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localrepo: iteratively derive local repository type...
localrepo: iteratively derive local repository type This commit implements the dynamic local repository type derivation that was explained in the recent commit bfeab472e3c0 "localrepo: create new function for instantiating a local repo object." Instead of a static localrepository class/type which must be customized after construction, we now dynamically construct a type by building up base classes/types to represent specific repository interfaces. Conceptually, the end state is similar to what was happening when various extensions would monkeypatch the __class__ of newly-constructed repo instances. However, the approach is inverted. Instead of making the instance then customizing it, we do the customization up front by influencing the behavior of the type then we instantiate that custom type. This approach gives us much more flexibility. For example, we can use completely separate classes for implementing different aspects of the repository. For example, we could have one class representing revlog-based file storage and another representing non-revlog based file storage. When then choose which implementation to use based on the presence of repo requirements. A concern with this approach is that it creates a lot more types and complexity and that complexity adds overhead. Yes, it is true that this approach will result in more types being created. Yes, this is more complicated than traditional "instantiate a static type." However, I believe the alternatives to supporting alternate storage backends are just as complicated. (Before I arrived at this solution, I had patches storing factory functions on local repo instances for e.g. constructing a file storage instance. We ended up having a handful of these. And this was logically identical to assigning custom methods. Since we were logically changing the type of the instance, I figured it would be better to just use specialized types instead of introducing levels of abstraction at run-time.) On the performance front, I don't believe that having N base classes has any significant performance overhead compared to just a single base class. Intuition says that Python will need to iterate the base classes to find an attribute. However, CPython caches method lookups: as long as the __class__ or MRO isn't changing, method attribute lookup should be constant time after first access. And non-method attributes are stored in __dict__, of which there is only 1 per object, so the number of base classes for __dict__ is irrelevant. Anyway, this commit splits up the monolithic completelocalrepository interface into sub-interfaces: 1 for file storage and 1 representing everything else. We've taught ``makelocalrepository()`` to call a series of factory functions which will produce types implementing specific interfaces. It then calls type() to create a new type from the built-up list of base types. This commit should be considered a start and not the end state. I suspect we'll hit a number of problems as we start to implement alternate storage backends: * Passing custom arguments to __init__ and setting custom attributes on __dict__. * Customizing the set of interfaces that are needed. e.g. the "readonly" intent could translate to not requesting an interface providing methods related to writing. * More ergonomic way for extensions to insert themselves so their callbacks aren't unconditionally called. * Wanting to modify vfs instances, other arguments passed to __init__. That being said, this code is usable in its current state and I'm convinced future commits will demonstrate the value in this approach. Differential Revision: https://phab.mercurial-scm.org/D4642

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convcmd.py
616 lines | 21.4 KiB | text/x-python | PythonLexer
# convcmd - convert extension commands definition
#
# Copyright 2005-2007 Matt Mackall <mpm@selenic.com>
#
# 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
import collections
import os
import shutil
from mercurial.i18n import _
from mercurial import (
encoding,
error,
hg,
pycompat,
scmutil,
util,
)
from mercurial.utils import dateutil
from . import (
bzr,
common,
cvs,
darcs,
filemap,
git,
gnuarch,
hg as hgconvert,
monotone,
p4,
subversion,
)
mapfile = common.mapfile
MissingTool = common.MissingTool
NoRepo = common.NoRepo
SKIPREV = common.SKIPREV
bzr_source = bzr.bzr_source
convert_cvs = cvs.convert_cvs
convert_git = git.convert_git
darcs_source = darcs.darcs_source
gnuarch_source = gnuarch.gnuarch_source
mercurial_sink = hgconvert.mercurial_sink
mercurial_source = hgconvert.mercurial_source
monotone_source = monotone.monotone_source
p4_source = p4.p4_source
svn_sink = subversion.svn_sink
svn_source = subversion.svn_source
orig_encoding = 'ascii'
def recode(s):
if isinstance(s, pycompat.unicode):
return s.encode(pycompat.sysstr(orig_encoding), 'replace')
else:
return s.decode('utf-8').encode(
pycompat.sysstr(orig_encoding), 'replace')
def mapbranch(branch, branchmap):
'''
>>> bmap = {b'default': b'branch1'}
>>> for i in [b'', None]:
... mapbranch(i, bmap)
'branch1'
'branch1'
>>> bmap = {b'None': b'branch2'}
>>> for i in [b'', None]:
... mapbranch(i, bmap)
'branch2'
'branch2'
>>> bmap = {b'None': b'branch3', b'default': b'branch4'}
>>> for i in [b'None', b'', None, b'default', b'branch5']:
... mapbranch(i, bmap)
'branch3'
'branch4'
'branch4'
'branch4'
'branch5'
'''
