cborutil: change buffering strategy
Profiling revealed that we were spending a lot of time on the
line that was concatenating the old buffer with the incoming data
when attempting to decode long byte strings, such as manifest
revisions.
Essentially, we were feeding N chunks of size len(X) << len(Y) into
decode() and continuously allocating a new, larger buffer to hold
the undecoded input. This created substantial memory churn and
slowed down execution.
Changing the code to aggregate pending chunks in a list until we
have enough data to fully decode the next atom makes things much
more efficient.
I don't have exact data, but I recall the old code spending >1s
on manifest fulltexts from the mozilla-unified repo. The new code
doesn't significantly appear in profile output.
Differential Revision: https://phab.mercurial-scm.org/D4854
$ cat << EOF > buggylocking.py
> """A small extension that tests our developer warnings
> """
>
> from mercurial import error, registrar, repair, util
>
> cmdtable = {}
> command = registrar.command(cmdtable)
>
> @command(b'buggylocking', [], '')
> def buggylocking(ui, repo):
> lo = repo.lock()
> wl = repo.wlock()
> wl.release()
> lo.release()
>
> @command(b'buggytransaction', [], '')
> def buggylocking(ui, repo):
> tr = repo.transaction(b'buggy')
> # make sure we rollback the transaction as we don't want to rely on the__del__
> tr.release()
>
> @command(b'properlocking', [], '')
> def properlocking(ui, repo):
> """check that reentrance is fine"""
> wl = repo.wlock()
> lo = repo.lock()
> tr = repo.transaction(b'proper')
> tr2 = repo.transaction(b'proper')
> lo2 = repo.lock()
> wl2 = repo.wlock()
> wl2.release()
> lo2.release()
> tr2.close()
> tr.close()
> lo.release()
> wl.release()
>
> @command(b'nowaitlocking', [], '')
> def nowaitlocking(ui, repo):
> lo = repo.lock()
> wl = repo.wlock(wait=False)
> wl.release()
> lo.release()
>
> @command(b'no-wlock-write', [], '')
> def nowlockwrite(ui, repo):
> with repo.vfs(b'branch', b'a'):
> pass
>
> @command(b'no-lock-write', [], '')
> def nolockwrite(ui, repo):
> with repo.svfs(b'fncache', b'a'):
> pass
>
> @command(b'stripintr', [], '')
> def stripintr(ui, repo):
> lo = repo.lock()
> tr = repo.transaction(b'foobar')
> try:
> repair.strip(repo.ui, repo, [repo[b'.'].node()])
> finally:
> lo.release()
> @command(b'oldanddeprecated', [], '')
> def oldanddeprecated(ui, repo):
> """test deprecation warning API"""
> def foobar(ui):
> ui.deprecwarn(b'foorbar is deprecated, go shopping', b'42.1337')
> foobar(ui)
> @command(b'nouiwarning', [], '')
> def nouiwarning(ui, repo):
> util.nouideprecwarn(b'this is a test', b'13.37')
> @command(b'programmingerror', [], '')
> def programmingerror(ui, repo):
> raise error.ProgrammingError(b'something went wrong', hint=b'try again')
> EOF
$ cat << EOF >> $HGRCPATH
> [extensions]
> buggylocking=$TESTTMP/buggylocking.py
> mock=$TESTDIR/mockblackbox.py
> blackbox=
> [devel]
> all-warnings=1
> EOF
$ hg init lock-checker
$ cd lock-checker
$ hg buggylocking
devel-warn: "wlock" acquired after "lock" at: $TESTTMP/buggylocking.py:* (buggylocking) (glob)
$ cat << EOF >> $HGRCPATH
> [devel]
> all=0
> check-locks=1
> EOF
$ hg buggylocking
devel-warn: "wlock" acquired after "lock" at: $TESTTMP/buggylocking.py:* (buggylocking) (glob)
#if no-chg
$ hg buggylocking --traceback
devel-warn: "wlock" acquired after "lock" at:
*/hg:* in <module> (glob) (?)
