2504 @command('debugdeltachain',

  2505     debugrevlogopts + formatteropts,

  2506     _('-c|-m|FILE'),

  2507     optionalrepo=True)

  2508 def debugdeltachain(ui, repo, file_=None, **opts):

  2509     """dump information about delta chains in a revlog

  2510 

  2511     Output can be templatized. Available template keywords are:

  2512 

  2513        rev          revision number

  2514        chainid      delta chain identifier (numbered by unique base)

  2515        chainlen     delta chain length to this revision

  2516        prevrev      previous revision in delta chain

  2517        deltatype    role of delta / how it was computed

  2518        compsize     compressed size of revision

  2519        uncompsize   uncompressed size of revision

  2520        chainsize    total size of compressed revisions in chain

  2521        chainratio   total chain size divided by uncompressed revision size

  2522                     (new delta chains typically start at ratio 2.00)

  2523        lindist      linear distance from base revision in delta chain to end

  2524                     of this revision

  2525        extradist    total size of revisions not part of this delta chain from

  2526                     base of delta chain to end of this revision; a measurement

  2527                     of how much extra data we need to read/seek across to read

  2528                     the delta chain for this revision

  2529        extraratio   extradist divided by chainsize; another representation of

  2530                     how much unrelated data is needed to load this delta chain

  2531     """

  2532     r = cmdutil.openrevlog(repo, 'debugdeltachain', file_, opts)

  2533     index = r.index

  2534     generaldelta = r.version & revlog.REVLOGGENERALDELTA

  2535 

  2536     def revinfo(rev):

  2537         iterrev = rev

  2538         e = index[iterrev]

  2539         chain = []

  2540         compsize = e[1]

  2541         uncompsize = e[2]

  2542         chainsize = 0

  2543 

  2544         if generaldelta:

  2545             if e[3] == e[5]:

  2546                 deltatype = 'p1'

  2547             elif e[3] == e[6]:

  2548                 deltatype = 'p2'

  2549             elif e[3] == rev - 1:

  2550                 deltatype = 'prev'

  2551             elif e[3] == rev:

  2552                 deltatype = 'base'

  2553             else:

  2554                 deltatype = 'other'

  2555         else:

  2556             if e[3] == rev:

  2557                 deltatype = 'base'

  2558             else:

  2559                 deltatype = 'prev'

  2560 

  2561         while iterrev != e[3]:

  2562             chain.append(iterrev)

  2563             chainsize += e[1]

  2564             if generaldelta:

  2565                 iterrev = e[3]

  2566             else:

  2567                 iterrev -= 1

  2568             e = index[iterrev]

  2569         else:

  2570             chainsize += e[1]

  2571             chain.append(iterrev)

  2572 

  2573         chain.reverse()

  2574         return compsize, uncompsize, deltatype, chain, chainsize

  2575 

  2576     fm = ui.formatter('debugdeltachain', opts)

  2577 

  2578     fm.plain('    rev  chain# chainlen     prev   delta       '

  2579              'size    rawsize  chainsize     ratio   lindist extradist '

  2580              'extraratio\n')

  2581 

  2582     chainbases = {}

  2583     for rev in r:

  2584         comp, uncomp, deltatype, chain, chainsize = revinfo(rev)

  2585         chainbase = chain[0]

  2586         chainid = chainbases.setdefault(chainbase, len(chainbases) + 1)

  2587         basestart = r.start(chainbase)

  2588         revstart = r.start(rev)

  2589         lineardist = revstart + comp - basestart

  2590         extradist = lineardist - chainsize

  2591         try:

  2592             prevrev = chain[-2]

  2593         except IndexError:

  2594             prevrev = -1

  2595 

  2596         chainratio = float(chainsize) / float(uncomp)

  2597         extraratio = float(extradist) / float(chainsize)

  2598 

  2599         fm.startitem()

  2600         fm.write('rev chainid chainlen prevrev deltatype compsize '

  2601                  'uncompsize chainsize chainratio lindist extradist '

  2602                  'extraratio',

  2603                  '%7d %7d %8d %8d %7s %10d %10d %10d %9.5f %9d %9d %10.5f\n',

  2604                  rev, chainid, len(chain), prevrev, deltatype, comp,

  2605                  uncomp, chainsize, chainratio, lineardist, extradist,

  2606                  extraratio,

  2607                  rev=rev, chainid=chainid, chainlen=len(chain),

  2608                  prevrev=prevrev, deltatype=deltatype, compsize=comp,

  2609                  uncompsize=uncomp, chainsize=chainsize,

  2610                  chainratio=chainratio, lindist=lineardist,

  2611                  extradist=extradist, extraratio=extraratio)

  2612 

  2613     fm.end()

  2614