Wagner Bruna <wbruna@softwareexpress.com.br> [Wed, 31 Aug 2016 13:58:33 -0300] rev 29850
i18n-pt_BR: synchronized with
a12d13eac513
liscju <piotr.listkiewicz@gmail.com> [Tue, 05 Jul 2016 09:37:07 +0200] rev 29849
files: change documentation to match its behaviour (
issue5276)
Documentation gave the usage pattern as '[OPTION]... [PATTERN]...'
when the command match given files as relpaths by default.
Matt Mackall <mpm@selenic.com> [Wed, 24 Aug 2016 17:43:45 -0700] rev 29848
templater: add template path to __base__ search
This does a fall-back check for style files or directories that are
in Mercurial's template path for user convenience.
We intentionally don't use this for the built-in coal style because we don't
want the style to mysteriously break if the working directory just
happens to have a file named "paper".
Gregory Szorc <gregory.szorc@gmail.com> [Thu, 25 Aug 2016 19:53:14 -0700] rev 29847
bundle2: fail faster when interrupted
Before this patch, bundle2 application attempted to consume remaining
bundle2 part data when the process is interrupted (SIGINT) or when
sys.exit is called (translated into a SystemExit exception). This
meant that if one of these occurred when applying a say 1 GB
changegroup bundle2 part being downloaded over a network, it may take
Mercurial *several minutes* to terminate after a SIGINT because the
process is waiting on the network to stream megabytes of data. This is
not a great user experience and a regression from bundle1. Furthermore,
many process supervisors tend to only give processes a finite amount of
time to exit after delivering SIGINT: if processes take too long to
self-terminate, a SIGKILL is issued and Mercurial has no opportunity to
clean up. This would mean orphaned locks and transactions. Not good.
This patch changes the bundle2 application behavior to fail faster
when an interrupt or system exit is requested. It does so by not
catching BaseException (which includes KeyboardInterrupt and
SystemExit) and by explicitly checking for these conditions in
yet another handler which would also seek to the end of the current
bundle2 part on failure.
The end result of this patch is that SIGINT is now reacted to
significantly faster: the active transaction is rolled back
immediately without waiting for incoming bundle2 data to be consumed.
This restores the pre-bundle2 behavior and makes Mercurial treat
signals with the urgency they deserve.
Augie Fackler <augie@google.com> [Tue, 23 Aug 2016 16:40:08 -0400] rev 29846
blackbox: also log alias expansions
This should be extremely useful for helping users debug without having
to see their complete configuration.
Shell aliases do not get their expansion logged, because we don't look
and see if we're in a repo before we dive into the execution of a
shell alias. As a result, the ui object doesn't know where to log.
Augie Fackler <augie@google.com> [Thu, 25 Aug 2016 01:06:32 -0400] rev 29845
test-clonebundles: accept another error string here
This is what happens if you run the test in a FreeBSD Jail, rather
than "connection refused".
Augie Fackler <augie@google.com> [Thu, 25 Aug 2016 01:26:39 -0400] rev 29844
tests: guard test-archive-symlink with unziplinks check
This fixes the test on FreeBSD, where the stock unzip doesn't
understand symlinks.
Augie Fackler <augie@google.com> [Thu, 25 Aug 2016 01:25:52 -0400] rev 29843
hghave: add a check for unzip(1) that understands symlinks
unzip(1) from the FreeBSD base system does not understand symlinks, so
test-archive-symlinks is busted.
Augie Fackler <augie@google.com> [Thu, 25 Aug 2016 01:00:54 -0400] rev 29842
test-https: drop two spurious --traceback flags
These make test failures scarier than they are.
Augie Fackler <augie@google.com> [Tue, 23 Aug 2016 11:26:08 -0400] rev 29841
extensions: change magic "shipped with hg" string
I've caught multiple extensions in the wild lying about being
'internal', so it's time to move the goalposts on people. Goalpost
moving will continue until third party extensions stop trying to
defeat the system.
Yuya Nishihara <yuya@tcha.org> [Thu, 25 Aug 2016 01:00:26 -0400] rev 29840
version: add formatter support
The license message isn't exported, which I don't think is useful and I
couldn't find a way to restructure it for JSON or template outputs.
Yuya Nishihara <yuya@tcha.org> [Tue, 16 Aug 2016 16:09:12 +0900] rev 29839
version: factor out mapping of internal/external labels
Prepares for formatter support, where translation should be disabled
conditionally.
