fix(rln-relay): scope of getEvents (#1672)

waku/v2/protocol/waku_rln_relay/group_manager/on_chain/group_manager.nim

@@ -60,7 +60,7 @@ type
 const DefaultKeyStorePath* = "rlnKeystore.json"
 const DefaultKeyStorePassword* = "password"
 
-template initializedGuard*(g: OnchainGroupManager): untyped =
+template initializedGuard(g: OnchainGroupManager): untyped =
   if not g.initialized:
     raise newException(ValueError, "OnchainGroupManager is not initialized")
 
@@ -156,7 +156,7 @@ method withdrawBatch*(g: OnchainGroupManager, idCommitments: seq[IDCommitment]):
 
     # TODO: after slashing is enabled on the contract
 
-proc parseEvent*(event: type MemberRegistered,
+proc parseEvent(event: type MemberRegistered,
                  log: JsonNode): GroupManagerResult[Membership] =
   ## parses the `data` parameter of the `MemberRegistered` event `log`
   ## returns an error if it cannot parse the `data` parameter
@@ -196,7 +196,16 @@ proc backfillRootQueue*(g: OnchainGroupManager, blockTable: BlockTable): Future[
         # add the backfilled root
         g.validRoots.addLast(g.validRootBuffer.popLast())
 
-proc getEvents*(g: OnchainGroupManager, fromBlock: BlockNumber, toBlock: Option[BlockNumber] = none(BlockNumber)): Future[BlockTable] {.async.} =
+proc insert(blockTable: var BlockTable, blockNumber: BlockNumber, member: Membership) =
+  if blockTable.hasKeyOrPut(blockNumber, @[member]):
+    try:
+      blockTable[blockNumber].add(member)
+    except KeyError: # qed
+      error "could not insert member into block table", blockNumber=blockNumber, member=member
+
+proc getRawEvents(g: OnchainGroupManager,
+                  fromBlock: BlockNumber,
+                  toBlock: Option[BlockNumber] = none(BlockNumber)): Future[JsonNode] {.async.} =
   initializedGuard(g)
 
   let ethRpc = g.ethRpc.get()
@@ -212,13 +221,24 @@ proc getEvents*(g: OnchainGroupManager, fromBlock: BlockNumber, toBlock: Option[
   else:
     normalizedToBlock = fromBlock
 
+  let events =  await rlnContract.getJsonLogs(MemberRegistered,
+                                              fromBlock = some(fromBlock.blockId()),
+                                              toBlock = some(normalizedToBlock.blockId()))
+  return events
+
+proc getBlockTables(g: OnchainGroupManager,
+                    fromBlock: BlockNumber,
+                    toBlock: Option[BlockNumber] = none(BlockNumber)): Future[(BlockTable, BlockTable)] {.async.} =
+  initializedGuard(g)
+
   var blockTable = default(BlockTable)
   var toRemoveBlockTable = default(BlockTable)
 
-  let events = await rlnContract.getJsonLogs(MemberRegistered, fromBlock = some(fromBlock.blockId()), toBlock = some(normalizedToBlock.blockId()))
+  let events = await g.getRawEvents(fromBlock, toBlock)
+
   if events.len == 0:
     debug "no events found"
-    return blockTable
+    return (blockTable, toRemoveBlockTable)
 
   for event in events:
     let blockNumber = parseHexInt(event["blockNumber"].getStr()).uint
@@ -232,21 +252,13 @@ proc getEvents*(g: OnchainGroupManager, fromBlock: BlockNumber, toBlock: Option[
     if removed:
       # remove the registration from the tree, per block
       warn "member removed from the tree as per canonical chain", index=parsedEvent.index
-      if toRemoveBlockTable.hasKey(blockNumber):
-        toRemoveBlockTable[blockNumber].add(parsedEvent)
-      else:
-        toRemoveBlockTable[blockNumber] = @[parsedEvent]
-
-    await g.backfillRootQueue(toRemoveBlockTable)
-
-    if blockTable.hasKey(blockNumber):
-      blockTable[blockNumber].add(parsedEvent)
+      toRemoveBlockTable.insert(blockNumber, parsedEvent)
     else:
-      blockTable[blockNumber] = @[parsedEvent]
+      blockTable.insert(blockNumber, parsedEvent)
 
