rust-nodemap: accounting for dead blocks
By the very append-only nature of the `NodeTree`, inserting
new blocks has the effect of making some of the older ones
useless as they become unreachable.
Therefore some automatic housekeeping will need to be provided.
This is standard procedure in the word of databases, under names
such as "repack" or "vacuum".
The new `masked_readonly_blocks()` will provide callers with
useful information to decide if the nodetree is ripe for
repacking, but all the `NodeTree` can provide is how many
blocks have been masked in the currently mutable part. Analysing
the readonly part would be way too long to do it for each
transaction and defeat the whole purpose of nodemap persistence.
Serializing callers (from the Python layer) will get this figure
before each extraction and maintain an aggregate counter of
unreachable blocks separately.
Note: at this point, the most efficient repacking is just to restart
afresh with a full rescan.
Differential Revision: https://phab.mercurial-scm.org/D8097
"""test line matching with some failing examples and some which warn
run-test.t only checks positive matches and can not see warnings
(both by design)
"""
from __future__ import absolute_import, print_function
import doctest
import os
import re
# this is hack to make sure no escape characters are inserted into the output
if 'TERM' in os.environ:
del os.environ['TERM']
run_tests = __import__('run-tests')
def prn(ex):
m = ex.args[0]
if isinstance(m, str):
print(m)
else:
print(m.decode('utf-8'))
def lm(expected, output):
r"""check if output matches expected
does it generally work?
>>> lm(b'H*e (glob)\n', b'Here\n')
True
fail on bad test data
>>> try: lm(b'a\n',b'a')
... except AssertionError as ex: print(ex)
missing newline
>>> try: lm(b'single backslash\n', b'single \backslash\n')
... except AssertionError as ex: prn(ex)
single backslash or unknown char
"""
assert expected.endswith(b'\n') and output.endswith(
b'\n'
), 'missing newline'
assert not re.search(
br'[^ \w\\/\r\n()*?]', expected + output
), b'single backslash or unknown char'
test = run_tests.TTest(b'test-run-test.t', b'.', b'.')
match, exact = test.linematch(expected, output)
if isinstance(match, str):
return 'special: ' + match
elif isinstance(match, bytes):
return 'special: ' + match.decode('utf-8')
else:
return bool(match) # do not return match object
def wintests():
r"""test matching like running on windows
enable windows matching on any os
>>> _osaltsep = os.altsep
>>> os.altsep = True
>>> _osname = os.name
>>> os.name = 'nt'
valid match on windows
>>> lm(b'g/a*/d (glob)\n', b'g\\abc/d\n')
True
direct matching, glob unnecessary
>>> lm(b'g/b (glob)\n', b'g/b\n')
'special: -glob'
missing glob
>>> lm(b'/g/c/d/fg\n', b'\\g\\c\\d/fg\n')
True
>>> lm(b'/g/c/d/fg\n', b'\\g\\c\\d\\fg\r\n')
True
restore os.altsep
>>> os.altsep = _osaltsep
>>> os.name = _osname
"""
pass
def otherostests():
r"""test matching like running on non-windows os
disable windows matching on any os
>>> _osaltsep = os.altsep
>>> os.altsep = False
>>> _osname = os.name
>>> os.name = 'nt'
backslash does not match slash
>>> lm(b'h/a* (glob)\n', b'h\\ab\n')
False
direct matching glob can not be recognized
>>> lm(b'h/b (glob)\n', b'h/b\n')
True
missing glob can not not be recognized
>>> lm(b'/h/c/df/g/\n', b'\\h/c\\df/g\\\n')
False
restore os.altsep
>>> os.altsep = _osaltsep
>>> os.name = _osname
"""
pass
if __name__ == '__main__':
doctest.testmod()