From b3917ea4b051cc542bd9f8ea0f49491bf7d131a7 Mon Sep 17 00:00:00 2001
From: Jacek Sieka <jacek@status.im>
Date: Fri, 20 Dec 2024 15:06:12 +0100
Subject: [PATCH] fix layer vtop after rollback

---
 nimbus/db/aristo/aristo_delta.nim                |  1 +
 nimbus/db/aristo/aristo_desc/desc_structural.nim |  6 ++----
 nimbus/db/aristo/aristo_init/memory_only.nim     |  4 ++--
 nimbus/db/aristo/aristo_init/persistent.nim      |  2 +-
 nimbus/db/aristo/aristo_tx/tx_frame.nim          | 13 +++++++++----
 nimbus/db/kvt/kvt_tx/tx_frame.nim                |  2 +-
 6 files changed, 16 insertions(+), 12 deletions(-)

diff --git a/nimbus/db/aristo/aristo_delta.nim b/nimbus/db/aristo/aristo_delta.nim
index 142e2a882a..b10ec811d1 100644
--- a/nimbus/db/aristo/aristo_delta.nim
+++ b/nimbus/db/aristo/aristo_delta.nim
@@ -83,6 +83,7 @@ proc deltaPersistent*(
     db.stoLeaves.put(mixPath, vtx)
 
   # Done with txRef, all saved to backend
+  db.txRef.layer.cTop = db.txRef.layer.vTop
   db.txRef.layer.sTab.clear()
   db.txRef.layer.kMap.clear()
   db.txRef.layer.accLeaves.clear()
diff --git a/nimbus/db/aristo/aristo_desc/desc_structural.nim b/nimbus/db/aristo/aristo_desc/desc_structural.nim
index e2fa26d2e6..1522d2127a 100644
--- a/nimbus/db/aristo/aristo_desc/desc_structural.nim
+++ b/nimbus/db/aristo/aristo_desc/desc_structural.nim
@@ -125,6 +125,8 @@ type
     accLeaves*: Table[Hash32, VertexRef]   ## Account path -> VertexRef
     stoLeaves*: Table[Hash32, VertexRef]   ## Storage path -> VertexRef
 
+    cTop*: VertexID                        ## Last committed vertex ID
+
   GetVtxFlag* = enum
     PeekCache
       ## Peek into, but don't update cache - useful on work loads that are
@@ -148,10 +150,6 @@ func setUsed*(vtx: VertexRef, nibble: uint8, used: static bool): VertexID =
       vtx.used and (not (1'u16 shl nibble))
   vtx.bVid(nibble)
 
-func init*(T: type LayerRef): T =
-  ## Constructor, returns empty layer
-  T()
-
 func hash*(node: NodeRef): Hash =
   ## Table/KeyedQueue/HashSet mixin
   cast[pointer](node).hash
diff --git a/nimbus/db/aristo/aristo_init/memory_only.nim b/nimbus/db/aristo/aristo_init/memory_only.nim
index b55320b42b..f3ff5257d2 100644
--- a/nimbus/db/aristo/aristo_init/memory_only.nim
+++ b/nimbus/db/aristo/aristo_init/memory_only.nim
@@ -56,10 +56,10 @@ proc init*(
 
   let db =
     when B is VoidBackendRef:
-      AristoDbRef(txRef: AristoTxRef(layer: LayerRef.init()))
+      AristoDbRef(txRef: AristoTxRef(layer: LayerRef()))
 
     elif B is MemBackendRef:
-      AristoDbRef(txRef: AristoTxRef(layer: LayerRef.init()), backend: memoryBackend())
+      AristoDbRef(txRef: AristoTxRef(layer: LayerRef()), backend: memoryBackend())
   db.txRef.db = db
   db
 
diff --git a/nimbus/db/aristo/aristo_init/persistent.nim b/nimbus/db/aristo/aristo_init/persistent.nim
index e6a6f14a26..4f214302e5 100644
--- a/nimbus/db/aristo/aristo_init/persistent.nim
+++ b/nimbus/db/aristo/aristo_init/persistent.nim
@@ -52,7 +52,7 @@ proc newAristoRdbDbRef(
         return err(rc.error)
       rc.value
     db = (AristoDbRef(
-      txRef: AristoTxRef(layer: LayerRef(vTop: vTop)),
+      txRef: AristoTxRef(layer: LayerRef(vTop: vTop, cTop: vTop)),
       backend: be,
       accLeaves: LruCache[Hash32, VertexRef].init(ACC_LRU_SIZE),
       stoLeaves: LruCache[Hash32, VertexRef].init(ACC_LRU_SIZE),
diff --git a/nimbus/db/aristo/aristo_tx/tx_frame.nim b/nimbus/db/aristo/aristo_tx/tx_frame.nim
index a67059ccc0..2cd061a390 100644
--- a/nimbus/db/aristo/aristo_tx/tx_frame.nim
+++ b/nimbus/db/aristo/aristo_tx/tx_frame.nim
@@ -40,8 +40,7 @@ proc txFrameBegin*(db: AristoDbRef, parent: AristoTxRef): Result[AristoTxRef,Ari
 
   let
     vTop = parent.layer.vTop
-    layer = LayerRef(
-      vTop:  vTop)
+    layer = LayerRef(vTop:  vTop, cTop: vTop)
 
   ok AristoTxRef(
     db:     db,
@@ -58,7 +57,10 @@ proc rollback*(
   ## performed for this transactio. The previous transaction is returned if
   ## there was any.
   # TODO Everyone using this txref should repoint their parent field
-  tx.layer = LayerRef()
+
+  let vTop = tx.layer[].cTop
+  tx.layer[] = Layer(vTop: vTop, cTop: vTop)
+
   ok()
 
 
@@ -69,8 +71,11 @@ proc commit*(
   ##
   # TODO Everyone using this txref should repoint their parent field
   doAssert tx.parent != nil, "should not commit the base tx"
-  mergeAndReset(tx.parent.layer[], tx.layer[])
 
+  # A rollback after commit should reset to the new vTop!
+  tx.layer[].cTop = tx.layer[].vTop
+
+  mergeAndReset(tx.parent.layer[], tx.layer[])
   ok()
 
 
diff --git a/nimbus/db/kvt/kvt_tx/tx_frame.nim b/nimbus/db/kvt/kvt_tx/tx_frame.nim
index 597fe47097..bed04badc1 100644
--- a/nimbus/db/kvt/kvt_tx/tx_frame.nim
+++ b/nimbus/db/kvt/kvt_tx/tx_frame.nim
@@ -52,7 +52,7 @@ proc rollback*(
   ## there was any.
   ##
 
-  tx.layer = LayerRef()
+  tx.layer[] = Layer()
   ok()
 
 proc commit*(