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
from __future__ import absolute_import
from __future__ import print_function
import unittest
from mercurial import (
mdiff,
pycompat,
)
from mercurial.dagop import (
annotateline,
_annotatedfile,
_annotatepair,
)
def tr(a):
return [annotateline(fctx, lineno, skip)
for fctx, lineno, skip in zip(a.fctxs, a.linenos, a.skips)]
class AnnotateTests(unittest.TestCase):
"""Unit tests for annotate code."""
def testannotatepair(self):
self.maxDiff = None # camelcase-required
oldfctx = b'old'
p1fctx, p2fctx, childfctx = b'p1', b'p2', b'c'
olddata = b'a\nb\n'
p1data = b'a\nb\nc\n'
p2data = b'a\nc\nd\n'
childdata = b'a\nb2\nc\nc2\nd\n'
diffopts = mdiff.diffopts()
def decorate(text, fctx):
n = text.count(b'\n')
linenos = pycompat.rangelist(1, n + 1)
return _annotatedfile([fctx] * n, linenos, [False] * n, text)
# Basic usage
oldann = decorate(olddata, oldfctx)
p1ann = decorate(p1data, p1fctx)
p1ann = _annotatepair([oldann], p1fctx, p1ann, False, diffopts)
self.assertEqual(tr(p1ann), [
annotateline(b'old', 1),
annotateline(b'old', 2),
annotateline(b'p1', 3),
])
p2ann = decorate(p2data, p2fctx)
p2ann = _annotatepair([oldann], p2fctx, p2ann, False, diffopts)
self.assertEqual(tr(p2ann), [
annotateline(b'old', 1),
annotateline(b'p2', 2),
annotateline(b'p2', 3),
])
# Test with multiple parents (note the difference caused by ordering)
childann = decorate(childdata, childfctx)
childann = _annotatepair([p1ann, p2ann], childfctx, childann, False,
diffopts)
self.assertEqual(tr(childann), [
annotateline(b'old', 1),
annotateline(b'c', 2),
annotateline(b'p2', 2),
annotateline(b'c', 4),
annotateline(b'p2', 3),
])
childann = decorate(childdata, childfctx)
childann = _annotatepair([p2ann, p1ann], childfctx, childann, False,
diffopts)
self.assertEqual(tr(childann), [
annotateline(b'old', 1),
annotateline(b'c', 2),
annotateline(b'p1', 3),
annotateline(b'c', 4),
annotateline(b'p2', 3),
])
# Test with skipchild (note the difference caused by ordering)
childann = decorate(childdata, childfctx)
childann = _annotatepair([p1ann, p2ann], childfctx, childann, True,
diffopts)
self.assertEqual(tr(childann), [
annotateline(b'old', 1),
annotateline(b'old', 2, True),
# note that this line was carried over from earlier so it is *not*
# marked skipped
annotateline(b'p2', 2),
annotateline(b'p2', 2, True),
annotateline(b'p2', 3),
])
childann = decorate(childdata, childfctx)
childann = _annotatepair([p2ann, p1ann], childfctx, childann, True,
diffopts)
self.assertEqual(tr(childann), [
annotateline(b'old', 1),
annotateline(b'old', 2, True),
annotateline(b'p1', 3),
annotateline(b'p1', 3, True),
annotateline(b'p2', 3),
])
if __name__ == '__main__':
import silenttestrunner
silenttestrunner.main(__name__)