view tests/test-flagprocessor.t @ 47120:7109a38830c9

dirstate-tree: Fold "tracked descendants" counter update in main walk

For the purpose of implementing `has_tracked_dir` (which means "has tracked
descendants) without an expensive sub-tree traversal, we maintaing a counter
of tracked descendants on each "directory" node of the tree-shaped dirstate.

Before this changeset, mutating or inserting a node at a given path would
involve:

* Walking the tree from root through ancestors to find the node or the spot
  where to insert it
* Looking at the previous node if any to decide what counter update is needed
* Performing any node mutation
* Walking the tree *again* to update counters in ancestor nodes

When profiling `hg status` on a large repo, this second walk takes times
while loading a the dirstate from disk.

It turns out we have enough information to decide before he first tree walk
what counter update is needed. This changeset merges the two walks, gaining
~10% of the total time for `hg update` (in the same hyperfine benchmark as
the previous changeset).

---

Profiling was done by compiling with this `.cargo/config`:

    [profile.release]
    debug = true

then running with:

    py-spy record -r 500 -n -o /tmp/hg.json --format speedscope -- \
    ./hg status -R $REPO --config experimental.dirstate-tree.in-memory=1

then visualizing the recorded JSON file in https://www.speedscope.app/

Differential Revision: https://phab.mercurial-scm.org/D10554

# Create server
  $ hg init server
  $ cd server
  $ cat >> .hg/hgrc << EOF
  > [extensions]
  > extension=$TESTDIR/flagprocessorext.py
  > EOF
  $ cd ../

# Clone server and enable extensions
  $ hg clone -q server client
  $ cd client
  $ cat >> .hg/hgrc << EOF
  > [extensions]
  > extension=$TESTDIR/flagprocessorext.py
  > EOF

# Commit file that will trigger the noop extension
  $ echo '[NOOP]' > noop
  $ hg commit -Aqm "noop"

# Commit file that will trigger the base64 extension
  $ echo '[BASE64]' > base64
  $ hg commit -Aqm 'base64'

# Commit file that will trigger the gzip extension
  $ echo '[GZIP]' > gzip
  $ hg commit -Aqm 'gzip'

# Commit file that will trigger noop and base64
  $ echo '[NOOP][BASE64]' > noop-base64
  $ hg commit -Aqm 'noop+base64'

# Commit file that will trigger noop and gzip
  $ echo '[NOOP][GZIP]' > noop-gzip
  $ hg commit -Aqm 'noop+gzip'

# Commit file that will trigger base64 and gzip
  $ echo '[BASE64][GZIP]' > base64-gzip
  $ hg commit -Aqm 'base64+gzip'

# Commit file that will trigger base64, gzip and noop
  $ echo '[BASE64][GZIP][NOOP]' > base64-gzip-noop
  $ hg commit -Aqm 'base64+gzip+noop'

# TEST: ensure the revision data is consistent
  $ hg cat noop
  [NOOP]
  $ hg debugdata noop 0
  [NOOP]

  $ hg cat -r . base64
  [BASE64]
  $ hg debugdata base64 0
  W0JBU0U2NF0K (no-eol)

  $ hg cat -r . gzip
  [GZIP]
  $ hg debugdata gzip 0
  x\x9c\x8bv\x8f\xf2\x0c\x88\xe5\x02\x00\x08\xc8\x01\xfd (no-eol) (esc)

  $ hg cat -r . noop-base64
  [NOOP][BASE64]
  $ hg debugdata noop-base64 0
  W05PT1BdW0JBU0U2NF0K (no-eol)

  $ hg cat -r . noop-gzip
  [NOOP][GZIP]
  $ hg debugdata noop-gzip 0
  x\x9c\x8b\xf6\xf3\xf7\x0f\x88\x8dv\x8f\xf2\x0c\x88\xe5\x02\x00\x1dH\x03\xf1 (no-eol) (esc)

  $ hg cat -r . base64-gzip
  [BASE64][GZIP]
  $ hg debugdata base64-gzip 0
  eJyLdnIMdjUziY12j/IMiOUCACLBBDo= (no-eol)

  $ hg cat -r . base64-gzip-noop
  [BASE64][GZIP][NOOP]
  $ hg debugdata base64-gzip-noop 0
  eJyLdnIMdjUziY12j/IMiI328/cPiOUCAESjBi4= (no-eol)