# If branch is None or empty, this commit is coming from the source
# repository's default branch and destined for the default branch in the
# destination repository. For such commits, using a literal "default"
# in branchmap below allows the user to map "default" to an alternate
# default branch in the destination repository.
branch = branchmap.get(branch or 'default', branch)
# At some point we used "None" literal to denote the default branch,
# attempt to use that for backward compatibility.
if (not branch):
branch = branchmap.get('None', branch)
return branch
source_converters = [
('cvs', convert_cvs, 'branchsort'),
('git', convert_git, 'branchsort'),
('svn', svn_source, 'branchsort'),
('hg', mercurial_source, 'sourcesort'),
('darcs', darcs_source, 'branchsort'),
('mtn', monotone_source, 'branchsort'),
('gnuarch', gnuarch_source, 'branchsort'),
('bzr', bzr_source, 'branchsort'),
('p4', p4_source, 'branchsort'),
]
sink_converters = [
('hg', mercurial_sink),
('svn', svn_sink),
]
def convertsource(ui, path, type, revs):
exceptions = []
if type and type not in [s[0] for s in source_converters]:
raise error.Abort(_('%s: invalid source repository type') % type)
for name, source, sortmode in source_converters:
try:
if not type or name == type:
return source(ui, name, path, revs), sortmode
except (NoRepo, MissingTool) as inst:
exceptions.append(inst)
if not ui.quiet:
for inst in exceptions:
ui.write("%s\n" % pycompat.bytestr(inst))
raise error.Abort(_('%s: missing or unsupported repository') % path)
def convertsink(ui, path, type):
if type and type not in [s[0] for s in sink_converters]:
raise error.Abort(_('%s: invalid destination repository type') % type)
for name, sink in sink_converters:
try:
if not type or name == type:
return sink(ui, name, path)
except NoRepo as inst:
ui.note(_("convert: %s\n") % inst)
except MissingTool as inst:
raise error.Abort('%s\n' % inst)
raise error.Abort(_('%s: unknown repository type') % path)
class progresssource(object):
def __init__(self, ui, source, filecount):
self.ui = ui
self.source = source
self.progress = ui.makeprogress(_('getting files'), unit=_('files'),
total=filecount)
def getfile(self, file, rev):
self.progress.increment(item=file)
return self.source.getfile(file, rev)
def targetfilebelongstosource(self, targetfilename):
return self.source.targetfilebelongstosource(targetfilename)
def lookuprev(self, rev):
return self.source.lookuprev(rev)
def close(self):
self.progress.complete()
class converter(object):
def __init__(self, ui, source, dest, revmapfile, opts):
self.source = source
self.dest = dest
self.ui = ui
self.opts = opts
self.commitcache = {}
self.authors = {}
self.authorfile = None
# Record converted revisions persistently: maps source revision
# ID to target revision ID (both strings). (This is how
# incremental conversions work.)
self.map = mapfile(ui, revmapfile)
# Read first the dst author map if any
authorfile = self.dest.authorfile()
if authorfile and os.path.exists(authorfile):
self.readauthormap(authorfile)
# Extend/Override with new author map if necessary
if opts.get('authormap'):
self.readauthormap(opts.get('authormap'))
self.authorfile = self.dest.authorfile()
self.splicemap = self.parsesplicemap(opts.get('splicemap'))
self.branchmap = mapfile(ui, opts.get('branchmap'))
def parsesplicemap(self, path):
""" check and validate the splicemap format and
return a child/parents dictionary.
