Update get_data_column_sidecars to take cells/proofs

specs/_features/eip7594/das-core.md

@@ -195,27 +195,34 @@ def recover_matrix(partial_matrix: Sequence[MatrixEntry],
 
 ```python
 def get_data_column_sidecars(signed_block: SignedBeaconBlock,
-                             blobs: Sequence[Blob]) -> Sequence[DataColumnSidecar]:
+                             cells_and_kzg_proofs: Sequence[Tuple[
+        Vector[Cell, CELLS_PER_EXT_BLOB],
+        Vector[KZGProof, CELLS_PER_EXT_BLOB]]]) -> Sequence[DataColumnSidecar]:
+    """
+    Given a signed block and the cells/proofs associated with each blob in the
+    block, assemble the sidecars which can be distributed to peers.
+
+    Since there is no method which converts cells to a blob, this method takes
+    cells/proofs instead of blobs so it can re-create sidecars after recovery.
+    """
+    blob_kzg_commitments = signed_block.message.body.blob_kzg_commitments
+    assert len(cells_and_kzg_proofs) == len(blob_kzg_commitments)
     signed_block_header = compute_signed_block_header(signed_block)
-    block = signed_block.message
     kzg_commitments_inclusion_proof = compute_merkle_proof(
-        block.body,
+        signed_block.message.body,
         get_generalized_index(BeaconBlockBody, 'blob_kzg_commitments'),
     )
-    cells_and_proofs = [compute_cells_and_kzg_proofs(blob) for blob in blobs]
-    blob_count = len(blobs)
-    cells = [cells_and_proofs[i][0] for i in range(blob_count)]
-    proofs = [cells_and_proofs[i][1] for i in range(blob_count)]
+
     sidecars = []
     for column_index in range(NUMBER_OF_COLUMNS):
-        column_cells = [cells[row_index][column_index]
-                        for row_index in range(blob_count)]
-        column_proofs = [proofs[row_index][column_index]
-                         for row_index in range(blob_count)]
+        column_cells, column_proofs = [], []
+        for cells, proofs in cells_and_kzg_proofs:
+            column_cells.append(cells[column_index])
+            column_proofs.append(proofs[column_index])
         sidecars.append(DataColumnSidecar(
             index=column_index,
             column=column_cells,
-            kzg_commitments=block.body.blob_kzg_commitments,
+            kzg_commitments=blob_kzg_commitments,
             kzg_proofs=column_proofs,
             signed_block_header=signed_block_header,
             kzg_commitments_inclusion_proof=kzg_commitments_inclusion_proof,

tests/core/pyspec/eth2spec/test/eip7594/merkle_proof/test_single_merkle_proof.py

@@ -38,7 +38,8 @@ def _run_blob_kzg_commitments_merkle_proof_test(spec, state, rng=None):
     block.body.execution_payload.transactions = [opaque_tx]
     block.body.execution_payload.block_hash = compute_el_block_hash(spec, block.body.execution_payload, state)
     signed_block = sign_block(spec, state, block, proposer_index=0)
-    column_sidcars = spec.get_data_column_sidecars(signed_block, blobs)
+    cells_and_kzg_proofs = [spec.compute_cells_and_kzg_proofs(blob) for blob in blobs]
+    column_sidcars = spec.get_data_column_sidecars(signed_block, cells_and_kzg_proofs)
     column_sidcar = column_sidcars[0]
 
     yield "object", block.body