removes Shred::new_empty_data_shred (#24714)

Shred::new_empty_data_shred returns an invalid shred (i.e.
shred.sanitize() returns error). The method is only used in tests and
can be easily replaced with Shred::new_from_data. To keep the shred api
surface small, this commit removes this method.

core/benches/cluster_info.rs

@@ -51,7 +51,8 @@ fn broadcast_shreds_bench(bencher: &mut Bencher) {
     let bank_forks = Arc::new(RwLock::new(BankForks::new(bank)));
 
     const NUM_SHREDS: usize = 32;
-    let shreds = vec![Shred::new_empty_data_shred(); NUM_SHREDS];
+    let shred = Shred::new_from_data(0, 0, 0, None, false, false, 0, 0, 0);
+    let shreds = vec![shred; NUM_SHREDS];
     let mut stakes = HashMap::new();
     const NUM_PEERS: usize = 200;
     for _ in 0..NUM_PEERS {

core/benches/cluster_nodes.rs

@@ -14,7 +14,7 @@ use {
         shred::Shred,
     },
     solana_runtime::bank::Bank,
-    solana_sdk::pubkey::Pubkey,
+    solana_sdk::{clock::Slot, pubkey::Pubkey},
     test::Bencher,
 };
 
@@ -31,16 +31,18 @@ fn make_cluster_nodes<R: Rng>(
 
 fn get_retransmit_peers_deterministic(
     cluster_nodes: &ClusterNodes<RetransmitStage>,
-    shred: &mut Shred,
+    slot: Slot,
     slot_leader: &Pubkey,
     root_bank: &Bank,
     num_simulated_shreds: usize,
 ) {
+    let parent_offset = if slot == 0 { 0 } else { 1 };
     for i in 0..num_simulated_shreds {
-        shred.set_index(i as u32);
+        let index = i as u32;
+        let shred = Shred::new_from_data(slot, index, parent_offset, None, false, false, 0, 0, 0);
         let (_neighbors, _children) = cluster_nodes.get_retransmit_peers(
             *slot_leader,
-            shred,
+            &shred,
             root_bank,
             solana_gossip::cluster_info::DATA_PLANE_FANOUT,
         );
@@ -54,12 +56,10 @@ fn get_retransmit_peers_deterministic_wrapper(b: &mut Bencher, unstaked_ratio: O
     let (nodes, cluster_nodes) = make_cluster_nodes(&mut rng, unstaked_ratio);
     let slot_leader = nodes[1..].choose(&mut rng).unwrap().id;
     let slot = rand::random::<u64>();
-    let mut shred = Shred::new_empty_data_shred();
-    shred.set_slot(slot);
     b.iter(|| {
         get_retransmit_peers_deterministic(
             &cluster_nodes,
-            &mut shred,
+            slot,
             &slot_leader,
             &bank,
             NUM_SIMULATED_SHREDS,

core/src/outstanding_requests.rs

@@ -107,7 +107,7 @@ pub(crate) mod tests {
         let repair_type = ShredRepairType::Orphan(9);
         let mut outstanding_requests = OutstandingRequests::default();
         let nonce = outstanding_requests.add_request(repair_type, timestamp());
-        let shred = Shred::new_empty_data_shred();
+        let shred = Shred::new_from_data(0, 0, 0, None, false, false, 0, 0, 0);
 
         let expire_timestamp = outstanding_requests
             .requests
@@ -127,7 +127,7 @@ pub(crate) mod tests {
         let mut outstanding_requests = OutstandingRequests::default();
         let nonce = outstanding_requests.add_request(repair_type, timestamp());
 
-        let shred = Shred::new_empty_data_shred();
+        let shred = Shred::new_from_data(0, 0, 0, None, false, false, 0, 0, 0);
         let mut expire_timestamp = outstanding_requests
             .requests
             .get(&nonce)

core/src/serve_repair.rs

@@ -1305,6 +1305,9 @@ mod tests {
 
     #[test]
     fn test_verify_shred_response() {
+        fn new_test_data_shred(slot: Slot, index: u32) -> Shred {
+            Shred::new_from_data(slot, index, 1, None, false, false, 0, 0, 0)
+        }
         let repair = ShredRepairType::Orphan(9);
         // Ensure new options are addded to this test
         match repair {
@@ -1317,41 +1320,34 @@ mod tests {
         let index = 5;
 
