feat: add batch update specific discriminator (#1579)

Author: ananas-block

program-libs/account-checks/src/discriminator.rs

@@ -1,6 +1,5 @@
 pub const ANCHOR_DISCRIMINATOR_LEN: usize = 8;
 
-
 pub trait Discriminator<const T: usize> {
     const DISCRIMINATOR: [u8; T];
     fn discriminator() -> [u8; T] {

program-libs/batched-merkle-tree/src/event.rs

@@ -1,11 +1,13 @@
 use crate::{BorshDeserialize, BorshSerialize};
 
-pub const BATCH_EVENT_DISCRIMINATOR: [u8; 8] = *b"BatchEvt";
+pub const BATCH_APPEND_EVENT_DISCRIMINATOR: u16 = 1;
+pub const BATCH_NULLIFY_EVENT_DISCRIMINATOR: u16 = 2;
+pub const BATCH_ADDRESS_APPEND_EVENT_DISCRIMINATOR: u16 = 3;
 
 #[repr(C)]
 #[derive(BorshDeserialize, BorshSerialize, Debug, PartialEq)]
 pub struct BatchAppendEvent {
-    pub discriminator: [u8; 8],
+    pub discriminator: u16,
     pub tree_type: u64,
     pub merkle_tree_pubkey: [u8; 32],
     pub batch_index: u64,

program-libs/batched-merkle-tree/src/merkle_tree.rs

@@ -34,7 +34,9 @@ use crate::{
     },
     errors::BatchedMerkleTreeError,
     event::{
-        BatchAddressAppendEvent, BatchAppendEvent, BatchNullifyEvent, BATCH_EVENT_DISCRIMINATOR,
+        BatchAddressAppendEvent, BatchAppendEvent, BatchNullifyEvent,
+        BATCH_ADDRESS_APPEND_EVENT_DISCRIMINATOR, BATCH_APPEND_EVENT_DISCRIMINATOR,
+        BATCH_NULLIFY_EVENT_DISCRIMINATOR,
     },
     merkle_tree_metadata::BatchedMerkleTreeMetadata,
     queue::{
@@ -431,7 +433,7 @@ impl<'a> BatchedMerkleTreeAccount<'a> {
         }
         // 6. Return the batch append event.
         Ok(BatchAppendEvent {
-            discriminator: BATCH_EVENT_DISCRIMINATOR,
+            discriminator: BATCH_APPEND_EVENT_DISCRIMINATOR,
             tree_type: self.tree_type,
             merkle_tree_pubkey: self.pubkey.to_bytes(),
             output_queue_pubkey: Some(queue_account.pubkey().to_bytes()),
@@ -550,10 +552,15 @@ impl<'a> BatchedMerkleTreeAccount<'a> {
             // Needs to be executed post mark_as_inserted_in_merkle_tree.
             self.zero_out_previous_batch_bloom_filter()?;
         }
+        let discriminator = if QueueType::from(QUEUE_TYPE) == QueueType::BatchedInput {
+            BATCH_NULLIFY_EVENT_DISCRIMINATOR
+        } else {
+            BATCH_ADDRESS_APPEND_EVENT_DISCRIMINATOR
+        };
 
         // 6. Return the batch nullify/address append event.
         Ok(BatchNullifyEvent {
-            discriminator: BATCH_EVENT_DISCRIMINATOR,
+            discriminator,
             tree_type: self.tree_type,
             merkle_tree_pubkey: self.pubkey.to_bytes(),
             batch_index: pending_batch_index as u64,
@@ -975,7 +982,7 @@ pub fn assert_nullify_event(
         .unwrap();
     let ref_event = BatchNullifyEvent {
         merkle_tree_pubkey: mt_pubkey.to_bytes(),
-        discriminator: BATCH_EVENT_DISCRIMINATOR,
+        discriminator: BATCH_NULLIFY_EVENT_DISCRIMINATOR,
         tree_type: old_account.tree_type,
         output_queue_pubkey: None,
         batch_index,
@@ -1006,7 +1013,7 @@ pub fn assert_batch_append_event_event(
         .unwrap();
     let ref_event = BatchAppendEvent {
         merkle_tree_pubkey: mt_pubkey.to_bytes(),
-        discriminator: BATCH_EVENT_DISCRIMINATOR,
+        discriminator: BATCH_APPEND_EVENT_DISCRIMINATOR,
         tree_type: old_account.tree_type,
         output_queue_pubkey: Some(old_output_queue_account.pubkey().to_bytes()),
         batch_index,
@@ -1036,7 +1043,7 @@ pub fn assert_batch_adress_event(
         .unwrap();
     let ref_event = BatchAppendEvent {
         merkle_tree_pubkey: mt_pubkey.to_bytes(),
-        discriminator: BATCH_EVENT_DISCRIMINATOR,
+        discriminator: BATCH_ADDRESS_APPEND_EVENT_DISCRIMINATOR,
         tree_type: old_account.tree_type,
         output_queue_pubkey: None,
         batch_index,