From 97e89b3afe2f9752538ffc6de29501114f07ec12 Mon Sep 17 00:00:00 2001
From: andri lim <jangko128@gmail.com>
Date: Wed, 13 Nov 2019 13:18:01 +0700
Subject: [PATCH] implement 'getCommittedStorage'

---
 nimbus/db/state_db.nim  | 13 +++++++++++--
 nimbus/p2p/executor.nim |  1 +
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/nimbus/db/state_db.nim b/nimbus/db/state_db.nim
index c8bd1ca94..3422db2c3 100644
--- a/nimbus/db/state_db.nim
+++ b/nimbus/db/state_db.nim
@@ -16,6 +16,7 @@ logScope:
 type
   AccountStateDB* = ref object
     trie: SecureHexaryTrie
+    originalRoot: KeccakHash   # will be updated for every transaction
 
   ReadOnlyStateDB* = distinct AccountStateDB
 
@@ -29,6 +30,7 @@ proc newAccountStateDB*(backingStore: TrieDatabaseRef,
                         root: KeccakHash, pruneTrie: bool): AccountStateDB =
   result.new()
   result.trie = initSecureHexaryTrie(backingStore, root, pruneTrie)
+  result.originalRoot = root
 
 template createRangeFromAddress(address: EthAddress): ByteRange =
   ## XXX: The name of this proc is intentionally long, because it
@@ -208,8 +210,15 @@ proc isDeadAccount*(db: AccountStateDB, address: EthAddress): bool =
     result = true
 
 proc getCommittedStorage*(db: AccountStateDB, address: EthAddress, slot: UInt256): UInt256 =
-  discard
-  # TODO: stub
+  let tmpHash = db.rootHash
+  db.rootHash = db.originalRoot
+  var exists: bool
+  (result, exists) = db.getStorage(address, slot)
+  db.rootHash = tmpHash
+
+proc updateOriginalRoot*(db: AccountStateDB) =
+  ## this proc will be called for every transaction
+  db.originalRoot = db.rootHash
 
 proc rootHash*(db: ReadOnlyStateDB): KeccakHash {.borrow.}
 proc getAccount*(db: ReadOnlyStateDB, address: EthAddress): Account {.borrow.}
diff --git a/nimbus/p2p/executor.nim b/nimbus/p2p/executor.nim
index 2bd729e70..096f82940 100644
--- a/nimbus/p2p/executor.nim
+++ b/nimbus/p2p/executor.nim
@@ -67,6 +67,7 @@ proc processTransaction*(tx: Transaction, sender: EthAddress, vmState: BaseVMSta
         debug "state clearing", account
         db.deleteAccount(account)
 
+  vmState.accountDb.updateOriginalRoot()
   result = gasUsed
 
 type