Mercurial > hg > mercurial-crew-with-dirclash
view mercurial/ancestor.py @ 5377:756a43a30e34
convert: readd --filemap
To handle merges correctly, this revision adds a filemap_source class
that wraps a converter_source and does the work necessary to calculate
the subgraph we're interested in.
The wrapped converter_source must provide a new getchangedfiles method
that, given a revision rev, and an index N, returns the list of files
that are different in rev and its Nth parent.
The implementation depends on the ability to skip some revisions and to
change the parents field of the commit objects that we returned earlier.
To make the conversion restartable, we assume the revisons in the
revmapfile are topologically sorted.
author | Alexis S. L. Carvalho <alexis@cecm.usp.br> |
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date | Thu, 04 Oct 2007 23:21:37 -0300 |
parents | eb0b4a2d70a9 |
children |
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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, 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