Mercurial > hg
view mercurial/state.py @ 42743:8c9a6adec67a
rust-discovery: using the children cache in add_missing
The DAG range computation often needs to get back to very old
revisions, and turns out to be disproportionately long, given
that the end goal is to remove the descendents of the given
missing revisons from the undecided set.
The fast iteration capabilities available in the Rust case make
it possible to avoid the DAG range entirely, at the cost of
precomputing the children cache, and to simply iterate on
children of the given missing revisions.
This is a case where staying on the same side of the interface
between the two languages has clear benefits.
On discoveries with initial undecided sets
small enough to bypass sampling entirely, the total cost of
computing the children cache and the subsequent iteration
becomes better than the Python + C counterpart, which relies on
reachableroots2.
For example, on a repo with more than one million revisions with
an initial undecided set of 11 elements, we get these figures:
Rust version with simple iteration
addcommons: 57.287us
first undecided computation: 184.278334ms
first children cache computation: 131.056us
addmissings iteration: 42.766us
first addinfo total: 185.24 ms
Python + C version
first addcommons: 0.29 ms
addcommons 0.21 ms
first undecided computation 191.35 ms
addmissings 45.75 ms
first addinfo total: 237.77 ms
On discoveries with large undecided sets, the initial price paid
makes the first addinfo slower than the Python + C version,
but that's more than compensated by the gain in sampling and
subsequent iterations.
Here's an extreme example with an undecided set of a million revisions:
Rust version:
first undecided computation: 293.842629ms
first children cache computation: 407.911297ms
addmissings iteration: 34.312869ms
first addinfo total: 776.02 ms
taking initial sample
query 2: sampling time: 1318.38 ms
query 2; still undecided: 1005013, sample size is: 200
addmissings: 143.062us
Python + C version:
first undecided computation 298.13 ms
addmissings 80.13 ms
first addinfo total: 399.62 ms
taking initial sample
query 2: sampling time: 3957.23 ms
query 2; still undecided: 1005013, sample size is: 200
addmissings 52.88 ms
Differential Revision: https://phab.mercurial-scm.org/D6428
author | Georges Racinet <georges.racinet@octobus.net> |
---|---|
date | Tue, 16 Apr 2019 01:16:39 +0200 |
parents | 3c16b9c0b099 |
children | 8c4f32b907e6 |
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# state.py - writing and reading state files in Mercurial # # Copyright 2018 Pulkit Goyal <pulkitmgoyal@gmail.com> # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. """ This file contains class to wrap the state for commands and other related logic. All the data related to the command state is stored as dictionary in the object. The class has methods using which the data can be stored to disk in a file under .hg/ directory. We store the data on disk in cbor, for which we use the CBOR format to encode the data. """ from __future__ import absolute_import from .i18n import _ from . import ( error, util, ) from .utils import ( cborutil, ) class cmdstate(object): """a wrapper class to store the state of commands like `rebase`, `graft`, `histedit`, `shelve` etc. Extensions can also use this to write state files. All the data for the state is stored in the form of key-value pairs in a dictionary. The class object can write all the data to a file in .hg/ directory and can populate the object data reading that file. Uses cbor to serialize and deserialize data while writing and reading from disk. """ def __init__(self, repo, fname): """ repo is the repo object fname is the file name in which data should be stored in .hg directory """ self._repo = repo self.fname = fname def read(self): """read the existing state file and return a dict of data stored""" return self._read() def save(self, version, data): """write all the state data stored to .hg/<filename> file we use third-party library cbor to serialize data to write in the file. """ if not isinstance(version, int): raise error.ProgrammingError("version of state file should be" " an integer") with self._repo.vfs(self.fname, 'wb', atomictemp=True) as fp: fp.write('%d\n' % version) for chunk in cborutil.streamencode(data): fp.write(chunk) def _read(self): """reads the state file and returns a dictionary which contain data in the same format as it was before storing""" with self._repo.vfs(self.fname, 'rb') as fp: try: int(fp.readline()) except ValueError: raise error.CorruptedState("unknown version of state file" " found") return cborutil.decodeall(fp.read())[0] def delete(self): """drop the state file if