Yuya Nishihara <yuya@tcha.org> [Tue, 16 Aug 2016 16:03:09 +0900] rev 29838
version: always build list of extension versions
This patch just moves "if ui.verbose:" to the inner loop, as preparation
for formatter support.
Yuya Nishihara <yuya@tcha.org> [Sun, 13 Mar 2016 19:59:39 +0900] rev 29837
formatter: add fm.nested(field) to either write or build sub items
We sometimes need to build nested items by formatter, but there was no
convenient way other than building and putting them manually by fm.data():
exts = []
for n, v in extensions:
fm.plain('%s %s\n' % (n, v))
exts.append({'name': n, 'ver': v})
fm.data(extensions=exts)
This should work for simple cases, but doing this would make it harder to
change the underlying data type for better templating support.
So this patch provides fm.nested(field), which returns new nested formatter
(or self if items aren't structured and just written to ui.) A nested formatter
stores items which will later be rendered by the parent formatter.
fn = fm.nested('extensions')
for n, v in extensions:
fn.startitem()
fn.write('name ver', '%s %s\n', n, v)
fn.end()
Nested items are directly exported to a template for now:
{extensions % "{name} {ver}\n"}
There's no {extensions} nor {join(extensions, sep)} yet. I have a plan for
them by extending fm.nested() API, but I want to revisit it after trying
out this API in the real world.
Yuya Nishihara <yuya@tcha.org> [Mon, 15 Aug 2016 13:51:14 +0900] rev 29836
formatter: factor out format*() functions to separate classes
New converter classes will be reused by a nested formatter. See the next
patch for details.
This change is also good in that the default values are defined uniquely
by the baseformatter.
Jun Wu <quark@fb.com> [Wed, 24 Aug 2016 11:24:07 +0100] rev 29835
crecord: restore SIGWINCH handler before return
Previously, the SIGWINCH handler does not get cleared and if the commit
message editor also needs SIGWINCH handling (like vim), the two SIGWINCH
handlers (the editor's, ours) will have a race. And we may erase the
editor's screen content.
This patch restores SIGWINCH handler to address the above issue.
Maciej Fijalkowski <fijall@gmail.com> [Sat, 20 Aug 2016 23:06:01 +0200] rev 29834
bdiff: implement cffi version of bdiff
Maciej Fijalkowski <fijall@gmail.com> [Thu, 28 Jul 2016 14:17:08 +0200] rev 29833
bdiff: implement cffi version of blocks
Tony Tung <tonytung@merly.org> [Fri, 19 Aug 2016 13:30:40 -0700] rev 29832
util: checknlink should remove file it creates if an exception occurs
There's no reason to leave the file behind.
Siddharth Agarwal <sid0@fb.com> [Tue, 23 Aug 2016 17:58:53 -0700] rev 29831
merge: remove files with extra actions from merge action list
See the comment for a detailed explanation why.
Even though this is a bug, I've sent it to 'default' rather than 'stable'
because it isn't triggered in any code paths in stock Mercurial, just with the
merge driver included. For the same reason I haven't included any tests here --
the merge driver is getting a new test.
Gregory Szorc <gregory.szorc@gmail.com> [Mon, 22 Aug 2016 21:48:50 -0700] rev 29830
revlog: use an LRU cache for delta chain bases
Profiling using statprof revealed a hotspot during changegroup
application calculating delta chain bases on generaldelta repos.
Essentially, revlog._addrevision() was performing a lot of redundant
work tracing the delta chain as part of determining when the chain
distance was acceptable. This was most pronounced when adding
revisions to manifests, which can have delta chains thousands of
revisions long.
There was a delta chain base cache on revlogs before, but it only
captured a single revision. This was acceptable before generaldelta,
when _addrevision would build deltas from the previous revision and
thus we'd pretty much guarantee a cache hit when resolving the delta
chain base on a subsequent _addrevision call. However, it isn't
suitable for generaldelta because parent revisions aren't necessarily
the last processed revision.
This patch converts the delta chain base cache to an LRU dict cache.
The cache can hold multiple entries, so generaldelta repos have a
higher chance of getting a cache hit.
