no really tested yet ...

nimbus/core/tx_pool/tx_tasks/tx_packer.nim

@@ -171,7 +171,7 @@ proc vmExecInit(xp: TxPoolRef): Result[TxPackerStateRef, string]
 
   let packer = TxPackerStateRef( # return value
     xp: xp,
-    tr: AristoDbMemory.newCoreDbRef().ctx.getMpt CtGeneric,
+    tr: AristoDbMemory.newCoreDbRef().ctx.getColumn(CtGeneric, clearData=true),
     balance: xp.chain.vmState.readOnlyStateDB.getBalance(xp.chain.feeRecipient),
     numBlobPerBlock: 0,
   )
@@ -255,7 +255,7 @@ proc vmExecCommit(pst: TxPackerStateRef)
   vmState.receipts.setLen(nItems)
 
   xp.chain.receipts = vmState.receipts
-  xp.chain.txRoot = pst.tr.getColumn.state.valueOr:
+  xp.chain.txRoot = pst.tr.state.valueOr:
     raiseAssert "vmExecCommit(): state() failed " & $$error
   xp.chain.stateRoot = vmState.stateDB.rootHash
 

nimbus/db/aristo/aristo_api.nim

@@ -130,6 +130,13 @@ type
       ## For a generic sub-tree starting at `root`, fetch the data record
       ## indexed by `path`.
 
+  AristoApiFetchGenericStateFn* =
+    proc(db: AristoDbRef;
+         root: VertexID;
+        ): Result[Hash256,AristoError]
+        {.noRaise.}
+      ## Fetch the Merkle hash of the argument `root`.
+
   AristoApiFetchStorageDataFn* =
     proc(db: AristoDbRef;
          path: openArray[byte];
@@ -434,6 +441,7 @@ type
     fetchAccountPayload*: AristoApiFetchAccountPayloadFn
     fetchAccountState*: AristoApiFetchAccountStateFn
     fetchGenericData*: AristoApiFetchGenericDataFn
+    fetchGenericState*: AristoApiFetchGenericStateFn
     fetchStorageData*: AristoApiFetchStorageDataFn
     fetchStorageState*: AristoApiFetchStorageStateFn
 
@@ -482,6 +490,7 @@ type
     AristoApiProfFetchAccountPayloadFn  = "fetchAccountPayload"
     AristoApiProfFetchAccountStateFn    = "fetchAccountState"
     AristoApiProfFetchGenericDataFn     = "fetchGenericData"
+    AristoApiProfFetchGenericStateFn    = "fetchGenericState"
     AristoApiProfFetchStorageDataFn     = "fetchStorageData"
     AristoApiProfFetchStorageStateFn    = "fetchStorageState"
 
@@ -547,6 +556,7 @@ when AutoValidateApiHooks:
     doAssert not api.fetchAccountPayload.isNil
     doAssert not api.fetchAccountState.isNil
     doAssert not api.fetchGenericData.isNil
+    doAssert not api.fetchGenericState.isNil
     doAssert not api.fetchStorageData.isNil
     doAssert not api.fetchStorageState.isNil
 
@@ -616,6 +626,7 @@ func init*(api: var AristoApiObj) =
   api.fetchAccountPayload = fetchAccountPayload
   api.fetchAccountState = fetchAccountState
   api.fetchGenericData = fetchGenericData
+  api.fetchGenericState = fetchGenericState
   api.fetchStorageData = fetchStorageData
   api.fetchStorageState = fetchStorageState
 
@@ -667,6 +678,7 @@ func dup*(api: AristoApiRef): AristoApiRef =
     fetchAccountPayload:  api.fetchAccountPayload,
     fetchAccountState:    api.fetchAccountState,
     fetchGenericData:     api.fetchGenericData,
+    fetchGenericState:    api.fetchGenericState,
     fetchStorageData:     api.fetchStorageData,
     fetchStorageState:    api.fetchStorageState,
 
@@ -777,6 +789,11 @@ func init*(
       AristoApiProfFetchGenericDataFn.profileRunner:
         result = api.fetchGenericData(a, b, c)
 
+  profApi.fetchGenericState =
+    proc(a: AristoDbRef; b: VertexID;): auto =
+      AristoApiProfFetchGenericStateFn.profileRunner:
+        result = api.fetchGenericState(a, b)
+
   profApi.fetchStorageData =
     proc(a: AristoDbRef; b: openArray[byte]; c: PathID;): auto =
       AristoApiProfFetchStorageDataFn.profileRunner:

nimbus/db/aristo/aristo_fetch.nim

@@ -66,6 +66,17 @@ proc retrieveStoID(
   ok stoID
 
 
+proc retrieveMerkleHash(
+    db: AristoDbRef;
+    root: VertexID;
+      ): Result[Hash256,AristoError] =
+  let key = db.getKeyRc(root).valueOr:
+    if error == GetKeyNotFound:
+      return ok(EMPTY_ROOT_HASH) # empty sub-tree
+    return err(error)
+  ok key.to(Hash256)
+
+
 proc hasPayload(
     db: AristoDbRef;
     root: VertexID;
@@ -107,11 +118,7 @@ proc fetchAccountState*(
     db: AristoDbRef;
       ): Result[Hash256,AristoError] =
   ## Fetch the Merkle hash of the account root.
-  let key = db.getKeyRc(VertexID 1).valueOr:
-    if error == GetKeyNotFound:
-      return ok(EMPTY_ROOT_HASH) # empty sub-tree
-    return err(error)
-  ok key.to(Hash256)
+  db.retrieveMerkleHash VertexID(1)
 
 proc hasPathAccount*(
     db: AristoDbRef;
@@ -136,6 +143,13 @@ proc fetchGenericData*(
   assert pyl.pType == RawData   # debugging only
   ok pyl.rawBlob
 
+proc fetchGenericState*(
+    db: AristoDbRef;
+    root: VertexID;
+      ): Result[Hash256,AristoError] =
+  ## Fetch the Merkle hash of the argument `root`.
+  db.retrieveMerkleHash root
+
 proc hasPathGeneric*(
     db: AristoDbRef;
     root: VertexID;
@@ -165,18 +179,11 @@ proc fetchStorageState*(
     accPath: PathID;
       ): Result[Hash256,AristoError] =
   ## Fetch the Merkle hash of the storage root related to `accPath`.
-  let
-    stoID = db.retrieveStoID(accPath).valueOr:
-      if error == FetchPathNotFound:
-        return ok(EMPTY_ROOT_HASH) # no sub-tree
-      return err(error)
-
-    key = db.getKeyRc(stoID).valueOr:
-      if error == GetKeyNotFound:
-        return ok(EMPTY_ROOT_HASH) # empty or no sub-tree
-      return err(error)
-
-  ok key.to(Hash256)
+  let stoID = db.retrieveStoID(accPath).valueOr:
+    if error == FetchPathNotFound:
+      return ok(EMPTY_ROOT_HASH) # no sub-tree
+    return err(error)
+  db.retrieveMerkleHash stoID
 
 proc hasPathStorage*(
     db: AristoDbRef;