Simplify beacon stream pivot update (#1435)

* Simplify pivot update

why:
  No need to fetch the pivot header from the network when it can be
  be made available in the ivot cache

also:
  Keep `txPool` update disabled while syncing

* Cosmetics, tune down some logging noise

* Support `snap/1` without `eth/6?`

why:
  Eth is not needed here.

* Snap is an (optional) extension of `eth`

so:
  It it must be supported somehow. Nevertheless it will be currently
  unused in the snap syncer.

nimbus/common/common.nim

@@ -34,7 +34,7 @@ type
     current: BlockNumber
     highest: BlockNumber
 
-  SyncReqNewHeadCB* = proc(number: BlockNumber; hash: Hash256) {.gcsafe.}
+  SyncReqNewHeadCB* = proc(header: BlockHeader) {.gcsafe.}
     ## Update head for syncing
 
   CommonRef* = ref object
@@ -362,10 +362,10 @@ proc initializeEmptyDb*(com: CommonRef)
       com.consensusType == ConsensusType.POS)
     doAssert(canonicalHeadHashKey().toOpenArray in trieDB)
 
-proc syncReqNewHead*(com: CommonRef; number: BlockNumber; hash: Hash256) =
+proc syncReqNewHead*(com: CommonRef; header: BlockHeader) =
   ## Used by RPC to update the beacon head for snap sync
   if not com.syncReqNewHead.isNil:
-    com.syncReqNewHead(number, hash)
+    com.syncReqNewHead(header)
 
 # ------------------------------------------------------------------------------
 # Getters

nimbus/rpc/engine_api.nim

@@ -250,7 +250,7 @@ proc setupEngineApi*(
         hash = blockHash
 
       # Update sync header (if any)
-      com.syncReqNewHead(header.blockNumber, blockHash)
+      com.syncReqNewHead(header)
 
       return simpleFCU(PayloadExecutionStatus.syncing)
 

nimbus/sync/snap/worker.nim

@@ -17,7 +17,7 @@ import
   ../../common as nimcom,
   ../../db/select_backend,
   ../../utils/prettify,
-  ".."/[protocol, sync_desc],
+  ".."/[handlers, protocol, sync_desc],
   ./worker/[pivot, ticker],
   ./worker/com/com_error,
   ./worker/db/[hexary_desc, snapdb_desc, snapdb_pivot],
@@ -106,6 +106,7 @@ proc setup*(ctx: SnapCtxRef; tickerOK: bool): bool =
   ## Global set up
   ctx.data.coveredAccounts = NodeTagRangeSet.init()
   noExceptionOops("worker.setup()"):
+    ctx.ethWireCtx.txPoolEnabled false
     ctx.chain.com.syncReqNewHead = ctx.pivotUpdateBeaconHeaderCB
   ctx.data.snapDb =
     if ctx.data.dbBackend.isNil: SnapDbRef.init(ctx.chain.db.db)
@@ -135,6 +136,8 @@ proc release*(ctx: SnapCtxRef) =
   if not ctx.data.ticker.isNil:
     ctx.data.ticker.stop()
     ctx.data.ticker = nil
+  noExceptionOops("worker.release()"):
+    ctx.ethWireCtx.txPoolEnabled true
   ctx.chain.com.syncReqNewHead = nil
 
 proc start*(buddy: SnapBuddyRef): bool =

nimbus/sync/snap/worker/pivot.nim

@@ -16,7 +16,6 @@ import
   stew/[interval_set, keyed_queue, sorted_set],
   ../../sync_desc,
   ".."/[constants, range_desc, worker_desc],
-  ./com/get_block_header,
   ./db/[hexary_error, snapdb_accounts, snapdb_pivot],
   ./pivot/[heal_accounts, heal_storage_slots,
            range_fetch_accounts, range_fetch_storage_slots,
@@ -166,8 +165,8 @@ proc tickerStats*(
       pivotBlock = some(env.stateHeader.blockNumber)
       procChunks = env.fetchAccounts.processed.chunks
       stoQuLen = some(env.storageQueueTotal())
-    if 0 < ctx.data.beaconNumber:
-      beaconBlock = some(ctx.data.beaconNumber)
+    if 0 < ctx.data.beaconHeader.blockNumber:
+      beaconBlock = some(ctx.data.beaconHeader.blockNumber)
 
