mercurial/state.py
author Pierre-Yves David <pierre-yves.david@octobus.net>
Wed, 16 Oct 2019 17:49:30 +0200
changeset 43254 181d28ba05da
parent 43117 8ff1ecfadcd1
child 43702 127d46468a45
permissions -rw-r--r--
copies: avoid instancing more changectx to access parent revisions We just need to know the revision numbers of the parents, creating full context is needlessly expensive. This provide a small, but noticeable performance boost. revision: large amount; added files: large amount; rename small amount; c3b14617fbd7 9ba6ab77fd29 before: ! wall 2.885636 comb 2.900000 user 2.870000 sys 0.030000 (median of 10) after: ! wall 2.702270 comb 2.710000 user 2.690000 sys 0.020000 (median of 10) revision: large amount; added files: small amount; rename small amount; c3b14617fbd7 f650a9b140d2 before: ! wall 4.298271 comb 4.290000 user 4.240000 sys 0.050000 (median of 10) after: ! wall 3.976610 comb 3.970000 user 3.920000 sys 0.050000 (median of 10) revision: large amount; added files: large amount; rename large amount; 08ea3258278e d9fa043f30c0 before: ! wall 0.773397 comb 0.770000 user 0.770000 sys 0.000000 (median of 11) after: ! wall 0.701634 comb 0.700000 user 0.700000 sys 0.000000 (median of 13) revision: small amount; added files: large amount; rename large amount; df6f7a526b60 a83dc6a2d56f before: ! wall 0.013585 comb 0.010000 user 0.010000 sys 0.000000 (median of 217) after: ! wall 0.013550 comb 0.010000 user 0.010000 sys 0.000000 (median of 218) revision: small amount; added files: large amount; rename small amount; 4aa4e1f8e19a 169138063d63 before: ! wall 0.003202 comb 0.000000 user 0.000000 sys 0.000000 (median of 929) after: ! wall 0.002993 comb 0.010000 user 0.010000 sys 0.000000 (median of 992) revision: small amount; added files: small amount; rename small amount; 4bc173b045a6 964879152e2e before: ! wall 0.000077 comb 0.000000 user 0.000000 sys 0.000000 (median of 12060) after: ! wall 0.000072 comb 0.000000 user 0.000000 sys 0.000000 (median of 12804) revision: medium amount; added files: large amount; rename medium amount; c95f1ced15f2 2c68e87c3efe before: ! wall 0.510614 comb 0.500000 user 0.500000 sys 0.000000 (median of 18) after: ! wall 0.473681 comb 0.470000 user 0.470000 sys 0.000000 (median of 20) revision: medium amount; added files: medium amount; rename small amount; d343da0c55a8 d7746d32bf9d before: ! wall 0.126552 comb 0.130000 user 0.130000 sys 0.000000 (median of 77) after: ! wall 0.115240 comb 0.110000 user 0.110000 sys 0.000000 (median of 85) Differential Revision: https://phab.mercurial-scm.org/D7122

# 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(
                b"version of state file should be an integer"
            )

        with self._repo.vfs(self.fname, b'wb', atomictemp=True) as fp:
            fp.write(b'%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, b'rb') as fp:
            try:
                int(fp.readline())
            except ValueError:
                raise error.CorruptedState(
                    b"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 = _(
                b'To continue:    hg %s --continue\n'
                b'To abort:       hg %s --abort'
            ) % (self._opname, self._opname)
            if self._stopflag:
                hint = hint + (
                    _(b'\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 _(b"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 _(b'%s in progress') % (self._opname)
        return self._cmdmsg

    def continuemsg(self):
        """ returns appropriate continue message corresponding to command"""
        return _(b'hg %s --continue') % (self._opname)

    def isunfinished(self, repo):
        """determines whether a multi-step operation is in progress
        or not
        """
        if self._opname == b'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=b"",
    cmdhint=b"",
    statushint=b"",
    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 == b'merge':
        _unfinishedstates.append(statecheckobj)
    else:
        _unfinishedstates.insert(0, statecheckobj)


addunfinished(
    b'update',
    fname=b'updatestate',
    clearable=True,
    cmdmsg=_(b'last update was interrupted'),
    cmdhint=_(b"use 'hg update' to get a consistent checkout"),
    statushint=_(b"To continue:    hg update ."),
)
addunfinished(
    b'bisect',
    fname=b'bisect.state',
    allowcommit=True,
    reportonly=True,
    statushint=_(
        b'To mark the changeset good:    hg bisect --good\n'
        b'To mark the changeset bad:     hg bisect --bad\n'
        b'To abort:                      hg bisect --reset\n'
    ),
)


def getrepostate(repo):
    # experimental config: commands.status.skipstates
    skip = set(repo.ui.configlist(b'commands', b'status.skipstates'))
    for state in _unfinishedstates:
        if state._opname in skip:
            continue
        if state.isunfinished(repo):
            return (state._opname, state.statusmsg())