view tests/test-mq-qrefresh-replace-log-message.t @ 26243:836291420d53

revlog: optionally cache the full text when adding revisions

revlog instances can cache the full text of a single revision. Typically
the most recently read revision is cached.

When adding a delta group via addgroup() and _addrevision(), the
full text isn't always computed: sometimes only the passed in delta is
sufficient for adding a new revision to the revlog.

When writing the changelog from a delta group, the just-added full
text revision is always read immediately after it is written because
the changegroup code needs to extract the set of files from the entry.
In other words, revision() is *always* being called and caching the full
text of the just-added revision is guaranteed to result in a cache hit,
making the cache worthwhile.

This patch adds support to _addrevision() for always building and
caching the full text. This option is currently only active when
processing changelog entries from a changegroup.

While the total number of revision() calls is the same, the location
matters: buildtext() calls into revision() on the base revision when
building the full text of the just-added revision. Since the previous
revision's _addrevision() built the full text and the the previous
revision is likely the base revision, this means that the base
revision's full text is likely cached and can be used to compute the
current full text from just a delta. No extra I/O required.

The end result is the changelog isn't opened and read after adding every
revision from a changegroup.

On my 2013 MacBook Pro running OS X 10.10.5 from an SSD and Python 2.7,
this patch impacted the time taken to apply ~262,000 changesets from a
mozilla-central gzip bundle:

  before: ~43s
  after:  ~32s

~25% reduction in changelog processing times. Not bad.

Environment setup for MQ

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "mq=" >> $HGRCPATH
  $ hg init
  $ hg qinit

Should fail if no patches applied
(this tests also that editor is not invoked if '--edit' is not
specified)

  $ hg qrefresh
  no patches applied
  [1]
  $ hg qrefresh -e
  no patches applied
  [1]
  $ hg qnew -m "First commit message" first-patch
  $ echo aaaa > file
  $ hg add file
  $ HGEDITOR=cat hg qrefresh

Should display 'First commit message'

  $ hg log -l1 --template "{desc}\n"
  First commit message

Testing changing message with -m
(this tests also that '--edit' can be used with '--message', and
that '[committemplate] changeset' definition and commit log specific
template keyword 'extramsg' work well)

  $ cat >> .hg/hgrc <<EOF
  > [committemplate]
  > listupfiles = {file_adds %
  >    "HG: added {file}\n"     }{file_mods %
  >    "HG: changed {file}\n"   }{file_dels %
  >    "HG: removed {file}\n"   }{if(files, "",
  >    "HG: no files changed\n")}
  > 
  > changeset = HG: this is customized commit template
  >     {desc}\n\n
  >     HG: Enter commit message.  Lines beginning with 'HG:' are removed.
  >     HG: {extramsg}
  >     HG: --
  >     HG: user: {author}
  >     HG: branch '{branch}'\n{listupfiles}
  > EOF

  $ echo bbbb > file
  $ HGEDITOR=cat hg qrefresh -m "Second commit message" -e
  HG: this is customized commit template
  Second commit message
  
  
  HG: Enter commit message.  Lines beginning with 'HG:' are removed.
  HG: Leave message empty to use default message.
  HG: --
  HG: user: test
  HG: branch 'default'
  HG: added file

  $ cat >> .hg/hgrc <<EOF
  > # disable customizing for subsequent tests
  > [committemplate]
  > changeset =
  > EOF

Should display 'Second commit message'

  $ hg log -l1 --template "{desc}\n"
  Second commit message

Testing changing message with -l

  $ echo "Third commit message" > logfile
  $ echo " This is the 3rd log message" >> logfile
  $ echo bbbb > file
  $ hg qrefresh -l logfile

Should display 'Third commit message\\\n This is the 3rd log message'

  $ hg log -l1 --template "{desc}\n"
  Third commit message
   This is the 3rd log message

Testing changing message with -l-

  $ hg qnew -m "First commit message" second-patch
  $ echo aaaa > file2
  $ hg add file2
  $ echo bbbb > file2
  $ (echo "Fifth commit message"; echo " This is the 5th log message") | hg qrefresh -l-

Should display 'Fifth commit message\\\n This is the 5th log message'

  $ hg log -l1 --template "{desc}\n"
  Fifth commit message
   This is the 5th log message

Test saving last-message.txt:

  $ cat > $TESTTMP/editor.sh << EOF
  > echo "==== before editing"
  > cat \$1
  > echo "===="
  > (echo; echo "test saving last-message.txt") >> \$1
  > EOF

  $ cat > $TESTTMP/commitfailure.py <<EOF
  > from mercurial import util
  > def reposetup(ui, repo):
  >     class commitfailure(repo.__class__):
  >         def commit(self, *args, **kwargs):
  >             raise util.Abort('emulating unexpected abort')
  >     repo.__class__ = commitfailure
  > EOF

  $ cat >> .hg/hgrc <<EOF
  > [extensions]
  > # this failure occurs before editor invocation
  > commitfailure = $TESTTMP/commitfailure.py
  > EOF

  $ hg qapplied
  first-patch
  second-patch
  $ hg tip --template "{files}\n"
  file2

(test that editor is not invoked before transaction starting)

  $ rm -f .hg/last-message.txt
  $ HGEDITOR="sh $TESTTMP/editor.sh" hg qrefresh -e
  refresh interrupted while patch was popped! (revert --all, qpush to recover)
  abort: emulating unexpected abort
  [255]
  $ test -f .hg/last-message.txt
  [1]

(reset applied patches and directory status)

  $ cat >> .hg/hgrc <<EOF
  > [extensions]
  > commitfailure = !
  > EOF

  $ hg qapplied
  first-patch
  $ hg status -A file2
  ? file2
  $ rm file2
  $ hg qpush -q second-patch
  now at: second-patch

(test that editor is invoked and commit message is saved into
"last-message.txt")

  $ cat >> .hg/hgrc <<EOF
  > [hooks]
  > # this failure occurs after editor invocation
  > pretxncommit.unexpectedabort = false
  > EOF

  $ rm -f .hg/last-message.txt
  $ hg status --rev "second-patch^1" -arm
  A file2
  $ HGEDITOR="sh $TESTTMP/editor.sh" hg qrefresh -e
  ==== before editing
  Fifth commit message
   This is the 5th log message
  
  
  HG: Enter commit message.  Lines beginning with 'HG:' are removed.
  HG: Leave message empty to use default message.
  HG: --
  HG: user: test
  HG: branch 'default'
  HG: added file2
  ====
  transaction abort!
  rollback completed
  note: commit message saved in .hg/last-message.txt
  refresh interrupted while patch was popped! (revert --all, qpush to recover)
  abort: pretxncommit.unexpectedabort hook exited with status 1
  [255]
  $ cat .hg/last-message.txt
  Fifth commit message
   This is the 5th log message
  
  
  
  test saving last-message.txt