log: slowpath: do not read the full changelog
When in the slowpath, we are examining _all_ changesets in revs.
We need to order reads so they happen increasingly for I/O performance.
Increasing windows were used to read changelog backwards in a windowed manner,
reading the changelog forward inside each window. But since no revision range
was specified, it was equivalent to reading the full changelog, even if a
single revision was passed to the commandline.
When --removed is used, we _need_ to scan all changesets, but if we're only
looking for file patterns, this is not necessary and we can stick to
the revspec that was given to us.
#!/usr/bin/env python
# Undump a dump from dumprevlog
# $ hg init
# $ undumprevlog < repo.dump
import sys
from mercurial import revlog, node, util, transaction
for fp in (sys.stdin, sys.stdout, sys.stderr):
util.set_binary(fp)
opener = util.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()