mercurial/changelog.py

cleanup of revlog.group when repository is local

revlog.group cached every chunk from the revlog, the behaviour was
needed to minimize the roundtrip with old-http.

The patch export the information that the repository is local or not
from the repository object down to the revlog.
Then it uses the workaround for old-http only if the repository is non-local.

The memory used server side when pulling goes down to less than 30Mo maximum
whereas without the patch more than 160Mo was used when cloning the linux kernel
repository.
The time used by cloning is roughly the same (although some caching could be
implemented if needed):
before
110.25user 20.90system 2:52.00elapsed 76%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (0major+708707minor)pagefaults 0swaps
after
112.85user 22.98system 2:50.66elapsed 79%CPU (0avgtext+0avgdata 0maxresident)k
0inputs+0outputs (0major+862862minor)pagefaults 0swaps

# changelog.py - changelog class for mercurial
#
# Copyright 2005 Matt Mackall <[e-mail]>
#
# This software may be used and distributed according to the terms
# of the GNU General Public License, incorporated herein by reference.

from revlog import *
from i18n import gettext as _
from demandload import demandload
demandload(globals(), "os time util")

class changelog(revlog):
    def __init__(self, opener, local=True):
        revlog.__init__(self, opener, "00changelog.i", "00changelog.d",
                        local=local)

    def extract(self, text):
        if not text:
            return (nullid, "", (0, 0), [], "")
        last = text.index("\n\n")
        desc = text[last + 2:]
        l = text[:last].splitlines()
        manifest = bin(l[0])
        user = l[1]
        date = l[2].split(' ')
        time = float(date.pop(0))
        try:
            # various tools did silly things with the time zone field.
            timezone = int(date[0])
        except:
            timezone = 0
        files = l[3:]
        return (manifest, user, (time, timezone), files, desc)

    def read(self, node):
        return self.extract(self.revision(node))

    def add(self, manifest, list, desc, transaction, p1=None, p2=None,
                  user=None, date=None):
        if date:
            # validate explicit (probably user-specified) date and
            # time zone offset. values must fit in signed 32 bits for
            # current 32-bit linux runtimes.
            try:
                when, offset = map(int, date.split(' '))
            except ValueError:
                raise ValueError(_('invalid date: %r') % date)
            if abs(when) > 0x7fffffff:
                raise ValueError(_('date exceeds 32 bits: %d') % when)
            if abs(offset) >= 43200:
                raise ValueError(_('impossible time zone offset: %d') % offset)
        else:
            date = "%d %d" % util.makedate()
        list.sort()
        l = [hex(manifest), user, date] + list + ["", desc]
        text = "\n".join(l)
        return self.addrevision(text, transaction, self.count(), p1, p2)