Mercurial > hg
view mercurial/ancestor.py @ 14077:c285bdb0572a
util.url: copy urllib.unquote() into util to improve startup times
The ui class uses util.hasscheme() in a couple of places, causing hg
to import urllib even when it doesn't need to. This copies
urllib.unquote() to avoid that import.
perfstartup time before the URL refactoring (8796fb6af67e):
! wall 0.050692 comb 0.000000 user 0.000000 sys 0.000000 (best of 100)
before this change:
! wall 0.064742 comb 0.000000 user 0.000000 sys 0.000000 (best of 100)
after this change:
! wall 0.052126 comb 0.000000 user 0.000000 sys 0.000000 (best of 100
author | Brodie Rao <brodie@bitheap.org> |
---|---|
date | Sat, 30 Apr 2011 09:43:23 -0700 |
parents | 22565ddb28e7 |
children | 1ffeeb91c55d |
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# ancestor.py - generic DAG ancestor algorithm for mercurial # # Copyright 2006 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. import heapq def ancestor(a, b, pfunc): """ Returns the common ancestor of a and b that is furthest from a root (as measured by longest path) or None if no ancestor is found. If there are multiple common ancestors at the same distance, the first one found is returned. pfunc must return a list of parent vertices for a given vertex """ if a == b: return a a, b = sorted([a, b]) # find depth from root of all ancestors # depth is stored as a negative for heapq parentcache = {} visit = [a, b] depth = {} while visit: vertex = visit[-1] pl = pfunc(vertex) parentcache[vertex] = pl if not pl: depth[vertex] = 0 visit.pop() else: for p in pl: if p == a or p == b: # did we find a or b as a parent? return p # we're done if p not in depth: visit.append(p) if visit[-1] == vertex: # -(maximum distance of parents + 1) depth[vertex] = min([depth[p] for p in pl]) - 1 visit.pop() # traverse ancestors in order of decreasing distance from root def ancestors(vertex): h = [(depth[vertex], vertex)] seen = set() while h: d, n = heapq.heappop(h) if n not in seen: seen.add(n) yield (d, n) for p in parentcache[n]: heapq.heappush(h, (depth[p], p)) def generations(vertex): sg, s = None, set() for g, v in ancestors(vertex): if g != sg: if sg: yield sg, s sg, s = g, set((v,)) else: s.add(v) yield sg, s x = generations(a) y = generations(b) gx = x.next() gy = y.next() # increment each ancestor list until it is closer to root than # the other, or they match try: while 1: if gx[0] == gy[0]: for v in gx[1]: if v in gy[1]: return v gy = y.next() gx = x.next() elif gx[0] > gy[0]: gy = y.next() else: gx = x.next() except StopIteration: return None