*/mercurial/dispatch.py:* in run (glob)
*/mercurial/dispatch.py:* in dispatch (glob)
*/mercurial/dispatch.py:* in _runcatch (glob)
*/mercurial/dispatch.py:* in _callcatch (glob)
*/mercurial/scmutil.py* in callcatch (glob)
*/mercurial/dispatch.py:* in _runcatchfunc (glob)
*/mercurial/dispatch.py:* in _dispatch (glob)
*/mercurial/dispatch.py:* in runcommand (glob)
*/mercurial/dispatch.py:* in _runcommand (glob)
*/mercurial/dispatch.py:* in <lambda> (glob)
*/mercurial/util.py:* in check (glob)
$TESTTMP/buggylocking.py:* in buggylocking (glob)
#else
$ hg buggylocking --traceback
devel-warn: "wlock" acquired after "lock" at:
*/hg:* in <module> (glob) (?)
*/mercurial/dispatch.py:* in run (glob)
*/mercurial/dispatch.py:* in dispatch (glob)
*/mercurial/dispatch.py:* in _runcatch (glob)
*/mercurial/dispatch.py:* in _callcatch (glob)
*/mercurial/scmutil.py:* in callcatch (glob)
*/mercurial/dispatch.py:* in _runcatchfunc (glob)
*/mercurial/dispatch.py:* in _dispatch (glob)
*/mercurial/dispatch.py:* in runcommand (glob)
*/mercurial/dispatch.py:* in _runcommand (glob)
*/mercurial/dispatch.py:* in <lambda> (glob)
*/mercurial/util.py:* in check (glob)
*/mercurial/commands.py:* in serve (glob)
*/mercurial/server.py:* in runservice (glob)
*/mercurial/commandserver.py:* in run (glob)
*/mercurial/commandserver.py:* in _mainloop (glob)
*/mercurial/commandserver.py:* in _runworker (glob)
*/mercurial/commandserver.py:* in _serverequest (glob)
*/mercurial/commandserver.py:* in serve (glob)
*/mercurial/commandserver.py:* in serveone (glob)
*/mercurial/chgserver.py:* in runcommand (glob)
*/mercurial/commandserver.py:* in runcommand (glob)
*/mercurial/dispatch.py:* in dispatch (glob)
*/mercurial/dispatch.py:* in _runcatch (glob)
*/mercurial/dispatch.py:* in _callcatch (glob)
*/mercurial/scmutil.py:* in callcatch (glob)
*/mercurial/dispatch.py:* in _runcatchfunc (glob)
*/mercurial/dispatch.py:* in _dispatch (glob)
*/mercurial/dispatch.py:* in runcommand (glob)
*/mercurial/dispatch.py:* in _runcommand (glob)
*/mercurial/dispatch.py:* in <lambda> (glob)
*/mercurial/util.py:* in check (glob)
$TESTTMP/buggylocking.py:* in buggylocking (glob)
#endif
$ hg properlocking
$ hg nowaitlocking
Writing without lock
$ hg no-wlock-write
devel-warn: write with no wlock: "branch" at: $TESTTMP/buggylocking.py:* (nowlockwrite) (glob)
$ hg no-lock-write
devel-warn: write with no lock: "fncache" at: $TESTTMP/buggylocking.py:* (nolockwrite) (glob)
Stripping from a transaction
$ echo a > a
$ hg add a
$ hg commit -m a
$ hg stripintr 2>&1 | egrep -v '^(\*\*| )'
Traceback (most recent call last):
*ProgrammingError: cannot strip from inside a transaction (glob)
$ hg oldanddeprecated
devel-warn: foorbar is deprecated, go shopping
(compatibility will be dropped after Mercurial-42.1337, update your code.) at: $TESTTMP/buggylocking.py:* (oldanddeprecated) (glob)
#if no-chg
$ hg oldanddeprecated --traceback
devel-warn: foorbar is deprecated, go shopping
(compatibility will be dropped after Mercurial-42.1337, update your code.) at:
*/hg:* in <module> (glob) (?)
