bundle2: implement consume() API on unbundlepart
We want bundle parts to not be seekable by default. That means
eliminating the generic seek() method.
A common pattern in bundle2.py is to seek to the end of the part
data. This is mainly used by the part iteration code to ensure
the underlying stream is advanced to the next bundle part.
In this commit, we establish a dedicated API for consuming a
bundle2 part data. We switch users of seek() to it.
The old implementation of seek(0, os.SEEK_END) would effectively
call self.read(). The new implementation calls self.read(32768)
in a loop. The old implementation would therefore assemble a
buffer to hold all remaining data being seeked over. For seeking
over large bundle parts, this would involve a large allocation and
a lot of overhead to collect intermediate data! This overhead can
be seen in the results for `hg perfbundleread`:
! bundle2 iterparts()
! wall 10.891305 comb 10.820000 user 7.990000 sys 2.830000 (best of 3)
! wall 8.070791 comb 8.060000 user 7.180000 sys 0.880000 (best of 3)
! bundle2 part seek()
! wall 12.991478 comb 10.390000 user 7.720000 sys 2.670000 (best of 3)
! wall 10.370142 comb 10.350000 user 7.430000 sys 2.920000 (best of 3)
Of course, skipping over large payload data isn't likely very common.
So I doubt the performance wins will be observed in the wild.
Differential Revision: https://phab.mercurial-scm.org/D1388
# Copyright 2007 Bryan O'Sullivan <bos@serpentine.com>
# Copyright 2007 Alexis S. L. Carvalho <alexis@cecm.usp.br>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from __future__ import absolute_import, print_function
import posixpath
import shlex
from mercurial.i18n import _
from mercurial import (
error,
)
from . import common
SKIPREV = common.SKIPREV
def rpairs(path):
'''Yield tuples with path split at '/', starting with the full path.
No leading, trailing or double '/', please.
>>> for x in rpairs(b'foo/bar/baz'): print(x)
('foo/bar/baz', '')
('foo/bar', 'baz')
('foo', 'bar/baz')
('.', 'foo/bar/baz')
'''
i = len(path)
while i != -1:
yield path[:i], path[i + 1:]
i = path.rfind('/', 0, i)
yield '.', path
def normalize(path):
''' We use posixpath.normpath to support cross-platform path format.
However, it doesn't handle None input. So we wrap it up. '''
if path is None:
return None
return posixpath.normpath(path)
class filemapper(object):
'''Map and filter filenames when importing.
A name can be mapped to itself, a new name, or None (omit from new
repository).'''
def __init__(self, ui, path=None):
self.ui = ui
self.include = {}
self.exclude = {}
self.rename = {}
self.targetprefixes = None
if path:
if self.parse(path):
raise error.Abort(_('errors in filemap'))
def parse(self, path):
errs = 0
def check(name, mapping, listname):
if not name:
self.ui.warn(_('%s:%d: path to %s is missing\n') %
(lex.infile, lex.lineno, listname))
return 1
if name in mapping:
self.ui.warn(_('%s:%d: %r already in %s list\n') %
(lex.infile, lex.lineno, name, listname))
return 1
if (name.startswith('/') or
name.endswith('/') or
'//' in name):
self.ui.warn(_('%s:%d: superfluous / in %s %r\n') %
(lex.infile, lex.lineno, listname, name))
return 1
return 0
lex = shlex.shlex(open(path), path, True)
lex.wordchars += '!@#$%^&*()-=+[]{}|;:,./<>?'
cmd = lex.get_token()
while cmd:
if cmd == 'include':
name = normalize(lex.get_token())
errs += check(name, self.exclude, 'exclude')
self.include[name] = name
elif cmd == 'exclude':
name = normalize(lex.get_token())
errs += check(name, self.include, 'include')
errs += check(name, self.rename, 'rename')
self.exclude[name] = name
elif cmd == 'rename':
src = normalize(lex.get_token())
dest = normalize(lex.get_token())
errs += check(src, self.exclude, 'exclude')
self.rename[src] = dest
elif cmd == 'source':
errs += self.parse(normalize(lex.get_token()))
else:
self.ui.warn(_('%s:%d: unknown directive %r\n') %
(lex.infile, lex.lineno, cmd))
errs += 1
cmd = lex.get_token()
return errs
def lookup(self, name, mapping):
name = normalize(name)
for pre, suf in rpairs(name):
try:
return mapping[pre], pre, suf
except KeyError:
pass
return '', name, ''
def istargetfile(self, filename):
"""Return true if the given target filename is covered as a destination
of the filemap. This is useful for identifying what parts of the target
repo belong to the source repo and what parts don't."""
