roger v1.0.0 Roger.KeySet
An opaque interface to storing keys and testing set member ship of keys. Like a bloom filter, but 100% probabilistic.
iex> {:ok, pid} = Roger.KeySet.start_link
iex> Roger.KeySet.add(pid, "bla")
:ok
iex> Roger.KeySet.contains?(pid, "bla")
true
iex> Roger.KeySet.contains?(pid, "beh")
false
Keys can also be removed:
iex> {:ok, pid} = Roger.KeySet.start_link
iex> Roger.KeySet.add(pid, "bla")
iex> Roger.KeySet.remove(pid, "bla")
:ok
iex> Roger.KeySet.contains?(pid, "bla")
false
The state of the keyset can be retrieved in binary format. This state is to be treated as an opaque datastructure. We can then load the state into a new keyset process.
The state can also be given as an argument when the keyset process is started.
iex> {:ok, pid} = Roger.KeySet.start_link
iex> Roger.KeySet.add(pid, "existing")
iex> {:ok, state} = Roger.KeySet.get_state(pid)
iex> {:ok, pid2} = Roger.KeySet.start_link(state: state)
iex> Roger.KeySet.contains?(pid2, "existing")
true
Many keys can also be added at once:
iex> {:ok, pid} = Roger.KeySet.start_link
iex> Roger.KeySet.add_many(pid, ~w(a b c))
:ok
iex> Roger.KeySet.contains?(pid, "a")
true
iex> Roger.KeySet.contains?(pid, "b")
true
iex> Roger.KeySet.contains?(pid, "c")
true
Two keysets can also be used in set operations. These will always be applied to the first keyset; the second is left untouched:
iex> {:ok, a} = Roger.KeySet.start_link
iex> Roger.KeySet.add_many(a, ~w(a1 a2 a3))
iex> {:ok, b} = Roger.KeySet.start_link
iex> Roger.KeySet.add_many(b, ~w(b1 b2))
iex> Roger.KeySet.union(a, b)
:ok
iex> Roger.KeySet.contains?(a, "b1")
true
iex> Roger.KeySet.contains?(b, "a1")
false
iex> Roger.KeySet.difference(a, b)
:ok
iex> Roger.KeySet.contains?(a, "b1")
false
Note: the current implementation is a MapSet but this is an implementation detail and likely to change.