feat: implement BeaconBlocksByRoot libp2p handler

lib/lambda_ethereum_consensus/p2p/incoming_requests/handler.ex

@@ -128,6 +128,35 @@ defmodule LambdaEthereumConsensus.P2P.IncomingRequests.Handler do
     end
   end
 
+  defp handle_req("beacon_blocks_by_root/2/ssz_snappy", message_id, message) do
+    with <<24, snappy_blocks_by_root_request::binary>> <- message,
+         {:ok, ssz_blocks_by_root_request} <- Snappy.decompress(snappy_blocks_by_root_request),
+         {:ok, blocks_by_root_request} <-
+           Ssz.from_ssz(ssz_blocks_by_root_request, SszTypes.BeaconBlocksByRootRequest) do
+      ## TODO: there should be check that the `start_slot` is not older than the `oldest_slot_with_block`
+      %SszTypes.BeaconBlocksByRootRequest{body: body} =
+        blocks_by_root_request
+
+      count = length(body)
+
+      count = min(count, ChainSpec.get("MAX_REQUEST_BLOCKS"))
+
+      "[Received BlocksByRoot Request] requested #{count} number of blocks"
+      |> Logger.info()
+
+      blocks =
+        body
+        |> Enum.slice(0..(count - 1))
+        |> Enum.map(&BlockStore.get_block/1)
+
+      response_chunk =
+        blocks
+        |> Enum.map_join(&create_block_response_chunk/1)
+
+      Libp2pPort.send_response(message_id, response_chunk)
+    end
+  end
+
   defp handle_req(protocol, _message_id, _message) do
     # This should never happen, since Libp2p only accepts registered protocols
     Logger.error("Unsupported protocol: #{protocol}")

lib/ssz_types/p2p/beacon_blocks_ by_root_response.ex

@@ -0,0 +1,17 @@
+defmodule SszTypes.BeaconBlocksByRootRequest do
+  @moduledoc """
+  Struct definition for `BeaconBlocksByRootRequest`.
+  Related definitions in `native/ssz_nif/src/types/`.
+  """
+
+  fields = [
+    :body
+  ]
+
+  @enforce_keys fields
+  defstruct fields
+
+  @type t :: %__MODULE__{
+          body: list(SszTypes.SignedBeaconBlock.t())
+        }
+end

lib/ssz_types/p2p/beacon_blocks_by_root_request.ex

@@ -0,0 +1,17 @@
+defmodule SszTypes.BeaconBlocksByRootResponse do
+  @moduledoc """
+  Struct definition for `BeaconBlocksByRootResponse`.
+  Related definitions in `native/ssz_nif/src/types/`.
+  """
+
+  fields = [
+    :body
+  ]
+
+  @enforce_keys fields
+  defstruct fields
+
+  @type t :: %__MODULE__{
+          body: list(SszTypes.root())
+        }
+end

native/ssz_nif/src/elx_types/p2p.rs

@@ -28,12 +28,28 @@ gen_struct!(
 
 gen_struct_with_config!(
     #[derive(NifStruct)]
-    #[module = "SszTypes.BeaconBlocksByRangeRequest"]
+    #[module = "SszTypes.BeaconBlocksByRangeResponse"]
     pub(crate) struct BeaconBlocksByRangeResponse<'a> {
         body: Vec<SignedBeaconBlock<'a>>,
     }
 );
 
+gen_struct!(
+    #[derive(NifStruct)]
+    #[module = "SszTypes.BeaconBlocksByRootRequest"]
+    pub(crate) struct BeaconBlocksByRootRequest<'a> {
+        body: Vec<Root<'a>>,
+    }
+);
+
+gen_struct_with_config!(
+    #[derive(NifStruct)]
+    #[module = "SszTypes.BeaconBlocksByRootResponse"]
+    pub(crate) struct BeaconBlocksByRootResponse<'a> {
+        body: Vec<SignedBeaconBlock<'a>>,
+    }
+);
+
 gen_struct_with_config!(
     #[derive(NifStruct)]
     #[module = "SszTypes.Metadata"]

native/ssz_nif/src/ssz_types/p2p.rs

@@ -27,6 +27,16 @@ pub(crate) struct BeaconBlocksByRangeResponse<C: Config> {
     pub(crate) body: VariableList<SignedBeaconBlock<C>, MaxRequestBlocks>,
 }
 
+#[derive(Encode, Decode, TreeHash)]
+pub(crate) struct BeaconBlocksByRootRequest {
+    pub(crate) body: VariableList<Root, MaxRequestBlocks>,
+}
+
+#[derive(Encode, Decode, TreeHash)]
+pub(crate) struct BeaconBlocksByRootResponse<C: Config> {
+    pub(crate) body: VariableList<SignedBeaconBlock<C>, MaxRequestBlocks>,
+}
+
 #[derive(Encode, Decode, TreeHash)]
 pub(crate) struct Metadata<C: Config> {
     pub(crate) seq_number: u64,