if self.targetprefixes is None:
self.targetprefixes = set()
for before, after in self.rename.iteritems():
self.targetprefixes.add(after)
# If "." is a target, then all target files are considered from the
# source.
if not self.targetprefixes or '.' in self.targetprefixes:
return True
filename = normalize(filename)
for pre, suf in rpairs(filename):
# This check is imperfect since it doesn't account for the
# include/exclude list, but it should work in filemaps that don't
# apply include/exclude to the same source directories they are
# renaming.
if pre in self.targetprefixes:
return True
return False
def __call__(self, name):
if self.include:
inc = self.lookup(name, self.include)[0]
else:
inc = name
if self.exclude:
exc = self.lookup(name, self.exclude)[0]
else:
exc = ''
if (not self.include and exc) or (len(inc) <= len(exc)):
return None
newpre, pre, suf = self.lookup(name, self.rename)
if newpre:
if newpre == '.':
return suf
if suf:
if newpre.endswith('/'):
return newpre + suf
return newpre + '/' + suf
return newpre
return name
def active(self):
return bool(self.include or self.exclude or self.rename)
# This class does two additional things compared to a regular source:
#
# - Filter and rename files. This is mostly wrapped by the filemapper
# class above. We hide the original filename in the revision that is
# returned by getchanges to be able to find things later in getfile.
#
# - Return only revisions that matter for the files we're interested in.
# This involves rewriting the parents of the original revision to
# create a graph that is restricted to those revisions.
#
# This set of revisions includes not only revisions that directly
# touch files we're interested in, but also merges that merge two
# or more interesting revisions.
class filemap_source(common.converter_source):
def __init__(self, ui, baseconverter, filemap):
super(filemap_source, self).__init__(ui)
self.base = baseconverter
self.filemapper = filemapper(ui, filemap)
self.commits = {}
# if a revision rev has parent p in the original revision graph, then
# rev will have parent self.parentmap[p] in the restricted graph.
self.parentmap = {}
# self.wantedancestors[rev] is the set of all ancestors of rev that
# are in the restricted graph.
self.wantedancestors = {}
self.convertedorder = None
self._rebuilt = False
self.origparents = {}
self.children = {}
self.seenchildren = {}
# experimental config: convert.ignoreancestorcheck
self.ignoreancestorcheck = self.ui.configbool('convert',
'ignoreancestorcheck')
def before(self):
self.base.before()
def after(self):
self.base.after()
def setrevmap(self, revmap):
# rebuild our state to make things restartable
#
# To avoid calling getcommit for every revision that has already
# been converted, we rebuild only the parentmap, delaying the
# rebuild of wantedancestors until we need it (i.e. until a
# merge).
#
# We assume the order argument lists the revisions in
# topological order, so that we can infer which revisions were
# wanted by previous runs.
self._rebuilt = not revmap
seen = {SKIPREV: SKIPREV}
dummyset = set()
converted = []
for rev in revmap.order:
mapped = revmap[rev]
wanted = mapped not in seen
if wanted:
seen[mapped] = rev
self.parentmap[rev] = rev
else:
self.parentmap[rev] = seen[mapped]
self.wantedancestors[rev] = dummyset
arg = seen[mapped]
if arg == SKIPREV:
arg = None
converted.append((rev, wanted, arg))
self.convertedorder = converted
return self.base.setrevmap(revmap)
def rebuild(self):
if self._rebuilt:
return True
self._rebuilt = True
self.parentmap.clear()
self.wantedancestors.clear()
self.seenchildren.clear()
for rev, wanted, arg in self.convertedorder:
if rev not in self.origparents:
try:
self.origparents[rev] = self.getcommit(rev).parents
except error.RepoLookupError:
self.ui.debug("unknown revmap source: %s\n" % rev)
continue
if arg is not None:
self.children[arg] = self.children.get(arg, 0) + 1
for rev, wanted, arg in self.convertedorder:
try:
parents = self.origparents[rev]
except KeyError:
continue # unknown revmap source
if wanted:
self.mark_wanted(rev, parents)
else:
self.mark_not_wanted(rev, arg)
self._discard(arg, *parents)
return True
def getheads(self):
return self.base.getheads()
def getcommit(self, rev):
# We want to save a reference to the commit objects to be able
# to rewrite their parents later on.
c = self.commits[rev] = self.base.getcommit(rev)
for p in c.parents:
self.children[p] = self.children.get(p, 0) + 1
return c
def _cachedcommit(self, rev):
if rev in self.commits:
return self.commits[rev]
return self.base.getcommit(rev)
def _discard(self, *revs):
for r in revs:
if r is None:
continue
self.seenchildren[r] = self.seenchildren.get(r, 0) + 1
if self.seenchildren[r] == self.children[r]:
self.wantedancestors.pop(r, None)
self.parentmap.pop(r, None)
del self.seenchildren[r]
if self._rebuilt:
del self.children[r]
def wanted(self, rev, i):
