Mercurial > hg
view mercurial/diffhelper.py @ 39409:2fe21c65777e
internals: document CBOR utilization
I spoke with some people at Mozilla about CBOR and they advised me
that we should be careful about the subset of CBOR we use in order
to mitigate security, performance, and compatibility concerns.
This commit establishes a document that attempts to formalize our
use of CBOR.
Its main limitations are on what types are allowed. It explicitly
enumerates which types are supported. Notable missing features
include:
* Indefinite-length arrays and maps
* Text strings (bytes all the way)
* Floats
* Date/time types
* Big integers
* Use of indefinite-length byte strings for map keys, values in
containers.
If we have a need for any of these, we can have a discussion about
them when the time comes.
Differential Revision: https://phab.mercurial-scm.org/D4412
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Tue, 28 Aug 2018 20:27:36 -0700 |
parents | e7aa113b14f7 |
children | 57875cf423c9 |
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# 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