627     The sparse read can be enabled with experimental.sparse-read = True

   627     The sparse read can be enabled with experimental.sparse-read = True

   628     """

   628     """

   629     opts = pycompat.byteskwargs(opts)

   629     opts = pycompat.byteskwargs(opts)

   630     r = cmdutil.openrevlog(repo, 'debugdeltachain', file_, opts)

   630     r = cmdutil.openrevlog(repo, 'debugdeltachain', file_, opts)

   631     index = r.index

   631     index = r.index

   632     generaldelta = r.version & revlog.FLAG_GENERALDELTA

   634     generaldelta = r.version & revlog.FLAG_GENERALDELTA

   633     withsparseread = getattr(r, '_withsparseread', False)

   635     withsparseread = getattr(r, '_withsparseread', False)

   634 

   636 

   635     def revinfo(rev):

   637     def revinfo(rev):

   636         e = index[rev]

   638         e = index[rev]

   674     chainbases = {}

   676     chainbases = {}

   675     for rev in r:

   677     for rev in r:

   676         comp, uncomp, deltatype, chain, chainsize = revinfo(rev)

   678         comp, uncomp, deltatype, chain, chainsize = revinfo(rev)

   677         chainbase = chain[0]

   679         chainbase = chain[0]

   678         chainid = chainbases.setdefault(chainbase, len(chainbases) + 1)

   680         chainid = chainbases.setdefault(chainbase, len(chainbases) + 1)

   681         basestart = start(chainbase)

   681         basestart = start(chainbase)

   682         revstart = start(rev)

   682         revstart = start(rev)

   683         lineardist = revstart + comp - basestart

   683         lineardist = revstart + comp - basestart

   684         extradist = lineardist - chainsize

   684         extradist = lineardist - chainsize

   685         try:

   685         try: