stream-clone: avoid opening a revlog in case we do not need it
Opening an revlog has a cost, especially if it is inline as we have to scan the
file and construct an index.
To prevent the associated slowdown, we just do a minimal scan to check that an
inline file is still inline, and simply stream the file without creating a
revlog when we can.
This provides a big boost compared to the previous changeset, even if the full
generation is still penalized by the initial gathering of information.
All benchmarks are run on linux with Python 3.10.7.
# benchmark.name = hg.exchange.stream.generate
# benchmark.variants.version = v2
### Compared to the previous changesets
We get a large win all across the board!
# mercurial-2018-08-01-zstd-sparse-revlog
before: 0.250694 seconds
after: 0.105986 seconds (-57.72%)
# pypy-2018-08-01-zstd-sparse-revlog
before: 3.885657 seconds
after: 1.709748 seconds (-56.00%)
# netbeans-2018-08-01-zstd-sparse-revlog
before: 16.679371 seconds
after: 7.687469 seconds (-53.91%)
# mozilla-central-2018-08-01-zstd-sparse-revlog
before: 38.575482 seconds
after: 17.520316 seconds (-54.58%)
# mozilla-try-2019-02-18-zstd-sparse-revlog
before: 81.160994 seconds
after: 37.073753 seconds (-54.32%)
### Compared to 6.4.3
We are still significantly slower than 6.4.3, the extra time is usually twice
slower than the extra time we observe on the locked section, which is a quite
interesting information.
Except for mercurial-central that is much faster. That discrepancy is not really
explained yet.
# mercurial-2018-08-01-zstd-sparse-revlog
6.4.3: 0.072560 seconds
after: 0.105986 seconds (+46.07%) (- 0.03 seconds)
# pypy-2018-08-01-zstd-sparse-revlog
6.4.3: 1.211193 seconds
after: 1.709748 seconds (+41.16%) (-0.45 seconds)
# netbeans-2018-08-01-zstd-sparse-revlog
6.4.3: 4.932843 seconds
after: 7.687469 seconds (+55.84%) (-2.75 seconds)
# mozilla-central-2018-08-01-zstd-sparse-revlog
6.4.3: 34.012226 seconds
after: 17.520316 seconds (-48.49%) (-16.49 seconds)
# mozilla-try-2019-02-18-zstd-sparse-revlog
6.4.3: 23.850555 seconds
after: 37.073753 seconds (+55.44%) (+13.22 seconds)
# pycompat.py - portability shim for python 3
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
"""Mercurial portability shim for python 3.
This contains aliases to hide python version-specific details from the core.
"""
import builtins
import codecs
import concurrent.futures as futures
import functools
import getopt
import http.client as httplib
import http.cookiejar as cookielib
import inspect
import io
import json
import os
import queue
import shlex
import socketserver
import struct
import sys
import tempfile
import xmlrpc.client as xmlrpclib
from typing import (
Any,
AnyStr,
BinaryIO,
Callable,
Dict,
Iterable,
Iterator,
List,
Mapping,
NoReturn,
Optional,
Sequence,
Tuple,
Type,
TypeVar,
cast,
overload,
)
ispy3 = sys.version_info[0] >= 3
ispypy = '__pypy__' in sys.builtin_module_names
TYPE_CHECKING = False
if not globals(): # hide this from non-pytype users
import typing
TYPE_CHECKING = typing.TYPE_CHECKING
_GetOptResult = Tuple[List[Tuple[bytes, bytes]], List[bytes]]
_T0 = TypeVar('_T0')
_T1 = TypeVar('_T1')
_S = TypeVar('_S')
_Tbytestr = TypeVar('_Tbytestr', bound='bytestr')
def future_set_exception_info(f, exc_info):
f.set_exception(exc_info[0])
FileNotFoundError = builtins.FileNotFoundError
def identity(a: _T0) -> _T0:
return a
def _rapply(f, xs):
if xs is None:
# assume None means non-value of optional data
return xs
if isinstance(xs, (list, set, tuple)):
return type(xs)(_rapply(f, x) for x in xs)
if isinstance(xs, dict):
return type(xs)((_rapply(f, k), _rapply(f, v)) for k, v in xs.items())
return f(xs)
def rapply(f, xs):
"""Apply function recursively to every item preserving the data structure
>>> def f(x):
... return 'f(%s)' % x
>>> rapply(f, None) is None
True
>>> rapply(f, 'a')
'f(a)'
>>> rapply(f, {'a'}) == {'f(a)'}
True
>>> rapply(f, ['a', 'b', None, {'c': 'd'}, []])
['f(a)', 'f(b)', None, {'f(c)': 'f(d)'}, []]
>>> xs = [object()]
>>> rapply(identity, xs) is xs
True
"""
if f is identity:
# fast path mainly for py2
return xs
return _rapply(f, xs)
if os.name == r'nt':
