hg-fast-export.py

   1 #!/usr/bin/env python
   2
   3 # Copyright (c) 2007, 2008 Rocco Rutte <pdmef@gmx.net> and others.
   4 # License: MIT <http://www.opensource.org/licenses/mit-license.php>
   5
   6 from mercurial import node
   7 from hg2git import setup_repo,fixup_user,get_branch,get_changeset
   8 from hg2git import load_cache,save_cache,get_git_sha1,set_default_branch,set_origin_name
   9 from optparse import OptionParser
  10 import re
  11 import sys
  12 import os
  13
  14 if sys.platform == "win32":
  15   # On Windows, sys.stdout is initially opened in text mode, which means that
  16   # when a LF (\n) character is written to sys.stdout, it will be converted
  17   # into CRLF (\r\n).  That makes git blow up, so use this platform-specific
  18   # code to change the mode of sys.stdout to binary.
  19   import msvcrt
  20   msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY)
  21
  22 # silly regex to catch Signed-off-by lines in log message
  23 sob_re=re.compile('^Signed-[Oo]ff-[Bb]y: (.+)$')
  24 # insert 'checkpoint' command after this many commits or none at all if 0
  25 cfg_checkpoint_count=0
  26 # write some progress message every this many file contents written
  27 cfg_export_boundary=1000
  28
  29 def gitmode(flags):
  30   return 'l' in flags and '120000' or 'x' in flags and '100755' or '100644'
  31
  32 def wr(msg=''):
  33   if msg:
  34     sys.stdout.write(msg)
  35   sys.stdout.write('\n')
  36   #map(lambda x: sys.stderr.write('\t[%s]\n' % x),msg.split('\n'))
  37
  38 def checkpoint(count):
  39   count=count+1
  40   if cfg_checkpoint_count>0 and count%cfg_checkpoint_count==0:
  41     sys.stderr.write("Checkpoint after %d commits\n" % count)
  42     wr('checkpoint')
  43     wr()
  44   return count
  45
  46 def revnum_to_revref(rev, old_marks):
  47   """Convert an hg revnum to a git-fast-import rev reference (an SHA1
  48   or a mark)"""
  49   return old_marks.get(rev) or ':%d' % (rev+1)
  50
  51 def file_mismatch(f1,f2):
  52   """See if two revisions of a file are not equal."""
  53   return node.hex(f1)!=node.hex(f2)
  54
  55 def split_dict(dleft,dright,l=[],c=[],r=[],match=file_mismatch):
  56   """Loop over our repository and find all changed and missing files."""
  57   for left in dleft.keys():
  58     right=dright.get(left,None)
  59     if right==None:
  60       # we have the file but our parent hasn't: add to left set
  61       l.append(left)
  62     elif match(dleft[left],right):
  63       # we have it but checksums mismatch: add to center set
  64       c.append(left)
  65   for right in dright.keys():
  66     left=dleft.get(right,None)
  67     if left==None:
  68       # if parent has file but we don't: add to right set
  69       r.append(right)
  70     # change is already handled when comparing child against parent
  71   return l,c,r
  72
  73 def get_filechanges(repo,revision,parents,mleft):
  74   """Given some repository and revision, find all changed/deleted files."""
  75   l,c,r=[],[],[]
  76   for p in parents:
  77     if p<0: continue
  78     mright=repo.changectx(p).manifest()
  79     l,c,r=split_dict(mleft,mright,l,c,r)
  80   l.sort()
  81   c.sort()
  82   r.sort()
  83   return l,c,r
  84
  85 def get_author(logmessage,committer,authors):
  86   """As git distincts between author and committer of a patch, try to
  87   extract author by detecting Signed-off-by lines.
  88
  89   This walks from the end of the log message towards the top skipping
  90   empty lines. Upon the first non-empty line, it walks all Signed-off-by
  91   lines upwards to find the first one. For that (if found), it extracts
  92   authorship information the usual way (authors table, cleaning, etc.)
  93
  94   If no Signed-off-by line is found, this defaults to the committer.
  95
  96   This may sound stupid (and it somehow is), but in log messages we
  97   accidentially may have lines in the middle starting with
  98   "Signed-off-by: foo" and thus matching our detection regex. Prevent
  99   that."""
