lfs: avoid quadratic performance in processing server responses
This is also adapted from the Facebook repo[1]. Unlike there, we were already
reading the download stream in chunks and immediately writing it to disk, so we
basically avoided the problem on download. There shouldn't be a lot of data to
read on upload, but it's better to get rid of this pattern.
[1] https://github.com/facebookexperimental/eden/commit/
82df66ffe97e21f3ee73dfec093c87500fc1f6a7
Differential Revision: https://phab.mercurial-scm.org/D7882
# 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,
pycompat,
util,
)
from .utils import cborutil
if pycompat.TYPE_CHECKING:
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())