# MBCS (or ANSI) filesystem encoding must be used as before.
# Otherwise non-ASCII filenames in existing repositories would be
# corrupted.
# This must be set once prior to any fsencode/fsdecode calls.
sys._enablelegacywindowsfsencoding() # pytype: disable=module-attr
fsencode = os.fsencode
fsdecode = os.fsdecode
oscurdir: bytes = os.curdir.encode('ascii')
oslinesep: bytes = os.linesep.encode('ascii')
osname: bytes = os.name.encode('ascii')
ospathsep: bytes = os.pathsep.encode('ascii')
ospardir: bytes = os.pardir.encode('ascii')
ossep: bytes = os.sep.encode('ascii')
osaltsep: Optional[bytes] = os.altsep.encode('ascii') if os.altsep else None
osdevnull: bytes = os.devnull.encode('ascii')
sysplatform: bytes = sys.platform.encode('ascii')
sysexecutable: bytes = os.fsencode(sys.executable) if sys.executable else b''
if TYPE_CHECKING:
@overload
def maplist(f: Callable[[_T0], _S], arg: Iterable[_T0]) -> List[_S]:
...
@overload
def maplist(
f: Callable[[_T0, _T1], _S], arg1: Iterable[_T0], arg2: Iterable[_T1]
) -> List[_S]:
...
def maplist(f, *args):
return list(map(f, *args))
def rangelist(*args) -> List[int]:
return list(range(*args))
def ziplist(*args):
return list(zip(*args))
rawinput = input
getargspec = inspect.getfullargspec
long = int
if builtins.getattr(sys, 'argv', None) is not None:
# On POSIX, the char** argv array is converted to Python str using
# Py_DecodeLocale(). The inverse of this is Py_EncodeLocale(), which
# isn't directly callable from Python code. In practice, os.fsencode()
# can be used instead (this is recommended by Python's documentation
# for sys.argv).
#
# On Windows, the wchar_t **argv is passed into the interpreter as-is.
# Like POSIX, we need to emulate what Py_EncodeLocale() would do. But
# there's an additional wrinkle. What we really want to access is the
# ANSI codepage representation of the arguments, as this is what
# `int main()` would receive if Python 3 didn't define `int wmain()`
# (this is how Python 2 worked). To get that, we encode with the mbcs
# encoding, which will pass CP_ACP to the underlying Windows API to
# produce bytes.
sysargv: List[bytes] = []
if os.name == r'nt':
sysargv = [a.encode("mbcs", "ignore") for a in sys.argv]
else:
sysargv = [fsencode(a) for a in sys.argv]
bytechr = struct.Struct('>B').pack
byterepr = b'%r'.__mod__
class bytestr(bytes):
"""A bytes which mostly acts as a Python 2 str
>>> bytestr(), bytestr(bytearray(b'foo')), bytestr(u'ascii'), bytestr(1)
('', 'foo', 'ascii', '1')
>>> s = bytestr(b'foo')
>>> assert s is bytestr(s)
__bytes__() should be called if provided:
>>> class bytesable:
... def __bytes__(self):
... return b'bytes'
>>> bytestr(bytesable())
'bytes'
There's no implicit conversion from non-ascii str as its encoding is
unknown:
>>> bytestr(chr(0x80)) # doctest: +ELLIPSIS
Traceback (most recent call last):
...
UnicodeEncodeError: ...
