracked --update-working-copy')
  [255]
  $ hg -R main tracked --update-working-copy
# d1/f, d3/f should be back
  $ hg -R main files
  main/d1/f
  main/d3/f
  main/d7/f
# d3/f should be modified (not clobbered by the widening), and d3/g should be untracked
  $ hg -R main st --all
  M d3/f
  ? d3/g
  ? d3/untracked
  I d3/ignored
  C d1/f
  C d7/f

We should also be able to unshare without breaking everything:

  $ hg share main share-unshare
  updating working directory
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd share-unshare
  $ hg unshare
  $ hg verify
  checking changesets
  checking manifests
  checking directory manifests (tree !)
  crosschecking files in changesets and manifests
  checking files
  checked 11 changesets with 3 changes to 3 files
  $ cd ..

Dirstate should be left alone when upgrading from version of hg that didn't support narrow+share

  $ hg share main share-upgrade
  updating working directory
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd share-upgrade
  $ echo x >> d1/f
  $ echo y >> d3/g
  $ hg add d3/g
  $ hg rm d7/f
  $ hg st
  M d1/f
  A d3/g
  R d7/f
Make it look like a repo from before narrow+share was supported
  $ rm .hg/narrowspec.dirstate
  $ hg ci -Am test
  abort: working copy's narrowspec is stale
  (run 'hg tracked --update-working-copy')
  [255]
  $ hg tracked --update-working-copy
  $ hg st
  M d1/f
  A d3/g
  R d7/f
  $ cd ..