Move transaction_hashes to transactions fetching to single query

Co-authored-by: jimmay5469 <jimmay5469@gmail.com>

apps/explorer/lib/explorer/chain.ex

@@ -603,6 +603,44 @@ defmodule Explorer.Chain do
     end
   end
 
+  @doc """
+  Converts list of `t:Explorer.Chain.Transaction.t/0` `hashes` to the list of `t:Explorer.Chain.Transaction.t/0`s for
+  those `hashes`.
+
+  Returns list of `%Explorer.Chain.Transaction{}`s if found
+
+      iex> [%Transaction{hash: hash1}, %Transaction{hash: hash2}] = insert_list(2, :transaction)
+      iex> [%Explorer.Chain.Transaction{hash: found_hash1}, %Explorer.Chain.Transaction{hash: found_hash2}] =
+      ...>   Explorer.Chain.hashes_to_transactions([hash1, hash2])
+      iex> found_hash1 == hash1
+      true
+      iex> found_hash2 == hash2
+      true
+
+  Returns `[]` if not found
+
+      iex> {:ok, hash} = Explorer.Chain.string_to_transaction_hash(
+      ...>   "0x9fc76417374aa880d4449a1f7f31ec597f00b1f6f3dd2d66f4c9c6c445836d8b"
+      ...> )
+      iex> Explorer.Chain.hashes_to_transactions([hash])
+      []
+
+  ## Options
+
+    * `:necessity_by_association` - use to load `t:association/0` as `:required` or `:optional`.  If an association is
+      `:required`, and the `t:Explorer.Chain.Transaction.t/0` has no associated record for that association, then the
+      `t:Explorer.Chain.Transaction.t/0` will not be included in the page `entries`.
+  """
+  @spec hashes_to_transactions([Hash.Full.t()], [necessity_by_association_option]) :: [Transaction.t()] | []
+  def hashes_to_transactions(hashes, options \\ []) when is_list(hashes) and is_list(options) do
+    necessity_by_association = Keyword.get(options, :necessity_by_association, %{})
+
+    fetch_transactions()
+    |> where([transaction], transaction.hash in ^hashes)
+    |> join_associations(necessity_by_association)
+    |> Repo.all()
+  end
+
   @doc """
   Bulk insert blocks from a list of blocks.
 

apps/explorer/test/explorer/chain_test.exs

@@ -4,7 +4,7 @@ defmodule Explorer.ChainTest do
   import Explorer.Factory
 
   alias Explorer.{Chain, Factory, PagingOptions, Repo}
-  alias Explorer.Chain.{Address, Block, InternalTransaction, Log, SmartContract, Transaction, Wei}
+  alias Explorer.Chain.{Address, Block, Hash, InternalTransaction, Log, SmartContract, Transaction, Wei}
   alias Explorer.Chain.Supply.ProofOfAuthority
 
   doctest Explorer.Chain
@@ -404,6 +404,35 @@ defmodule Explorer.ChainTest do
     end
   end
 
+  describe "hashes_to_transactions/2" do
+    test "with transaction with block required without block returns nil" do
+      [%Transaction{hash: hash_with_block1}, %Transaction{hash: hash_with_block2}] =
+        2
+        |> insert_list(:transaction)
+        |> with_block()
+
+      [%Transaction{hash: hash_without_index1}, %Transaction{hash: hash_without_index2}] = insert_list(2, :transaction)
+
+      assert [%Transaction{hash: ^hash_with_block2}, %Transaction{hash: ^hash_with_block1}] =
+               Chain.hashes_to_transactions(
+                 [hash_with_block1, hash_with_block2],
+                 necessity_by_association: %{block: :required}
+               )
+
+      assert [] =
+               Chain.hashes_to_transactions(
+                 [hash_without_index1, hash_without_index2],
+                 necessity_by_association: %{block: :required}
+               )
+
+      assert [%Transaction{hash: ^hash_without_index1}, %Transaction{hash: ^hash_without_index2}] =
+               Chain.hashes_to_transactions(
+                 [hash_without_index1, hash_without_index2],
+                 necessity_by_association: %{block: :optional}
+               )
+    end
+  end
+
   describe "list_blocks/2" do
     test "without blocks" do
       assert [] = Chain.list_blocks()
@@ -1545,6 +1574,12 @@ defmodule Explorer.ChainTest do
       assert_received {:chain_event, :logs, [%Log{}]}
     end
 