# Push to the server
  $ hg push
  pushing to $TESTTMP/server
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 7 changesets with 7 changes to 7 files

Ensure the data got to the server OK

  $ cd ../server
  $ hg cat -r 6e48f4215d24 noop
  [NOOP]
  $ hg debugdata noop 0
  [NOOP]

  $ hg cat -r 6e48f4215d24 base64
  [BASE64]
  $ hg debugdata base64 0
  W0JBU0U2NF0K (no-eol)

  $ hg cat -r 6e48f4215d24 gzip
  [GZIP]
  $ hg debugdata gzip 0
  x\x9c\x8bv\x8f\xf2\x0c\x88\xe5\x02\x00\x08\xc8\x01\xfd (no-eol) (esc)

  $ hg cat -r 6e48f4215d24 noop-base64
  [NOOP][BASE64]
  $ hg debugdata noop-base64 0
  W05PT1BdW0JBU0U2NF0K (no-eol)

  $ hg cat -r 6e48f4215d24 noop-gzip
  [NOOP][GZIP]
  $ hg debugdata noop-gzip 0
  x\x9c\x8b\xf6\xf3\xf7\x0f\x88\x8dv\x8f\xf2\x0c\x88\xe5\x02\x00\x1dH\x03\xf1 (no-eol) (esc)

  $ hg cat -r 6e48f4215d24 base64-gzip
  [BASE64][GZIP]
  $ hg debugdata base64-gzip 0
  eJyLdnIMdjUziY12j/IMiOUCACLBBDo= (no-eol)

  $ hg cat -r 6e48f4215d24 base64-gzip-noop
  [BASE64][GZIP][NOOP]
  $ hg debugdata base64-gzip-noop 0
  eJyLdnIMdjUziY12j/IMiI328/cPiOUCAESjBi4= (no-eol)

# Initialize new client (not cloning) and setup extension
  $ cd ..
  $ hg init client2
  $ cd client2
  $ cat >> .hg/hgrc << EOF
  > [paths]
  > default = $TESTTMP/server
  > [extensions]
  > extension=$TESTDIR/flagprocessorext.py
  > EOF

# Pull from server and update to latest revision
  $ hg pull default
  pulling from $TESTTMP/server
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 7 changesets with 7 changes to 7 files
  new changesets 07b1b9442c5b:6e48f4215d24
  (run 'hg update' to get a working copy)
  $ hg update
  7 files updated, 0 files merged, 0 files removed, 0 files unresolved

# TEST: ensure the revision data is consistent
  $ hg cat noop
  [NOOP]
  $ hg debugdata noop 0
  [NOOP]

  $ hg cat -r . base64
  [BASE64]
  $ hg debugdata base64 0
  W0JBU0U2NF0K (no-eol)

  $ hg cat -r . gzip
  [GZIP]
  $ hg debugdata gzip 0
  x\x9c\x8bv\x8f\xf2\x0c\x88\xe5\x02\x00\x08\xc8\x01\xfd (no-eol) (esc)

  $ hg cat -r . noop-base64
  [NOOP][BASE64]
  $ hg debugdata noop-base64 0
  W05PT1BdW0JBU0U2NF0K (no-eol)

  $ hg cat -r . noop-gzip
  [NOOP][GZIP]
  $ hg debugdata noop-gzip 0
  x\x9c\x8b\xf6\xf3\xf7\x0f\x88\x8dv\x8f\xf2\x0c\x88\xe5\x02\x00\x1dH\x03\xf1 (no-eol) (esc)

  $ hg cat -r . base64-gzip
  [BASE64][GZIP]
  $ hg debugdata base64-gzip 0
  eJyLdnIMdjUziY12j/IMiOUCACLBBDo= (no-eol)

  $ hg cat -r . base64-gzip-noop
  [BASE64][GZIP][NOOP]
  $ hg debugdata base64-gzip-noop 0
  eJyLdnIMdjUziY12j/IMiI328/cPiOUCAESjBi4= (no-eol)

# TEST: ensure a missing processor is handled
  $ echo '[FAIL][BASE64][GZIP][NOOP]' > fail-base64-gzip-noop
  $ hg commit -Aqm 'fail+base64+gzip+noop'
  abort: missing processor for flag '0x1'
  [50]
  $ rm fail-base64-gzip-noop