# Return True if we're directly interested in rev.
#
# i is an index selecting one of the parents of rev (if rev
# has no parents, i is None). getchangedfiles will give us
# the list of files that are different in rev and in the parent
# indicated by i. If we're interested in any of these files,
# we're interested in rev.
try:
files = self.base.getchangedfiles(rev, i)
except NotImplementedError:
raise error.Abort(_("source repository doesn't support --filemap"))
for f in files:
if self.filemapper(f):
return True
return False
def mark_not_wanted(self, rev, p):
# Mark rev as not interesting and update data structures.
if p is None:
# A root revision. Use SKIPREV to indicate that it doesn't
# map to any revision in the restricted graph. Put SKIPREV
# in the set of wanted ancestors to simplify code elsewhere
self.parentmap[rev] = SKIPREV
self.wantedancestors[rev] = {SKIPREV}
return
# Reuse the data from our parent.
self.parentmap[rev] = self.parentmap[p]
self.wantedancestors[rev] = self.wantedancestors[p]
def mark_wanted(self, rev, parents):
# Mark rev ss wanted and update data structures.
# rev will be in the restricted graph, so children of rev in
# the original graph should still have rev as a parent in the
# restricted graph.
self.parentmap[rev] = rev
# The set of wanted ancestors of rev is the union of the sets
# of wanted ancestors of its parents. Plus rev itself.
wrev = set()
for p in parents:
if p in self.wantedancestors:
wrev.update(self.wantedancestors[p])
else:
self.ui.warn(_('warning: %s parent %s is missing\n') %
(rev, p))
wrev.add(rev)
self.wantedancestors[rev] = wrev
def getchanges(self, rev, full):
parents = self.commits[rev].parents
if len(parents) > 1 and not self.ignoreancestorcheck:
self.rebuild()
# To decide whether we're interested in rev we:
#
# - calculate what parents rev will have if it turns out we're
# interested in it. If it's going to have more than 1 parent,
# we're interested in it.
#
# - otherwise, we'll compare it with the single parent we found.
# If any of the files we're interested in is different in the
# the two revisions, we're interested in rev.
# A parent p is interesting if its mapped version (self.parentmap[p]):
# - is not SKIPREV
# - is still not in the list of parents (we don't want duplicates)
# - is not an ancestor of the mapped versions of the other parents or
# there is no parent in the same branch than the current revision.
mparents = []
knownparents = set()
branch = self.commits[rev].branch
hasbranchparent = False
for i, p1 in enumerate(parents):
mp1 = self.parentmap[p1]
if mp1 == SKIPREV or mp1 in knownparents:
continue
isancestor = (not self.ignoreancestorcheck and
any(p2 for p2 in parents
if p1 != p2 and mp1 != self.parentmap[p2]
and mp1 in self.wantedancestors[p2]))
if not isancestor and not hasbranchparent and len(parents) > 1:
# This could be expensive, avoid unnecessary calls.
if self._cachedcommit(p1).branch == branch:
hasbranchparent = True
mparents.append((p1, mp1, i, isancestor))
knownparents.add(mp1)
# Discard parents ancestors of other parents if there is a
# non-ancestor one on the same branch than current revision.
if hasbranchparent:
mparents = [p for p in mparents if not p[3]]
wp = None
if mparents:
wp = max(p[2] for p in mparents)
mparents = [p[1] for p in mparents]
elif parents:
wp = 0
self.origparents[rev] = parents
closed = False
if 'close' in self.commits[rev].extra:
# A branch closing revision is only useful if one of its
# parents belong to the branch being closed
pbranches = [self._cachedcommit(p).branch for p in mparents]
if branch in pbranches:
closed = True
if len(mparents) < 2 and not closed and not self.wanted(rev, wp):
# We don't want this revision.
# Update our state and tell the convert process to map this
# revision to the same revision its parent as mapped to.
p = None
if parents:
p = parents[wp]
self.mark_not_wanted(rev, p)
self.convertedorder.append((rev, False, p))
self._discard(*parents)
return self.parentmap[rev]
# We want this revision.
# Rewrite the parents of the commit object
self.commits[rev].parents = mparents
self.mark_wanted(rev, parents)
self.convertedorder.append((rev, True, None))
self._discard(*parents)
# Get the real changes and do the filtering/mapping. To be
# able to get the files later on in getfile, we hide the
# original filename in the rev part of the return value.
changes, copies, cleanp2 = self.base.getchanges(rev, full)
files = {}
ncleanp2 = set(cleanp2)
for f, r in changes:
newf = self.filemapper(f)
if newf and (newf != f or newf not in files):
files[newf] = (f, r)
if newf != f:
ncleanp2.discard(f)
files = sorted(files.items())
ncopies = {}
for c in copies:
newc = self.filemapper(c)
if newc:
newsource = self.filemapper(copies[c])
if newsource:
ncopies[newc] = newsource
return files, ncopies, ncleanp2
def targetfilebelongstosource(self, targetfilename):
return self.filemapper.istargetfile(targetfilename)
def getfile(self, name, rev):
realname, realrev = rev
return self.base.getfile(realname, realrev)
def gettags(self):
return self.base.gettags()
def hasnativeorder(self):
return self.base.hasnativeorder()
def lookuprev(self, rev):
return self.base.lookuprev(rev)
def getbookmarks(self):
return self.base.getbookmarks()
def converted(self, rev, sinkrev):
self.base.converted(rev, sinkrev)