Stateless: Create snapshots before building witness during block import (#3542)

bhartnett · web-flow · commit 1195f9b75405 · 2025-08-06T07:58:31.000+08:00
diff --git a/execution_chain/core/chain/persist_blocks.nim b/execution_chain/core/chain/persist_blocks.nim
@@ -165,6 +165,11 @@ proc persistBlock*(p: var Persister, blk: Block): Result[void, string] =
     let parentTxFrame = vmState.ledger.txFrame
     vmState.ledger.txFrame = parentTxFrame.txFrameBegin()
 
+    # Creating a snapshot here significantly improves the performance of building
+    # the witness from the prestate, especially when the import batch size is
+    # set to a larger value.
+    parentTxFrame.checkpoint(p.parent.number, skipSnapshot = false)
+
     # Clear the caches before executing the block to ensure we collect the correct
     # witness keys and block hashes when processing the block as these will be used
     # when building the witness.
