remove QLC from User and Presence caches

lib/nostrum/cache/presence_cache.ex

@@ -92,42 +92,19 @@ defmodule Nostrum.Cache.PresenceCache do
   """
   @callback child_spec(term()) :: Supervisor.child_spec()
 
-  @doc """
-  Return a QLC query handle for cache read operations.
-
-  This is used by nostrum to provide any read operations on the cache. Write
-  operations still need to be implemented separately.
-
-  The Erlang manual on [Implementing a QLC
-  Table](https://www.erlang.org/doc/man/qlc.html#implementing_a_qlc_table)
-  contains examples for implementation. To prevent full table scans, accept
-  match specifications in your `TraverseFun` and implement a `LookupFun` as
-  documented.
-
-  The query handle must return items in the form `{{guild_id, user_id}, presence}`, where:
-  - `guild_id` is a `t:Nostrum.Struct.Guild.id/0`, and
-  - `user_id` is a `t:Nostrum.Struct.User.id/0`, and
-  - `presence` is a `t:presence/0`.
-
-  If your cache needs some form of setup or teardown for QLC queries (such as
-  opening connections), see `c:wrap_qlc/1`.
-  """
-  @doc since: "0.8.0"
-  @callback query_handle() :: :qlc.query_handle()
-
   @doc """
   A function that should wrap any `:qlc` operations.
 
   If you implement a cache that is backed by a database and want to perform
   cleanup and teardown actions such as opening and closing connections,
   managing transactions and so on, you want to implement this function. nostrum
-  will then effectively call `wrap_qlc(fn -> :qlc.e(...) end)`.
+  will then effectively call `wrap_query(fn -> ... end)`.
 
   If your cache does not need any wrapping, you can omit this.
   """
   @doc since: "0.8.0"
-  @callback wrap_qlc((-> result)) :: result when result: term()
-  @optional_callbacks wrap_qlc: 1
+  @callback wrap_query((-> result)) :: result when result: term()
+  @optional_callbacks wrap_query: 1
 
   # Dispatch
   @doc false
@@ -151,24 +128,18 @@ defmodule Nostrum.Cache.PresenceCache do
   end
 
   @doc """
-  Call `c:wrap_qlc/1` on the given cache, if implemented.
+  Call `c:wrap_query/1` on the given cache, if implemented.
 
   If no cache is given, calls out to the default cache.
   """
   @doc since: "0.8.0"
-  @spec wrap_qlc((-> result)) :: result when result: term()
-  @spec wrap_qlc(module(), (-> result)) :: result when result: term()
-  def wrap_qlc(cache \\ @configured_cache, fun) do
-    if function_exported?(cache, :wrap_qlc, 1) do
-      cache.wrap_qlc(fun)
+  @spec wrap_query((-> result)) :: result when result: term()
+  @spec wrap_query(module(), (-> result)) :: result when result: term()
+  def wrap_query(cache \\ @configured_cache, fun) do
+    if function_exported?(cache, :wrap_query, 1) do
+      cache.wrap_query(fun)
     else
       fun.()
     end
   end
-
-  @doc """
-  Return the QLC handle of the configured cache.
-  """
-  @doc since: "0.8.0"
-  defdelegate query_handle(), to: @configured_cache
 end

lib/nostrum/cache/presence_cache/ets.ex

@@ -84,10 +84,4 @@ defmodule Nostrum.Cache.PresenceCache.ETS do
       :ets.insert(@table_name, {{guild_id, p.user.id}, p})
     end)
   end
-
-  @impl PresenceCache
-  @doc "Retrieve a query handle for QLC queries."
-  @doc since: "0.8.0"
-  @spec query_handle :: :qlc.query_handle()
-  def query_handle, do: :ets.table(@table_name)
 end

lib/nostrum/cache/presence_cache/mnesia.ex

@@ -111,19 +111,9 @@ if Code.ensure_loaded?(:mnesia) do
     end
 
     @impl PresenceCache
-    @doc "Retrieve a query handle for the table."
+    @doc "Wrap query operations in a transaction."
     @doc since: "0.8.0"
-    @spec query_handle :: :qlc.query_handle()
-    def query_handle do
-      # Note: :"$1" holds a pair here (`{guild_id, user_id}`).
-      ms = [{{:_, :"$1", :"$2"}, [], [{{:"$1", :"$2"}}]}]
-      :mnesia.table(@table_name, {:traverse, {:select, ms}})
-    end
-
-    @impl PresenceCache
-    @doc "Wrap QLC operations in a transaction."
-    @doc since: "0.8.0"
-    def wrap_qlc(fun) do
+    def wrap_query(fun) do
       :mnesia.activity(:sync_transaction, fun)
     end
   end

lib/nostrum/cache/presence_cache/noop.ex

@@ -40,7 +40,4 @@ defmodule Nostrum.Cache.PresenceCache.NoOp do
   @impl PresenceCache
   @spec bulk_create(Guild.id(), [map]) :: :ok
   def bulk_create(_guild_id, _presences), do: :ok
-
-  @impl PresenceCache
-  def query_handle, do: :qlc.string_to_handle(~c"[].")
 end

lib/nostrum/cache/user_cache.ex

@@ -57,36 +57,19 @@ defmodule Nostrum.Cache.UserCache do
   """
   @callback delete(snowflake :: User.id()) :: :noop | User.t()
 
