view tests/test-treediscovery-legacy.t @ 42743:8c9a6adec67a

rust-discovery: using the children cache in add_missing

The DAG range computation often needs to get back to very old
revisions, and turns out to be disproportionately long, given
that the end goal is to remove the descendents of the given
missing revisons from the undecided set.

The fast iteration capabilities available in the Rust case make
it possible to avoid the DAG range entirely, at the cost of
precomputing the children cache, and to simply iterate on
children of the given missing revisions.

This is a case where staying on the same side of the interface
between the two languages has clear benefits.

On discoveries with initial undecided sets
small enough to bypass sampling entirely, the total cost of
computing the children cache and the subsequent iteration
becomes better than the Python + C counterpart, which relies on
reachableroots2.

For example, on a repo with more than one million revisions with
an initial undecided set of 11 elements, we get these figures:

Rust version with simple iteration
  addcommons: 57.287us
  first undecided computation: 184.278334ms
  first children cache computation: 131.056us
  addmissings iteration: 42.766us
  first addinfo total: 185.24 ms

Python + C version
  first addcommons: 0.29 ms
  addcommons 0.21 ms
  first undecided computation 191.35 ms
  addmissings 45.75 ms
  first addinfo total: 237.77 ms

On discoveries with large undecided sets, the initial price paid
makes the first addinfo slower than the Python + C version,
but that's more than compensated by the gain in sampling and
subsequent iterations.
Here's an extreme example with an undecided set of a million revisions:

Rust version:
  first undecided computation: 293.842629ms
  first children cache computation: 407.911297ms
  addmissings iteration: 34.312869ms
  first addinfo total: 776.02 ms
  taking initial sample
  query 2: sampling time: 1318.38 ms
  query 2; still undecided: 1005013, sample size is: 200
  addmissings: 143.062us

Python + C version:
  first undecided computation 298.13 ms
  addmissings 80.13 ms
  first addinfo total: 399.62 ms
  taking initial sample
  query 2: sampling time: 3957.23 ms
  query 2; still undecided: 1005013, sample size is: 200
  addmissings 52.88 ms

Differential Revision: https://phab.mercurial-scm.org/D6428

Tests discovery against servers without getbundle support:

  $ cat >> $HGRCPATH <<EOF
  > [ui]
  > logtemplate="{rev} {node|short}: {desc} {branches}\n"
  > EOF
  $ cp $HGRCPATH $HGRCPATH-withcap

  $ CAP="getbundle known changegroupsubset bundle2"
  $ . "$TESTDIR/notcapable"
  $ cp $HGRCPATH $HGRCPATH-nocap
  $ cp $HGRCPATH-withcap $HGRCPATH

Prep for test server without branchmap support

  $ CAP="branchmap"
  $ . "$TESTDIR/notcapable"
  $ cp $HGRCPATH $HGRCPATH-nocap-branchmap
  $ cp $HGRCPATH-withcap $HGRCPATH

Setup HTTP server control:

  $ remote=http://localhost:$HGPORT/
  $ export remote
  $ tstart() {
  >   echo '[web]' > $1/.hg/hgrc
  >   echo 'push_ssl = false' >> $1/.hg/hgrc
  >   echo 'allow_push = *' >> $1/.hg/hgrc
  >   cp $HGRCPATH-nocap $HGRCPATH
  >   hg serve -R $1 -p $HGPORT -d --pid-file=hg.pid -E errors.log
  >   cat hg.pid >> $DAEMON_PIDS
  > }
  $ tstop() {
  >   killdaemons.py
  >   cp $HGRCPATH-withcap $HGRCPATH
  > }

Both are empty:

  $ hg init empty1
  $ hg init empty2
  $ tstart empty2
  $ hg incoming -R empty1 $remote
  comparing with http://localhost:$HGPORT/
  no changes found
  [1]
  $ hg outgoing -R empty1 $remote
  comparing with http://localhost:$HGPORT/
  no changes found
  [1]
  $ hg pull -R empty1 $remote
  pulling from http://localhost:$HGPORT/
  no changes found
  $ hg push -R empty1 $remote
  pushing to http://localhost:$HGPORT/
  no changes found
  [1]
  $ tstop

Base repo:

  $ hg init main
  $ cd main
  $ hg debugbuilddag -mo '+2:tbase @name1 +3:thead1 <tbase @name2 +4:thead2 @both /thead1 +2:tmaintip'
  $ hg log -G
  o  11 a19bfa7e7328: r11 both
  |
  o  10 8b6bad1512e1: r10 both
  |
  o    9 025829e08038: r9 both
  |\
  | o  8 d8f638ac69e9: r8 name2
  | |
  | o  7 b6b4d315a2ac: r7 name2
  | |
  | o  6 6c6f5d5f3c11: r6 name2
  | |
  | o  5 70314b29987d: r5 name2
  | |
  o |  4 e71dbbc70e03: r4 name1
  | |
  o |  3 2c8d5d5ec612: r3 name1
  | |
  o |  2 a7892891da29: r2 name1
  |/
  o  1 0019a3b924fd: r1
  |
  o  0 d57206cc072a: r0
  
  $ cd ..
  $ tstart main

Full clone:

  $ hg clone main full
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd full
  $ hg incoming $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ hg outgoing $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ hg pull $remote
  pulling from http://localhost:$HGPORT/
  searching for changes
  no changes found
  $ hg push $remote
  pushing to http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ cd ..

Local is empty:

  $ cd empty1
  $ hg incoming $remote --rev name1
  comparing with http://localhost:$HGPORT/
  abort: cannot look up remote changes; remote repository does not support the 'changegroupsubset' capability!
  [255]
  $ hg incoming $remote
  comparing with http://localhost:$HGPORT/
  0 d57206cc072a: r0 
  1 0019a3b924fd: r1 
  2 a7892891da29: r2 name1
  3 2c8d5d5ec612: r3 name1
  4 e71dbbc70e03: r4 name1
  5 70314b29987d: r5 name2
  6 6c6f5d5f3c11: r6 name2
  7 b6b4d315a2ac: r7 name2
  8 d8f638ac69e9: r8 name2
  9 025829e08038: r9 both
  10 8b6bad1512e1: r10 both
  11 a19bfa7e7328: r11 both
  $ hg outgoing $remote
  comparing with http://localhost:$HGPORT/
  no changes found
  [1]
  $ hg push $remote
  pushing to http://localhost:$HGPORT/
  no changes found
  [1]
  $ hg pull $remote
  pulling from http://localhost:$HGPORT/
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 12 changesets with 24 changes to 2 files
  new changesets d57206cc072a:a19bfa7e7328
  (run 'hg update' to get a working copy)
  $ hg incoming $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ cd ..

Local is subset:

  $ cp $HGRCPATH-withcap $HGRCPATH
  $ hg clone main subset --rev name2 ; cd subset
  adding changesets
  adding manifests
  adding file changes
  added 6 changesets with 12 changes to 2 files
  new changesets d57206cc072a:d8f638ac69e9
  updating to branch name2
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cp $HGRCPATH-nocap $HGRCPATH
  $ hg incoming $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  6 a7892891da29: r2 name1
  7 2c8d5d5ec612: r3 name1
  8 e71dbbc70e03: r4 name1
  9 025829e08038: r9 both
  10 8b6bad1512e1: r10 both
  11 a19bfa7e7328: r11 both
  $ hg outgoing $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ hg push $remote
  pushing to http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ hg pull $remote
  pulling from http://localhost:$HGPORT/
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 6 changesets with 12 changes to 2 files
  new changesets a7892891da29:a19bfa7e7328
  (run 'hg update' to get a working copy)
  $ hg incoming $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ cd ..

