Tracker consists of shard-pool; exposes dirty_list operation

Author: Rafal Studnicki

lib/phoenix/tracker.ex

@@ -16,6 +16,7 @@ defmodule Phoenix.Tracker.State do
   @type context    :: %{name => clock}
   @type values     :: ets_id | :extracted | %{tag => {pid, topic, key, meta}}
   @type value      :: {{topic, pid, key}, meta, tag}
+  @type key_meta   :: {key, meta}
   @type delta      :: %State{mode: :delta}
   @type pid_lookup :: {pid, topic, key}
 
@@ -50,13 +51,13 @@ defmodule Phoenix.Tracker.State do
       %Phoenix.Tracker.State{...}
 
   """
-  @spec new(name) :: t
-  def new(replica) do
+  @spec new(name, atom) :: t
+  def new(replica, shard_name) do
     reset_delta(%State{
       replica: replica,
       context: %{replica => 0},
       mode: :normal,
-      values: :ets.new(:values, [:ordered_set]),
+      values: :ets.new(shard_name, [:named_table, :protected, :ordered_set]),
       pids: :ets.new(:pids, [:duplicate_bag]),
       replicas: %{replica => :up}})
   end
@@ -113,12 +114,22 @@ defmodule Phoenix.Tracker.State do
   @doc """
   Returns a list of elements for the topic who belong to an online replica.
   """
-  @spec get_by_topic(t, topic) :: [value]
+  @spec get_by_topic(t, topic) :: [key_meta]
   def get_by_topic(%State{values: values} = state, topic) do
-    replicas = down_replicas(state)
-    :ets.select(values, [{ {{topic, :_, :_}, :_, {:"$1", :_}},
-      not_in(:"$1", replicas), [:"$_"]}])
+    tracked_values(values, topic, down_replicas(state))
   end
+
+  @doc """
+  Performs table lookup for tracked elements in the topic, filtering out
+  those present on downed replicas.
+  """
+  def tracked_values(table, topic, down_replicas) do
+    :ets.select(table,
+      [{{{topic, :_, :"$1"}, :"$2", {:"$3", :_}},
+        not_in(:"$3", down_replicas),
+        [{{:"$1", :"$2"}}]}])
+  end
+
   defp not_in(_pos, []), do: []
   defp not_in(pos, replicas), do: [not: ors(pos, replicas)]
   defp ors(pos, [rep]), do: {:"==", pos, {rep}}

lib/phoenix/tracker/shard.ex

@@ -11,6 +11,8 @@ defmodule Phoenix.PubSub.PG2Test do
   @node1 :"node1@127.0.0.1"
   @node2 :"node2@127.0.0.1"
 
+  @receive_timeout 500
+
   setup config do
     size = config[:pool_size] || 1
     if config[:pool_size] do
@@ -29,15 +31,15 @@ defmodule Phoenix.PubSub.PG2Test do
 
       PubSub.subscribe(config.pubsub, config.topic)
       :ok = PubSub.direct_broadcast(@node1, config.pubsub, config.topic, :ping)
-      assert_receive {@node1, :ping}
+      assert_receive {@node1, :ping}, @receive_timeout
       :ok = PubSub.direct_broadcast!(@node1, config.pubsub, config.topic, :ping)
-      assert_receive {@node1, :ping}
+      assert_receive {@node1, :ping}, @receive_timeout
 
       :ok = PubSub.direct_broadcast(@node2, config.pubsub, config.topic, :ping)
-      refute_receive {@node1, :ping}
+      refute_receive {@node1, :ping}, @receive_timeout
 
       :ok = PubSub.direct_broadcast!(@node2, config.pubsub, config.topic, :ping)
-      refute_receive {@node1, :ping}
+      refute_receive {@node1, :ping}, @receive_timeout
     end
 
     @tag pool_size: size, topic: topic
@@ -46,15 +48,15 @@ defmodule Phoenix.PubSub.PG2Test do
 
       PubSub.subscribe(config.pubsub, config.topic)
       :ok = PubSub.direct_broadcast_from(@node1, config.pubsub, self(), config.topic, :ping)
-      assert_receive {@node1, :ping}
+      assert_receive {@node1, :ping}, @receive_timeout
       :ok = PubSub.direct_broadcast_from!(@node1, config.pubsub, self(), config.topic, :ping)
-      assert_receive {@node1, :ping}
+      assert_receive {@node1, :ping}, @receive_timeout
 
       :ok = PubSub.direct_broadcast_from(@node2, config.pubsub, self(), config.topic, :ping)
-      refute_receive {@node1, :ping}
+      refute_receive {@node1, :ping}, @receive_timeout
 
       :ok = PubSub.direct_broadcast_from!(@node2, config.pubsub, self(), config.topic, :ping)
-      refute_receive {@node1, :ping}
+      refute_receive {@node1, :ping}, @receive_timeout
     end
   end
 

lib/phoenix/tracker/state.ex

@@ -9,8 +9,8 @@ defmodule Phoenix.Tracker.DeltaGenerationTest do
     |> Enum.sort()
   end
 
-  defp new(node) do
-    State.new(node)
+  defp new(node, config) do
+    State.new(node, :"#{node} #{config.test}")
   end
 
   defp new_pid() do
@@ -23,9 +23,9 @@ defmodule Phoenix.Tracker.DeltaGenerationTest do
     |> Enum.sort()
   end
 
-  test "generations" do
-    s1 = new(:s1)
-    s2 = new(:s2)
+  test "generations", config do
+    s1 = new(:s1, config)
+    s2 = new(:s2, config)
     s1 = State.join(s1, new_pid(), "lobby", "user1", %{})
     assert [gen1, gen1, gen1] = gens = push(s1, [], s1.delta, [2, 5, 6])
     assert keys(gen1) == ["user1"]
@@ -86,9 +86,9 @@ defmodule Phoenix.Tracker.DeltaGenerationTest do
     assert sorted_clouds(gen3.clouds) == [{:s1, 3}, {:s1, 4}, {:s2, 1}, {:s2, 2}]
   end
 
-  test "does not include non-contiguous deltas" do
-    s1 = new(:s1)
-    s3 = new(:s3)
+  test "does not include non-contiguous deltas", config do
+    s1 = new(:s1, config)
+    s3 = new(:s3, config)
     s1 = State.join(s1, new_pid(), "lobby", "user1", %{})
     old_s3 = s3 = State.join(s3, new_pid(), "lobby", "user3", %{})
     s3 = State.reset_delta(s3)
@@ -99,10 +99,10 @@ defmodule Phoenix.Tracker.DeltaGenerationTest do
     assert [^gen1, ^gen1, ^gen1] = push(s1, gens, s3.delta, [5, 10, 15])
   end
 
-  test "remove_down_replicas" do
-    s1 = new(:s1)
-    s2 = new(:s2)
-    s3 = new(:s3)
+  test "remove_down_replicas", config do
+    s1 = new(:s1, config)
+    s2 = new(:s2, config)
+    s3 = new(:s3, config)
     s2 = State.join(s2, new_pid(), "lobby", "user2", %{})
     assert [gen1, gen1, gen1] = gens = push(s1, [], s2.delta, [5, 10, 15])
     assert [pruned_gen1, pruned_gen1, pruned_gen1] = DeltaGeneration.remove_down_replicas(gens, :s2)