changelog: add class to represent parsed changelog revisions
Currently, changelog entries are parsed into their respective
components at read time. Many operations are only interested
in a subset of fields of a changelog entry. The parsing and
storing of all the fields adds avoidable overhead.
This patch introduces the "changelogrevision" class. It takes
changelog raw text and exposes the parsed results as attributes.
The code for parsing changelog entries has been moved into its
construction function. changelog.read() has been modified to use
the new class internally while maintaining its existing API.
Future patches will make revision parsing lazy.
We implement the construction function of the new class with
__new__ instead of __init__ so we can use a named tuple to
represent the empty revision. This saves overhead and complexity
of coercing later versions of this class to represent an empty
instance.
While we are here, we add a method on changelog to obtain an
instance of the new type.
The overhead of constructing the new class regresses performance
of revsets accessing this data:
author(mpm)
0.896565
0.929984
desc(bug)
0.887169
0.935642 105%
date(2015)
0.878797
0.908094
extra(rebase_source)
0.865446
0.922624 106%
author(mpm) or author(greg)
1.801832
1.902112 105%
author(mpm) or desc(bug)
1.812438
1.860977
date(2015) or branch(default)
0.968276
1.005824
author(mpm) or desc(bug) or date(2015) or extra(rebase_source)
3.656193
3.743381
Once lazy parsing is implemented, these revsets will all be faster
than before. There is no performance change on revsets that do not
access this data. There /could/ be a performance regression on
operations that perform several changelog reads. However, I can't
think of anything outside of revsets and `hg log` (basically the
same as a revset) that would be impacted.
# hook.py - hook support for mercurial
#
# Copyright 2007 Matt Mackall <mpm@selenic.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from __future__ import absolute_import
import os
import sys
import time
from .i18n import _
from . import (
demandimport,
error,
extensions,
util,
)
def _pythonhook(ui, repo, name, hname, funcname, args, throw):
'''call python hook. hook is callable object, looked up as
name in python module. if callable returns "true", hook
fails, else passes. if hook raises exception, treated as
hook failure. exception propagates if throw is "true".
reason for "true" meaning "hook failed" is so that
unmodified commands (e.g. mercurial.commands.update) can
be run as hooks without wrappers to convert return values.'''
if callable(funcname):
obj = funcname
funcname = obj.__module__ + "." + obj.__name__
else:
d = funcname.rfind('.')
if d == -1:
raise error.HookLoadError(
_('%s hook is invalid: "%s" not in a module')
% (hname, funcname))
modname = funcname[:d]
oldpaths = sys.path
if util.mainfrozen():
# binary installs require sys.path manipulation
modpath, modfile = os.path.split(modname)
if modpath and modfile:
sys.path = sys.path[:] + [modpath]
modname = modfile
with demandimport.deactivated():
try:
obj = __import__(modname)
except (ImportError, SyntaxError):
e1 = sys.exc_info()
try:
# extensions are loaded with hgext_ prefix
obj = __import__("hgext_%s" % modname)
except (ImportError, SyntaxError):
e2 = sys.exc_info()
if ui.tracebackflag:
ui.warn(_('exception from first failed import '
'attempt:\n'))
ui.traceback(e1)
if ui.tracebackflag:
ui.warn(_('exception from second failed import '
'attempt:\n'))
ui.traceback(e2)
if not ui.tracebackflag:
tracebackhint = _(
'run with --traceback for stack trace')
else:
tracebackhint = None
raise error.HookLoadError(
_('%s hook is invalid: import of "%s" failed') %
(hname, modname), hint=tracebackhint)
sys.path = oldpaths
try:
for p in funcname.split('.')[1:]:
obj = getattr(obj, p)
except AttributeError:
raise error.HookLoadError(
_('%s hook is invalid: "%s" is not defined')
% (hname, funcname))
if not callable(obj):
raise error.HookLoadError(
_('%s hook is invalid: "%s" is not callable')
% (hname, funcname))
