From c9e6e7ed79886b702614e627a966fc9a4850f8f0 Mon Sep 17 00:00:00 2001
From: Karl-Johan Alm <karljohan-alm@garage.co.jp>
Date: Wed, 10 Apr 2019 11:40:35 +0900
Subject: [PATCH] wallet: add cachable amounts for caching credit/debit values

---
 src/script/ismine.h                    | 29 ++++++--
 src/wallet/test/coinselector_tests.cpp |  5 +-
 src/wallet/wallet.cpp                  | 94 ++++++++------------------
 src/wallet/wallet.h                    | 47 ++-----------
 4 files changed, 61 insertions(+), 114 deletions(-)

diff --git a/src/script/ismine.h b/src/script/ismine.h
index 601e70f70..55e28e225 100644
--- a/src/script/ismine.h
+++ b/src/script/ismine.h
@@ -9,6 +9,7 @@
 #include <script/standard.h>
 
 #include <stdint.h>
+#include <bitset>
 
 class CKeyStore;
 class CScript;
@@ -16,10 +17,11 @@ class CScript;
 /** IsMine() return codes */
 enum isminetype
 {
-    ISMINE_NO = 0,
-    ISMINE_WATCH_ONLY = 1,
-    ISMINE_SPENDABLE = 2,
-    ISMINE_ALL = ISMINE_WATCH_ONLY | ISMINE_SPENDABLE
+    ISMINE_NO         = 0,
+    ISMINE_WATCH_ONLY = 1 << 0,
+    ISMINE_SPENDABLE  = 1 << 1,
+    ISMINE_ALL        = ISMINE_WATCH_ONLY | ISMINE_SPENDABLE,
+    ISMINE_ENUM_ELEMENTS,
 };
 /** used for bitflags of isminetype */
 typedef uint8_t isminefilter;
@@ -27,4 +29,23 @@ typedef uint8_t isminefilter;
 isminetype IsMine(const CKeyStore& keystore, const CScript& scriptPubKey);
 isminetype IsMine(const CKeyStore& keystore, const CTxDestination& dest);
 
+/**
+ * Cachable amount subdivided into watchonly and spendable parts.
+ */
+struct CachableAmount
+{
+    // NO and ALL are never (supposed to be) cached
+    std::bitset<ISMINE_ENUM_ELEMENTS> m_cached;
+    CAmount m_value[ISMINE_ENUM_ELEMENTS];
+    inline void Reset()
+    {
+        m_cached.reset();
+    }
+    void Set(isminefilter filter, CAmount value)
+    {
+        m_cached.set(filter);
+        m_value[filter] = value;
+    }
+};
+
 #endif // BITCOIN_SCRIPT_ISMINE_H
diff --git a/src/wallet/test/coinselector_tests.cpp b/src/wallet/test/coinselector_tests.cpp
index b7ca746f8..34b9770e8 100644
--- a/src/wallet/test/coinselector_tests.cpp
+++ b/src/wallet/test/coinselector_tests.cpp
@@ -69,8 +69,7 @@ static void add_coin(const CAmount& nValue, int nAge = 6*24, bool fIsFromMe = fa
     std::unique_ptr<CWalletTx> wtx = MakeUnique<CWalletTx>(&testWallet, MakeTransactionRef(std::move(tx)));
     if (fIsFromMe)
     {
-        wtx->fDebitCached = true;
-        wtx->nDebitCached = 1;
+        wtx->m_amounts[CWalletTx::DEBIT].Set(ISMINE_SPENDABLE, 1);
     }
     COutput output(wtx.get(), nInput, nAge, true /* spendable */, true /* solvable */, true /* safe */);
     vCoins.push_back(output);
@@ -115,7 +114,7 @@ inline std::vector<OutputGroup>& GroupCoins(const std::vector<COutput>& coins)
 {
     static std::vector<OutputGroup> static_groups;
     static_groups.clear();
-    for (auto& coin : coins) static_groups.emplace_back(coin.GetInputCoin(), coin.nDepth, coin.tx->fDebitCached && coin.tx->nDebitCached == 1 /* HACK: we can't figure out the is_me flag so we use the conditions defined above; perhaps set safe to false for !fIsFromMe in add_coin() */, 0, 0);
+    for (auto& coin : coins) static_groups.emplace_back(coin.GetInputCoin(), coin.nDepth, coin.tx->m_amounts[CWalletTx::DEBIT].m_cached[ISMINE_SPENDABLE] && coin.tx->m_amounts[CWalletTx::DEBIT].m_value[ISMINE_SPENDABLE] == 1 /* HACK: we can't figure out the is_me flag so we use the conditions defined above; perhaps set safe to false for !fIsFromMe in add_coin() */, 0, 0);
     return static_groups;
 }
 
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index 4737e2f6f..c577ebeda 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -1932,33 +1932,26 @@ std::set<uint256> CWalletTx::GetConflicts() const
     return result;
 }
 