The impact of this change when processing changegroup additions is
significant. On a generaldelta conversion of the "mozilla-unified"
repo (which contains heads of the main Firefox repositories in
chronological order - this means there are lots of transitions between
heads in revlog order), this change has the following impact when
performing an `hg unbundle` of an uncompressed bundle of the repo:
before: 5:42 CPU time
after: 4:34 CPU time
Most of this time is saved when applying the changelog and manifest
revlogs:
before: 2:30 CPU time
after: 1:17 CPU time
That nearly a 50% reduction in CPU time applying changesets and
manifests!
Applying a gzipped bundle of the same repo (effectively simulating a
`hg clone` over HTTP) showed a similar speedup:
before: 5:53 CPU time
after: 4:46 CPU time
Wall time improvements were basically the same as CPU time.
I didn't measure explicitly, but it feels like most of the time
is saved when processing manifests. This makes sense, as large
manifests tend to have very long delta chains and thus benefit the
most from this cache.
So, this change effectively makes changegroup application (which is
used by `hg unbundle`, `hg clone`, `hg pull`, `hg unshelve`, and
various other commands) significantly faster when delta chains are
long (which can happen on repos with large numbers of files and thus
large manifests).
In theory, this change can result in more memory utilization. However,
we're caching a dict of ints. At most we have 200 ints + Python object
overhead per revlog. And, the cache is really only populated when
performing read-heavy operations, such as adding changegroups or
scanning an individual revlog. For memory bloat to be an issue, we'd
need to scan/read several revisions from several revlogs all while
having active references to several revlogs. I don't think there are
many operations that do this, so I don't think memory bloat from the
cache will be an issue.
Gregory Szorc <gregory.szorc@gmail.com> [Mon, 22 Aug 2016 20:17:36 -0700] rev 29829
revlog: remove unused variables
Gregory Szorc <gregory.szorc@gmail.com> [Mon, 22 Aug 2016 20:30:37 -0700] rev 29828
util: properly implement lrucachedict.get()
Before, it was returning the raw _lrucachenode instance instead of its
value.
Durham Goode <durham@fb.com> [Wed, 17 Aug 2016 13:25:13 -0700] rev 29827
manifest: change changectx to access manifest via manifestlog
This is the first place where we'll start using manifestctx instances instead of
manifestdict. This will facilitate using different manifestctx implementations
in the future.
Durham Goode <durham@fb.com> [Wed, 17 Aug 2016 13:25:13 -0700] rev 29826
manifest: use property instead of field for manifest revlog storage
The file caches we're using to avoid reloading the manifest from disk everytime
has an annoying bug that causes the in memory structure to not be reloaded if
the mtime and the size haven't changed. This causes a breakage in the tests
because the manifestlog is not being reloaded after a commit+strip operation in
mq (the mtime is the same because it all happens in the same second, and the
resulting size is the same because we add 1 and remove 1). The only reason this
doesn't affect the manifest itself is because we touch it so often that we
had already reloaded it after the commit, but before the strip.
Once the entire manifest has migrated to manifestlog, we can get rid of these
properties, since then the manifestlog will be touched after the commit, but
before the strip, as well.
Durham Goode <durham@fb.com> [Wed, 17 Aug 2016 13:25:13 -0700] rev 29825
manifest: introduce manifestlog and manifestctx classes
This is the start of a large refactoring of the manifest class. It introduces
the new manifestlog and manifestctx classes which will represent the collection
of all manifests and individual instances, respectively.
Future patches will begin to convert usages of repo.manifest to
repo.manifestlog, adding the necessary functionality to manifestlog and instance
as they are needed.
Durham Goode <durham@fb.com> [Wed, 17 Aug 2016 13:25:13 -0700] rev 29824
manifest: make manifest derive from manifestrevlog
As part of our refactoring to split the manifest concept from its storage, we
need to start moving the revlog specific parts of the manifest implementation to
a new class. This patch creates manifestrevlog and moves the fulltextcache onto
the base class.
Durham Goode <durham@fb.com> [Wed, 17 Aug 2016 13:25:13 -0700] rev 29823
manifest: break mancache into two caches
The old manifest cache cached both the inmemory representation and the raw text.
As part of the manifest refactor we want to separate the storage format from the
in memory representation, so let's split this cache into two caches.
This will let other manifest implementations participate in the in memory cache,
while allowing the revlog based implementations to still depend on the full text
caching where necessary.
