comparison mercurial/revlog.py @ 34825:4d5d5009bd75

revlog-sparse-read: add a lower-threshold for read block size

The option experimental.sparse-read.min-block-size specifies the minimal size
of a deltachain span, under which it won't be split by _slicechunk.

34824:e2ad93bcc084

        startbyte = start(revs[0])
        endbyte = start(revs[-1]) + length(revs[-1])
        deltachainspan = endbyte - startbyte

        if len(revs) <= 1:
            yield revs
            continue

        # Find where is the largest hole (this is where we would split) and
        # sum up the lengths of useful data to compute the density of the span

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

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

34825:4d5d5009bd75

        startbyte = start(revs[0])
        endbyte = start(revs[-1]) + length(revs[-1])
        deltachainspan = endbyte - startbyte

        if deltachainspan <= revlog._srminblocksize or len(revs) <= 1:
            yield revs
            continue

        # Find where is the largest hole (this is where we would split) and
        # sum up the lengths of useful data to compute the density of the span

        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):