pulkit updated this revision to Diff 7297. pulkit edited the summary of this revision.
REPOSITORY rHG Mercurial CHANGES SINCE LAST UPDATE https://phab.mercurial-scm.org/D2591?vs=6442&id=7297 REVISION DETAIL https://phab.mercurial-scm.org/D2591 AFFECTED FILES mercurial/state.py CHANGE DETAILS diff --git a/mercurial/state.py b/mercurial/state.py new file mode 100644 --- /dev/null +++ b/mercurial/state.py @@ -0,0 +1,93 @@ +# state.py - writing and reading state files in Mercurial +# +# Copyright 2018 Pulkit Goyal <pulkitmgo...@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 ( + 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, opts=None): + """ repo is the repo object + fname is the file name in which data should be stored in .hg directory + opts is a dictionary of data of the statefile + """ + self._repo = repo + self.fname = fname + if not opts: + self.opts = {} + else: + self.opts = opts + + def __nonzero__(self): + return self.exists() + + def __getitem__(self, key): + return self.opts[key] + + def __setitem__(self, key, value): + updates = {key: value} + self.opts.update(updates) + + def load(self): + """load the existing state file into the class object""" + op = self._read() + self.opts.update(op) + + def addopts(self, opts): + """add more key-value pairs to the data stored by the object""" + self.opts.update(opts) + + def save(self): + """write all the state data stored to .hg/<filename> file + + we use third-party library cbor to serialize data to write in the file. + """ + with self._repo.vfs(self.fname, 'wb', atomictemp=True) as fp: + cbor.dump(self.opts, fp) + + 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: + 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) To: pulkit, #hg-reviewers, indygreg Cc: indygreg, martinvonz, mercurial-devel _______________________________________________ Mercurial-devel mailing list Mercurial-devel@mercurial-scm.org https://www.mercurial-scm.org/mailman/listinfo/mercurial-devel
