From 84f8c9661ff64579409174d7a58ef16a0a205833 Mon Sep 17 00:00:00 2001
From: Anthony Fieroni <bvbfan@abv.bg>
Date: Thu, 11 Mar 2021 09:37:12 +0200
Subject: [PATCH] Introduce db version check at runtime

Signed-off-by: Anthony Fieroni <bvbfan@abv.bg>
---
 src/flushablestorage.h              |  3 +++
 src/init.cpp                        |  9 ++++++---
 src/masternodes/accountshistory.cpp | 24 ------------------------
 src/masternodes/accountshistory.h   |  3 ---
 src/masternodes/masternodes.cpp     | 14 ++++++++++++++
 src/masternodes/masternodes.h       |  7 +++++++
 6 files changed, 30 insertions(+), 30 deletions(-)

diff --git a/src/flushablestorage.h b/src/flushablestorage.h
index 631de1065f5..86aac311550 100644
--- a/src/flushablestorage.h
+++ b/src/flushablestorage.h
@@ -146,6 +146,9 @@ class CStorageLevelDB : public CStorageKV {
     std::unique_ptr<CStorageKVIterator> NewIterator() override {
         return MakeUnique<CStorageLevelDBIterator>(std::unique_ptr<CDBIterator>(db.NewIterator()));
     }
+    bool IsEmpty() {
+        return db.IsEmpty();
+    }
 
 private:
     CDBWrapper db;
diff --git a/src/init.cpp b/src/init.cpp
index b16d4a73caf..1fafc5202de 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -1586,13 +1586,16 @@ bool AppInitMain(InitInterfaces& interfaces)
                 pcustomcsDB = MakeUnique<CStorageLevelDB>(GetDataDir() / "enhancedcs", nDefaultDbCache << 20, false, fReset || fReindexChainState);
                 pcustomcsview.reset();
                 pcustomcsview = MakeUnique<CCustomCSView>(*pcustomcsDB.get());
-                if (!fReset && gArgs.GetBoolArg("-acindex", DEFAULT_ACINDEX)) {
-                    if (shouldMigrateOldRewardHistory(*pcustomcsview)) {
-                        strLoadError = _("Account history needs rebuild").translated;
+                if (!fReset && !fReindexChainState) {
+                    if (!pcustomcsDB->IsEmpty() && pcustomcsview->GetDbVersion() != CCustomCSView::DbVersion) {
+                        strLoadError = _("Account database is unsuitable").translated;
                         break;
                     }
                 }
 
+                // Ensure we are on latest DB version
+                pcustomcsview->SetDbVersion(CCustomCSView::DbVersion);
+
                 panchorauths.reset();
                 panchorauths = MakeUnique<CAnchorAuthIndex>();
                 panchorAwaitingConfirms.reset();
diff --git a/src/masternodes/accountshistory.cpp b/src/masternodes/accountshistory.cpp
index 59a8de23c18..9744ffc2c8a 100644
--- a/src/masternodes/accountshistory.cpp
+++ b/src/masternodes/accountshistory.cpp
@@ -23,27 +23,3 @@ Res CAccountsHistoryView::SetAccountHistory(const AccountHistoryKey& key, const
     WriteBy<ByAccountHistoryKey>(key, value);
     return Res::Ok();
 }
-
-bool shouldMigrateOldRewardHistory(CCustomCSView & view)
-{
-    auto it = view.GetRaw().NewIterator();
-    try {
-        auto prefix = oldRewardHistoryPrefix;
-        auto oldKey = std::make_pair(prefix, oldRewardHistoryKey{});
-        it->Seek(DbTypeToBytes(oldKey));
-        if (it->Valid() && BytesToDbType(it->Key(), oldKey) && oldKey.first == prefix) {
-            return true;
-        }
-        bool hasOldAccountHistory = false;
-        view.ForEachAccountHistory([&](AccountHistoryKey const & key, CLazySerialize<AccountHistoryValue>) {
-            if (key.txn == std::numeric_limits<uint32_t>::max()) {
-                hasOldAccountHistory = true;
-                return false;
-            }
-            return true;
-        }, { {}, 0, std::numeric_limits<uint32_t>::max() });
-        return hasOldAccountHistory;
-    } catch(...) {
-        return true;
-    }
-}
diff --git a/src/masternodes/accountshistory.h b/src/masternodes/accountshistory.h
index ab40475da3a..13005cb7c45 100644
--- a/src/masternodes/accountshistory.h
+++ b/src/masternodes/accountshistory.h
@@ -64,7 +64,4 @@ class CAccountsHistoryView : public virtual CStorageView
 
 static constexpr bool DEFAULT_ACINDEX = true;
 
-class CCustomCSView;
-bool shouldMigrateOldRewardHistory(CCustomCSView & view);
-
 #endif //DEFI_MASTERNODES_ACCOUNTSHISTORY_H
diff --git a/src/masternodes/masternodes.cpp b/src/masternodes/masternodes.cpp
index aded172940d..271e85ee5c3 100644
--- a/src/masternodes/masternodes.cpp
+++ b/src/masternodes/masternodes.cpp
@@ -26,6 +26,7 @@ const unsigned char DB_MASTERNODES = 'M';     // main masternodes table
 const unsigned char DB_MN_OPERATORS = 'o';    // masternodes' operators index
 const unsigned char DB_MN_OWNERS = 'w';       // masternodes' owners index
 const unsigned char DB_MN_HEIGHT = 'H';       // single record with last processed chain height
+const unsigned char DB_MN_VERSION = 'D';
 const unsigned char DB_MN_ANCHOR_REWARD = 'r';
 const unsigned char DB_MN_ANCHOR_CONFIRM = 'x';
 const unsigned char DB_MN_CURRENT_TEAM = 't';
@@ -541,6 +542,19 @@ std::vector<CAnchorConfirmDataPlus> CAnchorConfirmsView::GetAnchorConfirmData()
 /*
  *  CCustomCSView
  */
+int CCustomCSView::GetDbVersion() const
+{
+    int version;
+    if (Read(DB_MN_VERSION, version))
+        return version;
+    return 0;
+}
+
+void CCustomCSView::SetDbVersion(int version)
+{
+    Write(DB_MN_VERSION, version);
+}
+
 CTeamView::CTeam CCustomCSView::CalcNextTeam(const uint256 & stakeModifier)
 {
     if (stakeModifier == uint256())
diff --git a/src/masternodes/masternodes.h b/src/masternodes/masternodes.h
index 71dada468ab..8dd52e863df 100644
--- a/src/masternodes/masternodes.h
+++ b/src/masternodes/masternodes.h
@@ -218,6 +218,9 @@ class CCustomCSView
         , public CAnchorConfirmsView
 {
 public:
+    // Increase version when underlaying tables are changed
+    static constexpr const int DbVersion = 1;
+
     CCustomCSView() = default;
 
     CCustomCSView(CStorageKV & st)
@@ -244,6 +247,10 @@ class CCustomCSView
 
     bool CalculateOwnerRewards(CScript const & owner, uint32_t height);
 
+    void SetDbVersion(int version);
+
+    int GetDbVersion() const;
+
     CStorageKV& GetRaw() {
         return DB();
     }