-  return blockTable
+  return (blockTable, toRemoveBlockTable)
 
-proc seedBlockTableIntoTree*(g: OnchainGroupManager, blockTable: BlockTable): Future[void] {.async.} =
+proc handleValidEvents(g: OnchainGroupManager, blockTable: BlockTable): Future[void] {.async.} =
   initializedGuard(g)
 
   for blockNumber, members in blockTable.pairs():
@@ -268,30 +280,36 @@ proc seedBlockTableIntoTree*(g: OnchainGroupManager, blockTable: BlockTable): Fu
 
   return
 
-proc getEventsAndSeedIntoTree*(g: OnchainGroupManager,
-                               fromBlock: BlockNumber,
-                               toBlock: Option[BlockNumber] = none(BlockNumber)): Future[void] {.async.} =
+proc handleRemovedEvents(g: OnchainGroupManager, toRemoveBlockTable: BlockTable): Future[void] {.async.} =
+  initializedGuard(g)
+
+  await g.backfillRootQueue(toRemoveBlockTable)
+
+proc getAndHandleEvents(g: OnchainGroupManager,
+                        fromBlock: BlockNumber,
+                        toBlock: Option[BlockNumber] = none(BlockNumber)): Future[void] {.async.} =
   initializedGuard(g)
 
-  let events = await g.getEvents(fromBlock, toBlock)
-  await g.seedBlockTableIntoTree(events)
+  let (validEvents, removedEvents) = await g.getBlockTables(fromBlock, toBlock)
+  await g.handleRemovedEvents(removedEvents)
+  await g.handleValidEvents(validEvents)
   return
 
-proc getNewHeadCallback*(g: OnchainGroupManager): BlockHeaderHandler =
+proc getNewHeadCallback(g: OnchainGroupManager): BlockHeaderHandler =
   proc newHeadCallback(blockheader: BlockHeader) {.gcsafe.} =
       let latestBlock = blockheader.number.uint
       debug "block received", blockNumber = latestBlock
       # get logs from the last block
       try:
-        asyncSpawn g.getEventsAndSeedIntoTree(latestBlock)
+        asyncSpawn g.getAndHandleEvents(latestBlock)
       except CatchableError:
         warn "failed to handle log: ", error=getCurrentExceptionMsg()
   return newHeadCallback
 
 proc newHeadErrCallback(error: CatchableError) =
   warn "failed to get new head", error=error.msg
 
-proc startListeningToEvents*(g: OnchainGroupManager): Future[void] {.async.} =
+proc startListeningToEvents(g: OnchainGroupManager): Future[void] {.async.} =
   initializedGuard(g)
 
   let ethRpc = g.ethRpc.get()
@@ -301,11 +319,11 @@ proc startListeningToEvents*(g: OnchainGroupManager): Future[void] {.async.} =
   except CatchableError:
     raise newException(ValueError, "failed to subscribe to block headers: " & getCurrentExceptionMsg())
 
-proc startOnchainSync*(g: OnchainGroupManager, fromBlock: BlockNumber = BlockNumber(0)): Future[void] {.async.} =
+proc startOnchainSync(g: OnchainGroupManager, fromBlock: BlockNumber = BlockNumber(0)): Future[void] {.async.} =
   initializedGuard(g)
 
   try:
-    await g.getEventsAndSeedIntoTree(fromBlock, some(fromBlock))
+    await g.getAndHandleEvents(fromBlock, some(fromBlock))
   except CatchableError:
     raise newException(ValueError, "failed to get the history/reconcile missed blocks: " & getCurrentExceptionMsg())
 
@@ -315,7 +333,7 @@ proc startOnchainSync*(g: OnchainGroupManager, fromBlock: BlockNumber = BlockNum
   except CatchableError:
     raise newException(ValueError, "failed to start listening to events: " & getCurrentExceptionMsg())
 
-proc persistCredentials*(g: OnchainGroupManager): GroupManagerResult[void] =
+proc persistCredentials(g: OnchainGroupManager): GroupManagerResult[void] =
   if not g.saveKeystore:
     return ok()
   if g.idCredentials.isNone():