exists""" util.unlinkpath(self._repo.vfs.join(self.fname), ignoremissing=True) def exists(self): """check whether the state file exists or not""" return self._repo.vfs.exists(self.fname) class _statecheck(object): """a utility class that deals with multistep operations like graft, histedit, bisect, update etc and check whether such commands are in an unfinished conditition or not and return appropriate message and hint. It also has the ability to register and determine the states of any new multistep operation or multistep command extension. """ def __init__(self, opname, fname, clearable, allowcommit, reportonly, continueflag, stopflag, cmdmsg, cmdhint, statushint, abortfunc, continuefunc): self._opname = opname self._fname = fname self._clearable = clearable self._allowcommit = allowcommit self._reportonly = reportonly self._continueflag = continueflag self._stopflag = stopflag self._cmdmsg = cmdmsg self._cmdhint = cmdhint self._statushint = statushint self.abortfunc = abortfunc self.continuefunc = continuefunc def statusmsg(self): """returns the hint message corresponding to the command for hg status --verbose """ if not self._statushint: hint = (_('To continue: hg %s --continue\n' 'To abort: hg %s --abort') % (self._opname, self._opname)) if self._stopflag: hint = hint + (_('\nTo stop: hg %s --stop') % (self._opname)) return hint return self._statushint def hint(self): """returns the hint message corresponding to an interrupted operation """ if not self._cmdhint: return (_("use 'hg %s --continue' or 'hg %s --abort'") % (self._opname, self._opname)) return self._cmdhint def msg(self): """returns the status message corresponding to the command""" if not self._cmdmsg: return _('%s in progress') % (self._opname) return self._cmdmsg def continuemsg(self): """ returns appropriate continue message corresponding to command""" return _('hg %s --continue') % (self._opname) def isunfinished(self, repo): """determines whether a multi-step operation is in progress or not """ if self._opname == 'merge': return len(repo[None].parents()) > 1 else: return repo.vfs.exists(self._fname) # A list of statecheck objects for multistep operations like graft. _unfinishedstates = [] def addunfinished(opname, fname, clearable=False, allowcommit=False, reportonly=False, continueflag=False, stopflag=False, cmdmsg="", cmdhint="", statushint="", abortfunc=None, continuefunc=None): """this registers a new command or operation to unfinishedstates opname is the name the command or operation fname is the file name in which data should be stored in .hg directory. It is None for merge command. clearable boolean determines whether or not interrupted states can be cleared by running `hg update -C .` which in turn deletes the state file. allowcommit boolean decides whether commit is allowed during interrupted state or not. reportonly flag is used for operations like bisect where we just need to detect the operation using 'hg status --verbose' continueflag is a boolean determines whether or not a command supports `--continue` option or not. stopflag is a boolean that determines whether or not a command supports --stop flag cmdmsg is used to pass a different status message in case standard message of the format "abort: cmdname in progress" is not desired. cmdhint is used to pass a different hint message in case standard message of the format "To continue: hg cmdname --continue To abort: hg cmdname --abort" is not desired. statushint is used to pass a different status message in case standard message of the format ('To continue: hg cmdname --continue' 'To abort: hg cmdname --abort') is not desired abortfunc stores the function required to abort an unfinished state. continuefunc stores the function required to finish an interrupted operation. """ statecheckobj = _statecheck(opname, fname, clearable, allowcommit, reportonly, continueflag, stopflag, cmdmsg, cmdhint, statushint, abortfunc, continuefunc) if opname == 'merge': _unfinishedstates.append(statecheckobj) else: _unfinishedstates.insert(0, statecheckobj) addunfinished( 'update', fname='updatestate', clearable=True, cmdmsg=_('last update was interrupted'), cmdhint=_("use 'hg update' to get a consistent checkout"), statushint=_("To continue: hg update") ) addunfinished( 'bisect', fname='bisect.state', allowcommit=True, reportonly=True, statushint=_('To mark the changeset good: hg bisect --good\n' 'To mark the changeset bad: hg bisect --bad\n' 'To abort: hg bisect --reset\n') ) def getrepostate(repo): # experimental config: commands.status.skipstates skip = set(repo.ui.configlist('commands', 'status.skipstates')) for state in _unfinishedstates: if state._opname in skip: continue if state.isunfinished(repo): return (state._opname, state.statusmsg())