Remove account leaf cache

With static vid lookup we can find cached accounts in `O(1)` in the
regular caches - no need to waste time and effort on maintaining a
separate path-based cache for it.

5% speed bump from just the removal - more to be had by reallocating the
memory to other causes.

Author: arnetheduck

execution_chain/db/aristo/aristo_constants.nim

@@ -41,8 +41,7 @@ const
         v += 1'u64 shl (i * 4)
       v
 
-  ACC_LRU_SIZE* = 1024 * 1024
-    ## LRU cache size for accounts that have storage, see `.accLeaves` and
-    ## `.stoLeaves` fields of the main descriptor.
+  STO_LRU_SIZE* = 1024 * 1024
+    ## LRU cache size for the storage leaf cache (see AristoDbRef.stoLeaves)
 
 # End

execution_chain/db/aristo/aristo_delete.nim

@@ -147,15 +147,7 @@ proc deleteAccountRecord*(
   if stoID.isValid:
     ?db.delStoTreeImpl(stoID.vid, accPath)
 
-  let otherLeaf = ?db.deleteImpl(accHike)
-
-  db.layersPutAccLeaf(accPath, nil)
-
-  if otherLeaf.isValid:
-    db.layersPutAccLeaf(
-      Hash32(getBytes(NibblesBuf.fromBytes(accPath.data).replaceSuffix(otherLeaf.pfx))),
-      AccLeafRef(otherLeaf),
-    )
+  discard ?db.deleteImpl(accHike)
 
   ok()
 
@@ -214,7 +206,6 @@ proc deleteStorageData*(
     # De-register the deleted storage tree from the account record
     let leaf = AccLeafRef(wpAcc.vtx).dup # Dup on modify
     leaf.stoID.isValid = false
-    db.layersPutAccLeaf(accPath, leaf)
     db.layersPutVtx((accHike.root, wpAcc.vid), leaf)
 
   ok()
@@ -248,7 +239,6 @@ proc deleteStorageTree*(
   # De-register the deleted storage tree from the accounts record
   let leaf = accVtx.dup # Dup on modify
   leaf.stoID.isValid = false
-  db.layersPutAccLeaf(accPath, leaf)
   db.layersPutVtx((accHike.root, wpAcc.vid), leaf)
   ok()
 

execution_chain/db/aristo/aristo_desc.nim

@@ -68,7 +68,6 @@ type
     kMap*: Table[RootedVertexID,HashKey]   ## Merkle hash key mapping
     vTop*: VertexID                        ## Last used vertex ID
 
-    accLeaves*: Table[Hash32, AccLeafRef]  ## Account path -> VertexRef
     stoLeaves*: Table[Hash32, StoLeafRef]  ## Storage path -> VertexRef
 
     blockNumber*: Opt[uint64]              ## Block number set when checkpointing the frame
@@ -85,7 +84,6 @@ type
 
   Snapshot* = object
     vtx*: Table[RootedVertexID, VtxSnapshot]
-    acc*: Table[Hash32, (AccLeafRef, int)]
     sto*: Table[Hash32, (StoLeafRef, int)]
     level*: Opt[int] # when this snapshot was taken
 
@@ -110,14 +108,6 @@ type
 
     txRef*: AristoTxRef              ## Bottom-most in-memory frame
 
-    accLeaves*: LruCache[Hash32, AccLeafRef]
-      ## Account path to payload cache - accounts are frequently accessed by
-      ## account path when contracts interact with them - this cache ensures
-      ## that we don't have to re-traverse the storage trie for every such
-      ## interaction
-      ## TODO a better solution would probably be to cache this in a type
-      ## exposed to the high-level API
-
     stoLeaves*: LruCache[Hash32, StoLeafRef]
       ## Mixed account/storage path to payload cache - same as above but caches
       ## the full lookup of storage slots

execution_chain/db/aristo/aristo_fetch.nim

@@ -40,13 +40,6 @@ proc retrieveLeaf(
 
   return err(FetchPathNotFound)
 