Format checking has two parts.
1. generic format which is same across all source types
2. specific format checking which may be different for
different source type. This logic is implemented in
checkrevformat function in source files like
hg.py, subversion.py etc.
"""
if not path:
return {}
m = {}
try:
fp = open(path, 'rb')
for i, line in enumerate(util.iterfile(fp)):
line = line.splitlines()[0].rstrip()
if not line:
# Ignore blank lines
continue
# split line
lex = common.shlexer(data=line, whitespace=',')
line = list(lex)
# check number of parents
if not (2 <= len(line) <= 3):
raise error.Abort(_('syntax error in %s(%d): child parent1'
'[,parent2] expected') % (path, i + 1))
for part in line:
self.source.checkrevformat(part)
child, p1, p2 = line[0], line[1:2], line[2:]
if p1 == p2:
m[child] = p1
else:
m[child] = p1 + p2
# if file does not exist or error reading, exit
except IOError:
raise error.Abort(_('splicemap file not found or error reading %s:')
% path)
return m
def walktree(self, heads):
'''Return a mapping that identifies the uncommitted parents of every
uncommitted changeset.'''
visit = list(heads)
known = set()
parents = {}
numcommits = self.source.numcommits()
progress = self.ui.makeprogress(_('scanning'), unit=_('revisions'),
total=numcommits)
while visit:
n = visit.pop(0)
if n in known:
continue
if n in self.map:
m = self.map[n]
if m == SKIPREV or self.dest.hascommitfrommap(m):
continue
known.add(n)
progress.update(len(known))
commit = self.cachecommit(n)
parents[n] = []
for p in commit.parents:
parents[n].append(p)
visit.append(p)
progress.complete()
return parents
def mergesplicemap(self, parents, splicemap):
"""A splicemap redefines child/parent relationships. Check the
map contains valid revision identifiers and merge the new
links in the source graph.
"""
for c in sorted(splicemap):
if c not in parents:
if not self.dest.hascommitforsplicemap(self.map.get(c, c)):
# Could be in source but not converted during this run
self.ui.warn(_('splice map revision %s is not being '
'converted, ignoring\n') % c)
continue
pc = []
for p in splicemap[c]:
# We do not have to wait for nodes already in dest.
if self.dest.hascommitforsplicemap(self.map.get(p, p)):
continue
# Parent is not in dest and not being converted, not good
if p not in parents:
raise error.Abort(_('unknown splice map parent: %s') % p)
pc.append(p)
parents[c] = pc
def toposort(self, parents, sortmode):
'''Return an ordering such that every uncommitted changeset is
preceded by all its uncommitted ancestors.'''
def mapchildren(parents):
"""Return a (children, roots) tuple where 'children' maps parent
revision identifiers to children ones, and 'roots' is the list of
revisions without parents. 'parents' must be a mapping of revision
identifier to its parents ones.
"""
visit = collections.deque(sorted(parents))
seen = set()
children = {}
roots = []
while visit:
n = visit.popleft()
if n in seen:
continue
seen.add(n)
# Ensure that nodes without parents are present in the
# 'children' mapping.
children.setdefault(n, [])
hasparent = False
for p in parents[n]:
if p not in self.map:
visit.append(p)
hasparent = True
children.setdefault(p, []).append(n)
if not hasparent:
roots.append(n)
return children, roots
# Sort functions are supposed to take a list of revisions which
# can be converted immediately and pick one
def makebranchsorter():
"""If the previously converted revision has a child in the
eligible revisions list, pick it. Return the list head
otherwise. Branch sort attempts to minimize branch
switching, which is harmful for Mercurial backend
compression.