 100
 101   loglines=logmessage.split('\n')
 102   i=len(loglines)
 103   # from tail walk to top skipping empty lines
 104   while i>=0:
 105     i-=1
 106     if len(loglines[i].strip())==0: continue
 107     break
 108   if i>=0:
 109     # walk further upwards to find first sob line, store in 'first'
 110     first=None
 111     while i>=0:
 112       m=sob_re.match(loglines[i])
 113       if m==None: break
 114       first=m
 115       i-=1
 116     # if the last non-empty line matches our Signed-Off-by regex: extract username
 117     if first!=None:
 118       r=fixup_user(first.group(1),authors)
 119       return r
 120   return committer
 121
 122 def export_file_contents(ctx,manifest,files):
 123   count=0
 124   max=len(files)
 125   for file in files:
 126     # Skip .hgtags files. They only get us in trouble.
 127     if file == ".hgtags":
 128       sys.stderr.write('Skip %s\n' % (file))
 129       continue
 130     d=ctx.filectx(file).data()
 131     wr('M %s inline %s' % (gitmode(manifest.flags(file)),file))
 132     wr('data %d' % len(d)) # had some trouble with size()
 133     wr(d)
 134     count+=1
 135     if count%cfg_export_boundary==0:
 136       sys.stderr.write('Exported %d/%d files\n' % (count,max))
 137   if max>cfg_export_boundary:
 138     sys.stderr.write('Exported %d/%d files\n' % (count,max))
 139
 140 def sanitize_name(name,what="branch"):
 141   """Sanitize input roughly according to git-check-ref-format(1)"""
 142
 143   def dot(name):
 144     if name[0] == '.': return '_'+name[1:]
 145     return name
 146
 147   n=name
 148   p=re.compile('([[ ~^:?*]|\.\.)')
 149   n=p.sub('_', n)
 150   if n[-1] in ('/', '.'): n=n[:-1]+'_'
 151   n='/'.join(map(dot,n.split('/')))
 152   p=re.compile('_+')
 153   n=p.sub('_', n)
 154
 155   if n!=name:
 156     sys.stderr.write('Warning: sanitized %s [%s] to [%s]\n' % (what,name,n))
 157   return n
 158
 159 def export_commit(ui,repo,revision,old_marks,max,count,authors,sob,brmap):
 160   def get_branchname(name):
 161     if brmap.has_key(name):
 162       return brmap[name]
 163     n=sanitize_name(name)
 164     brmap[name]=n
 165     return n
 166
 167   (revnode,_,user,(time,timezone),files,desc,branch,_)=get_changeset(ui,repo,revision,authors)
 168
 169   branch=get_branchname(branch)
 170
 171   parents = [p for p in repo.changelog.parentrevs(revision) if p >= 0]
 172
 173   if len(parents)==0 and revision != 0:
 174     wr('reset refs/heads/%s' % branch)
 175
 176   wr('commit refs/heads/%s' % branch)
 177   wr('mark :%d' % (revision+1))
 178   if sob:
 179     wr('author %s %d %s' % (get_author(desc,user,authors),time,timezone))
 180   wr('committer %s %d %s' % (user,time,timezone))
 181   wr('data %d' % (len(desc)+1)) # wtf?
 182   wr(desc)
 183   wr()
 184
 185
 186   # Sort the parents based on revision ids so that we always get the
 187   # same resulting git repo, no matter how the revisions were
 188   # numbered.
