convert/gnuarch: follow continuation-of revisions

Built on top of previous patches:
 - continuation-of parsing
 - registered archives retrieval
 - use of fully qualified revisions

This allows the converter scanning for more source revisions
following the tree versions 'leaked' through the continuation-of
informations. Coupled with the registered archives retrieval, this
makes possible to decide to follow such a hint or stop scanning for
more revisions.

This also implies some changes in the retrieval of some base-0
revisions when they're continuation-of other revisions, in that
case a 'replay' will work where a simple 'get' fails because the
dir exists already. I found the code dealing with 'replay' quite
good as it has already a fallback to 'get' in the error path.

hgext/convert/gnuarch.py

@@ -1,303 +1,326
 # GNU Arch support for the convert extension
 
 from common import NoRepo, commandline, commit, converter_source
 from mercurial.i18n import _
 from mercurial import util
 import os, shutil, tempfile, stat, locale
 from email.Parser import Parser
 
 class gnuarch_source(converter_source, commandline):
 
     class gnuarch_rev:
         def __init__(self, rev):
             self.rev = rev
             self.summary = ''
             self.date = None
             self.author = ''
             self.continuationof = None
             self.add_files = []
             self.mod_files = []
             self.del_files = []
             self.ren_files = {}
             self.ren_dirs = {}
 
     def __init__(self, ui, path, rev=None):
         super(gnuarch_source, self).__init__(ui, path, rev=rev)
 
         if not os.path.exists(os.path.join(path, '{arch}')):
             raise NoRepo(_("%s does not look like a GNU Arch repo") % path)
 
         # Could use checktool, but we want to check for baz or tla.
         self.execmd = None
         if util.find_exe('baz'):
             self.execmd = 'baz'
         else:
             if util.find_exe('tla'):
                 self.execmd = 'tla'
             else:
                 raise util.Abort(_('cannot find a GNU Arch tool'))
 
         commandline.__init__(self, ui, self.execmd)
 
         self.path = os.path.realpath(path)
         self.tmppath = None
 
         self.treeversion = None
         self.lastrev = None
         self.changes = {}
         self.parents = {}
         self.tags = {}
         self.modecache = {}
         self.catlogparser = Parser()
         self.locale = locale.getpreferredencoding()
         self.archives = []
 
     def before(self):
         # Get registered archives
         self.archives = [i.rstrip('\n')
                          for i in self.runlines0('archives', '-n')]
 
         if self.execmd == 'tla':
             output = self.run0('tree-version', self.path)
         else:
             output = self.run0('tree-version', '-d', self.path)
         self.treeversion = output.strip()
 
-        self.ui.status(_('analyzing tree version %s...\n') % self.treeversion)
-
         # Get name of temporary directory
         version = self.treeversion.split('/')
         self.tmppath = os.path.join(tempfile.gettempdir(),
                                     'hg-%s' % version[1])
 
         # Generate parents dictionary
-        child = []
-        output, status = self.runlines('revisions', '-f', self.treeversion)
-        self.checkexit(status, 'archive registered?')
-        for l in output:
-            rev = l.strip()
-            self.changes[rev] = self.gnuarch_rev(rev)
+        self.parents[None] = []
+        treeversion = self.treeversion
+        child = None
+        while treeversion:
+            self.ui.status(_('analyzing tree version %s...\n') % treeversion)
+
+            archive = treeversion.split('/')[0]
+            if archive not in self.archives:
+                self.ui.status(_('tree analysis stopped because it points to an unregistered archive %s...\n') % archive)
+                break
+
+            # Get the complete list of revisions for that tree version
+            output, status = self.runlines('revisions', '-r', '-f', treeversion)
+            self.checkexit(status, 'failed retrieveing revisions for %s' % treeversion)
+
+            # No new iteration unless a revision has a continuation-of header
+            treeversion = None
+
+            for l in output:
+                rev = l.strip()
+                self.changes[rev] = self.gnuarch_rev(rev)
+                self.parents[rev] = []
 
-            # Read author, date and summary
-            catlog, status = self.run('cat-log', '-d', self.path, rev)
-            if status:
-                catlog = self.run0('cat-archive-log', rev)
-            self._parsecatlog(catlog, rev)
+                # Read author, date and summary
+                catlog, status = self.run('cat-log', '-d', self.path, rev)
+                if status:
+                    catlog  = self.run0('cat-archive-log', rev)
+                self._parsecatlog(catlog, rev)
+
+                # Populate the parents map
+                self.parents[child].append(rev)
 