Augie Fackler <augie@google.com> [Thu, 18 Aug 2016 11:32:02 -0400] rev 29822
dispatch: explicitly pass fancyopts optional arg as a keyword
I've been baffled by this a couple of times (mainly wondering if any
callers of fancyopts.fancyopts that don't use gnu=True exist), so
let's just specify this as a keyword argument to preserve sanity.
Maciej Fijalkowski <fijall@gmail.com> [Sat, 20 Aug 2016 23:05:18 +0200] rev 29821
osutil: fix the bug on OS X when we return more in listdir
The pointer arithmetic somehow got ommitted during the recent change to use
a struct.
Hannes Oldenburg <hannes.christian.oldenburg@gmail.com> [Sun, 21 Aug 2016 08:03:22 +0000] rev 29820
histedit: use samefile function from cmdutil
Replace usage of inefficient samefile function in collapse with a call to
cmdutil.samefile().
Hannes Oldenburg <hannes.christian.oldenburg@gmail.com> [Sun, 21 Aug 2016 08:00:18 +0000] rev 29819
cmdutil: extract samefile function from amend()
Yuya Nishihara <yuya@tcha.org> [Fri, 22 Apr 2016 21:32:30 +0900] rev 29818
templater: rename "right" argument of pad() function
Before, right=True meant right justify, which I think is left padding.
Yuya Nishihara <yuya@tcha.org> [Fri, 22 Apr 2016 21:29:13 +0900] rev 29817
templater: make pad() evaluate boolean argument (BC)
Otherwise it would crash if template expression was passed.
This patch unifies the way how boolean expression is evaluated, which involves
BC. Before "if(true)" and "pad(..., 'false')" were False, which are now True
since they are boolean literal and non-empty string respectively.
"func is runsymbol" is the same hack as evalstringliteral(), which is needed
for label() to take color literals.
Yuya Nishihara <yuya@tcha.org> [Thu, 18 Aug 2016 16:29:22 +0900] rev 29816
templater: fix if() to not evaluate False as bool('False')
Before, False was True. This patch fixes the issue by processing True/False
transparently. The other values (including integer 0) are tested as strings
for backward compatibility, which means "if(latesttagdistance)" never be False.
Should we change the behavior of "if(0)" as well?
Yuya Nishihara <yuya@tcha.org> [Thu, 18 Aug 2016 15:55:07 +0900] rev 29815
templater: make it clearer that _flatten() omits None
Gábor Stefanik <gabor.stefanik@nng.com> [Thu, 18 Aug 2016 17:25:10 +0200] rev 29814
revset: support "follow(renamed.py,
e22f4f3f06c3)" (
issue5334)
v2: fixes from review
Matt Mackall <mpm@selenic.com> [Wed, 17 Aug 2016 13:43:13 -0500] rev 29813
coal: use inheritance to derive from paper
This illustrates how much simpler this approach is, in particular the
effect of map-relative paths.
Matt Mackall <mpm@selenic.com> [Wed, 17 Aug 2016 13:40:27 -0500] rev 29812
templater: add inheritance support to style maps
We can now specify a base map file:
__base__ = path/to/map/file
That map file will be read and used to populate unset elements of the
current map. Unlike using %include, elements in the inherited class
will be read relative to that path.
This makes it much easier to make custom local tweaks to a style.
Yuya Nishihara <yuya@tcha.org> [Thu, 18 Aug 2016 18:43:48 +0900] rev 29811
killdaemons: prevent killing all user processes by bad pid file
When I was fixing the test-gpg issue, I noticed gpg-connect-agent could print
"-1" as a server pid if command was wrong. I'm not pretty sure but nobody
would want to kill their running applications by mistake.
Yuya Nishihara <yuya@tcha.org> [Wed, 17 Aug 2016 20:56:12 +0900] rev 29810
py3: automatically glob out line numbers from check-py3-compat output
It was boring task to update the result manually.
Yuya Nishihara <yuya@tcha.org> [Wed, 17 Aug 2016 20:52:50 +0900] rev 29809
py3: have check-py3-compat require pygments to get stable result
Pierre-Yves David <pierre-yves.david@ens-lyon.org> [Tue, 09 Aug 2016 17:06:35 +0200] rev 29808
computeoutgoing: move the function from 'changegroup' to 'exchange'
Now that all users are in exchange, we can safely move the code in the
'exchange' module. This function is really about processing the argument of a
'getbundle' call, so it even makes senses to do so.
