comparison mercurial/util.py @ 39565:2dcc68c7d25b

util: ability to change capacity when copying lrucachedict

This will allow us to easily replace an lrucachedict with one
with a higher or lower capacity as consumers deem necessary.

IMO it is easier to just create a new cache instance than to
muck with the capacity of an existing cache. Mutating an existing
cache's capacity feels more prone to bugs.

Differential Revision: https://phab.mercurial-scm.org/D4500

39564:5d75a3c16193

            n.markempty()
            n = n.next

        self._cache.clear()

    def copy(self):
        result = lrucachedict(self.capacity)

        # We copy entries by iterating in oldest-to-newest order so the copy
        # has the correct ordering.

        # Find the first non-empty entry.
        n = self._head.prev
        while n.key is _notset and n is not self._head:
            n = n.prev

        for i in range(len(self._cache)):
            result[n.key] = n.value
            n = n.prev

        return result

39565:2dcc68c7d25b

            n.markempty()
            n = n.next

        self._cache.clear()

    def copy(self, capacity=None):
        """Create a new cache as a copy of the current one.

        By default, the new cache has the same capacity as the existing one.
        But, the cache capacity can be changed as part of performing the
        copy.

        Items in the copy have an insertion/access order matching this
        instance.
        """

        capacity = capacity or self.capacity
        result = lrucachedict(capacity)

        # We copy entries by iterating in oldest-to-newest order so the copy
        # has the correct ordering.

        # Find the first non-empty entry.
        n = self._head.prev
        while n.key is _notset and n is not self._head:
            n = n.prev

        # We could potentially skip the first N items when decreasing capacity.
        # But let's keep it simple unless it is a performance problem.
        for i in range(len(self._cache)):
            result[n.key] = n.value
            n = n.prev

        return result