From fa8a341b88cabfd7f8d702db7cb9972b0804bf2a Mon Sep 17 00:00:00 2001
From: MarcoFalke <falke.marco@gmail.com>
Date: Sat, 20 Jun 2020 08:55:07 -0400
Subject: [PATCH] wallet: Replace CDataStream& with CDataStream&& where
 appropriate

The keys and values are only to be used once because their memory is set
to zero. Make that explicit by moving the bytes into the lower level
methods.
---
 src/wallet/bdb.cpp |  8 ++++----
 src/wallet/bdb.h   | 16 ++++++++--------
 2 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/src/wallet/bdb.cpp b/src/wallet/bdb.cpp
index a3a56aa51..267b147f3 100644
--- a/src/wallet/bdb.cpp
+++ b/src/wallet/bdb.cpp
@@ -804,7 +804,7 @@ std::string BerkeleyDatabaseVersion()
     return DbEnv::version(nullptr, nullptr, nullptr);
 }
 
-bool BerkeleyBatch::ReadKey(CDataStream& key, CDataStream& value)
+bool BerkeleyBatch::ReadKey(CDataStream&& key, CDataStream& value)
 {
     if (!pdb)
         return false;
@@ -820,7 +820,7 @@ bool BerkeleyBatch::ReadKey(CDataStream& key, CDataStream& value)
     return false;
 }
 
-bool BerkeleyBatch::WriteKey(CDataStream& key, CDataStream& value, bool overwrite)
+bool BerkeleyBatch::WriteKey(CDataStream&& key, CDataStream&& value, bool overwrite)
 {
     if (!pdb)
         return true;
@@ -835,7 +835,7 @@ bool BerkeleyBatch::WriteKey(CDataStream& key, CDataStream& value, bool overwrit
     return (ret == 0);
 }
 
-bool BerkeleyBatch::EraseKey(CDataStream& key)
+bool BerkeleyBatch::EraseKey(CDataStream&& key)
 {
     if (!pdb)
         return false;
@@ -848,7 +848,7 @@ bool BerkeleyBatch::EraseKey(CDataStream& key)
     return (ret == 0 || ret == DB_NOTFOUND);
 }
 
-bool BerkeleyBatch::HasKey(CDataStream& key)
+bool BerkeleyBatch::HasKey(CDataStream&& key)
 {
     if (!pdb)
         return false;
diff --git a/src/wallet/bdb.h b/src/wallet/bdb.h
index a2eaf9500..91116afd0 100644
--- a/src/wallet/bdb.h
+++ b/src/wallet/bdb.h
@@ -189,10 +189,10 @@ class BerkeleyBatch
     };
 
 private:
-    bool ReadKey(CDataStream& key, CDataStream& value);
-    bool WriteKey(CDataStream& key, CDataStream& value, bool overwrite=true);
-    bool EraseKey(CDataStream& key);
-    bool HasKey(CDataStream& key);
+    bool ReadKey(CDataStream&& key, CDataStream& value);
+    bool WriteKey(CDataStream&& key, CDataStream&& value, bool overwrite = true);
+    bool EraseKey(CDataStream&& key);
+    bool HasKey(CDataStream&& key);
 
 protected:
     Db* pdb;
@@ -228,7 +228,7 @@ public:
         ssKey << key;
 
         CDataStream ssValue(SER_DISK, CLIENT_VERSION);
-        if (!ReadKey(ssKey, ssValue)) return false;
+        if (!ReadKey(std::move(ssKey), ssValue)) return false;
         try {
             ssValue >> value;
             return true;
@@ -248,7 +248,7 @@ public:
         ssValue.reserve(10000);
         ssValue << value;
 
-        return WriteKey(ssKey, ssValue, fOverwrite);
+        return WriteKey(std::move(ssKey), std::move(ssValue), fOverwrite);
     }
 
     template <typename K>
@@ -258,7 +258,7 @@ public:
         ssKey.reserve(1000);
         ssKey << key;
 
-        return EraseKey(ssKey);
+        return EraseKey(std::move(ssKey));
     }
 
     template <typename K>
@@ -268,7 +268,7 @@ public:
         ssKey.reserve(1000);
         ssKey << key;
 
-        return HasKey(ssKey);
+        return HasKey(std::move(ssKey));
     }
 
     Dbc* GetCursor();