From 5b31813938356152e721396cea00b08ea62c3e7d Mon Sep 17 00:00:00 2001
From: practicalswift <practicalswift@users.noreply.github.com>
Date: Wed, 9 Aug 2017 16:24:12 +0200
Subject: [PATCH] Use unique_ptr for dbenv (DbEnv)

---
 src/wallet/db.cpp | 31 ++++++++++++++-----------------
 src/wallet/db.h   |  2 +-
 2 files changed, 15 insertions(+), 18 deletions(-)

diff --git a/src/wallet/db.cpp b/src/wallet/db.cpp
index 9f1d0c095ead0..11fb68278ba4f 100644
--- a/src/wallet/db.cpp
+++ b/src/wallet/db.cpp
@@ -77,13 +77,12 @@ void CDBEnv::EnvShutdown()
 
 void CDBEnv::Reset()
 {
-    delete dbenv;
-    dbenv = new DbEnv(DB_CXX_NO_EXCEPTIONS);
+    dbenv.reset(new DbEnv(DB_CXX_NO_EXCEPTIONS));
     fDbEnvInit = false;
     fMockDb = false;
 }
 
-CDBEnv::CDBEnv() : dbenv(NULL)
+CDBEnv::CDBEnv()
 {
     Reset();
 }
@@ -91,8 +90,6 @@ CDBEnv::CDBEnv() : dbenv(NULL)
 CDBEnv::~CDBEnv()
 {
     EnvShutdown();
-    delete dbenv;
-    dbenv = NULL;
 }
 
 void CDBEnv::Close()
@@ -184,8 +181,8 @@ CDBEnv::VerifyResult CDBEnv::Verify(const std::string& strFile, recoverFunc_type
     LOCK(cs_db);
     assert(mapFileUseCount.count(strFile) == 0);
 
-    Db db(dbenv, 0);
-    int result = db.verify(strFile.c_str(), NULL, NULL, 0);
+    Db db(dbenv.get(), 0);
+    int result = db.verify(strFile.c_str(), nullptr, nullptr, 0);
     if (result == 0)
         return VERIFY_OK;
     else if (recoverFunc == NULL)
@@ -225,8 +222,8 @@ bool CDB::Recover(const std::string& filename, void *callbackDataIn, bool (*reco
     }
     LogPrintf("Salvage(aggressive) found %u records\n", salvagedData.size());
 
-    std::unique_ptr<Db> pdbCopy(new Db(bitdb.dbenv, 0));
-    int ret = pdbCopy->open(NULL,               // Txn pointer
+    std::unique_ptr<Db> pdbCopy(new Db(bitdb.dbenv.get(), 0));
+    int ret = pdbCopy->open(nullptr,               // Txn pointer
                             filename.c_str(),   // Filename
                             "main",             // Logical db name
                             DB_BTREE,           // Database type
@@ -326,8 +323,8 @@ bool CDBEnv::Salvage(const std::string& strFile, bool fAggressive, std::vector<C
 
     std::stringstream strDump;
 
-    Db db(dbenv, 0);
-    int result = db.verify(strFile.c_str(), NULL, &strDump, flags);
+    Db db(dbenv.get(), 0);
+    int result = db.verify(strFile.c_str(), nullptr, &strDump, flags);
     if (result == DB_VERIFY_BAD) {
         LogPrintf("CDBEnv::Salvage : Database salvage found errors, all data may not be recoverable.\n");
         if (!fAggressive) {
@@ -408,7 +405,7 @@ CDB::CDB(CWalletDBWrapper& dbw, const char* pszMode, bool fFlushOnCloseIn) : pdb
         pdb = env->mapDb[strFilename];
         if (pdb == nullptr) {
             int ret;
-            std::unique_ptr<Db> pdb_temp(new Db(env->dbenv, 0));
+            std::unique_ptr<Db> pdb_temp(new Db(env->dbenv.get(), 0));
 
             bool fMockDb = env->IsMock();
             if (fMockDb) {
@@ -517,7 +514,7 @@ bool CDB::Rewrite(CWalletDBWrapper& dbw, const char* pszSkip)
                 std::string strFileRes = strFile + ".rewrite";
                 { // surround usage of db with extra {}
                     CDB db(dbw, "r");
-                    Db* pdbCopy = new Db(env->dbenv, 0);
+                    Db* pdbCopy = new Db(env->dbenv.get(), 0);
 
                     int ret = pdbCopy->open(NULL, // Txn pointer
                         strFileRes.c_str(),       // Filename
@@ -569,11 +566,11 @@ bool CDB::Rewrite(CWalletDBWrapper& dbw, const char* pszSkip)
                     delete pdbCopy;
                 }
                 if (fSuccess) {
-                    Db dbA(env->dbenv, 0);
-                    if (dbA.remove(strFile.c_str(), NULL, 0))
+                    Db dbA(env->dbenv.get(), 0);
+                    if (dbA.remove(strFile.c_str(), nullptr, 0))
                         fSuccess = false;
-                    Db dbB(env->dbenv, 0);
-                    if (dbB.rename(strFileRes.c_str(), NULL, strFile.c_str(), 0))
+                    Db dbB(env->dbenv.get(), 0);
+                    if (dbB.rename(strFileRes.c_str(), nullptr, strFile.c_str(), 0))
                         fSuccess = false;
                 }
                 if (!fSuccess)
diff --git a/src/wallet/db.h b/src/wallet/db.h
index 948b9ffa8af8b..a3e0c288cdef0 100644
--- a/src/wallet/db.h
+++ b/src/wallet/db.h
@@ -37,7 +37,7 @@ class CDBEnv
 
 public:
     mutable RecursiveMutex cs_db;
-    DbEnv *dbenv;
+    std::unique_ptr<DbEnv> dbenv;
     std::map<std::string, int> mapFileUseCount;
     std::map<std::string, Db*> mapDb;