Pierre-Yves David <pierre-yves.david@ens-lyon.org> [Tue, 09 Aug 2016 17:00:38 +0200] rev 29807
getchangegroup: take an 'outgoing' object as argument (API)
There is various version of this function that differ mostly by the way they
define the bundled set. The flexibility is now available in the outgoing object
itself so we move the complexity into the caller themself. This will allow use
to remove a good share of the similar function to obtains a changegroup in the
'changegroup.py' module.
An important side effect is that we stop calling 'computeoutgoing' in
'getchangegroup'. This is fine as code that needs such argument processing
is actually going through the 'exchange' module which already all this function
itself.
Pierre-Yves David <pierre-yves.david@ens-lyon.org> [Tue, 09 Aug 2016 22:31:38 +0200] rev 29806
outgoing: add a 'missingroots' argument
This argument can be used instead of 'commonheads' to determine the 'outgoing'
set. We remove the outgoingbetween function as its role can now be handled by
'outgoing' itself.
I've thought of using an external function instead of making the constructor
more complicated. However, there is low hanging fruit to improve the current
code flow by storing some side products of the processing of 'missingroots'. So
in my opinion it make senses to add all this to the class.
Pierre-Yves David <pierre-yves.david@ens-lyon.org> [Tue, 09 Aug 2016 15:55:44 +0200] rev 29805
outgoing: adds some default value for argument
We are about to introduce a third option to create an outgoing object:
'missingroots'. This argument will be mutually exclusive with 'commonheads' so
we implement some default value handling in preparation.
This will also help use to make more use of outgoing creation around the code
base.
Pierre-Yves David <pierre-yves.david@ens-lyon.org> [Tue, 09 Aug 2016 15:26:53 +0200] rev 29804
outgoing: pass a repo object to the constructor
We are to introduce more code constructing such object in the code base. It will
be more convenient to pass a repository object, all current users already
operate at the repository level anyway. More changes to the contructor argument
are coming in later changeset.
Hannes Oldenburg <hannes.christian.oldenburg@gmail.com> [Tue, 16 Aug 2016 08:21:16 +0000] rev 29803
match: remove matchessubrepo method (API)
Since it is no more used in cmdutil.{files,remove} and scmutil.addremove
we remove this method.
Hannes Oldenburg <hannes.christian.oldenburg@gmail.com> [Tue, 16 Aug 2016 08:15:12 +0000] rev 29802
subrepo: cleanup of subrepo filematcher logic
Previously in the worst case we iterated the files in matcher twice and
had a method only for this, which reimplemented logic in subdirmatchers
constructor. So we replaced the method with a subdirmatcher.files() call.
Yuya Nishihara <yuya@tcha.org> [Sun, 14 Aug 2016 14:46:24 +0900] rev 29801
pycompat: delay loading modules registered to stub
Replacement _pycompatstub designed to be compatible with our demandimporter.
try-except is replaced by version comparison because ImportError will no longer
be raised immediately.
Yuya Nishihara <yuya@tcha.org> [Tue, 16 Aug 2016 12:35:15 +0900] rev 29800
py3: import builtin wrappers automagically by code transformer
This should be less invasive than mucking builtins.
Since tokenize.untokenize() looks start/end positions of tokens, we calculates
them from the NEWLINE token of the future import.
Yuya Nishihara <yuya@tcha.org> [Sun, 14 Aug 2016 12:51:21 +0900] rev 29799
py3: provide (del|get|has|set)attr wrappers that accepts bytes
These functions will be imported automagically by our code transformer.
getattr() and setattr() are widely used in our code. We wouldn't probably
want to rewrite every single call of getattr/setattr. delattr() and hasattr()
aren't that important, but they are functions of the same kind.
Yuya Nishihara <yuya@tcha.org> [Sun, 14 Aug 2016 12:44:13 +0900] rev 29798
py3: check python version to enable builtins hack
Future patches will add (del|get|has|set)attr wrappers.
Yuya Nishihara <yuya@tcha.org> [Sun, 14 Aug 2016 12:41:54 +0900] rev 29797
py3: move xrange alias next to import lines
Builtin functions should be available in compatibility code.