ui.note(_("calling hook %s: %s\n") % (hname, funcname))
starttime = time.time()
try:
# redirect IO descriptors to the ui descriptors so hooks
# that write directly to these don't mess up the command
# protocol when running through the command server
old = sys.stdout, sys.stderr, sys.stdin
sys.stdout, sys.stderr, sys.stdin = ui.fout, ui.ferr, ui.fin
r = obj(ui=ui, repo=repo, hooktype=name, **args)
except Exception as exc:
if isinstance(exc, error.Abort):
ui.warn(_('error: %s hook failed: %s\n') %
(hname, exc.args[0]))
else:
ui.warn(_('error: %s hook raised an exception: '
'%s\n') % (hname, exc))
if throw:
raise
if not ui.tracebackflag:
ui.warn(_('(run with --traceback for stack trace)\n'))
ui.traceback()
return True, True
finally:
sys.stdout, sys.stderr, sys.stdin = old
duration = time.time() - starttime
ui.log('pythonhook', 'pythonhook-%s: %s finished in %0.2f seconds\n',
name, funcname, duration)
if r:
if throw:
raise error.HookAbort(_('%s hook failed') % hname)
ui.warn(_('warning: %s hook failed\n') % hname)
return r, False
def _exthook(ui, repo, name, cmd, args, throw):
ui.note(_("running hook %s: %s\n") % (name, cmd))
starttime = time.time()
env = {}
# make in-memory changes visible to external process
if repo is not None:
tr = repo.currenttransaction()
repo.dirstate.write(tr)
if tr and tr.writepending():
env['HG_PENDING'] = repo.root
for k, v in args.iteritems():
if callable(v):
v = v()
if isinstance(v, dict):
# make the dictionary element order stable across Python
# implementations
v = ('{' +
', '.join('%r: %r' % i for i in sorted(v.iteritems())) +
'}')
env['HG_' + k.upper()] = v
if repo:
cwd = repo.root
else:
cwd = os.getcwd()
r = ui.system(cmd, environ=env, cwd=cwd)
duration = time.time() - starttime
ui.log('exthook', 'exthook-%s: %s finished in %0.2f seconds\n',
name, cmd, duration)
if r:
desc, r = util.explainexit(r)
if throw:
raise error.HookAbort(_('%s hook %s') % (name, desc))
ui.warn(_('warning: %s hook %s\n') % (name, desc))
return r
def _allhooks(ui):
hooks = []
for name, cmd in ui.configitems('hooks'):
if not name.startswith('priority'):
priority = ui.configint('hooks', 'priority.%s' % name, 0)
hooks.append((-priority, len(hooks), name, cmd))
return [(k, v) for p, o, k, v in sorted(hooks)]
_redirect = False
def redirect(state):
global _redirect
_redirect = state
def hook(ui, repo, name, throw=False, **args):
if not ui.callhooks:
return False
hooks = []
for hname, cmd in _allhooks(ui):
if hname.split('.')[0] == name and cmd:
hooks.append((hname, cmd))
res = runhooks(ui, repo, name, hooks, throw=throw, **args)
r = False
for hname, cmd in hooks:
r = res[hname][0] or r
return r
def runhooks(ui, repo, name, hooks, throw=False, **args):
res = {}
oldstdout = -1
try:
for hname, cmd in hooks:
if oldstdout == -1 and _redirect:
try:
stdoutno = sys.__stdout__.fileno()
stderrno = sys.__stderr__.fileno()
# temporarily redirect stdout to stderr, if possible
if stdoutno >= 0 and stderrno >= 0:
sys.__stdout__.flush()
oldstdout = os.dup(stdoutno)
os.dup2(stderrno, stdoutno)
except (OSError, AttributeError):
# files seem to be bogus, give up on redirecting (WSGI, etc)
pass
if callable(cmd):
r, raised = _pythonhook(ui, repo, name, hname, cmd, args, throw)
elif cmd.startswith('python:'):
if cmd.count(':') >= 2:
path, cmd = cmd[7:].rsplit(':', 1)
path = util.expandpath(path)
if repo:
path = os.path.join(repo.root, path)
try:
mod = extensions.loadpath(path, 'hghook.%s' % hname)
except Exception:
ui.write(_("loading %s hook failed:\n") % hname)
raise
hookfn = getattr(mod, cmd)
else:
hookfn = cmd[7:].strip()
r, raised = _pythonhook(ui, repo, name, hname, hookfn, args,
throw)
else:
r = _exthook(ui, repo, hname, cmd, args, throw)
raised = False
res[hname] = r, raised
# The stderr is fully buffered on Windows when connected to a pipe.
# A forcible flush is required to make small stderr data in the
# remote side available to the client immediately.
sys.stderr.flush()
finally:
if _redirect and oldstdout >= 0:
os.dup2(oldstdout, stdoutno)
os.close(oldstdout)
return res