Add hg2git.py with library routines

Unfortunately, I can't do 'import hg-fast-export' from python itself, so
we need to move some common methods into 'hg2git.py' which is to be used
as a library for common hg->git routines.

Signed-off-by: Rocco Rutte <pdmef@gmx.net>

hg2git.py

@@ -0,0 +1,78 @@
+#!/usr/bin/env python
+
+# Copyright (c) 2007 Rocco Rutte <pdmef@gmx.net>
+# License: MIT <http://www.opensource.org/licenses/mit-license.php>
+
+from mercurial import repo,hg,cmdutil,util,ui,revlog,node
+import re
+import os
+
+# git branch for hg's default 'HEAD' branch
+cfg_master='master'
+# silly regex to see if user field has email address
+user_re=re.compile('([^<]+) (<[^>]+>)$')
+# silly regex to clean out user names
+user_clean_re=re.compile('^["]([^"]+)["]$')
+
+def setup_repo(url):
+  myui=ui.ui(interactive=False)
+  return myui,hg.repository(myui,url)
+
+def fixup_user(user,authors):
+  if authors!=None:
+    # if we have an authors table, try to get mapping
+    # by defaulting to the current value of 'user'
+    user=authors.get(user,user)
+  name,mail,m='','',user_re.match(user)
+  if m==None:
+    # if we don't have 'Name <mail>' syntax, use 'user
+    # <devnull@localhost>' if use contains no at and
+    # 'user <user>' otherwise
+    name=user
+    if '@' not in user:
+      mail='<devnull@localhost>'
+    else:
+      mail='<%s>' % user
+  else:
+    # if we have 'Name <mail>' syntax, everything is fine :)
+    name,mail=m.group(1),m.group(2)
+
+  # remove any silly quoting from username
+  m2=user_clean_re.match(name)
+  if m2!=None:
+    name=m2.group(1)
+  return '%s %s' % (name,mail)
+
+def get_branch(name):
+  if name=='HEAD':
+    name=cfg_master
+  return name
+
+def get_changeset(ui,repo,revision,authors={}):
+  node=repo.lookup(revision)
+  (manifest,user,(time,timezone),files,desc,extra)=repo.changelog.read(node)
+  tz="%+03d%02d" % (-timezone / 3600, ((-timezone % 3600) / 60))
+  branch=get_branch(extra.get('branch','master'))
+  return (node,manifest,fixup_user(user,authors),(time,tz),files,desc,branch,extra)
+
+def load_cache(filename):
+  cache={}
+  if not os.path.exists(filename):
+    return cache
+  f=open(filename,'r')
+  l=0
+  for line in f.readlines():
+    l+=1
+    fields=line.split(' ')
+    if fields==None or not len(fields)==2 or fields[0][0]!=':':
+      sys.stderr.write('Invalid file format in [%s], line %d\n' % (filename,l))
+      continue
+    # put key:value in cache, key without ^:
+    cache[fields[0][1:]]=fields[1].split('\n')[0]
+  f.close()
+  return cache
+
+def save_cache(filename,cache):
+  f=open(filename,'w+')
+  map(lambda x: f.write(':%s %s\n' % (str(x),str(cache.get(x)))),cache.keys())
+  f.close()