convert: readd --filemap

To handle merges correctly, this revision adds a filemap_source class
that wraps a converter_source and does the work necessary to calculate
the subgraph we're interested in.

The wrapped converter_source must provide a new getchangedfiles method
that, given a revision rev, and an index N, returns the list of files
that are different in rev and its Nth parent.

The implementation depends on the ability to skip some revisions and to
change the parents field of the commit objects that we returned earlier.

To make the conversion restartable, we assume the revisons in the
revmapfile are topologically sorted.

hgext/convert/__init__.py

@@ -11,6 +11,7 b' from darcs import darcs_source'
 from git import convert_git
 from hg import mercurial_source, mercurial_sink
 from subversion import convert_svn, debugsvnlog
+import filemap
 
 import os, shutil
 from mercurial import hg, ui, util, commands
@@ -378,6 +379,10 b' def convert(ui, src, dest=None, revmapfi'
             shutil.rmtree(dest, True)
         raise
 
+    fmap = opts.get('filemap')
+    if fmap:
+        srcc = filemap.filemap_source(ui, srcc, fmap)
+
     if not revmapfile:
         try:
             revmapfile = destc.revmapfile()

hgext/convert/common.py

@@ -96,6 +96,19 b' class converter_source(object):'
             except:
                 return s.decode(encoding, "replace").encode("utf-8")
 
+    def getchangedfiles(self, rev, i):
+        """Return the files changed by rev compared to parent[i].
+    
+        i is an index selecting one of the parents of rev.  The return
+        value should be the list of files that are different in rev and
+        this parent.
+
+        If rev has no parents, i is None.
+    
+        This function is only needed to support --filemap
+        """
+        raise NotImplementedError()
+
 class converter_sink(object):
     """Conversion sink (target) interface"""
 

hgext/convert/filemap.py

@@ -1,4 +1,5 b''
 # Copyright 2007 Bryan O'Sullivan <[e-mail]>
+# Copyright 2007 Alexis S. L. Carvalho <[e-mail]>
 #
 # This software may be used and distributed according to the terms of
 # the GNU General Public License, incorporated herein by reference.
@@ -6,6 +7,7 b''
 import shlex
 from mercurial.i18n import _
 from mercurial import util
+from common import SKIPREV
 
 def rpairs(name):
     e = len(name)
@@ -92,3 +94,237 b' class filemapper(object):'
 
     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
+#   and getmode.
+#
+# - 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(object):
+    def __init__(self, ui, baseconverter, filemap):
+        self.ui = 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 = {}
+
+    def setrevmap(self, revmap, order):
+        # 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 = util.set()
+        converted = []
+        for rev in 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, order)
+
+    def rebuild(self):
+        if self._rebuilt:
+            return True
+        self._rebuilt = True
+        pmap = self.parentmap.copy()
+        self.parentmap.clear()
+        self.wantedancestors.clear()
+        for rev, wanted, arg in self.convertedorder:
+            parents = self.origparents.get(rev)
+            if parents is None:
+                parents = self.base.getcommit(rev).parents
+            if wanted:
+                self.mark_wanted(rev, parents)
+            else:
+                self.mark_not_wanted(rev, arg)
+
+        assert pmap == self.parentmap
+        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.
+        self.commits[rev] = self.base.getcommit(rev)
+        return self.commits[rev]
+
+    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 util.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] = util.set((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 = util.set()
+        for p in parents:
+            wrev.update(self.wantedancestors[p])
+        wrev.add(rev)
+        self.wantedancestors[rev] = wrev
+
+    def getchanges(self, rev):
+        parents = self.commits[rev].parents
+        if len(parents) > 1:
+            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
+        mparents = []
+        wp = None
+        for i, p1 in enumerate(parents):
+            mp1 = self.parentmap[p1]
+            if mp1 == SKIPREV or mp1 in mparents:
+                continue
+            for p2 in parents:
+                if p1 == p2 or mp1 == self.parentmap[p2]:
+                    continue
+                if mp1 in self.wantedancestors[p2]:
+                    break
+            else:
+                mparents.append(mp1)
+                wp = i
+
+        if wp is None and parents:
+            wp = 0
+
+        self.origparents[rev] = parents
+
+        if len(mparents) < 2 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))
+            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))
+
+        # Get the real changes and do the filtering/mapping.
+        # To be able to get the files later on in getfile and getmode,
+        # we hide the original filename in the rev part of the return
+        # value.
+        changes, copies = self.base.getchanges(rev)
+        newnames = {}
+        files = []
+        for f, r in changes:
+            newf = self.filemapper(f)
+            if newf:
+                files.append((newf, (f, r)))
+                newnames[f] = newf
+
+        ncopies = {}
+        for c in copies:
+            newc = self.filemapper(c)
+            if newc:
+                newsource = self.filemapper(copies[c])
+                if newsource:
+                    ncopies[newc] = newsource
+
+        return files, ncopies
+
+    def getfile(self, name, rev):
+        realname, realrev = rev
+        return self.base.getfile(realname, realrev)
+
+    def getmode(self, name, rev):
+        realname, realrev = rev
+        return self.base.getmode(realname, realrev)
+
+    def gettags(self):
+        return self.base.gettags()
+
+    def before(self):
+        pass
+
+    def after(self):
+        pass