*/mercurial/dispatch.py:* in run (glob)
*/mercurial/dispatch.py:* in dispatch (glob)
*/mercurial/dispatch.py:* in _runcatch (glob)
*/mercurial/dispatch.py:* in _callcatch (glob)
*/mercurial/scmutil.py* in callcatch (glob)
*/mercurial/dispatch.py:* in _runcatchfunc (glob)
*/mercurial/dispatch.py:* in _dispatch (glob)
*/mercurial/dispatch.py:* in runcommand (glob)
*/mercurial/dispatch.py:* in _runcommand (glob)
*/mercurial/dispatch.py:* in <lambda> (glob)
*/mercurial/util.py:* in check (glob)
$TESTTMP/buggylocking.py:* in oldanddeprecated (glob)
#else
$ hg oldanddeprecated --traceback
devel-warn: foorbar is deprecated, go shopping
(compatibility will be dropped after Mercurial-42.1337, update your code.) at:
*/hg:* in <module> (glob)
*/mercurial/dispatch.py:* in run (glob)
*/mercurial/dispatch.py:* in dispatch (glob)
*/mercurial/dispatch.py:* in _runcatch (glob)
*/mercurial/dispatch.py:* in _callcatch (glob)
*/mercurial/scmutil.py:* in callcatch (glob)
*/mercurial/dispatch.py:* in _runcatchfunc (glob)
*/mercurial/dispatch.py:* in _dispatch (glob)
*/mercurial/dispatch.py:* in runcommand (glob)
*/mercurial/dispatch.py:* in _runcommand (glob)
*/mercurial/dispatch.py:* in <lambda> (glob)
*/mercurial/util.py:* in check (glob)
*/mercurial/commands.py:* in serve (glob)
*/mercurial/server.py:* in runservice (glob)
*/mercurial/commandserver.py:* in run (glob)
*/mercurial/commandserver.py:* in _mainloop (glob)
*/mercurial/commandserver.py:* in _runworker (glob)
*/mercurial/commandserver.py:* in _serverequest (glob)
*/mercurial/commandserver.py:* in serve (glob)
*/mercurial/commandserver.py:* in serveone (glob)
*/mercurial/chgserver.py:* in runcommand (glob)
*/mercurial/commandserver.py:* in runcommand (glob)
*/mercurial/dispatch.py:* in dispatch (glob)
*/mercurial/dispatch.py:* in _runcatch (glob)
*/mercurial/dispatch.py:* in _callcatch (glob)
*/mercurial/scmutil.py:* in callcatch (glob)
*/mercurial/dispatch.py:* in _runcatchfunc (glob)
*/mercurial/dispatch.py:* in _dispatch (glob)
*/mercurial/dispatch.py:* in runcommand (glob)
*/mercurial/dispatch.py:* in _runcommand (glob)
*/mercurial/dispatch.py:* in <lambda> (glob)
*/mercurial/util.py:* in check (glob)
$TESTTMP/buggylocking.py:* in oldanddeprecated (glob)
#endif
#if no-chg
$ hg blackbox -l 7
1970/01/01 00:00:00 bob @cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b (5000)> oldanddeprecated
1970/01/01 00:00:00 bob @cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b (5000)> devel-warn: foorbar is deprecated, go shopping
(compatibility will be dropped after Mercurial-42.1337, update your code.) at: $TESTTMP/buggylocking.py:* (oldanddeprecated) (glob)
1970/01/01 00:00:00 bob @cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b (5000)> oldanddeprecated exited 0 after * seconds (glob)
1970/01/01 00:00:00 bob @cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b (5000)> oldanddeprecated --traceback
1970/01/01 00:00:00 bob @cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b (5000)> devel-warn: foorbar is deprecated, go shopping
(compatibility will be dropped after Mercurial-42.1337, update your code.) at:
*/hg:* in <module> (glob) (?)
