hgext/convert/convcmd.py

checkheads: extract branchmap preprocessing

The checkheads function is far too complicated. This extract help to explicite
what part of the preprocessing are reused by the actual check.

This the first step toward a wider refactoring.

# convcmd - convert extension commands definition
#
# Copyright 2005-2007 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.

from common import NoRepo, MissingTool, SKIPREV, mapfile
from cvs import convert_cvs
from darcs import darcs_source
from git import convert_git
from hg import mercurial_source, mercurial_sink
from subversion import svn_source, svn_sink
from monotone import monotone_source
from gnuarch import gnuarch_source
from bzr import bzr_source
from p4 import p4_source
import filemap, common

import os, shutil
from mercurial import hg, util, encoding
from mercurial.i18n import _

orig_encoding = 'ascii'

def recode(s):
    if isinstance(s, unicode):
        return s.encode(orig_encoding, 'replace')
    else:
        return s.decode('utf-8').encode(orig_encoding, 'replace')

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, rev):
    exceptions = []
    if type and type not in [s[0] for s in source_converters]:
        raise util.Abort(_('%s: invalid source repository type') % type)
    for name, source, sortmode in source_converters:
        try:
            if not type or name == type:
                return source(ui, path, rev), sortmode
        except (NoRepo, MissingTool), inst:
            exceptions.append(inst)
    if not ui.quiet:
        for inst in exceptions:
            ui.write("%s\n" % inst)
    raise util.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 util.Abort(_('%s: invalid destination repository type') % type)
    for name, sink in sink_converters:
        try:
            if not type or name == type:
                return sink(ui, path)
        except NoRepo, inst:
            ui.note(_("convert: %s\n") % inst)
        except MissingTool, inst:
            raise util.Abort('%s\n' % inst)
    raise util.Abort(_('%s: unknown repository type') % path)

class progresssource(object):
    def __init__(self, ui, source, filecount):
        self.ui = ui
        self.source = source
        self.filecount = filecount
        self.retrieved = 0

    def getfile(self, file, rev):
        self.retrieved += 1
        self.ui.progress(_('getting files'), self.retrieved,
                         item=file, total=self.filecount)
        return self.source.getfile(file, rev)

    def lookuprev(self, rev):
        return self.source.lookuprev(rev)

    def close(self):
        self.ui.progress(_('getting files'), None)

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 = common.parsesplicemap(opts.get('splicemap'))
        self.branchmap = mapfile(ui, opts.get('branchmap'))

    def walktree(self, heads):
        '''Return a mapping that identifies the uncommitted parents of every
        uncommitted changeset.'''
        visit = heads
        known = set()
        parents = {}
        while visit:
            n = visit.pop(0)
            if n in known or n in self.map:
                continue
            known.add(n)
            self.ui.progress(_('scanning'), len(known), unit=_('revisions'))
            commit = self.cachecommit(n)
            parents[n] = []
            for p in commit.parents:
                parents[n].append(p)
                visit.append(p)
        self.ui.progress(_('scanning'), None)

        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 splicemap:
            if c not in parents:
                if not self.dest.hascommit(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.hascommit(self.map.get(p, p)):
                    continue
                # Parent is not in dest and not being converted, not good
                if p not in parents:
                    raise util.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
        preceeded 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 = parents.keys()
            seen = set()
            children = {}
            roots = []

            while visit:
                n = visit.pop(0)
                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 makedatesorter():
            """Sort revisions by date."""
            dates = {}
            def getdate(n):
                if n not in dates:
                    dates[n] = util.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()
        else:
            raise util.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 util.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 util.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, 'w+')
            for author in self.authors:
                ofile.write("%s=%s\n" % (author, self.authors[author]))
            ofile.close()

    def readauthormap(self, authorfile):
        afile = open(authorfile, 'r')
        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 = self.branchmap.get(commit.branch, commit.branch)
        self.commitcache[rev] = commit
        return commit

    def copy(self, rev):
        commit = self.commitcache[rev]

        changes = self.source.getchanges(rev)
        if isinstance(changes, basestring):
            if changes == SKIPREV:
                dest = SKIPREV
            else:
                dest = self.map[changes]
            self.map[rev] = dest
            return
        files, copies = 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') %
                           (parents, rev))
            parents = [self.map.get(p, p) for p in parents]
        except KeyError:
            parents = [b[0] for b in pbranches]
        source = progresssource(self.ui, self.source, len(files))
        newnode = self.dest.putcommit(files, copies, parents, commit,
                                      source, self.map)
        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"))
            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))
                self.ui.progress(_('converting'), i, unit=_('revisions'),
                                 total=len(t))
                self.copy(c)
            self.ui.progress(_('converting'), None)

            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):
    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'))

    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')
    sortmode = [m for m in sortmodes if opts.get(m)]
    if len(sortmode) > 1:
        raise util.Abort(_('more than one sort mode specified'))
    sortmode = sortmode and sortmode[0] or defaultsort
    if sortmode == 'sourcesort' and not srcc.hasnativeorder():
        raise util.Abort(_('--sourcesort 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:
        try:
            revmapfile = destc.revmapfile()
        except Exception:
            revmapfile = os.path.join(destc, "map")

    c = converter(ui, srcc, destc, revmapfile, opts)
    c.convert(sortmode)