feat: no need to indexing of sync strategy

waku/waku_rln_relay/group_manager/on_chain/group_manager.nim

@@ -68,7 +68,6 @@ type
     validRootBuffer*: Deque[MerkleNode]
     # interval loop to shut down gracefully
     blockFetchingActive*: bool
-    merkleProofsByIndex*: Table[Uint256, seq[Uint256]]
 
 const DefaultKeyStorePath* = "rlnKeystore.json"
 const DefaultKeyStorePassword* = "password"
@@ -92,16 +91,6 @@ template retryWrapper(
   retryWrapper(res, RetryStrategy.new(), errStr, g.onFatalErrorAction):
     body
 
-proc fetchMerkleProof*(g: OnchainGroupManager, index: Uint256) {.async.} =
-  ## Fetches and caches the Merkle proof elements for a given index
-  try:
-    let merkleProofInvocation = g.wakuRlnContract.get().merkleProofElements(index)
-    let merkleProof = await merkleProofInvocation.call()
-      # Await the contract call and extract the result
-    g.merkleProofsByIndex[index] = merkleProof
-  except CatchableError:
-    error "Failed to fetch merkle proof: " & getCurrentExceptionMsg()
-
 proc setMetadata*(
     g: OnchainGroupManager, lastProcessedBlock = none(BlockNumber)
 ): GroupManagerResult[void] =
@@ -361,10 +350,6 @@ proc handleEvents(
         toRemoveIndices = removalIndices,
       )
 
-      for i in 0 ..< rateCommitments.len:
-        let index = startIndex + MembershipIndex(i)
-        await g.fetchMerkleProof(stuint(index, 256))
-
       g.latestIndex = startIndex + MembershipIndex(rateCommitments.len)
       trace "new members added to the Merkle tree",
         commitments = rateCommitments.mapIt(it.inHex)
@@ -385,12 +370,6 @@ proc handleRemovedEvents(
     if members.anyIt(it[1]):
       numRemovedBlocks += 1
 
-    # Remove cached merkleProof for each removed member
-    for member in members:
-      if member[1]: # Check if the member is removed
-        let index = member[0].index
-        g.merkleProofsByIndex.del(stuint(index, 256))
-
   await g.backfillRootQueue(numRemovedBlocks)
 
 proc getAndHandleEvents(

waku/waku_rln_relay/group_manager/on_chain_sync/group_manager.nim

@@ -13,8 +13,16 @@ logScope:
   topics = "waku rln_relay onchain_sync_group_manager"
 
 type OnChainSyncGroupManager* = ref object of OnchainGroupManager
-  # Cache for merkle proofs by index
+
-  merkleProofsByIndex*: Table[Uint256, seq[Uint256]]
+proc fetchMerkleProof*(g: OnchainSyncGroupManager) {.async.} =
+  let index = stuint(g.membershipIndex.get(), 256)
+  try:
+    let merkleProofInvocation = g.wakuRlnContract.get().merkleProofElements(index)
+    let merkleProof = await merkleProofInvocation.call()
+      # Await the contract call and extract the result
+    return merkleProof
+  except CatchableError:
+    error "Failed to fetch merkle proof: " & getCurrentExceptionMsg()
 
 method generateProof*(
     g: OnChainSyncGroupManager,
@@ -32,20 +40,7 @@ method generateProof*(
   if g.userMessageLimit.isNone():
     return err("user message limit is not set")
 
-  # Retrieve the cached Merkle proof for the membership index
+  let merkleProof = g.fetchMerkleProof()
-  let index = stuint(g.membershipIndex.get(), 256)
-
-  if not g.merkleProofsByIndex.hasKey(index):
-    try:
-      let merkleProofInvocation = g.wakuRlnContract.get().merkleProofElements(index)
-      let merkleProof = await merkleProofInvocation.call()
-      g.merkleProofsByIndex[index] = merkleProof
-    except CatchableError:
-      return err("Failed to fetch merkle proof: " & getCurrentExceptionMsg())
-
-  let merkleProof = g.merkleProofsByIndex[index]
-  if merkleProof.len == 0:
-    return err("Merkle proof not found")
 
   # Prepare the witness
   let witness = Witness(
@@ -105,4 +100,4 @@ method generateProof*(
     shareY: shareY,
     nullifier: nullifier,
   )
-  return ok(output)
+  return ok(output)