Add genesis blockhash to blobs (#3953)

core/src/packet.rs

@@ -5,6 +5,7 @@ use bincode;
 use byteorder::{ByteOrder, LittleEndian};
 use serde::Serialize;
 use solana_metrics::counter::Counter;
+use solana_sdk::hash::Hash;
 pub use solana_sdk::packet::PACKET_DATA_SIZE;
 use solana_sdk::pubkey::Pubkey;
 use std::borrow::Borrow;
@@ -354,7 +355,8 @@ const SLOT_RANGE: std::ops::Range<usize> = range!(PARENT_RANGE.end, u64);
 const INDEX_RANGE: std::ops::Range<usize> = range!(SLOT_RANGE.end, u64);
 const ID_RANGE: std::ops::Range<usize> = range!(INDEX_RANGE.end, Pubkey);
 const FORWARDED_RANGE: std::ops::Range<usize> = range!(ID_RANGE.end, bool);
-const FLAGS_RANGE: std::ops::Range<usize> = range!(FORWARDED_RANGE.end, u32);
+const GENESIS_RANGE: std::ops::Range<usize> = range!(FORWARDED_RANGE.end, Hash);
+const FLAGS_RANGE: std::ops::Range<usize> = range!(GENESIS_RANGE.end, u32);
 const SIZE_RANGE: std::ops::Range<usize> = range!(FLAGS_RANGE.end, u64);
 
 macro_rules! align {
@@ -435,6 +437,14 @@ impl Blob {
         self.data[FORWARDED_RANGE][0] = u8::from(forward)
     }
 
+    pub fn set_genesis_blockhash(&mut self, blockhash: &Hash) {
+        self.data[GENESIS_RANGE].copy_from_slice(blockhash.as_ref())
+    }
+
+    pub fn genesis_blockhash(&self) -> Hash {
+        Hash::new(&self.data[GENESIS_RANGE])
+    }
+
     pub fn flags(&self) -> u32 {
         LittleEndian::read_u32(&self.data[FLAGS_RANGE])
     }
@@ -573,12 +583,24 @@ impl Blob {
     }
 }
 
-pub fn index_blobs(blobs: &[SharedBlob], id: &Pubkey, mut blob_index: u64, slot: u64, parent: u64) {
+pub fn index_blobs(blobs: &[SharedBlob], id: &Pubkey, blob_index: u64, slot: u64, parent: u64) {
+    index_blobs_with_genesis(blobs, id, &Hash::default(), blob_index, slot, parent)
+}
+
+pub fn index_blobs_with_genesis(
+    blobs: &[SharedBlob],
+    id: &Pubkey,
+    genesis: &Hash,
+    mut blob_index: u64,
+    slot: u64,
+    parent: u64,
+) {
     // enumerate all the blobs, those are the indices
     for blob in blobs.iter() {
         let mut blob = blob.write().unwrap();
 
         blob.set_index(blob_index);
+        blob.set_genesis_blockhash(genesis);
         blob.set_slot(slot);
         blob.set_parent(parent);
         blob.set_id(id);
@@ -837,4 +859,14 @@ mod tests {
         assert!(p1 != p2);
     }
 
+    #[test]
+    fn test_blob_genesis_blockhash() {
+        let mut blob = Blob::default();
+        assert_eq!(blob.genesis_blockhash(), Hash::default());
+
+        let hash = Hash::new(&Pubkey::new_rand().as_ref());
+        blob.set_genesis_blockhash(&hash);
+        assert_eq!(blob.genesis_blockhash(), hash);
+    }
+
 }