procutil: make stream detection in make_line_buffered more correct and strict
In make_line_buffered(), we don’t want to wrap the stream if we know that lines
get flushed to the underlying raw stream already.
Previously, the heuristic was too optimistic. It assumed that any stream which
is not an instance of io.BufferedIOBase doesn’t need wrapping. However, there
are buffered streams that aren’t instances of io.BufferedIOBase, like
Mercurial’s own winstdout.
The new logic is different in two ways:
First, only for the check, if unwraps any combination of WriteAllWrapper and
winstdout.
Second, it skips wrapping the stream only if it is an instance of io.RawIOBase
(or already wrapped). If it is an instance of io.BufferedIOBase, it gets
wrapped. In any other case, the function raises an exception. This ensures
that, if an unknown stream is passed or we add another wrapper in the future,
we don’t wrap the stream if it’s already line buffered or not wrap the stream
if it’s not line buffered. In fact, this was already helpful during development
of this change. Without it, I possibly would have forgot that WriteAllWrapper
needs to be ignored for the check, leading to unnecessary wrapping if stdout is
unbuffered.
The alternative would have been to always wrap unknown streams. However, I
don’t think that anyone would benefit from being less strict. We can expect
streams from the standard library to be subclassing either io.RawIOBase or
io.BufferedIOBase, so running Mercurial in the standard way should not regress
by this change. Py2exe might replace sys.stdout and sys.stderr, but that
currently breaks Mercurial anyway and also these streams don’t claim to be
interactive, so this function is not called for them.
import difflib
import random
import unittest
from mercurial import linelog
vecratio = 3 # number of replacelines / number of replacelines_vec
maxlinenum = 0xFFFFFF
maxb1 = 0xFFFFFF
maxdeltaa = 10
maxdeltab = 10
def _genedits(seed, endrev):
lines = []
random.seed(seed)
for rev in range(0, endrev):
n = len(lines)
a1 = random.randint(0, n)
a2 = random.randint(a1, min(n, a1 + maxdeltaa))
b1 = random.randint(0, maxb1)
b2 = random.randint(b1, b1 + maxdeltab)
usevec = not bool(random.randint(0, vecratio))
if usevec:
blines = [
(random.randint(0, rev), random.randint(0, maxlinenum))
for _ in range(b1, b2)
]
else:
blines = [(rev, bidx) for bidx in range(b1, b2)]
lines[a1:a2] = blines
yield lines, rev, a1, a2, b1, b2, blines, usevec
class linelogtests(unittest.TestCase):
def testlinelogencodedecode(self):
program = [
linelog._eof(0, 0),
linelog._jge(41, 42),
linelog._jump(0, 43),
linelog._eof(0, 0),
linelog._jl(44, 45),
linelog._line(46, 47),
]
ll = linelog.linelog(program, maxrev=100)
enc = ll.encode()
# round-trips okay
self.assertEqual(linelog.linelog.fromdata(enc)._program, ll._program)
self.assertEqual(linelog.linelog.fromdata(enc), ll)
# This encoding matches the encoding used by hg-experimental's
# linelog file, or is supposed to if it doesn't.
self.assertEqual(
enc,
(
b'\x00\x00\x01\x90\x00\x00\x00\x06'
b'\x00\x00\x00\xa4\x00\x00\x00*'
b'\x00\x00\x00\x00\x00\x00\x00+'
b'\x00\x00\x00\x00\x00\x00\x00\x00'
b'\x00\x00\x00\xb1\x00\x00\x00-'
b'\x00\x00\x00\xba\x00\x00\x00/'
),
)
def testsimpleedits(self):
ll = linelog.linelog()
# Initial revision: add lines 0, 1, and 2
ll.replacelines(1, 0, 0, 0, 3)
self.assertEqual(
[(l.rev, l.linenum) for l in ll.annotate(1)],
[
(1, 0),
(1, 1),
(1, 2),
],
)
# Replace line 1 with a new line
ll.replacelines(2, 1, 2, 1, 2)
self.assertEqual(
[(l.rev, l.linenum) for l in ll.annotate(2)],
[
(1, 0),
(2, 1),
(1, 2),
],
)
# delete a line out of 2
ll.replacelines(3, 1, 2, 0, 0)
self.assertEqual(
[(l.rev, l.linenum) for l in ll.annotate(3)],
[
(1, 0),
(1, 2),
],
)
# annotation of 1 is unchanged
self.assertEqual(
[(l.rev, l.linenum) for l in ll.annotate(1)],
[
(1, 0),
(1, 1),
(1, 2),
],
)
ll.annotate(3) # set internal state to revision 3
start = ll.getoffset(0)
end = ll.getoffset(1)
self.assertEqual(
ll.getalllines(start, end),
[
(1, 0),
(2, 1),
(1, 1),
],
)
self.assertEqual(
ll.getalllines(),
[
(1, 0),
(2, 1),
(1, 1),
(1, 2),
],
)
def testparseclinelogfile(self):