+CAmount CWalletTx::GetCachableAmount(AmountType type, const isminefilter& filter, bool recalculate) const
+{
+    auto& amount = m_amounts[type];
+    if (recalculate || !amount.m_cached[filter]) {
+        amount.Set(filter, type == DEBIT ? pwallet->GetDebit(*tx, filter) : pwallet->GetCredit(*tx, filter));
+    }
+    return amount.m_value[filter];
+}
+
 CAmount CWalletTx::GetDebit(const isminefilter& filter) const
 {
     if (tx->vin.empty())
         return 0;
 
     CAmount debit = 0;
-    if(filter & ISMINE_SPENDABLE)
-    {
-        if (fDebitCached)
-            debit += nDebitCached;
-        else
-        {
-            nDebitCached = pwallet->GetDebit(*tx, ISMINE_SPENDABLE);
-            fDebitCached = true;
-            debit += nDebitCached;
-        }
+    if (filter & ISMINE_SPENDABLE) {
+        debit += GetCachableAmount(DEBIT, ISMINE_SPENDABLE);
     }
-    if(filter & ISMINE_WATCH_ONLY)
-    {
-        if(fWatchDebitCached)
-            debit += nWatchDebitCached;
-        else
-        {
-            nWatchDebitCached = pwallet->GetDebit(*tx, ISMINE_WATCH_ONLY);
-            fWatchDebitCached = true;
-            debit += nWatchDebitCached;
-        }
+    if (filter & ISMINE_WATCH_ONLY) {
+        debit += GetCachableAmount(DEBIT, ISMINE_WATCH_ONLY);
     }
     return debit;
 }
@@ -1970,28 +1963,12 @@ CAmount CWalletTx::GetCredit(interfaces::Chain::Lock& locked_chain, const ismine
         return 0;
 
     CAmount credit = 0;
-    if (filter & ISMINE_SPENDABLE)
-    {
+    if (filter & ISMINE_SPENDABLE) {
         // GetBalance can assume transactions in mapWallet won't change
-        if (fCreditCached)
-            credit += nCreditCached;
-        else
-        {
-            nCreditCached = pwallet->GetCredit(*tx, ISMINE_SPENDABLE);
-            fCreditCached = true;
-            credit += nCreditCached;
-        }
+        credit += GetCachableAmount(CREDIT, ISMINE_SPENDABLE);
     }
-    if (filter & ISMINE_WATCH_ONLY)
-    {
-        if (fWatchCreditCached)
-            credit += nWatchCreditCached;
-        else
-        {
-            nWatchCreditCached = pwallet->GetCredit(*tx, ISMINE_WATCH_ONLY);
-            fWatchCreditCached = true;
-            credit += nWatchCreditCached;
-        }
+    if (filter & ISMINE_WATCH_ONLY) {
+        credit += GetCachableAmount(CREDIT, ISMINE_WATCH_ONLY);
     }
     return credit;
 }
@@ -1999,11 +1976,7 @@ CAmount CWalletTx::GetCredit(interfaces::Chain::Lock& locked_chain, const ismine
 CAmount CWalletTx::GetImmatureCredit(interfaces::Chain::Lock& locked_chain, bool fUseCache) const
 {
     if (IsImmatureCoinBase(locked_chain) && IsInMainChain(locked_chain)) {
-        if (fUseCache && fImmatureCreditCached)
-            return nImmatureCreditCached;
-        nImmatureCreditCached = pwallet->GetCredit(*tx, ISMINE_SPENDABLE);
-        fImmatureCreditCached = true;
-        return nImmatureCreditCached;
+        return GetCachableAmount(IMMATURE_CREDIT, ISMINE_SPENDABLE, !fUseCache);
     }
 
     return 0;
@@ -2014,23 +1987,15 @@ CAmount CWalletTx::GetAvailableCredit(interfaces::Chain::Lock& locked_chain, boo
     if (pwallet == nullptr)
         return 0;
 
+    // Avoid caching ismine for NO or ALL cases (could remove this check and simplify in the future).
+    bool allow_cache = filter == ISMINE_SPENDABLE || filter == ISMINE_WATCH_ONLY;
+
     // Must wait until coinbase is safely deep enough in the chain before valuing it
     if (IsImmatureCoinBase(locked_chain))
         return 0;
 
-    CAmount* cache = nullptr;
-    bool* cache_used = nullptr;
-
-    if (filter == ISMINE_SPENDABLE) {
-        cache = &nAvailableCreditCached;
-        cache_used = &fAvailableCreditCached;
-    } else if (filter == ISMINE_WATCH_ONLY) {
-        cache = &nAvailableWatchCreditCached;
-        cache_used = &fAvailableWatchCreditCached;
-    }
-
-    if (fUseCache && cache_used && *cache_used) {
-        return *cache;
+    if (fUseCache && allow_cache && m_amounts[AVAILABLE_CREDIT].m_cached[filter]) {
+        return m_amounts[AVAILABLE_CREDIT].m_value[filter];
     }
 