 189   parents.sort(key=repo.changelog.node, reverse=True)
 190
 191   ctx=repo.changectx(str(revision))
 192   man=ctx.manifest()
 193   added,changed,removed,type=[],[],[],''
 194
 195   if len(parents) == 0:
 196     # first revision: feed in full manifest
 197     added=man.keys()
 198     added.sort()
 199     type='full'
 200   else:
 201     wr('from %s' % revnum_to_revref(parents[0], old_marks))
 202     if len(parents) == 1:
 203       # later non-merge revision: feed in changed manifest
 204       # if we have exactly one parent, just take the changes from the
 205       # manifest without expensively comparing checksums
 206       f=repo.status(repo.lookup(parents[0]),revnode)[:3]
 207       added,changed,removed=f[1],f[0],f[2]
 208       type='simple delta'
 209     else: # a merge with two parents
 210       wr('merge %s' % revnum_to_revref(parents[1], old_marks))
 211       # later merge revision: feed in changed manifest
 212       # for many files comparing checksums is expensive so only do it for
 213       # merges where we really need it due to hg's revlog logic
 214       added,changed,removed=get_filechanges(repo,revision,parents,man)
 215       type='thorough delta'
 216
 217   sys.stderr.write('%s: Exporting %s revision %d/%d with %d/%d/%d added/changed/removed files\n' %
 218       (branch,type,revision+1,max,len(added),len(changed),len(removed)))
 219
 220   map(lambda r: wr('D %s' % r),removed)
 221   export_file_contents(ctx,man,added)
 222   export_file_contents(ctx,man,changed)
 223   wr()
 224
 225   return checkpoint(count)
 226
 227 def export_tags(ui,repo,old_marks,mapping_cache,count,authors):
 228   l=repo.tagslist()
 229   for tag,node in l:
 230     tag=sanitize_name(tag,"tag")
 231     # ignore latest revision
 232     if tag=='tip': continue
 233     # ignore tags to nodes that are missing (ie, 'in the future')
 234     if node.encode('hex_codec') not in mapping_cache:
 235       sys.stderr.write('Tag %s refers to unseen node %s\n' % (tag, node.encode('hex_codec')))
 236       continue
 237
 238     rev=int(mapping_cache[node.encode('hex_codec')])
 239
 240     ref=revnum_to_revref(rev, old_marks)
 241     if ref==None:
 242       sys.stderr.write('Failed to find reference for creating tag'
 243           ' %s at r%d\n' % (tag,rev))
 244       continue
 245     sys.stderr.write('Exporting tag [%s] at [hg r%d] [git %s]\n' % (tag,rev,ref))
 246     wr('reset refs/tags/%s' % tag)
 247     wr('from %s' % ref)
 248     wr()
 249     count=checkpoint(count)
 250   return count
 251
 252 def load_authors(filename):
 253   cache={}
 254   if not os.path.exists(filename):
 255     return cache
 256   f=open(filename,'r')
 257   l=0
 258   lre=re.compile('^([^=]+)[ ]*=[ ]*(.+)$')
 259   for line in f.readlines():
 260     l+=1
 261     m=lre.match(line)
 262     if m==None:
 263       sys.stderr.write('Invalid file format in [%s], line %d\n' % (filename,l))
 264       continue
 265     # put key:value in cache, key without ^:
 266     cache[m.group(1).strip()]=m.group(2).strip()
 267   f.close()
 268   sys.stderr.write('Loaded %d authors\n' % l)
 269   return cache
 270
 271 def branchtip(repo, heads):
 272   '''return the tipmost branch head in heads'''
 273   tip = heads[-1]
 274   for h in reversed(heads):
 275     if not repo[h].closesbranch():
 276       tip = h
 277       break
 278   return tip
 279
 280 def verify_heads(ui,repo,cache,force):
 281   branches={bn: branchtip(repo, heads)
 282             for bn, heads in repo.branchmap().iteritems()}
 283   l=[(-repo.changelog.rev(n), n, t) for t, n in branches.items()]
 284   l.sort()
 285
 286   # get list of hg's branches to verify, don't take all git has
 287   for _,_,b in l:
 288     b=get_branch(b)
 289     sha1=get_git_sha1(b)
 290     c=cache.get(b)
 291     if sha1!=c:
 292       sys.stderr.write('Error: Branch [%s] modified outside hg-fast-export:'
 293         '\n%s (repo) != %s (cache)\n' % (b,sha1,c))
 294       if not force: return False
 295