-proc cachedAccLeaf*(db: AristoTxRef; accPath: Hash32): Opt[AccLeafRef] =
-  # Return vertex from layers or cache, `nil` if it's known to not exist and
-  # none otherwise
-  db.layersGetAccLeaf(accPath) or
-    db.db.accLeaves.get(accPath) or
-    Opt.none(AccLeafRef)
-
 proc cachedStoLeaf*(db: AristoTxRef; mixPath: Hash32): Opt[StoLeafRef] =
   # Return vertex from layers or cache, `nil` if it's known to not exist and
   # none otherwise
@@ -132,18 +125,9 @@ proc retrieveAccLeaf(
     db: AristoTxRef;
     accPath: Hash32;
       ): Result[AccLeafRef,AristoError] =
-  if (let leafVtx = db.cachedAccLeaf(accPath); leafVtx.isSome()):
-    if not leafVtx[].isValid():
-      return err(FetchPathNotFound)
-    return ok leafVtx[]
-
-  let (staticVtx, path, next) = db.retrieveAccStatic(accPath).valueOr:
-    if error == FetchPathNotFound:
-      db.db.accLeaves.put(accPath, nil)
-    return err(error)
+  let (staticVtx, path, next) = ? db.retrieveAccStatic(accPath)
 
   if staticVtx.isValid():
-    db.db.accLeaves.put(accPath, staticVtx)
     return ok staticVtx
 
   # Updated payloads are stored in the layers so if we didn't find them there,
@@ -155,13 +139,10 @@ proc retrieveAccLeaf(
         # meaning that it was a hit - else searches for non-existing paths would
         # skew the results towards more depth than exists in the MPT
         db.db.lookups.hits += 1
-        db.db.accLeaves.put(accPath, nil)
       return err(error)
 
   db.db.lookups.higher += 1
 
-  db.db.accLeaves.put(accPath, AccLeafRef(leafVtx))
-
   ok AccLeafRef(leafVtx)
 
 proc retrieveMerkleHash(
@@ -215,11 +196,16 @@ proc fetchAccountHike*(
       ): Result[void,AristoError] =
   ## Expand account path to account leaf or return failure
 
-  # Prefer the leaf cache so as not to burden the lower layers
-  let leaf = db.cachedAccLeaf(accPath)
-  if leaf == Opt.some(AccLeafRef(nil)):
+  # Pre-lookup in case the account does not exist
+  let (staticVtx, path, next) = db.retrieveAccStatic(accPath).valueOr:
     return err(FetchAccInaccessible)
 
+  let leaf =
+    if staticVtx.isValid():
+      Opt.some(staticVtx)
+    else:
+      Opt.none(AccLeafRef)
+
   accPath.hikeUp(STATE_ROOT_VID, db, leaf, accHike).isOkOr:
     return err(FetchAccInaccessible)
 

execution_chain/db/aristo/aristo_init/init_common.nim

@@ -84,8 +84,7 @@ proc finishSession*(hdl: TypedPutHdlRef; db: TypedBackendRef) =
 proc initInstance*(db: AristoDbRef): Result[void, AristoError] =
   let vTop = ?db.getTuvFn()
   db.txRef = AristoTxRef(db: db, vTop: vTop, snapshot: Snapshot(level: Opt.some(0)))
-  db.accLeaves = LruCache[Hash32, AccLeafRef].init(ACC_LRU_SIZE)
-  db.stoLeaves = LruCache[Hash32, StoLeafRef].init(ACC_LRU_SIZE)
+  db.stoLeaves = LruCache[Hash32, StoLeafRef].init(STO_LRU_SIZE)
   ok()
 
 proc finish*(db: AristoDbRef; eradicate = false) =

execution_chain/db/aristo/aristo_layers.nim

@@ -58,18 +58,6 @@ func layersGetKeyOrVoid*(db: AristoTxRef; rvid: RootedVertexID): HashKey =
   ## Simplified version of `layersGetKey()`
   (db.layersGetKey(rvid).valueOr (VOID_HASH_KEY, 0))[0]
 