Yuya Nishihara <yuya@tcha.org> [Tue, 16 Aug 2016 17:15:54 +0900] rev 29796
check-code: allow assignment to hasattr variable
Yuya Nishihara <yuya@tcha.org> [Mon, 15 Aug 2016 16:07:55 +0900] rev 29795
debugobsolete: add formatter support (
issue5134)
It appears that computing index isn't cheap if --rev is specified. That's
why "index" field is available only if --index is specified.
I've named marker.flags() as "flag" because "flags" implies a list or dict
in template world.
Thanks to Piotr Listkiewicz for the initial implementation of this patch.
Yuya Nishihara <yuya@tcha.org> [Mon, 15 Aug 2016 12:58:33 +0900] rev 29794
formatter: add function to convert dict to appropriate format
This will be used to process key-value pairs by formatter. The default
field names and format are derived from the {extras} template keyword.
Tests will be added later.
Yuya Nishihara <yuya@tcha.org> [Mon, 15 Aug 2016 17:17:39 +0900] rev 29793
check-code: make dict() pattern less invasive
'foodict(x=y)' should be allowed.
Gregory Szorc <gregory.szorc@gmail.com> [Sun, 14 Aug 2016 21:29:46 -0700] rev 29792
hgweb: tweak zlib chunking behavior
When doing streaming compression with zlib, zlib appears to emit chunks
with data after ~20-30kb on average is available. In other words, most
calls to compress() return an empty string. On the mozilla-unified repo,
only 48,433 of 921,167 (5.26%) of calls to compress() returned data.
In other words, we were sending hundreds of thousands of empty chunks
via a generator where they touched who knows how many frames (my guess
is millions). Filtering out the empty chunks from the generator
cuts down on overhead.
In addition, we were previously feeding 8kb chunks into zlib
compression. Since this function tends to emit *compressed* data after
20-30kb is available, it would take several calls before data was
produced. We increase the amount of data fed in at a time to 32kb.
This reduces the number of calls to compress() from 921,167 to
115,146. It also reduces the number of output chunks from 48,433 to
31,377. This does increase the average output chunk size by a little.
But I don't think this will matter in most scenarios.
The combination of these 2 changes appears to shave ~6s CPU time
or ~3% from a server serving the mozilla-unified repo.
Yuya Nishihara <yuya@tcha.org> [Sun, 14 Aug 2016 17:07:05 +0900] rev 29791
test-gpg: run migration of v1 secret keys beforehand
This suppresses unwanted output at "hg sign".
Yuya Nishihara <yuya@tcha.org> [Sun, 14 Aug 2016 17:01:33 +0900] rev 29790
test-gpg: start gpg-agent under control of the test runner
GnuPG v2 automatically starts gpg-agent. We should kill the daemon process.
Yuya Nishihara <yuya@tcha.org> [Sun, 14 Aug 2016 16:49:47 +0900] rev 29789
test-gpg: make temporary copy of GNUPGHOME
GnuPG v2 will convert v1 secret keys and create a socket under $GNUPGHOME.
This patch makes sure no state would persist.
We no longer need to verify trustdb.gpg, which was added by
aae219a99a6e.
Gregory Szorc <gregory.szorc@gmail.com> [Mon, 15 Aug 2016 20:39:33 -0700] rev 29788
hgweb: document why we don't allow untrusted settings to control zlib
Added comment per discussion on mercurial-devel.
Gregory Szorc <gregory.szorc@gmail.com> [Sun, 14 Aug 2016 18:37:24 -0700] rev 29787
hgweb: profile HTTP requests
Currently, running `hg serve --profile` doesn't yield anything useful:
when the process is terminated the profiling output displays results
from the main thread, which typically spends most of its time in
select.select(). Furthermore, it has no meaningful results from
mercurial.* modules because the threads serving HTTP requests don't
actually get profiled.
This patch teaches the hgweb wsgi applications to profile individual
requests. If profiling is enabled, the profiler kicks in after
HTTP/WSGI environment processing but before Mercurial's main request
processing.
The profile results are printed to the configured profiling output.
If running `hg serve` from a shell, they will be printed to stderr,
just before the HTTP request line is logged. If profiling to a file,
we only write a single profile to the file because the file is not
opened in append mode. We could add support for appending to files
in a future patch if someone wants it.
Per request profiling doesn't work with the statprof profiler because
internally that profiler collects samples from the thread that
*initially* requested profiling be enabled. I have plans to address
this by vendoring Facebook's customized statprof and then improving
it.