*/mercurial/dispatch.py:* in run (glob)
*/mercurial/dispatch.py:* in dispatch (glob)
*/mercurial/dispatch.py:* in _runcatch (glob)
*/mercurial/dispatch.py:* in _callcatch (glob)
*/mercurial/scmutil.py* in callcatch (glob)
*/mercurial/dispatch.py:* in _runcatchfunc (glob)
*/mercurial/dispatch.py:* in _dispatch (glob)
*/mercurial/dispatch.py:* in runcommand (glob)
*/mercurial/dispatch.py:* in _runcommand (glob)
*/mercurial/dispatch.py:* in <lambda> (glob)
*/mercurial/util.py:* in check (glob)
$TESTTMP/buggylocking.py:* in oldanddeprecated (glob)
1970/01/01 00:00:00 bob @cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b (5000)> oldanddeprecated --traceback exited 0 after * seconds (glob)
1970/01/01 00:00:00 bob @cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b (5000)> blackbox -l 7
#else
$ hg blackbox -l 7
1970/01/01 00:00:00 bob @cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b (5000)> oldanddeprecated
1970/01/01 00:00:00 bob @cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b (5000)> devel-warn: foorbar is deprecated, go shopping
(compatibility will be dropped after Mercurial-42.1337, update your code.) at: $TESTTMP/buggylocking.py:* (oldanddeprecated) (glob)
1970/01/01 00:00:00 bob @cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b (5000)> oldanddeprecated exited 0 after * seconds (glob)
1970/01/01 00:00:00 bob @cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b (5000)> oldanddeprecated --traceback
1970/01/01 00:00:00 bob @cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b (5000)> devel-warn: foorbar is deprecated, go shopping
(compatibility will be dropped after Mercurial-42.1337, update your code.) at:
*/hg:* in <module> (glob)
*/mercurial/dispatch.py:* in run (glob)
*/mercurial/dispatch.py:* in dispatch (glob)
*/mercurial/dispatch.py:* in _runcatch (glob)
*/mercurial/dispatch.py:* in _callcatch (glob)
*/mercurial/scmutil.py:* in callcatch (glob)
*/mercurial/dispatch.py:* in _runcatchfunc (glob)
*/mercurial/dispatch.py:* in _dispatch (glob)
*/mercurial/dispatch.py:* in runcommand (glob)
*/mercurial/dispatch.py:* in _runcommand (glob)
*/mercurial/dispatch.py:* in <lambda> (glob)
*/mercurial/util.py:* in check (glob)
*/mercurial/commands.py:* in serve (glob)
*/mercurial/server.py:* in runservice (glob)
*/mercurial/commandserver.py:* in run (glob)
*/mercurial/commandserver.py:* in _mainloop (glob)
*/mercurial/commandserver.py:* in _runworker (glob)
*/mercurial/commandserver.py:* in _serverequest (glob)
*/mercurial/commandserver.py:* in serve (glob)
*/mercurial/commandserver.py:* in serveone (glob)
*/mercurial/chgserver.py:* in runcommand (glob)
*/mercurial/commandserver.py:* in runcommand (glob)
*/mercurial/dispatch.py:* in dispatch (glob)
*/mercurial/dispatch.py:* in _runcatch (glob)
*/mercurial/dispatch.py:* in _callcatch (glob)
*/mercurial/scmutil.py:* in callcatch (glob)
*/mercurial/dispatch.py:* in _runcatchfunc (glob)
*/mercurial/dispatch.py:* in _dispatch (glob)
*/mercurial/dispatch.py:* in runcommand (glob)
*/mercurial/dispatch.py:* in _runcommand (glob)
*/mercurial/dispatch.py:* in <lambda> (glob)
*/mercurial/util.py:* in check (glob)
$TESTTMP/buggylocking.py:* in oldanddeprecated (glob)
1970/01/01 00:00:00 bob @cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b (5000)> oldanddeprecated --traceback exited 0 after * seconds (glob)
1970/01/01 00:00:00 bob @cb9a9f314b8b07ba71012fcdbc544b5a4d82ff5b (5000)> blackbox -l 7
#endif
Test programming error failure:
$ hg buggytransaction 2>&1 | egrep -v '^ '