-func layersGetAccLeaf*(db: AristoTxRef; accPath: Hash32): Opt[AccLeafRef] =
-  for w in db.rstack(stopAtSnapshot = true):
-    if w.snapshot.level.isSome():
-      w.snapshot.acc.withValue(accPath, item):
-        return Opt.some(item[][0])
-      break
-
-    w.accLeaves.withValue(accPath, item):
-      return Opt.some(item[])
-
-  Opt.none(AccLeafRef)
-
 func layersGetStoLeaf*(db: AristoTxRef; mixPath: Hash32): Opt[StoLeafRef] =
   for w in db.rstack(stopAtSnapshot = true):
     if w.snapshot.level.isSome():
@@ -129,12 +117,6 @@ func layersResKeys*(db: AristoTxRef; hike: Hike, skip: int) =
   for i in (skip + 1)..hike.legs.len:
     db.layersResKey((hike.root, hike.legs[^i].wp.vid), hike.legs[^i].wp.vtx)
 
-func layersPutAccLeaf*(db: AristoTxRef; accPath: Hash32; leafVtx: AccLeafRef) =
-  db.accLeaves[accPath] = leafVtx
-
-  if db.snapshot.level.isSome():
-    db.snapshot.acc[accPath] = (leafVtx, db.level)
-
 func layersPutStoLeaf*(db: AristoTxRef; mixPath: Hash32; leafVtx: StoLeafRef) =
   db.stoLeaves[mixPath] = leafVtx
 
@@ -149,11 +131,9 @@ func isEmpty*(ly: AristoTxRef): bool =
   ## Returns `true` if the layer does not contain any changes, i.e. all the
   ## tables are empty.
   ly.snapshot.vtx.len == 0 and
-  ly.snapshot.acc.len == 0 and
   ly.snapshot.sto.len == 0 and
   ly.sTab.len == 0 and
   ly.kMap.len == 0 and
-  ly.accLeaves.len == 0 and
   ly.stoLeaves.len == 0
 
 proc copyFrom*(snapshot: var Snapshot, tx: AristoTxRef) =
@@ -163,8 +143,6 @@ proc copyFrom*(snapshot: var Snapshot, tx: AristoTxRef) =
     do:
       snapshot.vtx[rvid] = (vtx, VOID_HASH_KEY, tx.level)
 
-  for k, v in tx.accLeaves:
-    snapshot.acc[k] = (v, tx.level)
   for k, v in tx.stoLeaves:
     snapshot.sto[k] = (v, tx.level)
 
@@ -195,7 +173,6 @@ proc mergeAndReset*(trg, src: AristoTxRef) =
     mergeAndReset(trg.sTab, src.sTab)
     mergeAndReset(trg.kMap, src.kMap)
 
-  mergeAndReset(trg.accLeaves, src.accLeaves)
   mergeAndReset(trg.stoLeaves, src.stoLeaves)
 
 # ------------------------------------------------------------------------------

execution_chain/db/aristo/aristo_merge.nim

@@ -216,21 +216,11 @@ proc mergeAccountRecord*(
   ## not on the database already or different from `accRec`, and `false`
   ## otherwise.
   ##
-  let updated = db.mergePayloadImpl(
-    STATE_ROOT_VID, accPath, db.cachedAccLeaf(accPath), accRec
-  ).valueOr:
+  discard db.mergePayloadImpl(STATE_ROOT_VID, accPath, Opt.none(AccLeafRef), accRec).valueOr:
     if error == MergeNoAction:
       return ok false
     return err(error)
 
-  # Update leaf cache both of the merged value and potentially the displaced
-  # leaf resulting from splitting a leaf into a branch with two leaves
-  db.layersPutAccLeaf(accPath, updated[0])
-  if updated[1].isValid:
-    let otherPath =
-      Hash32(getBytes(NibblesBuf.fromBytes(accPath.data).replaceSuffix(updated[1].pfx)))
-    db.layersPutAccLeaf(otherPath, updated[2])
-
   ok true
 
 proc mergeStorageData*(
@@ -282,7 +272,6 @@ proc mergeStorageData*(
     # Make sure that there is an account that refers to that storage trie
     let leaf = AccLeafRef(accHike.legs[^1].wp.vtx).dup # Dup on modify
     leaf.stoID = useID
-    db.layersPutAccLeaf(accPath, leaf)
     db.layersPutVtx((STATE_ROOT_VID, accHike.legs[^1].wp.vid), leaf)
 
   ok()

execution_chain/db/aristo/aristo_tx_frame.nim

@@ -57,18 +57,13 @@ proc buildSnapshot(txFrame: AristoTxRef, minLevel: int) =
               tbl.del(k)
 
           txFrame.snapshot.vtx.delIfIt(it[2] < minLevel)
-          txFrame.snapshot.acc.delIfIt(it[1] < minLevel)
           txFrame.snapshot.sto.delIfIt(it[1] < minLevel)
 
       if frame.snapshot.level.isSome() and isKeyframe:
         txFrame.snapshot.vtx = initTable[RootedVertexID, VtxSnapshot](
           max(1024, max(frame.sTab.len, frame.snapshot.vtx.len))
         )
 
-        txFrame.snapshot.acc = initTable[Hash32, (AccLeafRef, int)](
-          max(1024, max(frame.accLeaves.len, frame.snapshot.acc.len))
-        )
-
         txFrame.snapshot.sto = initTable[Hash32, (StoLeafRef, int)](
           max(1024, max(frame.stoLeaves.len, frame.snapshot.sto.len))
         )
@@ -77,10 +72,6 @@ proc buildSnapshot(txFrame: AristoTxRef, minLevel: int) =
           if v[2] >= minLevel:
             txFrame.snapshot.vtx[k] = v
 
-        for k, v in frame.snapshot.acc:
-          if v[1] >= minLevel:
-            txFrame.snapshot.acc[k] = v
-
         for k, v in frame.snapshot.sto:
           if v[1] >= minLevel:
             txFrame.snapshot.sto[k] = v
@@ -141,8 +132,7 @@ proc persist*(
         # which caters to the scenario where changes from multiple blocks
         # have already been written to sTab and the changes can moved into
         # the bottom.
-        if (bottom.snapshot.vtx.len + bottom.snapshot.acc.len + bottom.snapshot.sto.len) ==
-            0:
+        if (bottom.snapshot.vtx.len + bottom.snapshot.sto.len) == 0:
           bottom.snapshot.level.reset()
         else:
           # Incoming snapshots already have sTab baked in - make sure we don't
@@ -212,27 +202,19 @@ with --debug-eager-state-root."""
   #      in-memory and on-disk state)
 
   # Copy back updated payloads
-  for accPath, vtx in txFrame.accLeaves:
-    if vtx == nil:
-      db.accLeaves.del(accPath)
-    else:
-      discard db.accLeaves.update(accPath, vtx)
-
   for mixPath, vtx in txFrame.stoLeaves:
     if vtx == nil:
       db.stoLeaves.del(mixPath)
     else:
       discard db.stoLeaves.update(mixPath, vtx)
 
   txFrame.snapshot.vtx.clear()
-  txFrame.snapshot.acc.clear()
   txFrame.snapshot.sto.clear()
   # Since txFrame is now the base, it contains all changes and therefore acts
   # as a snapshot
   txFrame.snapshot.level = Opt.some(txFrame.level)
   txFrame.sTab.clear()
   txFrame.kMap.clear()
-  txFrame.accLeaves.clear()
   txFrame.stoLeaves.clear()
   txFrame.blockNumber.reset()
 

execution_chain/db/opts.nim

@@ -33,11 +33,11 @@ const
     ## re-reads from file.
     ##
     ## A bit of space on top of the filter is left for data block caching
-  defaultRdbVtxCacheSize* = 512 * 1024 * 1024
+  defaultRdbVtxCacheSize* = 768 * 1024 * 1024
     ## Cache of branches and leaves in the state MPTs (world and account)
   defaultRdbKeyCacheSize* = 1280 * 1024 * 1024
     ## Hashes of the above
-  defaultRdbBranchCacheSize* = 1024 * 1024 * 1024
+  defaultRdbBranchCacheSize* = 1280 * 1024 * 1024
     ## Cache of branches and leaves in the state MPTs (world and account)