Hotfix for Optimism Ecotone batch blobs indexing (#9646)

* Hotfix for Optimism Ecotone batch blobs indexing

* Update changelog

---------

Co-authored-by: POA <33550681+poa@users.noreply.github.com>

CHANGELOG.md

@@ -21,6 +21,7 @@
 
 ### Fixes
 
+- [#9646](https://github.com/blockscout/blockscout/pull/9646) - Hotfix for Optimism Ecotone batch blobs indexing
 - [#9640](https://github.com/blockscout/blockscout/pull/9640) - Fix no function clause matching in `BENS.item_to_address_hash_strings/1`
 - [#9638](https://github.com/blockscout/blockscout/pull/9638) - Do not broadcast coin balance changes with empty value/delta
 - [#9635](https://github.com/blockscout/blockscout/pull/9635) - Reset missing ranges collector to max number after the cycle is done

apps/explorer/lib/explorer/chain/optimism/txn_batch.ex

@@ -102,13 +102,13 @@ defmodule Explorer.Chain.Optimism.TxnBatch do
         end
       end)
 
-    Enum.each(Range.new(output_len, byte_size(output) - 1), fn i ->
+    Enum.each(Range.new(output_len, byte_size(output) - 1, 1), fn i ->
       <<0>> = binary_part(output, i, 1)
     end)
 
     output = binary_part(output, 0, output_len)
 
-    Enum.each(Range.new(ipos, @blob_size - 1), fn i ->
+    Enum.each(Range.new(ipos, @blob_size - 1, 1), fn i ->
       <<0>> = binary_part(b, i, 1)
     end)
 
@@ -118,10 +118,10 @@ defmodule Explorer.Chain.Optimism.TxnBatch do
   end
 
   defp decode_eip4844_field_element(b, opos, ipos, output) do
-    <<_::binary-size(ipos), ipos_byte::size(8), insert::binary-size(32), _::binary>> = b
+    <<_::binary-size(ipos), ipos_byte::size(8), insert::binary-size(31), _::binary>> = b
 
     if Bitwise.band(ipos_byte, 0b11000000) == 0 do
-      <<output_before_opos::binary-size(opos), _::binary-size(32), rest::binary>> = output
+      <<output_before_opos::binary-size(opos), _::binary-size(31), rest::binary>> = output
 
       {ipos_byte, opos + 32, ipos + 32, output_before_opos <> insert <> rest}
     end

apps/indexer/lib/indexer/fetcher/optimism/txn_batch.ex

@@ -409,8 +409,9 @@ defmodule Indexer.Fetcher.Optimism.TxnBatch do
     end
   end
 
-  defp blobs_to_input(transaction_hash, blob_versioned_hashes, block_timestamp, blobs_api_url) do
-    Enum.reduce(blob_versioned_hashes, <<>>, fn blob_hash, acc ->
+  defp blobs_to_inputs(transaction_hash, blob_versioned_hashes, block_timestamp, blobs_api_url) do
+    blob_versioned_hashes
+    |> Enum.reduce([], fn blob_hash, acc ->
       with {:ok, response} <- http_get_request(blobs_api_url <> "/" <> blob_hash),
            blob_data = Map.get(response, "blob_data"),
            false <- is_nil(blob_data) do
@@ -425,8 +426,11 @@ defmodule Indexer.Fetcher.Optimism.TxnBatch do
           Logger.warning("Cannot decode the blob #{blob_hash} taken from the Blockscout Blobs API.")
           acc
         else
-          Logger.info("The input for transaction #{transaction_hash} is taken from the Blockscout Blobs API.")
-          acc <> decoded
+          Logger.info(
+            "The input for transaction #{transaction_hash} is taken from the Blockscout Blobs API. Blob hash: #{blob_hash}"
+          )
+
+          [decoded | acc]
         end
       else
         _ ->
@@ -470,8 +474,11 @@ defmodule Indexer.Fetcher.Optimism.TxnBatch do
             if is_nil(decoded_blob_data) do
               raise "Invalid blob"
             else
-              Logger.info("The input for transaction #{transaction_hash} is taken from the Beacon Node.")
-              acc <> decoded_blob_data
+              Logger.info(
+                "The input for transaction #{transaction_hash} is taken from the Beacon Node. Blob hash: #{blob_hash}"
+              )
+
+              [decoded_blob_data | acc]
             end
           rescue
             reason ->
@@ -483,6 +490,7 @@ defmodule Indexer.Fetcher.Optimism.TxnBatch do
           end
       end
     end)
+    |> Enum.reverse()
   end
 
   defp get_txn_batches_inner(
@@ -496,30 +504,31 @@ defmodule Indexer.Fetcher.Optimism.TxnBatch do
     transactions_filtered
     |> Enum.reduce({:ok, incomplete_channels, [], []}, fn tx,
                                                           {_, incomplete_channels_acc, batches_acc, sequences_acc} ->
-      input =
+      inputs =
         if tx.type == 3 do
-          # this is EIP-4844 transaction, so we get the input from the blobs
+          # this is EIP-4844 transaction, so we get the inputs from the blobs
           block_timestamp = get_block_timestamp_by_number(tx.block_number, blocks_params)
-          blobs_to_input(tx.hash, tx.blob_versioned_hashes, block_timestamp, blobs_api_url)
+          blobs_to_inputs(tx.hash, tx.blob_versioned_hashes, block_timestamp, blobs_api_url)
         else
-          tx.input
+          [tx.input]
         end
 
-      if tx.type == 3 and input == <<>> do
-        # skip this transaction as we cannot find or read its blobs
-        {:ok, incomplete_channels_acc, batches_acc, sequences_acc}
-      else
+      Enum.reduce(inputs, {:ok, incomplete_channels_acc, batches_acc, sequences_acc}, fn input,
+                                                                                         {_,
+                                                                                          new_incomplete_channels_acc,
+                                                                                          new_batches_acc,
+                                                                                          new_sequences_acc} ->
         handle_input(
           input,
           tx,
           blocks_params,
-          incomplete_channels_acc,
-          batches_acc,
-          sequences_acc,
+          new_incomplete_channels_acc,
+          new_batches_acc,
+          new_sequences_acc,
           genesis_block_l2,
           json_rpc_named_arguments_l2
         )
-      end
+      end)
     end)
   end