"""
prev = [None]
def picknext(nodes):
next = nodes[0]
for n in nodes:
if prev[0] in parents[n]:
next = n
break
prev[0] = next
return next
return picknext
def makesourcesorter():
"""Source specific sort."""
keyfn = lambda n: self.commitcache[n].sortkey
def picknext(nodes):
return sorted(nodes, key=keyfn)[0]
return picknext
def makeclosesorter():
"""Close order sort."""
keyfn = lambda n: ('close' not in self.commitcache[n].extra,
self.commitcache[n].sortkey)
def picknext(nodes):
return sorted(nodes, key=keyfn)[0]
return picknext
def makedatesorter():
"""Sort revisions by date."""
dates = {}
def getdate(n):
if n not in dates:
dates[n] = dateutil.parsedate(self.commitcache[n].date)
return dates[n]
def picknext(nodes):
return min([(getdate(n), n) for n in nodes])[1]
return picknext
if sortmode == 'branchsort':
picknext = makebranchsorter()
elif sortmode == 'datesort':
picknext = makedatesorter()
elif sortmode == 'sourcesort':
picknext = makesourcesorter()
elif sortmode == 'closesort':
picknext = makeclosesorter()
else:
raise error.Abort(_('unknown sort mode: %s') % sortmode)
children, actives = mapchildren(parents)
s = []
pendings = {}
while actives:
n = picknext(actives)
actives.remove(n)
s.append(n)
# Update dependents list
for c in children.get(n, []):
if c not in pendings:
pendings[c] = [p for p in parents[c] if p not in self.map]
try:
pendings[c].remove(n)
except ValueError:
raise error.Abort(_('cycle detected between %s and %s')
% (recode(c), recode(n)))
if not pendings[c]:
# Parents are converted, node is eligible
actives.insert(0, c)
pendings[c] = None
if len(s) != len(parents):
raise error.Abort(_("not all revisions were sorted"))
return s
def writeauthormap(self):
authorfile = self.authorfile
if authorfile:
self.ui.status(_('writing author map file %s\n') % authorfile)
ofile = open(authorfile, 'wb+')
for author in self.authors:
ofile.write(util.tonativeeol("%s=%s\n"
% (author, self.authors[author])))
ofile.close()
def readauthormap(self, authorfile):
afile = open(authorfile, 'rb')
for line in afile:
line = line.strip()
if not line or line.startswith('#'):
continue
try:
srcauthor, dstauthor = line.split('=', 1)
except ValueError:
msg = _('ignoring bad line in author map file %s: %s\n')
self.ui.warn(msg % (authorfile, line.rstrip()))
continue
srcauthor = srcauthor.strip()
dstauthor = dstauthor.strip()
if self.authors.get(srcauthor) in (None, dstauthor):
msg = _('mapping author %s to %s\n')
self.ui.debug(msg % (srcauthor, dstauthor))
self.authors[srcauthor] = dstauthor
continue
m = _('overriding mapping for author %s, was %s, will be %s\n')
self.ui.status(m % (srcauthor, self.authors[srcauthor], dstauthor))
afile.close()
def cachecommit(self, rev):
commit = self.source.getcommit(rev)
commit.author = self.authors.get(commit.author, commit.author)
commit.branch = mapbranch(commit.branch, self.branchmap)
self.commitcache[rev] = commit
return commit
def copy(self, rev):
commit = self.commitcache[rev]
full = self.opts.get('full')
changes = self.source.getchanges(rev, full)
if isinstance(changes, bytes):
if changes == SKIPREV:
dest = SKIPREV
else:
dest = self.map[changes]
self.map[rev] = dest
return
files, copies, cleanp2 = changes
pbranches = []
if commit.parents:
for prev in commit.parents:
if prev not in self.commitcache:
self.cachecommit(prev)
pbranches.append((self.map[prev],
self.commitcache[prev].branch))
self.dest.setbranch(commit.branch, pbranches)
try:
parents = self.splicemap[rev]
self.ui.status(_('spliced in %s as parents of %s\n') %
(_(' and ').join(parents), rev))
parents = [self.map.get(p, p) for p in parents]
except KeyError:
parents = [b[0] for b in pbranches]
parents.extend(self.map[x]
for x in commit.optparents
if x in self.map)
if len(pbranches) != 2:
cleanp2 = set()
if len(parents) < 3:
source = progresssource(self.ui, self.source, len(files))
else:
# For an octopus merge, we end up traversing the list of
# changed files N-1 times. This tweak to the number of
# files makes it so the progress bar doesn't overflow
# itself.
source = progresssource(self.ui, self.source,
len(files) * (len(parents) - 1))
newnode = self.dest.putcommit(files, copies, parents, commit,
source, self.map, full, cleanp2)
source.close()
self.source.converted(rev, newnode)
self.map[rev] = newnode
def convert(self, sortmode):
try:
self.source.before()
self.dest.before()
self.source.setrevmap(self.map)
self.ui.status(_("scanning source...\n"))
heads = self.source.getheads()
parents = self.walktree(heads)
self.mergesplicemap(parents, self.splicemap)
self.ui.status(_("sorting...\n"))
t = self.toposort(parents, sortmode)
num = len(t)
c = None
self.ui.status(_("converting...\n"))
progress = self.ui.makeprogress(_('converting'),
unit=_('revisions'), total=len(t))
for i, c in enumerate(t):
num -= 1
desc = self.commitcache[c].desc
if "\n" in desc:
desc = desc.splitlines()[0]
# convert log message to local encoding without using
# tolocal() because the encoding.encoding convert()
# uses is 'utf-8'
self.ui.status("%d %s\n" % (num, recode(desc)))
self.ui.note(_("source: %s\n") % recode(c))
progress.update(i)
self.copy(c)
progress.complete()
if not self.ui.configbool('convert', 'skiptags'):
tags = self.source.gettags()
ctags = {}
for k in tags:
v = tags[k]
if self.map.get(v, SKIPREV) != SKIPREV:
ctags[k] = self.map[v]
if c and ctags:
nrev, tagsparent = self.dest.puttags(ctags)
if nrev and tagsparent:
# write another hash correspondence to override the
# previous one so we don't end up with extra tag heads
tagsparents = [e for e in self.map.iteritems()
if e[1] == tagsparent]
if tagsparents:
self.map[tagsparents[0][0]] = nrev
bookmarks = self.source.getbookmarks()
cbookmarks = {}
for k in bookmarks:
v = bookmarks[k]
if self.map.get(v, SKIPREV) != SKIPREV:
cbookmarks[k] = self.map[v]
if c and cbookmarks:
self.dest.putbookmarks(cbookmarks)
self.writeauthormap()
finally:
self.cleanup()
def cleanup(self):
try:
self.dest.after()
finally:
self.source.after()
self.map.close()
def convert(ui, src, dest=None, revmapfile=None, **opts):
opts = pycompat.byteskwargs(opts)
global orig_encoding
orig_encoding = encoding.encoding
encoding.encoding = 'UTF-8'
# support --authors as an alias for --authormap
if not opts.get('authormap'):
opts['authormap'] = opts.get('authors')
if not dest:
dest = hg.defaultdest(src) + "-hg"
ui.status(_("assuming destination %s\n") % dest)
destc = convertsink(ui, dest, opts.get('dest_type'))
destc = scmutil.wrapconvertsink(destc)
try:
srcc, defaultsort = convertsource(ui, src, opts.get('source_type'),
opts.get('rev'))
except Exception:
for path in destc.created:
shutil.rmtree(path, True)
raise
sortmodes = ('branchsort', 'datesort', 'sourcesort', 'closesort')
sortmode = [m for m in sortmodes if opts.get(m)]
if len(sortmode) > 1:
raise error.Abort(_('more than one sort mode specified'))
if sortmode:
sortmode = sortmode[0]
else:
sortmode = defaultsort
if sortmode == 'sourcesort' and not srcc.hasnativeorder():
raise error.Abort(_('--sourcesort is not supported by this data source')
)
if sortmode == 'closesort' and not srcc.hasnativeclose():
raise error.Abort(_('--closesort is not supported by this data source'))
fmap = opts.get('filemap')
if fmap:
srcc = filemap.filemap_source(ui, srcc, fmap)
destc.setfilemapmode(True)
if not revmapfile:
revmapfile = destc.revmapfile()
c = converter(ui, srcc, destc, revmapfile, opts)
c.convert(sortmode)