     TickerStats(
       beaconBlock:   beaconBlock,
@@ -343,102 +342,48 @@ proc pivotApprovePeer*(buddy: SnapBuddyRef) {.async.} =
   let
     ctx = buddy.ctx
     peer = buddy.peer
-
-    # Cache beacon header data, iyt  might change while waiting for a peer
-    # reply message
-    beaconNumber = ctx.data.beaconNumber
-    beaconHash = ctx.data.beaconHash
-
+    beaconHeader = ctx.data.beaconHeader
   var
     pivotHeader: BlockHeader
-    pivotNumber: BlockNumber
-    peerNumber: BlockNumber # for error message
 
   block:
     let rc = ctx.data.pivotTable.lastValue
     if rc.isOk:
       pivotHeader = rc.value.stateHeader
-      pivotNumber = pivotHeader.blockNumber
 
   # Check whether the pivot needs to be updated
-  if pivotNumber + pivotBlockDistanceMin < beaconNumber:
-    let rc = await buddy.getBlockHeader(beaconHash)
-    if rc.isErr:
-      buddy.ctrl.zombie = true
-      return
+  if pivotHeader.blockNumber + pivotBlockDistanceMin < beaconHeader.blockNumber:
+    # If the entry before the previous entry is unused, then run a pool mode
+    # based session (which should enable a pivot table purge).
+    block:
+      let rc = ctx.data.pivotTable.beforeLast
+      if rc.isOk and rc.value.data.fetchAccounts.processed.isEmpty:
+        ctx.poolMode = true
 
-    # Sanity check => append a new pivot environment
-    if rc.value.blockNumber == beaconNumber:
-
-      # If the entry before the previous entry is unused, then run a pool mode
-      # based session (which should enable a pivot table purge).
-      block:
-        let rx = ctx.data.pivotTable.beforeLast
-        if rx.isOk and rx.value.data.fetchAccounts.processed.isEmpty:
-          ctx.poolMode = true
-
-      when extraTraceMessages:
-        trace "New pivot from beacon chein", peer, pivotNumber,
-          beaconNumber, beaconHash, poolMode=ctx.poolMode
-
-      discard ctx.data.pivotTable.lruAppend(
-        rc.value.stateRoot, SnapPivotRef.init(ctx, rc.value),
-        pivotTableLruEntriesMax)
-
-      # Done, buddy runs on updated environment. It has proved already that it
-      # supports the current header.
-      return
-
-    # Header/block number mismatch => process at the end of function
-    peerNumber = rc.value.blockNumber
-
-  elif 0 < pivotNumber:
-    # So there was no reason to update update then pivot. Verify that
-    # the pivot header can be fetched from peer.
-    let
-      pivotHash = pivotHeader.hash
-      rc = await buddy.getBlockHeader(pivotHash)
-    if rc.isErr:
-      when extraTraceMessages:
-        trace "Header unsupported by peer", peer, pivotNumber, pivotHash
-      buddy.ctrl.zombie = true
-      return
-
-    # Sanity check
-    if rc.value.blockNumber == beaconNumber:
-      return
-
-    # Header/block number mismatch => process at the end of function
-    peerNumber = rc.value.blockNumber
-
-  else:
-    # Not ready yet for initialising. Currently there is no pivot, at all
     when extraTraceMessages:
-      trace "Beacon chain header not ready yet", peer
+      trace "New pivot from beacon chain", peer,
+        pivot=("#" & $pivotHeader.blockNumber),
+        beacon=("#" & $beaconHeader.blockNumber), poolMode=ctx.poolMode
+
+    discard ctx.data.pivotTable.lruAppend(
+      beaconHeader.stateRoot, SnapPivotRef.init(ctx, beaconHeader),
+      pivotTableLruEntriesMax)
+
+    pivotHeader = beaconHeader
+
+  # Not ready yet?
+  if pivotHeader.blockNumber == 0:
     buddy.ctrl.stopped = true
-    return
-
-  # Header/block number mismatch
-  trace "Oops, cannot approve peer due to header mismatch", peer, peerNumber,
-    beaconNumber, hash=beaconHash
-
-  # Reset cache
-  ctx.data.beaconNumber = 0.u256
-  ctx.data.beaconHash = Hash256.default
-
-  # See you later :)
-  buddy.ctrl.stopped = true
 