-            self.parents[rev] = child
-            child = [rev]
-            if rev == self.rev:
-                break
-        self.parents[None] = child
+                # Keep track of the current revision as the child of the next
+                # revision scanned
+                child = rev
+
+                # Check if we have to follow the usual incremental history
+                # or if we have to 'jump' to a different treeversion given
+                # by the continuation-of header.
+                if self.changes[rev].continuationof:
+                    treeversion = '--'.join(self.changes[rev].continuationof.split('--')[:-1])
+                    break
+
+                # If we reached a base-0 revision w/o any continuation-of
+                # header, it means the tree history ends here.
+                if rev[-6:] == 'base-0':
+                    break
 
     def after(self):
         self.ui.debug(_('cleaning up %s\n') % self.tmppath)
         shutil.rmtree(self.tmppath, ignore_errors=True)
 
     def getheads(self):
         return self.parents[None]
 
     def getfile(self, name, rev):
         if rev != self.lastrev:
             raise util.Abort(_('internal calling inconsistency'))
 
         # Raise IOError if necessary (i.e. deleted files).
         if not os.path.exists(os.path.join(self.tmppath, name)):
             raise IOError
 
         data, mode = self._getfile(name, rev)
         self.modecache[(name, rev)] = mode
 
         return data
 
     def getmode(self, name, rev):
         return self.modecache[(name, rev)]
 
     def getchanges(self, rev):
         self.modecache = {}
         self._update(rev)
         changes = []
         copies = {}
 
         for f in self.changes[rev].add_files:
             changes.append((f, rev))
 
         for f in self.changes[rev].mod_files:
             changes.append((f, rev))
 
         for f in self.changes[rev].del_files:
             changes.append((f, rev))
 
         for src in self.changes[rev].ren_files:
             to = self.changes[rev].ren_files[src]
             changes.append((src, rev))
             changes.append((to, rev))
             copies[src] = to
 
         for src in self.changes[rev].ren_dirs:
             to = self.changes[rev].ren_dirs[src]
             chgs, cps = self._rendirchanges(src, to);
             changes += [(f, rev) for f in chgs]
             for c in cps:
                 copies[c] = cps[c]
 
         self.lastrev = rev
         return util.sort(changes), copies
 
     def getcommit(self, rev):
         changes = self.changes[rev]
         return commit(author = changes.author, date = changes.date,
                       desc = changes.summary, parents = self.parents[rev], rev=rev)
 
     def gettags(self):
         return self.tags
 
     def _execute(self, cmd, *args, **kwargs):
         cmdline = [self.execmd, cmd]
         cmdline += args
         cmdline = [util.shellquote(arg) for arg in cmdline]
         cmdline += ['>', util.nulldev, '2>', util.nulldev]
         cmdline = util.quotecommand(' '.join(cmdline))
         self.ui.debug(cmdline, '\n')
         return os.system(cmdline)
 
     def _update(self, rev):
-        if rev[-6:] == 'base-0':
-            # Initialise 'base-0' revision
+        self.ui.debug(_('applying revision %s...\n') % rev)
+        changeset, status = self.runlines('replay', '-d', self.tmppath,
+                                              rev)
+        if status:
+            # Something went wrong while merging (baz or tla
+            # issue?), get latest revision and try from there
+            shutil.rmtree(self.tmppath, ignore_errors=True)
             self._obtainrevision(rev)
         else:
-            self.ui.debug(_('applying revision %s...\n') % rev)
-            changeset, status = self.runlines('replay', '-d', self.tmppath,
-                                              rev)
-            if status:
-                # Something went wrong while merging (baz or tla
-                # issue?), get latest revision and try from there
-                shutil.rmtree(self.tmppath, ignore_errors=True)
-                self._obtainrevision(rev)
-            else:
-                old_rev = self.parents[rev][0]
-                self.ui.debug(_('computing changeset between %s and %s...\n')
-                              % (old_rev, rev))
-                self._parsechangeset(changeset, rev)
+            old_rev = self.parents[rev][0]
+            self.ui.debug(_('computing changeset between %s and %s...\n')
+                          % (old_rev, rev))
+            self._parsechangeset(changeset, rev)
 
