view tests/test-transaction-safety.t @ 47682:78f7f0d490ee

dirstate-v2: Move fixed-size tree metadata into the docket file

Before this changeset, the dirstate-v2 data file contained not only nodes
and paths that may be reused when appending to an existing file,
but also some fixed-size metadata that applies to the entire tree
and was added at the end of the data file for every append.

This moves that metadata into the docket file, so that repeated "append"
operations without meaningful changes don’t actually need to grow any file.

Differential Revision: https://phab.mercurial-scm.org/D11098

Test transaction safety
=======================

#testcases revlogv1 revlogv2 changelogv2

#if revlogv1

  $ cat << EOF >> $HGRCPATH
  > [experimental]
  > revlogv2=no
  > EOF

#endif

#if revlogv2

  $ cat << EOF >> $HGRCPATH
  > [experimental]
  > revlogv2=enable-unstable-format-and-corrupt-my-data
  > EOF

#endif

#if changelogv2

  $ cat << EOF >> $HGRCPATH
  > [format]
  > exp-use-changelog-v2=enable-unstable-format-and-corrupt-my-data
  > EOF

#endif

This test basic case to make sure external process do not see transaction
content until it is committed.

# TODO: also add an external reader accessing revlog files while they are written
#       (instead of during transaction finalisation)

# TODO: also add stream clone and hardlink clone happening during these transaction.

setup
-----

synchronisation+output script:

  $ mkdir sync
  $ mkdir output
  $ mkdir script
  $ HG_TEST_FILE_EXT_WAITING=$TESTTMP/sync/ext_waiting
  $ export HG_TEST_FILE_EXT_WAITING
  $ HG_TEST_FILE_EXT_UNLOCK=$TESTTMP/sync/ext_unlock
  $ export HG_TEST_FILE_EXT_UNLOCK
  $ HG_TEST_FILE_EXT_DONE=$TESTTMP/sync/ext_done
  $ export HG_TEST_FILE_EXT_DONE
  $ cat << EOF > script/external.sh
  > #!/bin/sh
  > "$RUNTESTDIR/testlib/wait-on-file" 5 "$HG_TEST_FILE_EXT_UNLOCK" "$HG_TEST_FILE_EXT_WAITING"
  > hg log --rev 'tip' -T 'external: {rev} {desc}\n' > "$TESTTMP/output/external.out"
  > touch "$HG_TEST_FILE_EXT_DONE"
  > EOF
  $ cat << EOF > script/internal.sh
  > #!/bin/sh
  > hg log --rev 'tip' -T 'internal: {rev} {desc}\n' > "$TESTTMP/output/internal.out"
  > "$RUNTESTDIR/testlib/wait-on-file" 5 "$HG_TEST_FILE_EXT_DONE" "$HG_TEST_FILE_EXT_UNLOCK"
  > EOF


Automated commands:

  $ make_one_commit() {
  > rm -f $TESTTMP/sync/*
  > rm -f $TESTTMP/output/*
  > hg log --rev 'tip' -T 'pre-commit: {rev} {desc}\n'
  > echo x >> a
  > sh $TESTTMP/script/external.sh & hg commit -m "$1"
  > cat $TESTTMP/output/external.out
  > cat $TESTTMP/output/internal.out
  > hg log --rev 'tip' -T 'post-tr:  {rev} {desc}\n'
  > }


  $ make_one_pull() {
  > rm -f $TESTTMP/sync/*
  > rm -f $TESTTMP/output/*
  > hg log --rev 'tip' -T 'pre-commit: {rev} {desc}\n'
  > echo x >> a
  > sh $TESTTMP/script/external.sh & hg pull ../other-repo/ --rev "$1" --force --quiet
  > cat $TESTTMP/output/external.out
  > cat $TESTTMP/output/internal.out
  > hg log --rev 'tip' -T 'post-tr:  {rev} {desc}\n'
  > }

prepare a large source to which to pull from:

The source is large to unsure we don't use inline more after the pull

  $ hg init other-repo
  $ hg -R other-repo debugbuilddag .+500


prepare an empty repository where to make test:

  $ hg init repo
  $ cd repo
  $ touch a
  $ hg add a

prepare a small extension to controll inline size

  $ mkdir $TESTTMP/ext
  $ cat << EOF > $TESTTMP/ext/small_inline.py
  > from mercurial import revlog
  > revlog._maxinline = 64 * 100
  > EOF




  $ cat << EOF >> $HGRCPATH
  > [extensions]
  > small_inline=$TESTTMP/ext/small_inline.py
  > [hooks]
  > pretxnclose = sh $TESTTMP/script/internal.sh
  > EOF

check this is true for the initial commit (inline → inline)
-----------------------------------------------------------

the repository should still be inline (for relevant format)

  $ make_one_commit first
  pre-commit: -1 
  external: -1 
  internal: 0 first
  post-tr:  0 first

#if revlogv1

  $ hg debugrevlog -c | grep inline
  flags  : inline

#endif

check this is true for extra commit (inline → inline)
-----------------------------------------------------

the repository should still be inline (for relevant format)

#if revlogv1

  $ hg debugrevlog -c | grep inline
  flags  : inline

#endif

  $ make_one_commit second
  pre-commit: 0 first
  external: 0 first
  internal: 1 second
  post-tr:  1 second

#if revlogv1

  $ hg debugrevlog -c | grep inline
  flags  : inline

#endif

check this is true for a small pull (inline → inline)
-----------------------------------------------------

the repository should still be inline (for relevant format)

#if revlogv1

  $ hg debugrevlog -c | grep inline
  flags  : inline

#endif

  $ make_one_pull 3
  pre-commit: 1 second
  warning: repository is unrelated
  external: 1 second
  internal: 5 r3
  post-tr:  5 r3

#if revlogv1

  $ hg debugrevlog -c | grep inline
  flags  : inline

#endif

Make a large pull (inline → no-inline)
---------------------------------------

the repository should no longer be inline (for relevant format)

#if revlogv1

  $ hg debugrevlog -c | grep inline
  flags  : inline

#endif

  $ make_one_pull 400
  pre-commit: 5 r3
  external: 5 r3
  internal: 402 r400
  post-tr:  402 r400

#if revlogv1

  $ hg debugrevlog -c | grep inline
  [1]

#endif

check this is true for extra commit (no-inline → no-inline)
-----------------------------------------------------------

the repository should no longer be inline (for relevant format)

#if revlogv1

  $ hg debugrevlog -c | grep inline
  [1]

#endif

  $ make_one_commit third
  pre-commit: 402 r400
  external: 402 r400
  internal: 403 third
  post-tr:  403 third

#if revlogv1

  $ hg debugrevlog -c | grep inline
  [1]

#endif


Make a  pull (not-inline → no-inline)
-------------------------------------

the repository should no longer be inline (for relevant format)

#if revlogv1

  $ hg debugrevlog -c | grep inline
  [1]

#endif

  $ make_one_pull tip
  pre-commit: 403 third
  external: 403 third
  internal: 503 r500
  post-tr:  503 r500

#if revlogv1

  $ hg debugrevlog -c | grep inline
  [1]

#endif