Mercurial > hg
view tests/test-lrucachedict.py @ 31467:08ecec297521
bdiff: use Python memory allocator in fixws
Python has its own memory allocation APIs. For allocations
<= 512 bytes, it allocates memory from arenas. This means that
average small allocations don't call the system allocator, which
makes them faster. Also, arena allocations cut down on memory
fragmentation, which can matter for performance in long-running
processes.
Another advantage of using the Python memory allocator is that
allocations are tracked by Python. This is a bigger deal in
Python 3, as modern versions of Python have some decent built-in
tools for examining memory usage, leaks, etc.
This patch converts a trivial malloc() + free() in the bdiff code
to use the Python allocator APIs. Since the object being
operated on is a line, chances are it will use an arena. So,
this could have a net positive impact on performance (although
I didn't measure it).
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Thu, 09 Mar 2017 11:54:25 -0800 |
parents | 79add5a4e857 |
children | 067f7d2c7d60 |
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from __future__ import absolute_import, print_function from mercurial import ( util, ) def printifpresent(d, xs, name='d'): for x in xs: present = x in d print("'%s' in %s: %s" % (x, name, present)) if present: print("%s['%s']: %s" % (name, x, d[x])) def test_lrucachedict(): d = util.lrucachedict(4) d['a'] = 'va' d['b'] = 'vb' d['c'] = 'vc' d['d'] = 'vd' # all of these should be present printifpresent(d, ['a', 'b', 'c', 'd']) # 'a' should be dropped because it was least recently used d['e'] = 've' printifpresent(d, ['a', 'b', 'c', 'd', 'e']) assert d.get('a') is None assert d.get('e') == 've' # touch entries in some order (get or set). d['e'] d['c'] = 'vc2' d['d'] d['b'] = 'vb2' # 'e' should be dropped now d['f'] = 'vf' printifpresent(d, ['b', 'c', 'd', 'e', 'f']) d.clear() printifpresent(d, ['b', 'c', 'd', 'e', 'f']) # Now test dicts that aren't full. d = util.lrucachedict(4) d['a'] = 1 d['b'] = 2 d['a'] d['b'] printifpresent(d, ['a', 'b']) # test copy method d = util.lrucachedict(4) d['a'] = 'va3' d['b'] = 'vb3' d['c'] = 'vc3' d['d'] = 'vd3' dc = d.copy() # all of these should be present print("\nAll of these should be present:") printifpresent(dc, ['a', 'b', 'c', 'd'], 'dc') # 'a' should be dropped because it was least recently used print("\nAll of these except 'a' should be present:") dc['e'] = 've3' printifpresent(dc, ['a', 'b', 'c', 'd', 'e'], 'dc') # contents and order of original dict should remain unchanged print("\nThese should be in reverse alphabetical order and read 'v?3':") dc['b'] = 'vb3_new' for k in list(iter(d)): print("d['%s']: %s" % (k, d[k])) if __name__ == '__main__': test_lrucachedict()