state: add a pytype annotation

Differential Revision: https://phab.mercurial-scm.org/D7383

mercurial/state.py

@@ -1,270 +1,280 b''
 # state.py - writing and reading state files in Mercurial
 #
 # Copyright 2018 Pulkit Goyal <[e-mail]>
 #
 # 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
 
+if not globals():
+    from typing import (
+        Any,
+        Dict,
+    )
+
+    for t in (Any, Dict):
+        assert t
+
 
 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):
+        # type: () -> Dict[bytes, Any]
         """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())