comparison mercurial/revlog.py @ 34881:8c9b08a0c48c

sparse-read: skip gaps too small to be worth splitting

Splitting at too small gaps might not be worthwhile. With this changeset,
we stop considering splitting on too small gaps. The threshold is configurable.
We arbitrarily pick 256K as a default value because it seems "okay".
Further testing on various repositories and setups will be needed to tune it.

The option name is 'experimental.sparse-read.min-gap-size`, and replaces
`experimental.sparse-read.min-block-size` which is not used any more.

34880:9e18ab7f7240

        revstart = start(rev)
        revlen = length(rev)

        if prevend is not None:
            gapsize = revstart - prevend
            if gapsize:
                heapq.heappush(gapsheap, (-gapsize, i))

        prevend = revstart + revlen

    # Collect the indices of the largest holes until the density is acceptable

        self._nodepos = None
        self._compengine = 'zlib'
        self._maxdeltachainspan = -1
        self._withsparseread = False
        self._srdensitythreshold = 0.25
        self._srminblocksize = 262144

        mmapindexthreshold = None
        v = REVLOG_DEFAULT_VERSION
        opts = getattr(opener, 'options', None)
        if opts is not None:

            if mmaplargeindex and 'mmapindexthreshold' in opts:
                mmapindexthreshold = opts['mmapindexthreshold']
            self._withsparseread = bool(opts.get('with-sparse-read', False))
            if 'sparse-read-density-threshold' in opts:
                self._srdensitythreshold = opts['sparse-read-density-threshold']
            if 'sparse-read-min-block-size' in opts:
                self._srminblocksize = opts['sparse-read-min-block-size']

        if self._chunkcachesize <= 0:
            raise RevlogError(_('revlog chunk cache size %r is not greater '
                                'than 0') % self._chunkcachesize)
        elif self._chunkcachesize & (self._chunkcachesize - 1):

34881:8c9b08a0c48c

        revstart = start(rev)
        revlen = length(rev)

        if prevend is not None:
            gapsize = revstart - prevend
            # only consider holes that are large enough
            if gapsize > revlog._srmingapsize:
                heapq.heappush(gapsheap, (-gapsize, i))

        prevend = revstart + revlen

    # Collect the indices of the largest holes until the density is acceptable

        self._nodepos = None
        self._compengine = 'zlib'
        self._maxdeltachainspan = -1
        self._withsparseread = False
        self._srdensitythreshold = 0.25
        self._srmingapsize = 262144

        mmapindexthreshold = None
        v = REVLOG_DEFAULT_VERSION
        opts = getattr(opener, 'options', None)
        if opts is not None:

            if mmaplargeindex and 'mmapindexthreshold' in opts:
                mmapindexthreshold = opts['mmapindexthreshold']
            self._withsparseread = bool(opts.get('with-sparse-read', False))
            if 'sparse-read-density-threshold' in opts:
                self._srdensitythreshold = opts['sparse-read-density-threshold']
            if 'sparse-read-min-gap-size' in opts:
                self._srmingapsize = opts['sparse-read-min-gap-size']

        if self._chunkcachesize <= 0:
            raise RevlogError(_('revlog chunk cache size %r is not greater '
                                'than 0') % self._chunkcachesize)
        elif self._chunkcachesize & (self._chunkcachesize - 1):