 
 proc pivotUpdateBeaconHeaderCB*(ctx: SnapCtxRef): SyncReqNewHeadCB =
   ## Update beacon header. This function is intended as a call back function
   ## for the RPC module.
-  result = proc(number: BlockNumber; hash: Hash256) {.gcsafe.} =
-    if ctx.data.beaconNumber < number:
-      when extraTraceMessages:
-        trace "External beacon info update", number, hash
-      ctx.data.beaconNumber = number
-      ctx.data.beaconHash = hash
+  result = proc(h: BlockHeader) {.gcsafe.} =
+    if ctx.data.beaconHeader.blockNumber < h.blockNumber:
+      # when extraTraceMessages:
+      #   trace "External beacon info update", header=("#" & $h.blockNumber)
+      ctx.data.beaconHeader = h
 
 # ------------------------------------------------------------------------------
 # End

nimbus/sync/snap/worker/ticker.nim

@@ -123,8 +123,8 @@ proc runLogTicker(t: TickerRef) {.gcsafe.} =
      tickerLogSuppressMax < (now - t.visited):
     var
       nAcc, nSto, bulk: string
-      pivot = "n/a"
-      beacon = "n/a"
+      pv = "n/a"
+      bc = "n/a"
       nStoQue = "n/a"
     let
       recoveryDone = t.lastRecov
@@ -132,7 +132,7 @@ proc runLogTicker(t: TickerRef) {.gcsafe.} =
          "(" & data.accountsFill[1].pc99 & ")" &
          "/" & data.accountsFill[2].pc99 &
          "~" & data.nAccountStats.uint.toSI
-      buddies = t.nBuddies
+      nInst = t.nBuddies
 
       # With `int64`, there are more than 29*10^10 years range for seconds
       up = (now - t.started).seconds.uint64.toSI
@@ -144,9 +144,9 @@ proc runLogTicker(t: TickerRef) {.gcsafe.} =
 
     noFmtError("runLogTicker"):
       if data.pivotBlock.isSome:
-        pivot = &"#{data.pivotBlock.get}/{data.nQueues}"
+        pv = &"#{data.pivotBlock.get}/{data.nQueues}"
       if data.beaconBlock.isSome:
-        beacon = &"#{data.beaconBlock.get}"
+        bc = &"#{data.beaconBlock.get}"
       nAcc = (&"{(data.nAccounts[0]+0.5).int64}" &
               &"({(data.nAccounts[1]+0.5).int64})")
       nSto = (&"{(data.nSlotLists[0]+0.5).int64}" &
@@ -157,13 +157,13 @@ proc runLogTicker(t: TickerRef) {.gcsafe.} =
 
     if t.recovery:
       info "Snap sync statistics (recovery)",
-        up, buddies, beacon, pivot, nAcc, accCov, nSto, nStoQue, mem
+        up, nInst, bc, pv, nAcc, accCov, nSto, nStoQue, mem
     elif recoveryDone:
       info "Snap sync statistics (recovery done)",
-        up, buddies, beacon, pivot, nAcc, accCov, nSto, nStoQue, mem
+        up, nInst, bc, pv, nAcc, accCov, nSto, nStoQue, mem
     else:
       info "Snap sync statistics",
-        up, buddies, beacon, pivot, nAcc, accCov, nSto, nStoQue, mem
+        up, nInst, bc, pv, nAcc, accCov, nSto, nStoQue, mem
 
   t.setLogTicker(Moment.fromNow(tickerLogInterval))
 

nimbus/sync/snap/worker_desc.nim

@@ -96,8 +96,7 @@ type
 
     # Pivot table
     pivotTable*: SnapPivotTable        ## Per state root environment
-    beaconNumber*: BlockNumber         ## Running on beacon chain
-    beaconHash*: Hash256               ## Ditto
+    beaconHeader*: BlockHeader         ## Running on beacon chain
     coveredAccounts*: NodeTagRangeSet  ## Derived from all available accounts
     covAccTimesFull*: uint             ## # of 100% coverages
     recovery*: SnapRecoveryRef         ## Current recovery checkpoint/context