view mercurial/pushkey.py @ 23497:5817f71c2336

obsstore: disable garbage collection during initialization (issue4456)

Python garbage collection is triggered by container creation. So code that
creates a lot of tuples tends to trigger GC a lot. We disable the gc during
obsolescence marker parsing and associated initialization. This provides an
interesting speedup (25%).

Load marker function on my 58758 markers repo:
before: 0.468247 seconds
after:  0.344362 seconds

The benefit is a bit less visible overall. With python2.6 on my system I see:
after:  0.60
before: 0.53

The difference is probably explained by the delaying of a costly GC. (but there
is still a win). Marking involved tuples, lists and dicts as ignorable by the
garbage collector should give us more benefit. But this is another adventure.

Thanks goes to Siddharth Agarwal for the lead.

# pushkey.py - dispatching for pushing and pulling keys
#
# Copyright 2010 Matt Mackall <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

import bookmarks, phases, obsolete, encoding

def _nslist(repo):
    n = {}
    for k in _namespaces:
        n[k] = ""
    if not obsolete.isenabled(repo, obsolete.exchangeopt):
        n.pop('obsolete')
    return n

_namespaces = {"namespaces": (lambda *x: False, _nslist),
               "bookmarks": (bookmarks.pushbookmark, bookmarks.listbookmarks),
               "phases": (phases.pushphase, phases.listphases),
               "obsolete": (obsolete.pushmarker, obsolete.listmarkers),
              }

def register(namespace, pushkey, listkeys):
    _namespaces[namespace] = (pushkey, listkeys)

def _get(namespace):
    return _namespaces.get(namespace, (lambda *x: False, lambda *x: {}))

def push(repo, namespace, key, old, new):
    '''should succeed iff value was old'''
    pk = _get(namespace)[0]
    return pk(repo, key, old, new)

def list(repo, namespace):
    '''return a dict'''
    lk = _get(namespace)[1]
    return lk(repo)

encode = encoding.fromlocal

decode = encoding.tolocal

def encodekeys(keys):
    """encode the content of a pushkey namespace for exchange over the wire"""
    return '\n'.join(['%s\t%s' % (encode(k), encode(v)) for k, v in keys])

def decodekeys(data):
    """decode the content of a pushkey namespace from exchange over the wire"""
    result = {}
    for l in data.splitlines():
        k, v = l.split('\t')
        result[decode(k)] = decode(v)
    return result