mercurial/util.py

39566:bd9d3a89f07b

    """A node in a doubly linked list.

    Holds a reference to nodes on either side as well as a key-value
    pair for the dictionary entry.
    """
    __slots__ = (u'next', u'prev', u'key', u'value')

    def __init__(self):
        self.next = None
        self.prev = None

        self.key = _notset
        self.value = None

    def markempty(self):
        """Mark the node as emptied."""
        self.key = _notset

class lrucachedict(object):
    """Dict that caches most recent accesses and sets.

    The dict consists of an actual backing dict - indexed by original

    The head node is the newest entry in the cache. If the cache is full,
    we recycle head.prev and make it the new head. Cache accesses result in
    the node being moved to before the existing head and being marked as the
    new head node.
    """
    def __init__(self, max):
        self._cache = {}

        self._head = head = _lrucachenode()
        head.prev = head
        head.next = head
        self._size = 1
        self.capacity = max

    def __len__(self):
        return len(self._cache)

    def __contains__(self, k):

    def __getitem__(self, k):
        node = self._cache[k]
        self._movetohead(node)
        return node.value

    def __setitem__(self, k, v):
        node = self._cache.get(k)
        # Replace existing value and mark as newest.
        if node is not None:
            node.value = v
            self._movetohead(node)
            return

        if self._size < self.capacity:
            node = self._addcapacity()

            # Grab the last/oldest item.
            node = self._head.prev

        # At capacity. Kill the old entry.
        if node.key is not _notset:
            del self._cache[node.key]

        node.key = k
        node.value = v
        self._cache[k] = node
        # And mark it as newest entry. No need to adjust order since it
        # is already self._head.prev.
        self._head = node

    def __delitem__(self, k):
        node = self._cache.pop(k)
        node.markempty()

        # Temporarily mark as newest item before re-adjusting head to make
        # this node the oldest item.
        self._movetohead(node)

            return default

    def clear(self):
        n = self._head
        while n.key is not _notset:
            n.markempty()
            n = n.next

        self._cache.clear()

            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

    def popoldest(self):

        key, value = n.key, n.value

        # And remove it from the cache and mark it as empty.
        del self._cache[n.key]
        n.markempty()

        return key, value

    def _movetohead(self, node):

39567:ee087f0d7db5

    """A node in a doubly linked list.

    Holds a reference to nodes on either side as well as a key-value
    pair for the dictionary entry.
    """
    __slots__ = (u'next', u'prev', u'key', u'value', u'cost')

    def __init__(self):
        self.next = None
        self.prev = None

        self.key = _notset
        self.value = None
        self.cost = 0

    def markempty(self):
        """Mark the node as emptied."""
        self.key = _notset
        self.value = None
        self.cost = 0

class lrucachedict(object):
    """Dict that caches most recent accesses and sets.

    The dict consists of an actual backing dict - indexed by original

    The head node is the newest entry in the cache. If the cache is full,
    we recycle head.prev and make it the new head. Cache accesses result in
    the node being moved to before the existing head and being marked as the
    new head node.

    Items in the cache can be inserted with an optional "cost" value. This is
    simply an integer that is specified by the caller. The cache can be queried
    for the total cost of all items presently in the cache.
    """
    def __init__(self, max):
        self._cache = {}

        self._head = head = _lrucachenode()
        head.prev = head
        head.next = head
        self._size = 1
        self.capacity = max
        self.totalcost = 0

    def __len__(self):
        return len(self._cache)

    def __contains__(self, k):

    def __getitem__(self, k):
        node = self._cache[k]
        self._movetohead(node)
        return node.value

    def insert(self, k, v, cost=0):
        """Insert a new item in the cache with optional cost value."""
        node = self._cache.get(k)
        # Replace existing value and mark as newest.
        if node is not None:
            self.totalcost -= node.cost
            node.value = v
            node.cost = cost
            self.totalcost += cost
            self._movetohead(node)
            return

        if self._size < self.capacity:
            node = self._addcapacity()

            # Grab the last/oldest item.
            node = self._head.prev

        # At capacity. Kill the old entry.
        if node.key is not _notset:
            self.totalcost -= node.cost
            del self._cache[node.key]

        node.key = k
        node.value = v
        node.cost = cost
        self.totalcost += cost
        self._cache[k] = node
        # And mark it as newest entry. No need to adjust order since it
        # is already self._head.prev.
        self._head = node

    def __setitem__(self, k, v):
        self.insert(k, v)

    def __delitem__(self, k):
        node = self._cache.pop(k)
        self.totalcost -= node.cost
        node.markempty()

        # Temporarily mark as newest item before re-adjusting head to make
        # this node the oldest item.
        self._movetohead(node)

            return default

    def clear(self):
        n = self._head
        while n.key is not _notset:
            self.totalcost -= n.cost
            n.markempty()
            n = n.next

        self._cache.clear()

            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.insert(n.key, n.value, cost=n.cost)
            n = n.prev

        return result

    def popoldest(self):

        key, value = n.key, n.value

        # And remove it from the cache and mark it as empty.
        del self._cache[n.key]
        self.totalcost -= n.cost
        n.markempty()

        return key, value

    def _movetohead(self, node):