graphmod: restore generator nature of dagwalker
9966c95b8c4f introduced the ability to walk the DAG
given arbitrary revisions, but changed the behaviour of
it to return a list of all nodes (and create a changectx
for each one) rather than doing it lazily.
This has a pretty significant impact on performance for large
repositories (tested on CPython repo, with output disabled):
$ time hg glog
real 0m2.642s
user 0m2.560s
sys 0m0.080s
Before 9966c95b8c4f:
$ time hg glog
real 0m0.143s
user 0m0.112s
sys 0m0.032s
And after this fix:
$ time hg glog
real 0m0.213s
user 0m0.184s
sys 0m0.028s
#!/usr/bin/env python
# Undump a dump from dumprevlog
# $ hg init
# $ undumprevlog < repo.dump
import sys
from mercurial import revlog, node, scmutil, util, transaction
for fp in (sys.stdin, sys.stdout, sys.stderr):
util.set_binary(fp)
opener = scmutil.opener('.', False)
tr = transaction.transaction(sys.stderr.write, opener, "undump.journal")
while 1:
l = sys.stdin.readline()
if not l:
break
if l.startswith("file:"):
f = l[6:-1]
r = revlog.revlog(opener, f)
print f
elif l.startswith("node:"):
n = node.bin(l[6:-1])
elif l.startswith("linkrev:"):
lr = int(l[9:-1])
elif l.startswith("parents:"):
p = l[9:-1].split()
p1 = node.bin(p[0])
p2 = node.bin(p[1])
elif l.startswith("length:"):
length = int(l[8:-1])
sys.stdin.readline() # start marker
d = sys.stdin.read(length)
sys.stdin.readline() # end marker
r.addrevision(d, tr, lr, p1, p2)
tr.close()