-  @doc """
-  Return a query handle for usage with `:qlc`.
-
-  This is used by nostrum to provide automatic joins between the member and the
-  user cache, and may be used for other functions in the future.
-
-  The Erlang manual on [Implementing a QLC
-  Table](https://www.erlang.org/doc/man/qlc.html#implementing_a_qlc_table)
-  contains examples for implementation.
-
-  The query handle must return items in the form `{user_id, user}`, where
-  `user_id` is a `t:Nostrum.Struct.User.id/0` and `user` is a
-  `t:Nostrum.Struct.User.t/0`.
-  """
-  @doc since: "0.7.0"
-  @callback query_handle() :: :qlc.query_handle()
-
   @doc """
   A function that should wrap any `:qlc` operations.
 
   If you implement a cache that is backed by a database and want to perform
   cleanup and teardown actions such as opening and closing connections,
   managing transactions and so on, you want to implement this function. Nostrum
-  will then effectively call `wrap_qlc(fn -> :qlc.e(...) end)`.
+  will then effectively call `wrap_query(fn -> ... end)`.
 
   If your cache does not need any wrapping, you can omit this.
   """
   @doc since: "0.8.0"
-  @callback wrap_qlc((-> result)) :: result when result: term()
-  @optional_callbacks wrap_qlc: 1
+  @callback wrap_query((-> result)) :: result when result: term()
+  @optional_callbacks wrap_query: 1
 
   @doc """
   Retrieve the child specification for starting this mapping under a supervisor.
@@ -116,22 +99,17 @@ defmodule Nostrum.Cache.UserCache do
   @spec get!(User.id()) :: no_return | User.t()
   def get!(id) when is_snowflake(id), do: id |> get() |> Util.bangify_find(id, __MODULE__)
 
-  @doc "Call `c:query_handle/0` on the configured cache."
-  @doc since: "0.8.0"
-  @spec query_handle() :: :qlc.query_handle()
-  defdelegate query_handle, to: @configured_cache
-
   @doc """
-  Call `c:wrap_qlc/1` on the given cache, if implemented.
+  Call `c:wrap_query/1` on the given cache, if implemented.
 
   If no cache is given, calls out to the default cache.
   """
   @doc since: "0.8.0"
-  @spec wrap_qlc((-> result)) :: result when result: term()
-  @spec wrap_qlc(module(), (-> result)) :: result when result: term()
-  def wrap_qlc(cache \\ @configured_cache, fun) do
-    if function_exported?(cache, :wrap_qlc, 1) do
-      cache.wrap_qlc(fun)
+  @spec wrap_query((-> result)) :: result when result: term()
+  @spec wrap_query(module(), (-> result)) :: result when result: term()
+  def wrap_query(cache \\ @configured_cache, fun) do
+    if function_exported?(cache, :wrap_query, 1) do
+      cache.wrap_query(fun)
     else
       fun.()
     end

lib/nostrum/cache/user_cache/ets.ex

@@ -109,12 +109,4 @@ defmodule Nostrum.Cache.UserCache.ETS do
         :noop
     end
   end
-
-  @doc "Get a QLC query handle for the user cache."
-  @doc since: "0.7.0"
-  @impl Nostrum.Cache.UserCache
-  @spec query_handle :: :qlc.query_handle()
-  def query_handle do
-    :ets.table(@table_name)
-  end
 end

lib/nostrum/cache/user_cache/mnesia.ex

@@ -134,16 +134,9 @@ if Code.ensure_loaded?(:mnesia) do
       end)
     end
 
-    @impl UserCache
-    @doc "Get a QLC query handle for the user cache."
-    @spec query_handle :: :qlc.query_handle()
-    def query_handle do
-      :mnesia.table(@table_name)
-    end
-
     @impl UserCache
     @doc "Wrap QLC operations in a transaction."
-    def wrap_qlc(fun) do
+    def wrap_query(fun) do
       :mnesia.activity(:sync_transaction, fun)
     end
   end

lib/nostrum/cache/user_cache/noop.ex

@@ -34,7 +34,4 @@ defmodule Nostrum.Cache.UserCache.NoOp do
 
   @impl Nostrum.Cache.UserCache
   def delete(_id), do: :noop
-
-  @impl Nostrum.Cache.UserCache
-  def query_handle, do: :qlc.string_to_handle(~c"[].")
 end