Remote is empty:

  $ tstop ; tstart empty2
  $ cd main
  $ hg incoming $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ hg outgoing $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  0 d57206cc072a: r0 
  1 0019a3b924fd: r1 
  2 a7892891da29: r2 name1
  3 2c8d5d5ec612: r3 name1
  4 e71dbbc70e03: r4 name1
  5 70314b29987d: r5 name2
  6 6c6f5d5f3c11: r6 name2
  7 b6b4d315a2ac: r7 name2
  8 d8f638ac69e9: r8 name2
  9 025829e08038: r9 both
  10 8b6bad1512e1: r10 both
  11 a19bfa7e7328: r11 both
  $ hg pull $remote
  pulling from http://localhost:$HGPORT/
  searching for changes
  no changes found
  $ hg push $remote
  pushing to http://localhost:$HGPORT/
  searching for changes
  remote: adding changesets
  remote: adding manifests
  remote: adding file changes
  remote: added 12 changesets with 24 changes to 2 files
  $ hg outgoing $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ cd ..

Local is superset:

  $ tstop
  $ hg clone main subset2 --rev name2
  adding changesets
  adding manifests
  adding file changes
  added 6 changesets with 12 changes to 2 files
  new changesets d57206cc072a:d8f638ac69e9
  updating to branch name2
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ tstart subset2
  $ cd main
  $ hg incoming $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ hg outgoing $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  2 a7892891da29: r2 name1
  3 2c8d5d5ec612: r3 name1
  4 e71dbbc70e03: r4 name1
  9 025829e08038: r9 both
  10 8b6bad1512e1: r10 both
  11 a19bfa7e7328: r11 both
  $ hg pull $remote
  pulling from http://localhost:$HGPORT/
  searching for changes
  no changes found
  $ hg push $remote
  pushing to http://localhost:$HGPORT/
  searching for changes
  abort: push creates new remote branches: both, name1!
  (use 'hg push --new-branch' to create new remote branches)
  [255]
  $ hg push $remote --new-branch
  pushing to http://localhost:$HGPORT/
  searching for changes
  remote: adding changesets
  remote: adding manifests
  remote: adding file changes
  remote: added 6 changesets with 12 changes to 2 files
  $ hg outgoing $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ cd ..

Partial pull:

  $ tstop ; tstart main
  $ hg clone $remote partial --rev name2
  abort: partial pull cannot be done because other repository doesn't support changegroupsubset.
  [255]
  $ hg init partial; cd partial
  $ hg incoming $remote --rev name2
  comparing with http://localhost:$HGPORT/
  abort: cannot look up remote changes; remote repository does not support the 'changegroupsubset' capability!
  [255]
  $ hg pull $remote --rev name2
  pulling from http://localhost:$HGPORT/
  abort: partial pull cannot be done because other repository doesn't support changegroupsubset.
  [255]
  $ cd ..

  $ tstop

Exercise pushing to server without branchmap capability

  $ cp $HGRCPATH-nocap-branchmap $HGRCPATH-nocap
  $ hg init rlocal
  $ cd rlocal
  $ echo A > A
  $ hg ci -Am A
  adding A
  $ cd ..
  $ hg clone rlocal rremote
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cd rlocal
  $ echo B > B
  $ hg ci -Am B
  adding B
  $ cd ..
  $ tstart rremote

  $ cd rlocal
  $ hg incoming $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ hg outgoing $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  1 27547f69f254: B 
  $ hg pull $remote
  pulling from http://localhost:$HGPORT/
  searching for changes
  no changes found
  1 local changesets published
  $ hg push $remote
  pushing to http://localhost:$HGPORT/
  searching for changes
  remote: adding changesets
  remote: adding manifests
  remote: adding file changes
  remote: added 1 changesets with 1 changes to 1 files
  $ hg outgoing $remote
  comparing with http://localhost:$HGPORT/
  searching for changes
  no changes found
  [1]
  $ cd ..

  $ tstop