 296   # verify that branch has exactly one head
 297   t={}
 298   for h in repo.heads():
 299     (_,_,_,_,_,_,branch,_)=get_changeset(ui,repo,h)
 300     if t.get(branch,False):
 301       sys.stderr.write('Error: repository has at least one unnamed head: hg r%s\n' %
 302           repo.changelog.rev(h))
 303       if not force: return False
 304     t[branch]=True
 305
 306   return True
 307
 308 def hg2git(repourl,m,marksfile,mappingfile,headsfile,tipfile,authors={},sob=False,force=False):
 309   _max=int(m)
 310
 311   old_marks=load_cache(marksfile,lambda s: int(s)-1)
 312   mapping_cache=load_cache(mappingfile)
 313   heads_cache=load_cache(headsfile)
 314   state_cache=load_cache(tipfile)
 315
 316   ui,repo=setup_repo(repourl)
 317
 318   if not verify_heads(ui,repo,heads_cache,force):
 319     return 1
 320
 321   try:
 322     tip=repo.changelog.count()
 323   except AttributeError:
 324     tip=len(repo)
 325
 326   min=int(state_cache.get('tip',0))
 327   max=_max
 328   if _max<0 or max>tip:
 329     max=tip
 330
 331   for rev in range(0,max):
 332         (revnode,_,_,_,_,_,_,_)=get_changeset(ui,repo,rev,authors)
 333         mapping_cache[revnode.encode('hex_codec')] = str(rev)
 334
 335
 336   c=0
 337   brmap={}
 338   for rev in range(min,max):
 339     c=export_commit(ui,repo,rev,old_marks,max,c,authors,sob,brmap)
 340
 341   state_cache['tip']=max
 342   state_cache['repo']=repourl
 343   save_cache(tipfile,state_cache)
 344   save_cache(mappingfile,mapping_cache)
 345
 346   c=export_tags(ui,repo,old_marks,mapping_cache,c,authors)
 347
 348   sys.stderr.write('Issued %d commands\n' % c)
 349
 350   return 0
 351
 352 if __name__=='__main__':
 353   def bail(parser,opt):
 354     sys.stderr.write('Error: No %s option given\n' % opt)
 355     parser.print_help()
 356     sys.exit(2)
 357
 358   parser=OptionParser()
 359
 360   parser.add_option("-m","--max",type="int",dest="max",
 361       help="Maximum hg revision to import")
 362   parser.add_option("--mapping",dest="mappingfile",
 363       help="File to read last run's hg-to-git SHA1 mapping")
 364   parser.add_option("--marks",dest="marksfile",
 365       help="File to read git-fast-import's marks from")
 366   parser.add_option("--heads",dest="headsfile",
 367       help="File to read last run's git heads from")
 368   parser.add_option("--status",dest="statusfile",
 369       help="File to read status from")
 370   parser.add_option("-r","--repo",dest="repourl",
 371       help="URL of repo to import")
 372   parser.add_option("-s",action="store_true",dest="sob",
 373       default=False,help="Enable parsing Signed-off-by lines")
 374   parser.add_option("-A","--authors",dest="authorfile",
 375       help="Read authormap from AUTHORFILE")
 376   parser.add_option("-f","--force",action="store_true",dest="force",
 377       default=False,help="Ignore validation errors by force")
 378   parser.add_option("-M","--default-branch",dest="default_branch",
 379       help="Set the default branch")
 380   parser.add_option("-o","--origin",dest="origin_name",
 381       help="use <name> as namespace to track upstream")
 382
 383   (options,args)=parser.parse_args()
 384
 385   m=-1
 386   if options.max!=None: m=options.max
 387
 388   if options.marksfile==None: bail(parser,'--marks')
 389   if options.mappingfile==None: bail(parser,'--mapping')
 390   if options.headsfile==None: bail(parser,'--heads')
 391   if options.statusfile==None: bail(parser,'--status')
 392   if options.repourl==None: bail(parser,'--repo')
 393
 394   a={}
 395   if options.authorfile!=None:
 396     a=load_authors(options.authorfile)
 397
 398   if options.default_branch!=None:
 399     set_default_branch(options.default_branch)
 400
 401   if options.origin_name!=None:
 402     set_origin_name(options.origin_name)
 403
 404   sys.exit(hg2git(options.repourl,m,options.marksfile,options.mappingfile,options.headsfile,
 405     options.statusfile,authors=a,sob=options.sob,force=options.force))