view tests/test-strip-cross.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

test stripping of filelogs where the linkrev doesn't always increase

  $ echo '[extensions]' >> $HGRCPATH
  $ echo 'strip =' >> $HGRCPATH
  $ commit()
  > {
  >     hg up -qC null
  >     count=1
  >     for i in "$@"; do
  >         for f in $i; do
  >             mkdir -p `dirname $f`
  >             echo $count > $f
  >         done
  >         count=`expr $count + 1`
  >     done
  >     hg commit -qAm "$*"
  > }

2 1 0 2 0 1 2

  $ mkdir files
  $ cd files
  $ hg init orig
  $ cd orig
  $ commit '201 210'
  $ commit '102 120' '210'
  $ commit '021'
  $ commit '201' '021 120'
  $ commit '012 021' '102 201' '120 210'
  $ commit '102 120' '012 210' '021 201'
  $ commit '201 210' '021 120' '012 102'
  $ cd ..
  $ hg clone -q -U -r 4 -r 5 -r 6 orig crossed
  $ cd crossed

  $ for i in 012 021 102 120 201 210; do
  >     echo $i
  >     hg debugindex $i
  >     echo
  > done
  012
     rev linkrev nodeid       p1           p2
       0       0 b8e02f643373 000000000000 000000000000
       1       1 5d9299349fc0 000000000000 000000000000
       2       2 2661d26c6496 000000000000 000000000000
  
  021
     rev linkrev nodeid       p1           p2
       0       0 b8e02f643373 000000000000 000000000000
       1       2 5d9299349fc0 000000000000 000000000000
       2       1 2661d26c6496 000000000000 000000000000
  
  102
     rev linkrev nodeid       p1           p2
       0       1 b8e02f643373 000000000000 000000000000
       1       0 5d9299349fc0 000000000000 000000000000
       2       2 2661d26c6496 000000000000 000000000000
  
  120
     rev linkrev nodeid       p1           p2
       0       1 b8e02f643373 000000000000 000000000000
       1       2 5d9299349fc0 000000000000 000000000000
       2       0 2661d26c6496 000000000000 000000000000
  
  201
     rev linkrev nodeid       p1           p2
       0       2 b8e02f643373 000000000000 000000000000
       1       0 5d9299349fc0 000000000000 000000000000
       2       1 2661d26c6496 000000000000 000000000000
  
  210
     rev linkrev nodeid       p1           p2
       0       2 b8e02f643373 000000000000 000000000000
       1       1 5d9299349fc0 000000000000 000000000000
       2       0 2661d26c6496 000000000000 000000000000
  
  $ cd ..
  $ for i in 0 1 2; do
  >     hg clone -q -U --pull crossed $i
  >     echo "% Trying to strip revision $i"
  >     hg --cwd $i strip $i
  >     echo "% Verifying"
  >     hg --cwd $i verify
  >     echo
  > done
  % Trying to strip revision 0
  saved backup bundle to $TESTTMP/files/0/.hg/strip-backup/cbb8c2f0a2e3-239800b9-backup.hg
  % Verifying
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 2 changesets with 12 changes to 6 files
  
  % Trying to strip revision 1
  saved backup bundle to $TESTTMP/files/1/.hg/strip-backup/124ecc0cbec9-6104543f-backup.hg
  % Verifying
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 2 changesets with 12 changes to 6 files
  
  % Trying to strip revision 2
  saved backup bundle to $TESTTMP/files/2/.hg/strip-backup/f6439b304a1a-c6505a5f-backup.hg
  % Verifying
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 2 changesets with 12 changes to 6 files
  
  $ cd ..

Do a similar test where the manifest revlog has unordered linkrevs
  $ mkdir manifests
  $ cd manifests
  $ hg init orig
  $ cd orig
  $ commit 'file'
  $ commit 'other'
  $ commit '' 'other'
  $ HGUSER=another-user; export HGUSER
  $ commit 'file'
  $ commit 'other' 'file'
  $ cd ..
  $ hg clone -q -U -r 1 -r 2 -r 3 -r 4 orig crossed
  $ cd crossed
  $ hg debugindex --manifest
     rev linkrev nodeid       p1           p2
       0       2 6bbc6fee55c2 000000000000 000000000000
       1       0 1c556153fe54 000000000000 000000000000
       2       1 1f76dba919fd 000000000000 000000000000
       3       3 bbee06ad59d5 000000000000 000000000000

  $ cd ..
  $ for i in 2 3; do
  >     hg clone -q -U --pull crossed $i
  >     echo "% Trying to strip revision $i"
  >     hg --cwd $i strip $i
  >     echo "% Verifying"
  >     hg --cwd $i verify
  >     echo
  > done
  % Trying to strip revision 2
  saved backup bundle to $TESTTMP/manifests/2/.hg/strip-backup/f3015ad03c03-4d98bdc2-backup.hg
  % Verifying
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 3 changesets with 3 changes to 2 files
  
  % Trying to strip revision 3
  saved backup bundle to $TESTTMP/manifests/3/.hg/strip-backup/9632aa303aa4-69192e3f-backup.hg
  % Verifying
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 3 changesets with 3 changes to 2 files
  
  $ cd ..

Now a similar test for a non-root manifest revlog
  $ cat >> $HGRCPATH <<EOF
  > [experimental]
  > treemanifests = yes
  > EOF
  $ mkdir treemanifests
  $ cd treemanifests
  $ 
  $ hg --config experimental.treemanifest=True init orig
  $ cd orig
  $ commit 'dir/file'
  $ commit 'dir/other'
  $ commit '' 'dir/other'
  $ HGUSER=yet-another-user; export HGUSER
  $ commit 'otherdir dir/file'
  $ commit 'otherdir dir/other' 'otherdir dir/file'
  $ cd ..
  $ hg --config experimental.treemanifest=True clone -q -U -r 1 -r 2 -r 3 -r 4 orig crossed
  $ cd crossed
  $ hg debugindex --dir dir
     rev linkrev nodeid       p1           p2
       0       2 6bbc6fee55c2 000000000000 000000000000
       1       0 1c556153fe54 000000000000 000000000000
       2       1 1f76dba919fd 000000000000 000000000000
       3       3 bbee06ad59d5 000000000000 000000000000

  $ cd ..
  $ for i in 2 3; do
  >     hg --config experimental.treemanifest=True clone -q -U --pull crossed $i
  >     echo "% Trying to strip revision $i"
  >     hg --cwd $i strip $i
  >     echo "% Verifying"
  >     hg --cwd $i verify
  >     echo
  > done
  % Trying to strip revision 2
  saved backup bundle to $TESTTMP/treemanifests/2/.hg/strip-backup/145f5c75f9ac-a105cfbe-backup.hg
  % Verifying
  checking changesets
  checking manifests
  checking directory manifests
  crosschecking files in changesets and manifests
  checking files
  checked 3 changesets with 4 changes to 3 files
  
  % Trying to strip revision 3
  saved backup bundle to $TESTTMP/treemanifests/3/.hg/strip-backup/e4e3de5c3cb2-f4c70376-backup.hg
  % Verifying
  checking changesets
  checking manifests
  checking directory manifests
  crosschecking files in changesets and manifests
  checking files
  checked 3 changesets with 4 changes to 3 files
  
  $ cd ..