dirstate-tree: Add tree traversal/iteration
Like Python’s, Rust’s iterators are "external" in that they are driven
by a caller who calls a `next` method. This is as opposed to "internal"
iterators who drive themselves and call a callback for each item.
Writing an internal iterator traversing a tree is easy with recursion,
but internal iterators cannot rely on the call stack in that way,
they must save in an explicit object all state that they need to be
preserved across two `next` calls.
This algorithm uses a `Vec` as a stack that contains what would be
local variables on the call stack if we could use recursion.
Differential Revision: https://phab.mercurial-scm.org/D10370
from __future__ import absolute_import
import unittest
import silenttestrunner
from mercurial import (
error,
scmutil,
)
class mockfile(object):
def __init__(self, name, fs):
self.name = name
self.fs = fs
def __enter__(self):
return self
def __exit__(self, *args, **kwargs):
pass
def write(self, text):
self.fs.contents[self.name] = text
def read(self):
return self.fs.contents[self.name]
class mockvfs(object):
def __init__(self):
self.contents = {}
def read(self, path):
return mockfile(path, self).read()
def readlines(self, path):
# lines need to contain the trailing '\n' to mock the real readlines
return [l for l in mockfile(path, self).read().splitlines(True)]
def __call__(self, path, mode, atomictemp):
return mockfile(path, self)
class testsimplekeyvaluefile(unittest.TestCase):
def setUp(self):
self.vfs = mockvfs()
def testbasicwritingiandreading(self):
dw = {b'key1': b'value1', b'Key2': b'value2'}
scmutil.simplekeyvaluefile(self.vfs, b'kvfile').write(dw)
self.assertEqual(
sorted(self.vfs.read(b'kvfile').split(b'\n')),
[b'', b'Key2=value2', b'key1=value1'],
)
dr = scmutil.simplekeyvaluefile(self.vfs, b'kvfile').read()
self.assertEqual(dr, dw)
if not getattr(unittest.TestCase, 'assertRaisesRegex', False):
# Python 3.7 deprecates the regex*p* version, but 2.7 lacks
# the regex version.
assertRaisesRegex = ( # camelcase-required
unittest.TestCase.assertRaisesRegexp
)
def testinvalidkeys(self):
d = {b'0key1': b'value1', b'Key2': b'value2'}
with self.assertRaisesRegex(
error.ProgrammingError, 'keys must start with a letter.*'
):
scmutil.simplekeyvaluefile(self.vfs, b'kvfile').write(d)
d = {b'key1@': b'value1', b'Key2': b'value2'}
with self.assertRaisesRegex(error.ProgrammingError, 'invalid key.*'):
scmutil.simplekeyvaluefile(self.vfs, b'kvfile').write(d)
def testinvalidvalues(self):
d = {b'key1': b'value1', b'Key2': b'value2\n'}
with self.assertRaisesRegex(error.ProgrammingError, 'invalid val.*'):
scmutil.simplekeyvaluefile(self.vfs, b'kvfile').write(d)
def testcorruptedfile(self):
self.vfs.contents[b'badfile'] = b'ababagalamaga\n'
with self.assertRaisesRegex(
error.CorruptedState, 'dictionary.*element.*'
):
scmutil.simplekeyvaluefile(self.vfs, b'badfile').read()
def testfirstline(self):
dw = {b'key1': b'value1'}
scmutil.simplekeyvaluefile(self.vfs, b'fl').write(dw, firstline=b'1.0')
self.assertEqual(self.vfs.read(b'fl'), b'1.0\nkey1=value1\n')
dr = scmutil.simplekeyvaluefile(self.vfs, b'fl').read(
firstlinenonkeyval=True
)
self.assertEqual(dr, {b'__firstline': b'1.0', b'key1': b'value1'})
if __name__ == "__main__":
silenttestrunner.main(__name__)