commit: improve the files field of changelog for merges
Currently, the files list of merge commits repeats all the deletions
(either actual deletions, or files that got renamed) that happened
between base and p2 of the merge. If p2 is the main branch, the list
can easily be much bigger than the change being merged.
This results in various problems worth improving:
- changelog is bigger than necessary
- `hg log directory` lists many unrelated merge commits, and `hg log
-v -r commit` frequently fills multiple screens worth of files
- it possibly slows down adjustlinkrev, by forcing it to read more
manifests, and that function can certainly be a bottleneck
- the server side of pulls can waste a lot of time simply opening the
filelogs for pointless files (the constant factors for opening even
a tiny filelog is apparently pretty bad)
So stop listing such files as described in the code. Impacted merge
commits and their descendants get a different hash than they would
have without this. This doesn't seem problematic, except for
convert. The previous commit helped with that in the hg->hg case (but
if you do svn->hg twice from scratch, hashes can still change).
The rest of the description is numbers. I don't have much to report,
because recreating the files list of existing repositories is not
easy:
- debugupgradeformat and bundle/unbundle don't recreate the list
- export/import tends to choke quickly applying patches or on
description that contain diffs,
- merge commits from the convert extension don't have the right files
list for reasons orthogonal to the current commit
- replaying the merge with hg update/hg merge/hg revert --all/hg
commit can end up failing in hg revert
- I wasn't sure that using debugsetparents + debugrebuilddirstate
would really build the right thing
I measured commit time before and after this change, in a case with no
files filtered out, several files filtered out (no difference) and 5k
files filtered out (+1% time).
Recreating the 100 more recent merges in a private repo, the
concatenated uncompressed files lists goes from 1.12MB to
0.52MB. Excluding 3 merges that are not representative, then the size
goes from 570k to 15k.
I converted part of mozilla-central, and observed file list shrinking
quite a bit too, starting at the very first merge,
733641d9feaf, going
from 550 files to 10 files (although they have relatively few merges,
so they probably wouldn't care).
Differential Revision: https://phab.mercurial-scm.org/D6613
#!/usr/bin/env python
from __future__ import absolute_import
import errno
import os
import signal
import sys
import time
if os.name =='nt':
import ctypes
_BOOL = ctypes.c_long
_DWORD = ctypes.c_ulong
_UINT = ctypes.c_uint
_HANDLE = ctypes.c_void_p
ctypes.windll.kernel32.CloseHandle.argtypes = [_HANDLE]
ctypes.windll.kernel32.CloseHandle.restype = _BOOL
ctypes.windll.kernel32.GetLastError.argtypes = []
ctypes.windll.kernel32.GetLastError.restype = _DWORD
ctypes.windll.kernel32.OpenProcess.argtypes = [_DWORD, _BOOL, _DWORD]
ctypes.windll.kernel32.OpenProcess.restype = _HANDLE
ctypes.windll.kernel32.TerminateProcess.argtypes = [_HANDLE, _UINT]
ctypes.windll.kernel32.TerminateProcess.restype = _BOOL
ctypes.windll.kernel32.WaitForSingleObject.argtypes = [_HANDLE, _DWORD]
ctypes.windll.kernel32.WaitForSingleObject.restype = _DWORD
def _check(ret, expectederr=None):
if ret == 0:
winerrno = ctypes.GetLastError()
if winerrno == expectederr:
return True
raise ctypes.WinError(winerrno)
def kill(pid, logfn, tryhard=True):
logfn('# Killing daemon process %d' % pid)
PROCESS_TERMINATE = 1
PROCESS_QUERY_INFORMATION = 0x400
SYNCHRONIZE = 0x00100000
WAIT_OBJECT_0 = 0
WAIT_TIMEOUT = 258
WAIT_FAILED = _DWORD(0xFFFFFFFF).value
handle = ctypes.windll.kernel32.OpenProcess(
PROCESS_TERMINATE|SYNCHRONIZE|PROCESS_QUERY_INFORMATION,
False, pid)
if handle is None:
_check(0, 87) # err 87 when process not found
return # process not found, already finished
try:
r = ctypes.windll.kernel32.WaitForSingleObject(handle, 100)
if r == WAIT_OBJECT_0:
pass # terminated, but process handle still available
elif r == WAIT_TIMEOUT:
_check(ctypes.windll.kernel32.TerminateProcess(handle, -1))
elif r == WAIT_FAILED:
_check(0) # err stored in GetLastError()
# TODO?: forcefully kill when timeout
# and ?shorter waiting time? when tryhard==True
r = ctypes.windll.kernel32.WaitForSingleObject(handle, 100)
# timeout = 100 ms
if r == WAIT_OBJECT_0:
pass # process is terminated
elif r == WAIT_TIMEOUT:
logfn('# Daemon process %d is stuck')
elif r == WAIT_FAILED:
_check(0) # err stored in GetLastError()
except: #re-raises
ctypes.windll.kernel32.CloseHandle(handle) # no _check, keep error
raise
_check(ctypes.windll.kernel32.CloseHandle(handle))
else:
def kill(pid, logfn, tryhard=True):
try:
os.kill(pid, 0)
logfn('# Killing daemon process %d' % pid)
os.kill(pid, signal.SIGTERM)
if tryhard:
for i in range(10):
time.sleep(0.05)
os.kill(pid, 0)
else:
time.sleep(0.1)
os.kill(pid, 0)
logfn('# Daemon process %d is stuck - really killing it' % pid)
os.kill(pid, signal.SIGKILL)
except OSError as err:
if err.errno != errno.ESRCH:
raise
def killdaemons(pidfile, tryhard=True, remove=False, logfn=None):
if not logfn:
logfn = lambda s: s
# Kill off any leftover daemon processes
try:
pids = []
with open(pidfile) as fp:
for line in fp:
try:
pid = int(line)
if pid <= 0:
raise ValueError
except ValueError:
logfn('# Not killing daemon process %s - invalid pid'
% line.rstrip())
continue
pids.append(pid)
for pid in pids:
kill(pid, logfn, tryhard)
if remove:
os.unlink(pidfile)
except IOError:
pass
if __name__ == '__main__':
if len(sys.argv) > 1:
path, = sys.argv[1:]
else:
path = os.environ["DAEMON_PIDS"]
killdaemons(path, remove=True)