Mercurial > hg
view mercurial/pvec.py @ 21424:d13b4ecdb680
test: split test-largefile.t in multiple file
The `test-largefiles.t` unified test is significantly longer (about 30%) than
any other tests in the mercurial test suite. As a result, its is alway the last
test my test runner is waiting for at the end of a run.
In practice, this means that `test-largefile.t` is wasting half a minute of my
life every times I'm running the mercurial test suites. This probably mean more
a few cumulated day by now.
I've finally decided to split it up in multiple smaller tests to bring it back in
reasonable length.
This changeset extracts independent test cases in two files. One dedicated to
wire protocole testing, and another one dedicated to all other tests that could
be independently extracted.
No test case were haltered in the making of this changeset.
Various timing available below. All timing have been done on a with 90 jobs on a
64 cores machine. Similar result are shown on firefly (20 jobs on 12 core).
General timing of the whole run
--------------------------------
We see a 25% real time improvement for no significant cpu time impact.
Before split:
real 2m1.149s
user 58m4.662s
sys 11m28.563s
After split:
real 1m31.977s
user 57m45.993s
sys 11m33.634s
Last test to finish (using run-test.py --time)
----------------------------------------------
test-largefile.t is now finishing at the same time than other slow tests.
Before split:
Time Test
119.280 test-largefiles.t
93.995 test-mq.t
89.897 test-subrepo.t
86.920 test-glog.t
85.508 test-rename-merge2.t
83.594 test-revset.t
79.824 test-keyword.t
78.077 test-mq-header-date.t
After split:
Time Test
90.414 test-mq.t
88.594 test-largefiles.t
85.363 test-subrepo.t
81.059 test-glog.t
78.927 test-rename-merge2.t
78.021 test-revset.t
77.777 test-command-template.t
Timing of largefile test themself
-----------------------------------
Running only tests prefixed with "test-largefiles".
No significant change in cumulated time.
Before:
Time Test
58.673 test-largefiles.t
2.931 test-largefiles-cache.t
0.583 test-largefiles-small-disk.t
After:
Time Test
31.754 test-largefiles.t
17.460 test-largefiles-misc.t
8.888 test-largefiles-wireproto.t
2.864 test-largefiles-cache.t
0.580 test-largefiles-small-disk.t
author | Pierre-Yves David <pierre-yves.david@fb.com> |
---|---|
date | Fri, 16 May 2014 13:18:57 -0700 |
parents | 5093d2a87ff6 |
children | bcc319d936a3 |
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# pvec.py - probabilistic vector clocks for Mercurial # # Copyright 2012 Matt Mackall <mpm@selenic.com> # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. ''' A "pvec" is a changeset property based on the theory of vector clocks that can be compared to discover relatedness without consulting a graph. This can be useful for tasks like determining how a disconnected patch relates to a repository. Currently a pvec consist of 448 bits, of which 24 are 'depth' and the remainder are a bit vector. It is represented as a 70-character base85 string. Construction: - a root changeset has a depth of 0 and a bit vector based on its hash - a normal commit has a changeset where depth is increased by one and one bit vector bit is flipped based on its hash - a merge changeset pvec is constructed by copying changes from one pvec into the other to balance its depth Properties: - for linear changes, difference in depth is always <= hamming distance - otherwise, changes are probably divergent - when hamming distance is < 200, we can reliably detect when pvecs are near Issues: - hamming distance ceases to work over distances of ~ 200 - detecting divergence is less accurate when the common ancestor is very close to either revision or total distance is high - this could probably be improved by modeling the relation between delta and hdist Uses: - a patch pvec can be used to locate the nearest available common ancestor for resolving conflicts - ordering of patches can be established without a DAG - two head pvecs can be compared to determine whether push/pull/merge is needed and approximately how many changesets are involved - can be used to find a heuristic divergence measure between changesets on different branches ''' import base85, util from node import nullrev _size = 448 # 70 chars b85-encoded _bytes = _size / 8 _depthbits = 24 _depthbytes = _depthbits / 8 _vecbytes = _bytes - _depthbytes _vecbits = _vecbytes * 8 _radius = (_vecbits - 30) / 2 # high probability vectors are related def _bin(bs): '''convert a bytestring to a long''' v = 0 for b in bs: v = v * 256 + ord(b) return v def _str(v, l): bs = "" for p in xrange(l): bs = chr(v & 255) + bs v >>= 8 return bs def _split(b): '''depth and bitvec''' return _bin(b[:_depthbytes]), _bin(b[_depthbytes:]) def _join(depth, bitvec): return _str(depth, _depthbytes) + _str(bitvec, _vecbytes) def _hweight(x): c = 0 while x: if x & 1: c += 1 x >>= 1 return c _htab = [_hweight(x) for x in xrange(256)] def _hamming(a, b): '''find the hamming distance between two longs''' d = a ^ b c = 0 while d: c += _htab[d & 0xff] d >>= 8 return c def _mergevec(x, y, c): # Ideally, this function would be x ^ y ^ ancestor, but finding # ancestors is a nuisance. So instead we find the minimal number # of changes to balance the depth and hamming distance d1, v1 = x d2, v2 = y if d1 < d2: d1, d2, v1, v2 = d2, d1, v2, v1 hdist = _hamming(v1, v2) ddist = d1 - d2 v = v1 m = v1 ^ v2 # mask of different bits i = 1 if hdist > ddist: # if delta = 10 and hdist = 100, then we need to go up 55 steps # to the ancestor and down 45 changes = (hdist - ddist + 1) / 2 else: # must make at least one change changes = 1 depth = d1 + changes # copy changes from v2 if m: while changes: if m & i: v ^= i changes -= 1 i <<= 1 else: v = _flipbit(v, c) return depth, v def _flipbit(v, node): # converting bit strings to longs is slow bit = (hash(node) & 0xffffffff) % _vecbits return v ^ (1<<bit) def ctxpvec(ctx): '''construct a pvec for ctx while filling in the cache''' r = ctx._repo if not util.safehasattr(r, "_pveccache"): r._pveccache = {} pvc = r._pveccache if ctx.rev() not in pvc: cl = r.changelog for n in xrange(ctx.rev() + 1): if n not in pvc: node = cl.node(n) p1, p2 = cl.parentrevs(n) if p1 == nullrev: # start with a 'random' vector at root pvc[n] = (0, _bin((node * 3)[:_vecbytes])) elif p2 == nullrev: d, v = pvc[p1] pvc[n] = (d + 1, _flipbit(v, node)) else: pvc[n] = _mergevec(pvc[p1], pvc[p2], node) bs = _join(*pvc[ctx.rev()]) return pvec(base85.b85encode(bs)) class pvec(object): def __init__(self, hashorctx): if isinstance(hashorctx, str): self._bs = hashorctx self._depth, self._vec = _split(base85.b85decode(hashorctx)) else: self._vec = ctxpvec(hashorctx) def __str__(self): return self._bs def __eq__(self, b): return self._vec == b._vec and self._depth == b._depth def __lt__(self, b): delta = b._depth - self._depth if delta < 0: return False # always correct if _hamming(self._vec, b._vec) > delta: return False return True def __gt__(self, b): return b < self def __or__(self, b): delta = abs(b._depth - self._depth) if _hamming(self._vec, b._vec) <= delta: return False return True def __sub__(self, b): if self | b: raise ValueError("concurrent pvecs") return self._depth - b._depth def distance(self, b): d = abs(b._depth - self._depth) h = _hamming(self._vec, b._vec) return max(d, h) def near(self, b): dist = abs(b.depth - self._depth) if dist > _radius or _hamming(self._vec, b._vec) > _radius: return False