Mercurial > hg > mercurial-crew-with-dirclash
view mercurial/ancestor.py @ 5420:6d1bd20ae14d
Execution bit detection fixes for VFAT on Linux
On Linux VFAT execution mode can be modified, but changes don't
persist a filesy stem remount. The current test can be trickled by
this. We can help with the det ection of VFAT checking whether new
files get created with the execution bits on
(as usually these partitions are mounted with the exec option, for
convenience)
.
author | Rafael Villar Burke <pachi@rvburke.com> |
---|---|
date | Fri, 05 Oct 2007 01:52:53 +0200 |
parents | eb0b4a2d70a9 |
children |
line wrap: on
line source
# 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, incorporated herein by reference. import heapq def ancestor(a, b, pfunc): """ return the least common ancestor of nodes a and b or None if there is no such ancestor. pfunc must return a list of parent vertices """ if a == b: return a # find depth from root of all ancestors visit = [a, b] depth = {} while visit: vertex = visit[-1] pl = pfunc(vertex) 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: 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 = {} while h: d, n = heapq.heappop(h) if n not in seen: seen[n] = 1 yield (d, n) for p in pfunc(n): heapq.heappush(h, (depth[p], p)) def generations(vertex): sg, s = None, {} for g, v in ancestors(vertex): if g != sg: if sg: yield sg, s sg, s = g, {v:1} else: s[v] = 1 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