Comparison between bytestr and bytes should work:
>>> assert bytestr(b'foo') == b'foo'
>>> assert b'foo' == bytestr(b'foo')
>>> assert b'f' in bytestr(b'foo')
>>> assert bytestr(b'f') in b'foo'
Sliced elements should be bytes, not integer:
>>> s[1], s[:2]
(b'o', b'fo')
>>> list(s), list(reversed(s))
([b'f', b'o', b'o'], [b'o', b'o', b'f'])
As bytestr type isn't propagated across operations, you need to cast
bytes to bytestr explicitly:
>>> s = bytestr(b'foo').upper()
>>> t = bytestr(s)
>>> s[0], t[0]
(70, b'F')
Be careful to not pass a bytestr object to a function which expects
bytearray-like behavior.
>>> t = bytes(t) # cast to bytes
>>> assert type(t) is bytes
"""
# Trick pytype into not demanding Iterable[int] be passed to __new__(),
# since the appropriate bytes format is done internally.
#
# https://github.com/google/pytype/issues/500
if TYPE_CHECKING:
def __init__(self, s: object = b'') -> None:
pass
def __new__(cls: Type[_Tbytestr], s: object = b'') -> _Tbytestr:
if isinstance(s, bytestr):
return s
if not isinstance(
s, (bytes, bytearray)
) and not builtins.hasattr( # hasattr-py3-only
s, u'__bytes__'
):
s = str(s).encode('ascii')
return bytes.__new__(cls, s)
# The base class uses `int` return in py3, but the point of this class is to
# behave like py2.
def __getitem__(self, key) -> bytes: # pytype: disable=signature-mismatch
s = bytes.__getitem__(self, key)
if not isinstance(s, bytes):
s = bytechr(s)
return s
# The base class expects `Iterator[int]` return in py3, but the point of
# this class is to behave like py2.
def __iter__(self) -> Iterator[bytes]: # pytype: disable=signature-mismatch
return iterbytestr(bytes.__iter__(self))
def __repr__(self) -> str:
return bytes.__repr__(self)[1:] # drop b''
def iterbytestr(s: Iterable[int]) -> Iterator[bytes]:
"""Iterate bytes as if it were a str object of Python 2"""
return map(bytechr, s)
if TYPE_CHECKING:
@overload
def maybebytestr(s: bytes) -> bytestr:
...
@overload
def maybebytestr(s: _T0) -> _T0:
...
def maybebytestr(s):
"""Promote bytes to bytestr"""
if isinstance(s, bytes):
return bytestr(s)
return s
def sysbytes(s: AnyStr) -> bytes:
"""Convert an internal str (e.g. keyword, __doc__) back to bytes
This never raises UnicodeEncodeError, but only ASCII characters
can be round-trip by sysstr(sysbytes(s)).
"""
if isinstance(s, bytes):
return s
return s.encode('utf-8')
def sysstr(s: AnyStr) -> str:
"""Return a keyword str to be passed to Python functions such as
getattr() and str.encode()
This never raises UnicodeDecodeError. Non-ascii characters are
considered invalid and mapped to arbitrary but unique code points
such that 'sysstr(a) != sysstr(b)' for all 'a != b'.
"""
if isinstance(s, builtins.str):
return s
return s.decode('latin-1')
def strurl(url: AnyStr) -> str:
"""Converts a bytes url back to str"""
if isinstance(url, bytes):
return url.decode('ascii')
return url
def bytesurl(url: AnyStr) -> bytes:
"""Converts a str url to bytes by encoding in ascii"""
if isinstance(url, str):
return url.encode('ascii')
return url
def raisewithtb(exc: BaseException, tb) -> NoReturn:
"""Raise exception with the given traceback"""
raise exc.with_traceback(tb)
def getdoc(obj: object) -> Optional[bytes]:
"""Get docstring as bytes; may be None so gettext() won't confuse it
with _('')"""
doc = builtins.getattr(obj, '__doc__', None)
if doc is None:
return doc
return sysbytes(doc)
def _wrapattrfunc(f):
@functools.wraps(f)
def w(object, name, *args):
return f(object, sysstr(name), *args)
return w
# these wrappers are automagically imported by hgloader
delattr = _wrapattrfunc(builtins.delattr)
getattr = _wrapattrfunc(builtins.getattr)
hasattr = _wrapattrfunc(builtins.hasattr)
setattr = _wrapattrfunc(builtins.setattr)
xrange = builtins.range
unicode = str
def open(
name,
mode: AnyStr = b'r',
buffering: int = -1,
encoding: Optional[str] = None,
) -> Any:
# TODO: assert binary mode, and cast result to BinaryIO?
return builtins.open(name, sysstr(mode), buffering, encoding)
safehasattr = _wrapattrfunc(builtins.hasattr)
def _getoptbwrapper(
orig, args: Sequence[bytes], shortlist: bytes, namelist: Sequence[bytes]
) -> _GetOptResult:
"""
Takes bytes arguments, converts them to unicode, pass them to
getopt.getopt(), convert the returned values back to bytes and then
return them for Python 3 compatibility as getopt.getopt() don't accepts
bytes on Python 3.
