Mercurial > hg
view mercurial/dicthelpers.py @ 18878:3cfaace0441e
copies._forwardcopies: use set operations to find missing files
This is a performance win for a number of reasons:
- We don't iterate over contexts, which avoids a completely unnecessary sorted
call + the O(number of files) abstraction cost of doing that.
- We don't check membership in a context, which avoids another
O(number of files) abstraction cost.
- We iterate over the manifests in C instead of Python.
For a large repo with 170,000 files, this improves perfpathcopies from 0.34
seconds to 0.07. Anything that uses pathcopies, such as rebase or diff --git
between two revisions, benefits.
author | Siddharth Agarwal <sid0@fb.com> |
---|---|
date | Thu, 04 Apr 2013 20:22:29 -0700 |
parents | 40c679748fa9 |
children | ed46c2b98b0d |
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# dicthelpers.py - helper routines for Python dicts # # Copyright 2013 Facebook # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. def diff(d1, d2, default=None): '''Return all key-value pairs that are different between d1 and d2. This includes keys that are present in one dict but not the other, and keys whose values are different. The return value is a dict with values being pairs of values from d1 and d2 respectively, and missing values represented as default.''' res = {} if d1 is d2: # same dict, so diff is empty return res for k1, v1 in d1.iteritems(): if k1 in d2: v2 = d2[k1] if v1 != v2: res[k1] = (v1, v2) else: res[k1] = (v1, default) for k2 in d2: if k2 not in d1: res[k2] = (default, d2[k2]) return res def join(d1, d2, default=None): '''Return all key-value pairs from both d1 and d2. This is akin to an outer join in relational algebra. The return value is a dict with values being pairs of values from d1 and d2 respectively, and missing values represented as default.''' res = {} for k1, v1 in d1.iteritems(): if k1 in d2: res[k1] = (v1, d2[k1]) else: res[k1] = (v1, default) if d1 is d2: return res for k2 in d2: if k2 not in d1: res[k2] = (default, d2[k2]) return res