         // Orphan
-        let mut shred = Shred::new_empty_data_shred();
-        shred.set_slot(slot);
+        let shred = new_test_data_shred(slot, 0);
         let request = ShredRepairType::Orphan(slot);
         assert!(request.verify_response(&shred));
-        shred.set_slot(slot - 1);
+        let shred = new_test_data_shred(slot - 1, 0);
         assert!(request.verify_response(&shred));
-        shred.set_slot(slot + 1);
+        let shred = new_test_data_shred(slot + 1, 0);
         assert!(!request.verify_response(&shred));
 
         // HighestShred
-        shred = Shred::new_empty_data_shred();
-        shred.set_slot(slot);
-        shred.set_index(index);
+        let shred = new_test_data_shred(slot, index);
         let request = ShredRepairType::HighestShred(slot, index as u64);
         assert!(request.verify_response(&shred));
-        shred.set_index(index + 1);
+        let shred = new_test_data_shred(slot, index + 1);
         assert!(request.verify_response(&shred));
-        shred.set_index(index - 1);
+        let shred = new_test_data_shred(slot, index - 1);
         assert!(!request.verify_response(&shred));
-        shred.set_slot(slot - 1);
-        shred.set_index(index);
+        let shred = new_test_data_shred(slot - 1, index);
         assert!(!request.verify_response(&shred));
-        shred.set_slot(slot + 1);
+        let shred = new_test_data_shred(slot + 1, index);
         assert!(!request.verify_response(&shred));
 
         // Shred
-        shred = Shred::new_empty_data_shred();
-        shred.set_slot(slot);
-        shred.set_index(index);
+        let shred = new_test_data_shred(slot, index);
         let request = ShredRepairType::Shred(slot, index as u64);
         assert!(request.verify_response(&shred));
-        shred.set_index(index + 1);
+        let shred = new_test_data_shred(slot, index + 1);
         assert!(!request.verify_response(&shred));
-        shred.set_slot(slot + 1);
-        shred.set_index(index);
+        let shred = new_test_data_shred(slot + 1, index);
         assert!(!request.verify_response(&shred));
     }
 

ledger/src/shred.rs

@@ -371,7 +371,7 @@ impl Shred {
         position: u16,
         version: u16,
     ) -> Self {
-        let header = ShredCommonHeader {
+        let common_header = ShredCommonHeader {
             shred_type: ShredType::Code,
             index,
             slot,
@@ -384,14 +384,6 @@ impl Shred {
             num_coding_shreds,
             position,
         };
-        Shred::new_empty_from_header(header, DataShredHeader::default(), coding_header)
-    }
-
-    fn new_empty_from_header(
-        common_header: ShredCommonHeader,
-        data_header: DataShredHeader,
-        coding_header: CodingShredHeader,
-    ) -> Self {
         let mut payload = vec![0; SHRED_PAYLOAD_SIZE];
         let mut start = 0;
         Self::serialize_obj_into(
@@ -401,38 +393,21 @@ impl Shred {
             &common_header,
         )
         .expect("Failed to write header into shred buffer");
-        match common_header.shred_type {
-            ShredType::Data => Self::serialize_obj_into(
-                &mut start,
-                SIZE_OF_DATA_SHRED_HEADER,
-                &mut payload,
-                &data_header,
-            )
-            .expect("Failed to write data header into shred buffer"),
-            ShredType::Code => Self::serialize_obj_into(
-                &mut start,
-                SIZE_OF_CODING_SHRED_HEADER,
-                &mut payload,
-                &coding_header,
-            )
-            .expect("Failed to write coding header into shred buffer"),
-        };
+        Self::serialize_obj_into(
+            &mut start,
+            SIZE_OF_CODING_SHRED_HEADER,
+            &mut payload,
+            &coding_header,
+        )
+        .expect("Failed to write coding header into shred buffer");
         Shred {
             common_header,
-            data_header,
+            data_header: DataShredHeader::default(),
             coding_header,
             payload,
         }
     }
 
-    pub fn new_empty_data_shred() -> Self {
-        Self::new_empty_from_header(
-            ShredCommonHeader::default(),
-            DataShredHeader::default(),
-            CodingShredHeader::default(),
-        )
-    }
-
     /// Unique identifier for each shred.
     pub fn id(&self) -> ShredId {
         ShredId(self.slot(), self.index(), self.shred_type())