** Unknown exception encountered with possibly-broken third-party extension buggylocking
** which supports versions unknown of Mercurial.
** Please disable buggylocking and try your action again.
** If that fixes the bug please report it to the extension author.
** Python * (glob)
** Mercurial Distributed SCM (*) (glob)
** Extensions loaded: * (glob)
** ProgrammingError: transaction requires locking
Traceback (most recent call last):
*ProgrammingError: transaction requires locking (glob)
$ hg programmingerror 2>&1 | egrep -v '^ '
** Unknown exception encountered with possibly-broken third-party extension buggylocking
** which supports versions unknown of Mercurial.
** Please disable buggylocking and try your action again.
** If that fixes the bug please report it to the extension author.
** Python * (glob)
** Mercurial Distributed SCM (*) (glob)
** Extensions loaded: * (glob)
** ProgrammingError: something went wrong
** (try again)
Traceback (most recent call last):
*ProgrammingError: something went wrong (glob)
Old style deprecation warning
$ hg nouiwarning
$TESTTMP/buggylocking.py:*: DeprecationWarning: this is a test (glob)
(compatibility will be dropped after Mercurial-13.37, update your code.)
util.nouideprecwarn(b'this is a test', b'13.37')
(disabled outside of test run)
$ HGEMITWARNINGS= hg nouiwarning
Test warning on config option access and registration
$ cat << EOF > ${TESTTMP}/buggyconfig.py
> """A small extension that tests our developer warnings for config"""
>
> from mercurial import registrar, configitems
>
> cmdtable = {}
> command = registrar.command(cmdtable)
>
> configtable = {}
> configitem = registrar.configitem(configtable)
>
> configitem(b'test', b'some', default=b'foo')
> configitem(b'test', b'dynamic', default=configitems.dynamicdefault)
> configitem(b'test', b'callable', default=list)
> # overwrite a core config
> configitem(b'ui', b'quiet', default=False)
> configitem(b'ui', b'interactive', default=None)
>
> @command(b'buggyconfig')
> def cmdbuggyconfig(ui, repo):
> repo.ui.config(b'ui', b'quiet', True)
> repo.ui.config(b'ui', b'interactive', False)
> repo.ui.config(b'test', b'some', b'bar')
> repo.ui.config(b'test', b'some', b'foo')
> repo.ui.config(b'test', b'dynamic', b'some-required-default')
> repo.ui.config(b'test', b'dynamic')
> repo.ui.config(b'test', b'callable', [])
> repo.ui.config(b'test', b'callable', b'foo')
> repo.ui.config(b'test', b'unregistered')
> repo.ui.config(b'unregistered', b'unregistered')
> EOF
$ hg --config "extensions.buggyconfig=${TESTTMP}/buggyconfig.py" buggyconfig
devel-warn: extension 'buggyconfig' overwrite config item 'ui.interactive' at: */mercurial/extensions.py:* (_loadextra) (glob)
devel-warn: extension 'buggyconfig' overwrite config item 'ui.quiet' at: */mercurial/extensions.py:* (_loadextra) (glob)
devel-warn: specifying a mismatched default value for a registered config item: 'ui.quiet' 'True' at: $TESTTMP/buggyconfig.py:* (cmdbuggyconfig) (glob)
devel-warn: specifying a mismatched default value for a registered config item: 'ui.interactive' 'False' at: $TESTTMP/buggyconfig.py:* (cmdbuggyconfig) (glob)
devel-warn: specifying a mismatched default value for a registered config item: 'test.some' 'bar' at: $TESTTMP/buggyconfig.py:* (cmdbuggyconfig) (glob)
devel-warn: config item requires an explicit default value: 'test.dynamic' at: $TESTTMP/buggyconfig.py:* (cmdbuggyconfig) (glob)
devel-warn: specifying a mismatched default value for a registered config item: 'test.callable' 'foo' at: $TESTTMP/buggyconfig.py:* (cmdbuggyconfig) (glob)
devel-warn: accessing unregistered config item: 'test.unregistered' at: $TESTTMP/buggyconfig.py:* (cmdbuggyconfig) (glob)
devel-warn: accessing unregistered config item: 'unregistered.unregistered' at: $TESTTMP/buggyconfig.py:* (cmdbuggyconfig) (glob)
$ cd ..