treemanifest: create treemanifest class
There are a number of problems with large and flat manifests. Copying
from http://mercurial.selenic.com/wiki/ManifestShardingPlan:
* manifest too large for RAM
* manifest resolution too much CPU (long delta chains)
* committing is slow because entire manifest has to be hashed
* impossible for narrow clone to leave out part of manifest as all is
needed to calculate new hash
* diffing two revisions involves traversing entire subdirectories
even if identical
This is a first step in a series introducing a manifest revlog per
directory.
This change adds a new manifest class: treemanifest, which is a tree
where each node has a dict of files (nodeids), a dict of flags, and a
dict of subdirectories (treemanifests). So far, it behaves just like
manifestdict, but it will later help us write one manifest revlog per
directory. The new class is still unused; it will be used after the
next change.
The code is not yet optimized. Running with it (see below) makes most
or all operations slower. Once we start storing manifest revlogs for
every directory, it should be possible to make many of these
operations much faster. The fastdelta() optimization has been
intentionally not implemented for the treemanifests. We can implement
it later if necessary.
All tests pass when run with the following patch (and without, of
couse):
--- a/mercurial/manifest.py Thu Mar 19 11:08:42 2015 -0700
+++ b/mercurial/manifest.py Thu Mar 19 11:15:50 2015 -0700
@@ -596,7 +596,7 @@ class manifest(revlog.revlog):
return None, None
def add(self, m, transaction, link, p1, p2, added, removed):
- if p1 in self._mancache:
+ if False and p1 in self._mancache:
# If our first parent is in the manifest cache, we can
# compute a delta here using properties we know about the
# manifest up-front, which may save time later for the
@@ -626,3 +626,5 @@ class manifest(revlog.revlog):
self._mancache[n] = (m, arraytext)
return n
+
+manifestdict = treemanifest
# py3kcompat.py - compatibility definitions for running hg in py3k
#
# Copyright 2010 Renato Cunha <renatoc@gmail.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
import builtins
from numbers import Number
def bytesformatter(format, args):
'''Custom implementation of a formatter for bytestrings.
This function currently relies on the string formatter to do the
formatting and always returns bytes objects.
>>> bytesformatter(20, 10)
0
>>> bytesformatter('unicode %s, %s!', ('string', 'foo'))
b'unicode string, foo!'
>>> bytesformatter(b'test %s', 'me')
b'test me'
>>> bytesformatter('test %s', 'me')
b'test me'
>>> bytesformatter(b'test %s', b'me')
b'test me'
>>> bytesformatter('test %s', b'me')
b'test me'
>>> bytesformatter('test %d: %s', (1, b'result'))
b'test 1: result'
'''
# The current implementation just converts from bytes to unicode, do
# what's needed and then convert the results back to bytes.
# Another alternative is to use the Python C API implementation.
if isinstance(format, Number):
# If the fixer erroneously passes a number remainder operation to
# bytesformatter, we just return the correct operation
return format % args
if isinstance(format, bytes):
format = format.decode('utf-8', 'surrogateescape')
if isinstance(args, bytes):
args = args.decode('utf-8', 'surrogateescape')
if isinstance(args, tuple):
newargs = []
for arg in args:
if isinstance(arg, bytes):
arg = arg.decode('utf-8', 'surrogateescape')
newargs.append(arg)
args = tuple(newargs)
ret = format % args
return ret.encode('utf-8', 'surrogateescape')
builtins.bytesformatter = bytesformatter
origord = builtins.ord
def fakeord(char):
if isinstance(char, int):
return char
return origord(char)
builtins.ord = fakeord
if __name__ == '__main__':
import doctest
doctest.testmod()