+    test "publishes transaction hashes data to subscribers on insert" do
+      Chain.subscribe_to_events(:transactions)
+      Chain.import_blocks(@import_data)
+      assert_received {:chain_event, :transactions, [%Hash{}]}
+    end
+
     test "does not broadcast if broadcast option is false" do
       non_broadcast_data = Keyword.merge(@import_data, broadcast: false)
 

apps/explorer_web/lib/explorer_web/notifier.ex

@@ -20,7 +20,11 @@ defmodule ExplorerWeb.Notifier do
   end
 
   def handle_event({:chain_event, :transactions, transaction_hashes}) do
-    Enum.each(transaction_hashes, &broadcast_transaction/1)
+    transaction_hashes
+    |> Chain.hashes_to_transactions(
+      necessity_by_association: %{block: :required, from_address: :optional, to_address: :optional}
+    )
+    |> Enum.each(&broadcast_transaction/1)
   end
 
   defp broadcast_balance(%Address{hash: address_hash} = address) do
@@ -30,26 +34,17 @@ defmodule ExplorerWeb.Notifier do
     })
   end
 
-  defp broadcast_transaction(transaction_hash) do
-    case Chain.hash_to_transaction(
-           transaction_hash,
-           necessity_by_association: %{block: :required, from_address: :optional, to_address: :optional}
-         ) do
-      {:ok, transaction} ->
-        Endpoint.broadcast("addresses:#{transaction.from_address_hash}", "transaction", %{
-          address: transaction.from_address,
-          transaction: transaction
-        })
-
-        if transaction.to_address_hash && transaction.to_address_hash != transaction.from_address_hash do
-          Endpoint.broadcast("addresses:#{transaction.to_address_hash}", "transaction", %{
-            address: transaction.to_address,
-            transaction: transaction
-          })
-        end
+  defp broadcast_transaction(transaction) do
+    Endpoint.broadcast("addresses:#{transaction.from_address_hash}", "transaction", %{
+      address: transaction.from_address,
+      transaction: transaction
+    })
 
-      {:error, _} ->
-        nil
+    if transaction.to_address_hash && transaction.to_address_hash != transaction.from_address_hash do
+      Endpoint.broadcast("addresses:#{transaction.to_address_hash}", "transaction", %{
+        address: transaction.to_address,
+        transaction: transaction
+      })
     end
   end
 end

apps/explorer_web/test/explorer_web/features/viewing_addresses_test.exs

@@ -233,18 +233,20 @@ defmodule ExplorerWeb.ViewingAddressesTest do
   end
 
   test "viewing new transactions via live update", %{addresses: addresses, session: session} do
-    transaction =
-      :transaction
-      |> insert(from_address: addresses.lincoln)
+    [transaction1, transaction2] =
+      2
+      |> insert_list(:transaction, from_address: addresses.lincoln)
       |> with_block()
 
     session
     |> AddressPage.visit_page(addresses.lincoln)
     |> assert_has(AddressPage.balance())
 
-    Notifier.handle_event({:chain_event, :transactions, [transaction.hash]})
+    Notifier.handle_event({:chain_event, :transactions, [transaction1.hash, transaction2.hash]})
 
-    assert_has(session, AddressPage.transaction(transaction))
+    session
+    |> assert_has(AddressPage.transaction(transaction1))
+    |> assert_has(AddressPage.transaction(transaction2))
   end
 
   test "transaction count live updates", %{addresses: addresses, session: session} do