comparison mercurial/debugcommands.py @ 50317:af776c3d5c3e stable

debugdeltachain: stop summing the same chain over and over

Before this patch, delta chain size was computed from scratch for each chain,
disregarding the fact very likely already computed the same of length-1 prefix
for another revisions.

We not cache delta chain size and shortcut the computation when we see them.

Just for my mercurial-devel clone, this move the computation from about 17.5
second to about 4.8 seconds.

50316:87f0155d68aa

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

    # security to avoid crash on corrupted revlogs
    total_revs = len(index)

    def revinfo(rev):
        e = index[rev]
        compsize = e[revlog_constants.ENTRY_DATA_COMPRESSED_LENGTH]
        uncompsize = e[revlog_constants.ENTRY_DATA_UNCOMPRESSED_LENGTH]
        chainsize = 0

        base = e[revlog_constants.ENTRY_DELTA_BASE]
        p1 = e[revlog_constants.ENTRY_PARENT_1]
        p2 = e[revlog_constants.ENTRY_PARENT_2]

                deltatype = b'base'
            else:
                deltatype = b'prev'

        chain = r._deltachain(rev)[0]
        for iterrev in chain:
            e = index[iterrev]
            chainsize += e[revlog_constants.ENTRY_DATA_COMPRESSED_LENGTH]

        return p1, p2, compsize, uncompsize, deltatype, chain, chainsize

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

    fm.plain(
        b'    rev      p1      p2  chain# chainlen     prev   delta       '

50317:af776c3d5c3e

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

    # security to avoid crash on corrupted revlogs
    total_revs = len(index)

    chain_size_cache = {}

    def revinfo(rev):
        e = index[rev]
        compsize = e[revlog_constants.ENTRY_DATA_COMPRESSED_LENGTH]
        uncompsize = e[revlog_constants.ENTRY_DATA_UNCOMPRESSED_LENGTH]

        base = e[revlog_constants.ENTRY_DELTA_BASE]
        p1 = e[revlog_constants.ENTRY_PARENT_1]
        p2 = e[revlog_constants.ENTRY_PARENT_2]

                deltatype = b'base'
            else:
                deltatype = b'prev'

        chain = r._deltachain(rev)[0]
        chain_size = 0
        for iter_rev in reversed(chain):
            cached = chain_size_cache.get(iter_rev)
            if cached is not None:
                chain_size += cached
                break
            e = index[iter_rev]
            chain_size += e[revlog_constants.ENTRY_DATA_COMPRESSED_LENGTH]
        chain_size_cache[rev] = chain_size

        return p1, p2, compsize, uncompsize, deltatype, chain, chain_size

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

    fm.plain(
        b'    rev      p1      p2  chain# chainlen     prev   delta       '