Mercurial > hg
view tests/hghave @ 48671:f1ed5c304f45
encoding: fix trim() to be O(n) instead of O(n^2)
`encoding.trim()` iterated over the possible lengths smaller than the
input and created a slice for each. It then calculated the column
width of the result, which is of course O(n), so the overall algorithm
was O(n). This patch rewrites it to iterate over the unicode
characters, keeping track of the length so far. Also, the old
algorithm started from the end of the string, which made it much worse
when the input is large and the limit is small (such as the typical 72
we pass to it).
You can time it by running something like this:
```
time python3 -c 'from mercurial.utils import stringutil; print(stringutil.ellipsis(b"0123456789" * 1000, 5))'
```
That drops from 4.05 s to 83 ms with this patch (and most of that is
of course startup time).
Differential Revision: https://phab.mercurial-scm.org/D12089
author | Martin von Zweigbergk <martinvonz@google.com> |
---|---|
date | Wed, 26 Jan 2022 10:11:01 -0800 |
parents | 23f5ed6dbcb1 |
children | 6000f5b25c9b |
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#!/usr/bin/env python """Test the running system for features availability. Exit with zero if all features are there, non-zero otherwise. If a feature name is prefixed with "no-", the absence of feature is tested. """ from __future__ import absolute_import, print_function import hghave import optparse import os import sys checks = hghave.checks def list_features(): for name, feature in sorted(checks.items()): desc = feature[1] print(name + ':', desc) def test_features(): failed = 0 for name, feature in checks.items(): check, _ = feature try: check() except Exception as e: print("feature %s failed: %s" % (name, e)) failed += 1 return failed parser = optparse.OptionParser("%prog [options] [features]") parser.add_option( "--test-features", action="store_true", help="test available features" ) parser.add_option( "--list-features", action="store_true", help="list available features" ) def _loadaddon(): if 'TESTDIR' in os.environ: # loading from '.' isn't needed, because `hghave` should be # running at TESTTMP in this case path = os.environ['TESTDIR'] else: path = '.' if not os.path.exists(os.path.join(path, 'hghaveaddon.py')): return sys.path.insert(0, path) try: import hghaveaddon assert hghaveaddon # silence pyflakes except BaseException as inst: sys.stderr.write( 'failed to import hghaveaddon.py from %r: %s\n' % (path, inst) ) sys.exit(2) sys.path.pop(0) if __name__ == '__main__': options, args = parser.parse_args() _loadaddon() if options.list_features: list_features() sys.exit(0) if options.test_features: sys.exit(test_features()) hghave.require(args)