# TEST: ensure we cannot register several flag processors on the same flag
  $ cat >> .hg/hgrc << EOF
  > [extensions]
  > extension=$TESTDIR/flagprocessorext.py
  > duplicate=$TESTDIR/flagprocessorext.py
  > EOF
  $ hg debugrebuilddirstate
  Traceback (most recent call last):
    File "*/mercurial/extensions.py", line *, in _runextsetup (glob)
      extsetup(ui)
    File "*/tests/flagprocessorext.py", line *, in extsetup (glob)
      flagutil.addflagprocessor( (py38 !)
      validatehash, (no-py38 !)
    File "*/mercurial/revlogutils/flagutil.py", line *, in addflagprocessor (glob)
      insertflagprocessor(flag, processor, flagprocessors)
    File "*/mercurial/revlogutils/flagutil.py", line *, in insertflagprocessor (glob)
      raise error.Abort(msg)
  mercurial.error.Abort: cannot register multiple processors on flag '0x8'. (py3 !)
  Abort: cannot register multiple processors on flag '0x8'. (no-py3 !)
  *** failed to set up extension duplicate: cannot register multiple processors on flag '0x8'.
  $ hg st 2>&1 | egrep 'cannot register multiple processors|flagprocessorext'
    File "*/tests/flagprocessorext.py", line *, in extsetup (glob)
  mercurial.error.Abort: cannot register multiple processors on flag '0x8'. (py3 !)
  Abort: cannot register multiple processors on flag '0x8'. (no-py3 !)
  *** failed to set up extension duplicate: cannot register multiple processors on flag '0x8'.
    File "*/tests/flagprocessorext.py", line *, in b64decode (glob)

  $ cd ..

# TEST: bundle repo
  $ hg init bundletest
  $ cd bundletest

  $ cat >> .hg/hgrc << EOF
  > [extensions]
  > flagprocessor=$TESTDIR/flagprocessorext.py
  > EOF

  $ for i in 0 single two three 4; do
  >   echo '[BASE64]a-bit-longer-'$i > base64
  >   hg commit -m base64-$i -A base64
  > done

  $ hg update 2 -q
  $ echo '[BASE64]a-bit-longer-branching' > base64
  $ hg commit -q -m branching

#if repobundlerepo
  $ hg bundle --base 1 bundle.hg
  4 changesets found
  $ hg --config extensions.strip= strip -r 2 --no-backup --force -q
  $ hg -R bundle.hg log --stat -T '{rev} {desc}\n' base64
  5 branching
   base64 |  2 +-
   1 files changed, 1 insertions(+), 1 deletions(-)
  
  4 base64-4
   base64 |  2 +-
   1 files changed, 1 insertions(+), 1 deletions(-)
  
  3 base64-three
   base64 |  2 +-
   1 files changed, 1 insertions(+), 1 deletions(-)
  
  2 base64-two
   base64 |  2 +-
   1 files changed, 1 insertions(+), 1 deletions(-)
  
  1 base64-single
   base64 |  2 +-
   1 files changed, 1 insertions(+), 1 deletions(-)
  
  0 base64-0
   base64 |  1 +
   1 files changed, 1 insertions(+), 0 deletions(-)
  

  $ hg bundle -R bundle.hg --base 1 bundle-again.hg -q
  $ hg -R bundle-again.hg log --stat -T '{rev} {desc}\n' base64
  5 branching
   base64 |  2 +-
   1 files changed, 1 insertions(+), 1 deletions(-)
  
  4 base64-4
   base64 |  2 +-
   1 files changed, 1 insertions(+), 1 deletions(-)
  
  3 base64-three
   base64 |  2 +-
   1 files changed, 1 insertions(+), 1 deletions(-)
  
  2 base64-two
   base64 |  2 +-
   1 files changed, 1 insertions(+), 1 deletions(-)
  
  1 base64-single
   base64 |  2 +-
   1 files changed, 1 insertions(+), 1 deletions(-)
  
  0 base64-0
   base64 |  1 +
   1 files changed, 1 insertions(+), 0 deletions(-)
  
  $ rm bundle.hg bundle-again.hg
#endif

# TEST: hg status

  $ hg status
  $ hg diff