From 66db32f2e7f7032350b031f8b5a710a2d8dcb23a Mon Sep 17 00:00:00 2001
From: wires <wires@noreply.wires.systems>
Date: Mon, 7 Apr 2025 11:20:18 -0400
Subject: [PATCH] reduce messaging to vnode manager

---
 apps/kv/src/kv_vnode_manager.erl | 43 ++++++++++++++++++--------------
 1 file changed, 24 insertions(+), 19 deletions(-)

diff --git a/apps/kv/src/kv_vnode_manager.erl b/apps/kv/src/kv_vnode_manager.erl
index ee8f07c..8bcc42e 100644
--- a/apps/kv/src/kv_vnode_manager.erl
+++ b/apps/kv/src/kv_vnode_manager.erl
@@ -11,9 +11,7 @@
 %%% gen_server callbacks
 -export([init/1, handle_call/3, handle_cast/2]).
 
--record(kv_vnode_manager, {table :: ets:table()}).
-
--type state() :: #kv_vnode_manager{}.
+-type state() :: {}.
 
 %%% public api
 
@@ -23,37 +21,44 @@ start_link() ->
 -spec get_local(Key :: binary()) -> {ok, Value :: term()} | none.
 get_local(Key) ->
     Index = kv_ring:key_to_index(Key),
-    gen_server:call(?MODULE, {get, Index, Key}).
+    VNode = get_vnode(Index),
+    kv_vnode:get(VNode, Key).
 
 -spec put_local(Key :: binary(), Value :: term()) -> ok.
 put_local(Key, Value) ->
     Index = kv_ring:key_to_index(Key),
-    gen_server:cast(?MODULE, {put, Index, Key, Value}).
+    VNode = get_vnode(Index),
+    kv_vnode:put(VNode, Key, Value).
 
 %%% gen_server callbacks
 
 -spec init([]) -> {ok, state()}.
 init([]) ->
-    {ok, #kv_vnode_manager{table = ets:new(?MODULE, [set])}}.
+    ?MODULE = ets:new(?MODULE, [set, protected, named_table, {read_concurrency, true}]),
+    {ok, {}}.
 
-handle_call({get, Index, Key}, _From, State) ->
-    VNode = get_vnode(Index, State),
-    {reply, kv_vnode:get(VNode, Key), State}.
+handle_call({get_vnode, Index}, _From, State) ->
+    VNode =
+        case ets:lookup(?MODULE, Index) of
+            [{_, Pid}] ->
+                Pid;
+            [] ->
+                {ok, Pid} = kv_vnode_sup:start_vnode(Index),
+                ets:insert(?MODULE, {Index, Pid}),
+                Pid
+        end,
+    {reply, VNode, State}.
 
-handle_cast({put, Index, Key, Value}, State) ->
-    VNode = get_vnode(Index, State),
-    ok = kv_vnode:put(VNode, Key, Value),
-    {noreply, State}.
+handle_cast(_, _) ->
+    error(not_implemented).
 
 %%% internal functions
 
--spec get_vnode(Index :: kv_ring:index(), state()) -> pid().
-get_vnode(Index, #kv_vnode_manager{table = Table}) ->
-    case ets:lookup(Table, Index) of
+-spec get_vnode(Index :: kv_ring:index()) -> pid().
+get_vnode(Index) ->
+    case ets:lookup(?MODULE, Index) of
         [{_, Pid}] ->
             Pid;
         [] ->
-            {ok, Pid} = kv_vnode_sup:start_vnode(Index),
-            ets:insert(Table, {Index, Pid}),
-            Pid
+            gen_server:call(?MODULE, {get_vnode, Index})
     end.