From 39d4f0a1f388bb4105f4c4c4a560975ce1247420 Mon Sep 17 00:00:00 2001
From: Pawan Dhananjay <pawandhananjay@gmail.com>
Date: Wed, 8 Feb 2023 13:00:18 +0530
Subject: [PATCH] Add BlobSidecar type

---
 consensus/types/src/blob_sidecar.rs | 51 +++++++++++++++++++++++++++++
 consensus/types/src/lib.rs          |  4 ++-
 crypto/kzg/src/kzg_commitment.rs    |  6 ++++
 3 files changed, 60 insertions(+), 1 deletion(-)
 create mode 100644 consensus/types/src/blob_sidecar.rs

diff --git a/consensus/types/src/blob_sidecar.rs b/consensus/types/src/blob_sidecar.rs
new file mode 100644
index 000000000..3a2012839
--- /dev/null
+++ b/consensus/types/src/blob_sidecar.rs
@@ -0,0 +1,51 @@
+use crate::test_utils::TestRandom;
+use crate::{Blob, EthSpec, Hash256, SignedRoot, Slot};
+use derivative::Derivative;
+use kzg::{KzgCommitment, KzgProof};
+use serde_derive::{Deserialize, Serialize};
+use ssz::Encode;
+use ssz_derive::{Decode, Encode};
+use test_random_derive::TestRandom;
+use tree_hash_derive::TreeHash;
+
+#[derive(
+    Debug,
+    Clone,
+    Serialize,
+    Deserialize,
+    Encode,
+    Decode,
+    TreeHash,
+    Default,
+    TestRandom,
+    Derivative,
+    arbitrary::Arbitrary,
+)]
+#[serde(bound = "T: EthSpec")]
+#[arbitrary(bound = "T: EthSpec")]
+#[derivative(PartialEq, Hash(bound = "T: EthSpec"))]
+pub struct BlobSidecar<T: EthSpec> {
+    pub block_root: Hash256,
+    // TODO: fix the type, should fit in u8 as well
+    pub index: u64,
+    pub slot: Slot,
+    pub block_parent_root: Hash256,
+    pub proposer_index: u64,
+    pub blob: Blob<T>,
+    pub kzg_commitment: KzgCommitment,
+    pub kzg_proof: KzgProof,
+}
+
+impl<T: EthSpec> SignedRoot for BlobSidecar<T> {}
+
+impl<T: EthSpec> BlobSidecar<T> {
+    pub fn empty() -> Self {
+        Self::default()
+    }
+
+    #[allow(clippy::integer_arithmetic)]
+    pub fn max_size() -> usize {
+        // Fixed part
+        Self::empty().as_ssz_bytes().len()
+    }
+}
diff --git a/consensus/types/src/lib.rs b/consensus/types/src/lib.rs
index 380f5e527..4ec740eff 100644
--- a/consensus/types/src/lib.rs
+++ b/consensus/types/src/lib.rs
@@ -99,6 +99,7 @@ pub mod slot_data;
 #[cfg(feature = "sqlite")]
 pub mod sqlite;
 
+pub mod blob_sidecar;
 pub mod blobs_sidecar;
 pub mod signed_block_and_blobs;
 pub mod transaction;
@@ -121,7 +122,8 @@ pub use crate::beacon_block_body::{
 pub use crate::beacon_block_header::BeaconBlockHeader;
 pub use crate::beacon_committee::{BeaconCommittee, OwnedBeaconCommittee};
 pub use crate::beacon_state::{BeaconTreeHashCache, Error as BeaconStateError, *};
-pub use crate::blobs_sidecar::{Blobs, BlobsSidecar, KzgCommitments};
+pub use crate::blob_sidecar::BlobSidecar;
+pub use crate::blobs_sidecar::BlobsSidecar;
 pub use crate::bls_to_execution_change::BlsToExecutionChange;
 pub use crate::chain_spec::{ChainSpec, Config, Domain};
 pub use crate::checkpoint::Checkpoint;
diff --git a/crypto/kzg/src/kzg_commitment.rs b/crypto/kzg/src/kzg_commitment.rs
index 16fe1d830..7a43d7009 100644
--- a/crypto/kzg/src/kzg_commitment.rs
+++ b/crypto/kzg/src/kzg_commitment.rs
@@ -20,6 +20,12 @@ impl Display for KzgCommitment {
     }
 }
 
+impl Default for KzgCommitment {
+    fn default() -> Self {
+        KzgCommitment([0; KZG_COMMITMENT_BYTES_LEN])
+    }
+}
+
 impl TreeHash for KzgCommitment {
     fn tree_hash_type() -> tree_hash::TreeHashType {
         <[u8; KZG_COMMITMENT_BYTES_LEN] as TreeHash>::tree_hash_type()