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rust: module policy with importrust...
rust: module policy with importrust We introduce two rust+c module policies and a new `policy.importrust()` that makes use of them. This simple approach provides runtime switching of implementations, which is crucial for the performance measurements such as those Octobus does with ASV. It can also be useful for bug analysis. It also has the advantage of making conditionals in Rust callers more uniform, in particular abstracting over specifics like `demandimport` At this point, the build stays unchanged, with the rust-cpython based `rustext` module being built if HGWITHRUSTEXT=cpython. More transparency for the callers, i.e., just using `policy.importmod` would be a much longer term and riskier effort for the following reasons: 1. It would require to define common module boundaries for the three or four cases (pure, c, rust+ext, cffi) and that is premature with the Rust extension currently under heavy development in areas that are outside the scope of the C extensions. 2. It would imply internal API changes that are not currently wished, as the case of ancestors demonstrates. 3. The lack of data or property-like attributes (tp_member and tp_getset) in current `rust-cpython` makes it impossible to achieve direct transparent replacement of pure Python classes by Rust extension code, meaning that the caller sometimes has to be able to make adjustments or provide additional wrapping.

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diffhelper.py
78 lines | 2.2 KiB | text/x-python | PythonLexer
# diffhelper.py - helper routines for patch
#
# Copyright 2009 Matt Mackall <mpm@selenic.com> and others
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from __future__ import absolute_import
from .i18n import _
from . import (
error,
pycompat,
)
def addlines(fp, hunk, lena, lenb, a, b):
"""Read lines from fp into the hunk
The hunk is parsed into two arrays, a and b. a gets the old state of
the text, b gets the new state. The control char from the hunk is saved
when inserting into a, but not b (for performance while deleting files.)
"""
while True:
todoa = lena - len(a)
todob = lenb - len(b)
num = max(todoa, todob)
if num == 0:
break
for i in pycompat.xrange(num):
s = fp.readline()
if not s:
raise error.ParseError(_('incomplete hunk'))
if s == "\\ No newline at end of file\n":
fixnewline(hunk, a, b)
continue
if s == '\n' or s == '\r\n':
# Some patches may be missing the control char
# on empty lines. Supply a leading space.
s = ' ' + s
hunk.append(s)
if s.startswith('+'):
b.append(s[1:])
elif s.startswith('-'):
a.append(s)
else:
b.append(s[1:])
a.append(s)
def fixnewline(hunk, a, b):
"""Fix up the last lines of a and b when the patch has no newline at EOF"""
l = hunk[-1]
# tolerate CRLF in last line
if l.endswith('\r\n'):
hline = l[:-2]
else:
hline = l[:-1]
if hline.startswith((' ', '+')):
b[-1] = hline[1:]
if hline.startswith((' ', '-')):
a[-1] = hline
hunk[-1] = hline
def testhunk(a, b, bstart):
"""Compare the lines in a with the lines in b
a is assumed to have a control char at the start of each line, this char
is ignored in the compare.
"""
alen = len(a)
blen = len(b)
if alen > blen - bstart or bstart < 0:
return False
for i in pycompat.xrange(alen):
if a[i][1:] != b[i + bstart]:
return False
return True