Class _LocalStack

celery/utils/threads.py:155–252

Local stack. This class works similar to a :class:`Local` but keeps a stack of objects instead. This is best explained with an example:: >>> ls = LocalStack() >>> ls.push(42) >>> ls.top 42 >>> ls.push(23) >>> ls.top 23 >>> ls

class _LocalStack:
    class="st">"""Local stack.

    This class works similar to a :class:`Local` but keeps a stack
    of objects instead.  This is best explained with an example::

        >>> ls = LocalStack()
        >>> ls.push(42)
        >>> ls.top
        42
        >>> ls.push(23)
        >>> ls.top
        23
        >>> ls.pop()
        23
        >>> ls.top
        42

    They can be force released by using a :class:`LocalManager` or with
    the :func:`release_local` function but the correct way is to pop the
    item from the stack after using.  When the stack is empty it will
    no longer be bound to the current context (and as such released).

    By calling the stack without arguments it will return a proxy that
    resolves to the topmost item on the stack.
    class="st">"""

    def __init__(self):
        self._local = Local()

    def __release_local__(self):
        self._local.__release_local__()

    def _get__ident_func__(self):
        return self._local.__ident_func__

    def _set__ident_func__(self, value):
        object.__setattr__(self._local, &class="cm">#x27;__ident_func__', value)
    __ident_func__ = property(_get__ident_func__, _set__ident_func__)
    del _get__ident_func__, _set__ident_func__

    def __call__(self):
        def _lookup():
            rv = self.top
            if rv is None:
                raise RuntimeError(&class="cm">#x27;object unbound')
            return rv
        return Proxy(_lookup)

    def push(self, obj):
        class="st">""class="st">"Push a new item to the stack."class="st">""
        rv = getattr(self._local, &class="cm">#x27;stack', None)
        if rv is None:
            class="cm"># pylint: disable=assigning-non-slot
            class="cm"># This attribute is defined now.
            self._local.stack = rv = []
        rv.append(obj)
        return rv