Mercurial > hg
annotate mercurial/ancestor.py @ 11578:bb7af1de5e38
discovery: remove duplication for new remote head discovery
author | Benoit Boissinot <benoit.boissinot@ens-lyon.org> |
---|---|
date | Thu, 15 Jul 2010 21:44:51 +0200 |
parents | 67bb9d78f05e |
children | 4f8067c94729 |
rev | line source |
---|---|
3135
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
1 # ancestor.py - generic DAG ancestor algorithm for mercurial |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
2 # |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
3 # Copyright 2006 Matt Mackall <mpm@selenic.com> |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
4 # |
8225
46293a0c7e9f
updated license to be explicit about GPL version 2
Martin Geisler <mg@lazybytes.net>
parents:
7882
diff
changeset
|
5 # This software may be used and distributed according to the terms of the |
10263 | 6 # GNU General Public License version 2 or any later version. |
3135
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
7 |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
8 import heapq |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
9 |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
10 def ancestor(a, b, pfunc): |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
11 """ |
9915
806e6b6cb8d8
ancestor: improve docstring
Sune Foldager <cryo@cyanite.org>
parents:
8465
diff
changeset
|
12 return a minimal-distance ancestor of nodes a and b, or None if there is no |
806e6b6cb8d8
ancestor: improve docstring
Sune Foldager <cryo@cyanite.org>
parents:
8465
diff
changeset
|
13 such ancestor. Note that there can be several ancestors with the same |
806e6b6cb8d8
ancestor: improve docstring
Sune Foldager <cryo@cyanite.org>
parents:
8465
diff
changeset
|
14 (minimal) distance, and the one returned is arbitrary. |
3135
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
15 |
9915
806e6b6cb8d8
ancestor: improve docstring
Sune Foldager <cryo@cyanite.org>
parents:
8465
diff
changeset
|
16 pfunc must return a list of parent vertices for a given vertex |
3135
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
17 """ |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
18 |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
19 if a == b: |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
20 return a |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
21 |
11418
67bb9d78f05e
merge: sort arguments to stabilize the ancestor search
Matt Mackall <mpm@selenic.com>
parents:
10264
diff
changeset
|
22 a, b = sorted([a, b]) |
67bb9d78f05e
merge: sort arguments to stabilize the ancestor search
Matt Mackall <mpm@selenic.com>
parents:
10264
diff
changeset
|
23 |
3135
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
24 # find depth from root of all ancestors |
7882
8d78fc991b71
ancestor: caching the parent list to improve performance
Nicolas Dumazet <nicdumz.commits@gmail.com>
parents:
6429
diff
changeset
|
25 parentcache = {} |
3135
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
26 visit = [a, b] |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
27 depth = {} |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
28 while visit: |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
29 vertex = visit[-1] |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
30 pl = pfunc(vertex) |
7882
8d78fc991b71
ancestor: caching the parent list to improve performance
Nicolas Dumazet <nicdumz.commits@gmail.com>
parents:
6429
diff
changeset
|
31 parentcache[vertex] = pl |
3135
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
32 if not pl: |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
33 depth[vertex] = 0 |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
34 visit.pop() |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
35 else: |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
36 for p in pl: |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
37 if p == a or p == b: # did we find a or b as a parent? |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
38 return p # we're done |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
39 if p not in depth: |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
40 visit.append(p) |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
41 if visit[-1] == vertex: |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
42 depth[vertex] = min([depth[p] for p in pl]) - 1 |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
43 visit.pop() |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
44 |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
45 # traverse ancestors in order of decreasing distance from root |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
46 def ancestors(vertex): |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
47 h = [(depth[vertex], vertex)] |
8465
23429ebd3f9d
ancestor: use set instead of dict
Benoit Boissinot <benoit.boissinot@ens-lyon.org>
parents:
8225
diff
changeset
|
48 seen = set() |
3135
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
49 while h: |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
50 d, n = heapq.heappop(h) |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
51 if n not in seen: |
8465
23429ebd3f9d
ancestor: use set instead of dict
Benoit Boissinot <benoit.boissinot@ens-lyon.org>
parents:
8225
diff
changeset
|
52 seen.add(n) |
3135
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
53 yield (d, n) |
7882
8d78fc991b71
ancestor: caching the parent list to improve performance
Nicolas Dumazet <nicdumz.commits@gmail.com>
parents:
6429
diff
changeset
|
54 for p in parentcache[n]: |
3135
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
55 heapq.heappush(h, (depth[p], p)) |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
56 |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
57 def generations(vertex): |
8465
23429ebd3f9d
ancestor: use set instead of dict
Benoit Boissinot <benoit.boissinot@ens-lyon.org>
parents:
8225
diff
changeset
|
58 sg, s = None, set() |
3673
eb0b4a2d70a9
white space and line break cleanups
Thomas Arendsen Hein <thomas@intevation.de>
parents:
3135
diff
changeset
|
59 for g, v in ancestors(vertex): |
3135
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
60 if g != sg: |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
61 if sg: |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
62 yield sg, s |
8465
23429ebd3f9d
ancestor: use set instead of dict
Benoit Boissinot <benoit.boissinot@ens-lyon.org>
parents:
8225
diff
changeset
|
63 sg, s = g, set((v,)) |
3135
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
64 else: |
8465
23429ebd3f9d
ancestor: use set instead of dict
Benoit Boissinot <benoit.boissinot@ens-lyon.org>
parents:
8225
diff
changeset
|
65 s.add(v) |
3135
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
66 yield sg, s |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
67 |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
68 x = generations(a) |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
69 y = generations(b) |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
70 gx = x.next() |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
71 gy = y.next() |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
72 |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
73 # increment each ancestor list until it is closer to root than |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
74 # the other, or they match |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
75 try: |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
76 while 1: |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
77 if gx[0] == gy[0]: |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
78 for v in gx[1]: |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
79 if v in gy[1]: |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
80 return v |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
81 gy = y.next() |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
82 gx = x.next() |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
83 elif gx[0] > gy[0]: |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
84 gy = y.next() |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
85 else: |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
86 gx = x.next() |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
87 except StopIteration: |
b1db258e875c
Abstract ancestor algorithm into generic function
Matt Mackall <mpm@selenic.com>
parents:
diff
changeset
|
88 return None |