This command can be used for testing the performance of producing the
changelog portion of a changegroup.
We could use additional perf* commands for testing other parts of
changegroup. Those can be written another time, when they are needed.
(And those may want to refactor the changegroup generation API so code
can be reused.) Speaking of code reuse, yes, this command does reinvent
a small wheel. I didn't want to scope bloat to change the changegroup
API because that will invite bikeshedding.
We can't use fctx.linkrev() because follow() revset tries hard to simulate
the traversal of changelog DAG, not filelog DAG. This patch fixes
_makefollowlogfilematcher() to walk file ancestors in the same way as
revset._follow().
I'll factor out a common function in future patches.
groupchunks() is a generic "turn a file object into a generator"
function. It isn't limited to changegroups. Rename the argument
and update the docstring to reflect this.
We already support multiple primitive for listing files, which were
affected by the current changeset.
This patch adds files() which returns files of the current changeset
matching a given pattern or fileset query via the "set:" prefix.
There are two reasons that rebase should be done this way:
1. This would make rebasing faster because it would minimize the total
number of files to be checked out in the process, as it don't need
to switch back and forth between branches.
2. It makes resolving conflicts easier as user has a better context.
This commit changes the behavior in "Test multiple root handling" of
test-rebase-obsolete.t. It is an expected change which reflects the new
behavior that commits in a branch are grouped together when rebased.
Add an if True: placeholder for a profiling context manager that
will be added in the next commit, for the purpose of reducing size
of the diff due to trivial indentation changes.
This change should be a no-op.
Before this patch, if steps below occurs at "the same time in sec",
all of mtime, ctime and size are same between (1) and (3).
1. append data to revlog-style file (and close transaction)
2. discard appended data by truncation of rollback
3. append same size but different data to revlog-style file again
Therefore, cache validation doesn't work after (3) as expected.
To avoid file stat ambiguity around truncation, this patch opens a
file with checkambig=True.
This is a part of ExactCacheValidationPlan.
https://www.mercurial-scm.org/wiki/ExactCacheValidationPlan
Before this patch, if steps below occurs at "the same time in sec",
all of mtime, ctime and size are same between (1) and (3).
1. append data to revlog-style file (and close transaction)
2. discard appended data by truncation of strip
3. append same size but different data to revlog-style file again
Therefore, cache validation doesn't work after (3) as expected.
To avoid such file stat ambiguity around truncation, this patch opens
a file with checkambig=True.
This patch also introduces "with" statement style, to ensure immediate
invocation of close() after truncation, because closing file is the
only trigger to check (and get rid of) file stat ambiguity.
This is a part of ExactCacheValidationPlan.
https://www.mercurial-scm.org/wiki/ExactCacheValidationPlan
If steps below occurs at "the same time in sec", all of mtime, ctime
and size are same between (1) and (3).
1. append data to 00changelog.i (and close transaction)
2. discard appended data by truncation (strip or rollback)
3. append same size but different data to 00changelog.i again
Therefore, cache validation doesn't work after (3) as expected.
To avoid such file stat ambiguity around truncation, this patch
specifies checkambig=True to revlog.__init__(). This makes revlog
write changes out with checkambig=True.
Even though changes of 00changelog.i themselves are written out at
changelog._finalize(), this checkambig=True is needed, because
revlog.checkinlinesize(), which is invoked at the end of
changelog._finalize(), might replace already changed 00changelog.i by
converted one.
Even after this patch, avoiding file stat ambiguity of 00changelog.i
around truncation isn't yet completed, because truncation side isn't
aware of this issue.
This is a part of ExactCacheValidationPlan.
https://www.mercurial-scm.org/wiki/ExactCacheValidationPlan
If steps below occurs at "the same time in sec", all of mtime, ctime
and size are same between (1) and (3).
1. append data to 00changelog.i (and close transaction)
2. discard appended data by truncation (strip or rollback)
3. append same size but different data to 00changelog.i again
Therefore, cache validation doesn't work after (3) as expected.
To avoid such file stat ambiguity around truncation, this patch
specifies checkambig=True for renaming or opening to write changes out
at finalization.
Even after this patch, avoiding file stat ambiguity of 00changelog.i
around truncation isn't yet completed, because truncation side isn't
aware of this issue.
This is a part of ExactCacheValidationPlan.
https://www.mercurial-scm.org/wiki/ExactCacheValidationPlan
If steps below occurs at "the same time in sec", all of mtime, ctime
and size are same between (1) and (3).
1. append data to 00manifest.i (and close transaction)
2. discard appended data by truncation (strip or rollback)
3. append same size but different data to 00manifest.i again
Therefore, cache validation doesn't work after (3) as expected.
To avoid such file stat ambiguity around truncation, this patch
specifies checkambig=True to revlog.__init__(). This makes revlog
write changes out with checkambig=True.
Even after this patch, avoiding file stat ambiguity of 00manifest.i
around truncation isn't yet completed, because truncation side isn't
aware of this issue.
This is a part of ExactCacheValidationPlan.
https://www.mercurial-scm.org/wiki/ExactCacheValidationPlan
This allows revlog-style files to be written out with checkambig=True
easily.
Because avoiding file stat ambiguity is needed only for filecache-ed
manifest and changelog, this patch does:
- use False for default value of checkambig
- focus only on writing changes of index file out
This patch also adds optional argument checkambig to _divert/_delay
for changelog, to safely accept checkambig specified in revlog
layer. But this argument can be fully ignored, because:
- changes are written into other than index file, if name != target
- changes are never written into index file, otherwise
(into pending file by _divert, or into in-memory buffer by _delay)
This is a part of ExactCacheValidationPlan.
https://www.mercurial-scm.org/wiki/ExactCacheValidationPlan
In Mercurial source tree, opening a file in "a"/"a+" mode like below
doesn't specify atomictemp=True for vfs, and this avoids file stat
ambiguity check by atomictempfile.
- writing changes out in revlog layer uses "a+" mode
- truncation in repair.strip() uses "a" mode
- truncation in transaction._playback() uses "a" mode
If steps below occurs at "the same time in sec", all of mtime, ctime
and size are same between (1) and (3).
1. append data to revlog-style file (and close transaction)
2. discard appended data by truncation (strip or rollback)
3. append same size but different data to revlog-style file again
Therefore, cache validation doesn't work after (3) as expected.
This patch uses checkambigatclosing in checkambig=True but
atomictemp=False case, to check (and get rid of) file stat ambiguity
at closing.
This is a part of ExactCacheValidationPlan.
https://www.mercurial-scm.org/wiki/ExactCacheValidationPlan
In Mercurial source tree, opening a file in "a"/"a+" mode like below
doesn't specify atomictemp=True for vfs, and this avoids file stat
ambiguity check by atomictempfile.
- writing changes out in revlog layer uses "a+" mode
- truncation in repair.strip() uses "a" mode
- truncation in transaction._playback() uses "a" mode
If steps below occurs at "the same time in sec", all of mtime, ctime
and size are same between (1) and (3).
1. append data to revlog-style file (and close transaction)
2. discard appended data by truncation (strip or rollback)
3. append same size but different data to revlog-style file again
Therefore, cache validation doesn't work after (3) as expected.
This patch adds file object wrapper class checkambigatclosing to check
(and get rid of) ambiguity at closing. It is used by vfs in subsequent
patch.
This is a part of ExactCacheValidationPlan.
https://www.mercurial-scm.org/wiki/ExactCacheValidationPlan
BTW, checkambigatclosing is tested in test-filecache.py, even though
it doesn't use filecache itself, because filecache assumes that file
stat ambiguity never occurs (and there is no another test-*.py related
to filecache).
