Feat/reset

CHANGELOG.md

@@ -1,5 +1,14 @@
+## v0.1.2 (2024-12-30)
+
+### Implements Reset function
+
+- `GenCache.reset(pid)`
+- or macro-based module: `SomeCache.reset()`
+
+
 ## v0.1.1 (2024-09-09)
 
+
 ### Quality of life improvements
 
 - allow configuring default ttl when starting the server
@@ -11,4 +20,4 @@
 
 ### First release
 
-- already quite usable, there might still be some missing  features
+- already quite usable, there might still be some missing  features

README.md

@@ -27,6 +27,11 @@ res = MyCache.request({IO, :puts, ["Hello World"]})
 # this will not execute the MFA tuple and just return the cached result
 res = MyCache.request({IO, :puts, ["Hello World"]})
 
+# remove a single entry from cache
+MyCache.remove({IO, :puts, ["Hello World"]})
+
+# Reset the complete cache
+MyCache.reset()
 
 # add custom ttl for the given key
 res = MyCache.request({IO, :puts, ["Quick one"]}, ttl: :timer.seconds(5))
@@ -59,4 +64,3 @@ end
 Documentation can be generated with [ExDoc](https://github.com/elixir-lang/ex_doc)
 and published on [HexDocs](https://hexdocs.pm). Once published, the docs can
 be found at <https://hexdocs.pm/gen_cache>.
-

lib/gen_cache.ex

@@ -67,6 +67,7 @@ defmodule GenCache do
   def request(pid, request, opts \\ []), do: :gen_statem.call(pid, {:request, request, opts})
   def remove(pid, request), do: :gen_statem.call(pid, {:remove, request})
   def get_state(pid), do: :gen_statem.call(pid, :get_state)
+  def reset(pid), do: :gen_statem.call(pid, :reset)
 
   ### INTERNAL ###
 
@@ -87,6 +88,11 @@ defmodule GenCache do
     {:keep_state, data, [{:reply, from, :ok}]}
   end
 
+  def handle_event({:call, from}, :reset, _state, data) do
+    data = reset_cache(data)
+    {:keep_state, data, [{:reply, from, :ok}]}
+  end
+
   #
   def handle_event({:call, from}, {:request, request, req_opts}, _, data) do
     ttl = Keyword.get(req_opts, :ttl, @default_ttl)
@@ -184,6 +190,10 @@ defmodule GenCache do
     %Data{data | cache: Map.delete(data.cache, request)}
   end
 
+  def reset_cache(data) do
+    %Data{data | cache: %{}, valid_until: %{}, ttl: %{}}
+  end
+
   defp get_from_cache(data, request) do
     res = Map.get(data.cache, request, nil)
 

lib/gen_cache/macro.ex

@@ -58,6 +58,7 @@ defmodule GenCache.Macro do
 
       def remove(request), do: :gen_statem.call(__MODULE__, {:remove, request})
       def get_state(), do: :gen_statem.call(__MODULE__, :get_state)
+      def reset(), do: :gen_statem.call(__MODULE__, :reset)
 
       ### INTERNAL ###
 

lib/gen_cache/macro_test.exs

@@ -20,4 +20,17 @@ defmodule GenCache.MacroTest do
     {:ok, pid} = TestCache.start_link()
     assert {:error, {:already_started, pid}} == TestCache.start_link()
   end
+
+  test "reset works" do
+    TestCache.start_link()
+    TestCache.request({Process, :send, [self(), :start, []]})
+    TestCache.request({Process, :send, [self(), :start, []]})
+    assert_received :start
+    refute_received :start
+
+    ## RESET clears the cache, so the next request MUST be executed
+    TestCache.reset()
+    TestCache.request({Process, :send, [self(), :start, []]})
+    assert_received :start
+  end
 end

lib/gen_cache_test.exs

@@ -136,6 +136,42 @@ defmodule GenCacheTest do
     end
   end
 
+  describe "reset" do
+    test "resets cache" do
+      {:ok, pid} = GenCache.start_link([])
+      GenCache.request(pid, req_tuple(1))
+      GenCache.request(pid, req_tuple(2))
+      res = clean_state(pid)
+
+      assert res == %GenCache.Data{
+               ttl: %{
+                 {GenCacheTest.ReqBackend, :fetch, [1]} => 30000,
+                 {GenCacheTest.ReqBackend, :fetch, [2]} => 30000
+               },
+               busy: %{},
+               cache: %{
+                 {GenCacheTest.ReqBackend, :fetch, [1]} => "RESULT: 1",
+                 {GenCacheTest.ReqBackend, :fetch, [2]} => "RESULT: 2"
+               },
+               valid_until: %{},
+               purge_loop: 5000,
+               default_ttl: 30000
+             }
+
+      GenCache.reset(pid)
+      res = clean_state(pid)
+
+      assert res == %GenCache.Data{
+               ttl: %{},
+               busy: %{},
+               cache: %{},
+               valid_until: %{},
+               purge_loop: 5000,
+               default_ttl: 30000
+             }
+    end
+  end
+
   describe "raising response" do
     test "is not cached" do
       defmodule RaisingBackend do

mix.exs

@@ -2,7 +2,7 @@ defmodule GenCache.MixProject do
   use Mix.Project
 
   @github_url "https://github.com/maxohq/gen_cache"
-  @version "0.1.1"
+  @version "0.1.2"
   @description "gen_statem based generic cache with MFA-based keys"
 
   def project do