Mercurial > hg
view mercurial/state.py @ 38526:313a940d49a3
ui: add an uninterruptable context manager that can block SIGINT
The blocking of SIGINT is not done by default, but my hope is that we
will one day. This was inspired by Facebook's "nointerrupt" extension,
which is a bit more heavy-handed than this (whole commands are treated
as unsafe to interrupt). A future patch will enable this for varying
bits of Mercurial that are performing unsafe operations.
It's intentional that the KeyboardInterrupt is raised as the context
manager exits: during the span of the context manager interrupting
Mercurial could lead to data loss, but typically those spans are
fairly narrow, so we can let the unsafe block complete and then
terminate hg (which will leave the repo in a consistent state, even if
it's not the user's desired state).
.. api::
New context manager ``ui.uninterruptable()`` to mark portions of a command
as potentially unsafe places to interrupt Mercurial with Control-C or
similar.
Differential Revision: https://phab.mercurial-scm.org/D3716
author | Augie Fackler <augie@google.com> |
---|---|
date | Wed, 27 Jun 2018 10:47:14 -0400 |
parents | 6f67bfe4b82f |
children | 5bfab9400daf |
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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 third party cbor library to serialize and deserialize data. """ from __future__ import absolute_import from .thirdparty import cbor from . import ( error, util, ) 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) cbor.dump(data, fp, canonical=True) 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 cbor.load(fp) 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)