     def _getfile(self, name, rev):
         mode = os.lstat(os.path.join(self.tmppath, name)).st_mode
         if stat.S_ISLNK(mode):
             data = os.readlink(os.path.join(self.tmppath, name))
             mode = mode and 'l' or ''
         else:
             data = open(os.path.join(self.tmppath, name), 'rb').read()
             mode = (mode & 0111) and 'x' or ''
         return data, mode
 
     def _exclude(self, name):
         exclude = [ '{arch}', '.arch-ids', '.arch-inventory' ]
         for exc in exclude:
             if name.find(exc) != -1:
                 return True
         return False
 
     def _readcontents(self, path):
         files = []
         contents = os.listdir(path)
         while len(contents) > 0:
             c = contents.pop()
             p = os.path.join(path, c)
             # os.walk could be used, but here we avoid internal GNU
             # Arch files and directories, thus saving a lot time.
             if not self._exclude(p):
                 if os.path.isdir(p):
                     contents += [os.path.join(c, f) for f in os.listdir(p)]
                 else:
                     files.append(c)
         return files
 
     def _rendirchanges(self, src, dest):
         changes = []
         copies = {}
         files = self._readcontents(os.path.join(self.tmppath, dest))
         for f in files:
             s = os.path.join(src, f)
             d = os.path.join(dest, f)
             changes.append(s)
             changes.append(d)
             copies[s] = d
         return changes, copies
 
     def _obtainrevision(self, rev):
         self.ui.debug(_('obtaining revision %s...\n') % rev)
         output = self._execute('get', rev, self.tmppath)
         self.checkexit(output)
         self.ui.debug(_('analysing revision %s...\n') % rev)
         files = self._readcontents(self.tmppath)
         self.changes[rev].add_files += files
 
     def _stripbasepath(self, path):
         if path.startswith('./'):
             return path[2:]
         return path
 
     def _parsecatlog(self, data, rev):
         try:
             catlog = self.catlogparser.parsestr(data)
             self.changes[rev].date = util.datestr(
                 util.strdate(catlog['Standard-date'],
                              '%Y-%m-%d %H:%M:%S'))
             self.changes[rev].author = catlog['Creator']
             self.changes[rev].summary = catlog['Summary']
             if catlog.has_key('Continuation-of'):
                 self.changes[rev].continuationof = catlog['Continuation-of']
 	except Exception, err:
             raise util.Abort(_('could not parse cat-log of %s') % rev)
 
     def _parsechangeset(self, data, rev):
         for l in data:
             l = l.strip()
             # Added file (ignore added directory)
             if l.startswith('A') and not l.startswith('A/'):
                 file = self._stripbasepath(l[1:].strip())
                 if not self._exclude(file):
                     self.changes[rev].add_files.append(file)
             # Deleted file (ignore deleted directory)
             elif l.startswith('D') and not l.startswith('D/'):
                 file = self._stripbasepath(l[1:].strip())
                 if not self._exclude(file):
                     self.changes[rev].del_files.append(file)
             # Modified binary file
             elif l.startswith('Mb'):
                 file = self._stripbasepath(l[2:].strip())
                 if not self._exclude(file):
                     self.changes[rev].mod_files.append(file)
             # Modified link
             elif l.startswith('M->'):
                 file = self._stripbasepath(l[3:].strip())
                 if not self._exclude(file):
                     self.changes[rev].mod_files.append(file)
             # Modified file
             elif l.startswith('M'):
                 file = self._stripbasepath(l[1:].strip())
                 if not self._exclude(file):
                     self.changes[rev].mod_files.append(file)
             # Renamed file (or link)
             elif l.startswith('=>'):
                 files = l[2:].strip().split(' ')
                 if len(files) == 1:
                     files = l[2:].strip().split('\t')
                 src = self._stripbasepath(files[0])
                 dst = self._stripbasepath(files[1])
                 if not self._exclude(src) and not self._exclude(dst):
                     self.changes[rev].ren_files[src] = dst
             # Conversion from file to link or from link to file (modified)
             elif l.startswith('ch'):
                 file = self._stripbasepath(l[2:].strip())
                 if not self._exclude(file):
                     self.changes[rev].mod_files.append(file)
             # Renamed directory
             elif l.startswith('/>'):
                 dirs = l[2:].strip().split(' ')
                 if len(dirs) == 1:
                     dirs = l[2:].strip().split('\t')
                 src = self._stripbasepath(dirs[0])
                 dst = self._stripbasepath(dirs[1])
                 if not self._exclude(src) and not self._exclude(dst):
                     self.changes[rev].ren_dirs[src] = dst