# This data is what the replacements in testsimpleedits
# produce when fed to the original linelog.c implementation.
data = (
b'\x00\x00\x00\x0c\x00\x00\x00\x0f'
b'\x00\x00\x00\x00\x00\x00\x00\x02'
b'\x00\x00\x00\x05\x00\x00\x00\x06'
b'\x00\x00\x00\x06\x00\x00\x00\x00'
b'\x00\x00\x00\x00\x00\x00\x00\x07'
b'\x00\x00\x00\x06\x00\x00\x00\x02'
b'\x00\x00\x00\x00\x00\x00\x00\x00'
b'\x00\x00\x00\t\x00\x00\x00\t'
b'\x00\x00\x00\x00\x00\x00\x00\x0c'
b'\x00\x00\x00\x08\x00\x00\x00\x05'
b'\x00\x00\x00\x06\x00\x00\x00\x01'
b'\x00\x00\x00\x00\x00\x00\x00\x05'
b'\x00\x00\x00\x0c\x00\x00\x00\x05'
b'\x00\x00\x00\n\x00\x00\x00\x01'
b'\x00\x00\x00\x00\x00\x00\x00\t'
)
llc = linelog.linelog.fromdata(data)
self.assertEqual(
[(l.rev, l.linenum) for l in llc.annotate(1)],
[
(1, 0),
(1, 1),
(1, 2),
],
)
self.assertEqual(
[(l.rev, l.linenum) for l in llc.annotate(2)],
[
(1, 0),
(2, 1),
(1, 2),
],
)
self.assertEqual(
[(l.rev, l.linenum) for l in llc.annotate(3)],
[
(1, 0),
(1, 2),
],
)
# Check we emit the same bytecode.
ll = linelog.linelog()
# Initial revision: add lines 0, 1, and 2
ll.replacelines(1, 0, 0, 0, 3)
# Replace line 1 with a new line
ll.replacelines(2, 1, 2, 1, 2)
# delete a line out of 2
ll.replacelines(3, 1, 2, 0, 0)
diff = '\n ' + '\n '.join(
difflib.unified_diff(
ll.debugstr().splitlines(),
llc.debugstr().splitlines(),
'python',
'c',
lineterm='',
)
)
self.assertEqual(ll._program, llc._program, 'Program mismatch: ' + diff)
# Done as a secondary step so we get a better result if the
# program is where the mismatch is.
self.assertEqual(ll, llc)
self.assertEqual(ll.encode(), data)
def testanothersimplecase(self):
ll = linelog.linelog()
ll.replacelines(3, 0, 0, 0, 2)
ll.replacelines(4, 0, 2, 0, 0)
self.assertEqual([(l.rev, l.linenum) for l in ll.annotate(4)], [])
self.assertEqual(
[(l.rev, l.linenum) for l in ll.annotate(3)], [(3, 0), (3, 1)]
)
# rev 2 is empty because contents were only ever introduced in rev 3
self.assertEqual([(l.rev, l.linenum) for l in ll.annotate(2)], [])
def testrandomedits(self):
# Inspired by original linelog tests.
seed = random.random()
numrevs = 2000
ll = linelog.linelog()
# Populate linelog
for lines, rev, a1, a2, b1, b2, blines, usevec in _genedits(
seed, numrevs
):
if usevec:
ll.replacelines_vec(rev, a1, a2, blines)
else:
ll.replacelines(rev, a1, a2, b1, b2)
ll.annotate(rev)
self.assertEqual(ll.annotateresult, lines)
# Verify we can get back these states by annotating each rev
for lines, rev, a1, a2, b1, b2, blines, usevec in _genedits(
seed, numrevs
):
ar = ll.annotate(rev)
self.assertEqual([(l.rev, l.linenum) for l in ar], lines)
def testinfinitebadprogram(self):
ll = linelog.linelog.fromdata(
b'\x00\x00\x00\x00\x00\x00\x00\x02' # header
b'\x00\x00\x00\x00\x00\x00\x00\x01' # JUMP to self
)
with self.assertRaises(linelog.LineLogError):
# should not be an infinite loop and raise
ll.annotate(1)
if __name__ == '__main__':
import silenttestrunner
silenttestrunner.main(__name__)