Mercurial > hg
view mercurial/pycompat.py @ 40393:229d23cdb203
exchangev2: support fetching shallow files history
This commit teaches the exchangev2 client code to handle fetching shallow
files data.
Only shallow fetching of files data is supported: shallow fetching of
changeset and manifest data is explicitly not yet supported.
Previously, we would fetch file revisions for changesets that were received
by the current pull operation. In the new model, we calculate the set of
"relevant" changesets given the pull depth and only fetch files data for
those changesets.
We also teach the "filesdata" command invocation to vary parameters as needed.
The implementation here is far from complete or optimal. Subsequent pulls will
end up re-fetching a lot of files data. But the application of this data should
mostly be a no-op on the client, so it isn't a big deal.
Depending on the order file revisions are fetched in, revisions could get
inserted with the wrong revision number relationships. I think the best way
to deal with this is to remove revision numbers from storage and to either
dynamically derive them (by reconstructing a DAG from nodes/parents) or remove
revision numbers from the file storage interface completely.
A missing API that we'll likely want to write pretty soon is "ensure files
for revision(s) are present." We can kind of cajole exchangev2.pull() to do
this. But it isn't very efficient. For example, in simple cases like
widening the store to obtain data for a single revision, it is probably
more efficient to walk the manifest and find exactly which file revisions
are missing and to make explicit requests for just their data. In more
advanced cases, asking the server for all files data may be more efficient,
even though it requires sending data the client already has. There is tons
of room for future experimentation here. And TBH I'm not sure what the
final state will be.
Anyway, this commit gets us pretty close to being able to have shallow
and narrow checkouts with exchangev2/sqlite storage. Close enough that a
minimal extension should be able to provide fill in the gaps until the code
in core stabilizes and there is a user-facing way to trigger the
narrow/shallow bits from `hg clone` without also implying using of the
narrow extension...
Differential Revision: https://phab.mercurial-scm.org/D5169
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Fri, 19 Oct 2018 12:30:49 +0200 |
parents | 24e493ec2229 |
children | 1b49b84d5ed5 |
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# 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. """ from __future__ import absolute_import import getopt import inspect import os import shlex import sys import tempfile ispy3 = (sys.version_info[0] >= 3) ispypy = (r'__pypy__' in sys.builtin_module_names) if not ispy3: import cookielib import cPickle as pickle import httplib import Queue as queue import SocketServer as socketserver import xmlrpclib from .thirdparty.concurrent import futures def future_set_exception_info(f, exc_info): f.set_exception_info(*exc_info) else: import concurrent.futures as futures import http.cookiejar as cookielib import http.client as httplib import pickle import queue as queue import socketserver import xmlrpc.client as xmlrpclib def future_set_exception_info(f, exc_info): f.set_exception(exc_info[0]) def identity(a): 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 ispy3: import builtins import functools import io import struct fsencode = os.fsencode fsdecode = os.fsdecode oscurdir = os.curdir.encode('ascii') oslinesep = os.linesep.encode('ascii') osname = os.name.encode('ascii') ospathsep = os.pathsep.encode('ascii') ospardir = os.pardir.encode('ascii') ossep = os.sep.encode('ascii') osaltsep = os.altsep if osaltsep: osaltsep = osaltsep.encode('ascii') sysplatform = sys.platform.encode('ascii') sysexecutable = sys.executable if sysexecutable: sysexecutable = os.fsencode(sysexecutable) bytesio = io.BytesIO # TODO deprecate stringio name, as it is a lie on Python 3. stringio = bytesio def maplist(*args): return list(map(*args)) def rangelist(*args): return list(range(*args)) def ziplist(*args): return list(zip(*args)) rawinput = input getargspec = inspect.getfullargspec long = int # TODO: .buffer might not exist if std streams were replaced; we'll need # a silly wrapper to make a bytes stream backed by a unicode one. stdin = sys.stdin.buffer stdout = sys.stdout.buffer stderr = sys.stderr.buffer # Since Python 3 converts argv to wchar_t type by Py_DecodeLocale() on Unix, # we can use os.fsencode() to get back bytes argv. # # https://hg.python.org/cpython/file/v3.5.1/Programs/python.c#l55 # # TODO: On Windows, the native argv is wchar_t, so we'll need a different # workaround to simulate the Python 2 (i.e. ANSI Win32 API) behavior. if getattr(sys, 'argv', None) is not None: sysargv = list(map(os.fsencode, sys.argv)) bytechr = struct.Struct(r'>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(object): ... 