     CAmount nCredit = 0;
@@ -2046,22 +2011,17 @@ CAmount CWalletTx::GetAvailableCredit(interfaces::Chain::Lock& locked_chain, boo
         }
     }
 
-    if (cache) {
-        *cache = nCredit;
-        assert(cache_used);
-        *cache_used = true;
+    if (allow_cache) {
+        m_amounts[AVAILABLE_CREDIT].Set(filter, nCredit);
     }
+
     return nCredit;
 }
 
 CAmount CWalletTx::GetImmatureWatchOnlyCredit(interfaces::Chain::Lock& locked_chain, const bool fUseCache) const
 {
     if (IsImmatureCoinBase(locked_chain) && IsInMainChain(locked_chain)) {
-        if (fUseCache && fImmatureWatchCreditCached)
-            return nImmatureWatchCreditCached;
-        nImmatureWatchCreditCached = pwallet->GetCredit(*tx, ISMINE_WATCH_ONLY);
-        fImmatureWatchCreditCached = true;
-        return nImmatureWatchCreditCached;
+        return GetCachableAmount(IMMATURE_CREDIT, ISMINE_WATCH_ONLY, !fUseCache);
     }
 
     return 0;
diff --git a/src/wallet/wallet.h b/src/wallet/wallet.h
index 62ba0aa96..80a4e37bc 100644
--- a/src/wallet/wallet.h
+++ b/src/wallet/wallet.h
@@ -369,24 +369,11 @@ public:
     std::multimap<int64_t, CWalletTx*>::const_iterator m_it_wtxOrdered;
 
     // memory only
-    mutable bool fDebitCached;
-    mutable bool fCreditCached;
-    mutable bool fImmatureCreditCached;
-    mutable bool fAvailableCreditCached;
-    mutable bool fWatchDebitCached;
-    mutable bool fWatchCreditCached;
-    mutable bool fImmatureWatchCreditCached;
-    mutable bool fAvailableWatchCreditCached;
+    enum AmountType { DEBIT, CREDIT, IMMATURE_CREDIT, AVAILABLE_CREDIT, AMOUNTTYPE_ENUM_ELEMENTS };
+    CAmount GetCachableAmount(AmountType type, const isminefilter& filter, bool recalculate = false) const;
+    mutable CachableAmount m_amounts[AMOUNTTYPE_ENUM_ELEMENTS];
     mutable bool fChangeCached;
     mutable bool fInMempool;
-    mutable CAmount nDebitCached;
-    mutable CAmount nCreditCached;
-    mutable CAmount nImmatureCreditCached;
-    mutable CAmount nAvailableCreditCached;
-    mutable CAmount nWatchDebitCached;
-    mutable CAmount nWatchCreditCached;
-    mutable CAmount nImmatureWatchCreditCached;
-    mutable CAmount nAvailableWatchCreditCached;
     mutable CAmount nChangeCached;
 
     CWalletTx(const CWallet* pwalletIn, CTransactionRef arg) : CMerkleTx(std::move(arg))
@@ -403,24 +390,8 @@ public:
         nTimeReceived = 0;
         nTimeSmart = 0;
         fFromMe = false;
-        fDebitCached = false;
-        fCreditCached = false;
-        fImmatureCreditCached = false;
-        fAvailableCreditCached = false;
-        fWatchDebitCached = false;
-        fWatchCreditCached = false;
-        fImmatureWatchCreditCached = false;
-        fAvailableWatchCreditCached = false;
         fChangeCached = false;
         fInMempool = false;
-        nDebitCached = 0;
-        nCreditCached = 0;
-        nImmatureCreditCached = 0;
-        nAvailableCreditCached = 0;
-        nWatchDebitCached = 0;
-        nWatchCreditCached = 0;
-        nAvailableWatchCreditCached = 0;
-        nImmatureWatchCreditCached = 0;
         nChangeCached = 0;
         nOrderPos = -1;
     }
@@ -464,14 +435,10 @@ public:
     //! make sure balances are recalculated
     void MarkDirty()
     {
-        fCreditCached = false;
-        fAvailableCreditCached = false;
-        fImmatureCreditCached = false;
-        fWatchDebitCached = false;
-        fWatchCreditCached = false;
-        fAvailableWatchCreditCached = false;
-        fImmatureWatchCreditCached = false;
-        fDebitCached = false;
+        m_amounts[DEBIT].Reset();
+        m_amounts[CREDIT].Reset();
+        m_amounts[IMMATURE_CREDIT].Reset();
+        m_amounts[AVAILABLE_CREDIT].Reset();
         fChangeCached = false;
     }