"""
args = [a.decode('latin-1') for a in args]
shortlist = shortlist.decode('latin-1')
namelist = [a.decode('latin-1') for a in namelist]
opts, args = orig(args, shortlist, namelist)
opts = [(a[0].encode('latin-1'), a[1].encode('latin-1')) for a in opts]
args = [a.encode('latin-1') for a in args]
return opts, args
def strkwargs(dic: Mapping[bytes, _T0]) -> Dict[str, _T0]:
"""
Converts the keys of a python dictonary to str i.e. unicodes so that
they can be passed as keyword arguments as dictionaries with bytes keys
can't be passed as keyword arguments to functions on Python 3.
"""
dic = {k.decode('latin-1'): v for k, v in dic.items()}
return dic
def byteskwargs(dic: Mapping[str, _T0]) -> Dict[bytes, _T0]:
"""
Converts keys of python dictionaries to bytes as they were converted to
str to pass that dictonary as a keyword argument on Python 3.
"""
dic = {k.encode('latin-1'): v for k, v in dic.items()}
return dic
# TODO: handle shlex.shlex().
def shlexsplit(
s: bytes, comments: bool = False, posix: bool = True
) -> List[bytes]:
"""
Takes bytes argument, convert it to str i.e. unicodes, pass that into
shlex.split(), convert the returned value to bytes and return that for
Python 3 compatibility as shelx.split() don't accept bytes on Python 3.
"""
ret = shlex.split(s.decode('latin-1'), comments, posix)
return [a.encode('latin-1') for a in ret]
iteritems = lambda x: x.items()
itervalues = lambda x: x.values()
json_loads = json.loads
isjython: bool = sysplatform.startswith(b'java')
isdarwin: bool = sysplatform.startswith(b'darwin')
islinux: bool = sysplatform.startswith(b'linux')
isposix: bool = osname == b'posix'
iswindows: bool = osname == b'nt'
def getoptb(
args: Sequence[bytes], shortlist: bytes, namelist: Sequence[bytes]
) -> _GetOptResult:
return _getoptbwrapper(getopt.getopt, args, shortlist, namelist)
def gnugetoptb(
args: Sequence[bytes], shortlist: bytes, namelist: Sequence[bytes]
) -> _GetOptResult:
return _getoptbwrapper(getopt.gnu_getopt, args, shortlist, namelist)
def mkdtemp(
suffix: bytes = b'', prefix: bytes = b'tmp', dir: Optional[bytes] = None
) -> bytes:
return tempfile.mkdtemp(suffix, prefix, dir)
# text=True is not supported; use util.from/tonativeeol() instead
def mkstemp(
suffix: bytes = b'', prefix: bytes = b'tmp', dir: Optional[bytes] = None
) -> Tuple[int, bytes]:
return tempfile.mkstemp(suffix, prefix, dir)
# TemporaryFile does not support an "encoding=" argument on python2.
# This wrapper file are always open in byte mode.
def unnamedtempfile(mode: Optional[bytes] = None, *args, **kwargs) -> BinaryIO:
if mode is None:
mode = 'w+b'
else:
mode = sysstr(mode)
assert 'b' in mode
return cast(BinaryIO, tempfile.TemporaryFile(mode, *args, **kwargs))
# NamedTemporaryFile does not support an "encoding=" argument on python2.
# This wrapper file are always open in byte mode.
def namedtempfile(
mode: bytes = b'w+b',
bufsize: int = -1,
suffix: bytes = b'',
prefix: bytes = b'tmp',
dir: Optional[bytes] = None,
delete: bool = True,
):
mode = sysstr(mode)
assert 'b' in mode
return tempfile.NamedTemporaryFile(
mode, bufsize, suffix=suffix, prefix=prefix, dir=dir, delete=delete
)