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 """ def __new__(cls, s=b''): if isinstance(s, bytestr): return s if (not isinstance(s, (bytes, bytearray)) and not hasattr(s, u'__bytes__')): # hasattr-py3-only s = str(s).encode(u'ascii') return bytes.__new__(cls, s) def __getitem__(self, key): s = bytes.__getitem__(self, key) if not isinstance(s, bytes): s = bytechr(s) return s def __iter__(self): return iterbytestr(bytes.__iter__(self)) def __repr__(self): return bytes.__repr__(self)[1:] # drop b'' def iterbytestr(s): """Iterate bytes as if it were a str object of Python 2""" return map(bytechr, s) def maybebytestr(s): """Promote bytes to bytestr""" if isinstance(s, bytes): return bytestr(s) return s def sysbytes(s): """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)). """ return s.encode(u'utf-8') def sysstr(s): """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(u'latin-1') def strurl(url): """Converts a bytes url back to str""" if isinstance(url, bytes): return url.decode(u'ascii') return url def bytesurl(url): """Converts a str url to bytes by encoding in ascii""" if isinstance(url, str): return url.encode(u'ascii') return url def raisewithtb(exc, tb): """Raise exception with the given traceback""" raise exc.with_traceback(tb) def getdoc(obj): """Get docstring as bytes; may be None so gettext() won't confuse it with _('')""" doc = getattr(obj, u'__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=b'r', buffering=-1, encoding=None): return builtins.open(name, sysstr(mode), buffering, encoding) safehasattr = _wrapattrfunc(builtins.hasattr) def _getoptbwrapper(orig, args, shortlist, namelist): """ 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): """ Converts the keys of a python dictonary to str i.e. unicodes so that they can be passed as keyword arguments as dictonaries with bytes keys can't be passed as keyword arguments to functions on Python 3. """ dic = dict((k.decode('latin-1'), v) for k, v in dic.iteritems()) return dic def byteskwargs(dic): """ Converts keys of python dictonaries to bytes as they were converted to str to pass that dictonary as a keyword argument on Python 3. """ dic = dict((k.encode('latin-1'), v) for k, v in dic.iteritems()) return dic # TODO: handle shlex.shlex(). def shlexsplit(s, comments=False, posix=True): """ 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] else: import cStringIO xrange = xrange unicode = unicode bytechr = chr byterepr = repr bytestr = str iterbytestr = iter maybebytestr = identity sysbytes = identity sysstr = identity strurl = identity bytesurl = identity # this can't be parsed on Python 3 exec('def raisewithtb(exc, tb):\n' ' raise exc, None, tb\n') def fsencode(filename): """ Partial backport from os.py in Python 3, which only accepts bytes. In Python 2, our paths should only ever be bytes, a unicode path indicates a bug. """ if isinstance(filename, str): return filename else: raise TypeError( r"expect str, not %s" % type(filename).__name__) # In Python 2, fsdecode() has a very chance to receive bytes. So it's # better not to touch Python 2 part as it's already working fine. fsdecode = identity def getdoc(obj): return getattr(obj, '__doc__', None) _notset = object() def safehasattr(thing, attr): return getattr(thing, attr, _notset) is not _notset def _getoptbwrapper(orig, args, shortlist, namelist): return orig(args, shortlist, namelist) strkwargs = identity byteskwargs = identity oscurdir = os.curdir oslinesep = os.linesep osname = os.name ospathsep = os.pathsep ospardir = os.pardir ossep = os.sep osaltsep = os.altsep long = long stdin = sys.stdin stdout = sys.stdout stderr = sys.stderr if getattr(sys, 'argv', None) is not None: sysargv = sys.argv sysplatform = sys.platform sysexecutable = sys.executable shlexsplit = shlex.split bytesio = cStringIO.StringIO stringio = bytesio maplist = map rangelist = range ziplist = zip rawinput = raw_input getargspec = inspect.getargspec isjython = sysplatform.startswith(b'java') isdarwin = sysplatform == b'darwin' isposix = osname == b'posix' iswindows = osname == b'nt' def getoptb(args, shortlist, namelist): return _getoptbwrapper(getopt.getopt, args, shortlist, namelist) def gnugetoptb(args, shortlist, namelist): return _getoptbwrapper(getopt.gnu_getopt, args, shortlist, namelist) def mkdtemp(suffix=b'', prefix=b'tmp', dir=None): return tempfile.mkdtemp(suffix, prefix, dir) # text=True is not supported; use util.from/tonativeeol() instead def mkstemp(suffix=b'', prefix=b'tmp', dir=None): return tempfile.mkstemp(suffix, prefix, dir) # mode must include 'b'ytes as encoding= is not supported def namedtempfile(mode=b'w+b', bufsize=-1, suffix=b'', prefix=b'tmp', dir=None, delete=True): mode = sysstr(mode) assert r'b' in mode return tempfile.NamedTemporaryFile(mode, bufsize, suffix=suffix, prefix=prefix, dir=dir, delete=delete)