Merge #9353: Add data() method to CDataStream (and use it)

5113474 wallet: Use CDataStream.data() (Wladimir J. van der Laan)
e2300ff bench: Use CDataStream.data() (Wladimir J. van der Laan)
adff950 dbwrapper: Use new .data() method of CDataStream (Wladimir J. van der Laan)
a2141e4 streams: Remove special cases for ancient MSVC (Wladimir J. van der Laan)
af4c44c streams: Add data() method to CDataStream (Wladimir J. van der Laan)

src/bench/verify_script.cpp

@@ -93,7 +93,7 @@ static void VerifyScriptBench(benchmark::State& state)
             txCredit.vout[0].scriptPubKey.data(),
             txCredit.vout[0].scriptPubKey.size(),
             txCredit.vout[0].nValue,
-            (const unsigned char*)&stream[0], stream.size(), 0, flags, nullptr);
+            (const unsigned char*)stream.data(), stream.size(), 0, flags, nullptr);
         assert(csuccess == 1);
 #endif
     }

src/dbwrapper.h

@@ -67,12 +67,12 @@ public:
     {
         ssKey.reserve(DBWRAPPER_PREALLOC_KEY_SIZE);
         ssKey << key;
-        leveldb::Slice slKey(&ssKey[0], ssKey.size());
+        leveldb::Slice slKey(ssKey.data(), ssKey.size());
 
         ssValue.reserve(DBWRAPPER_PREALLOC_VALUE_SIZE);
         ssValue << value;
         ssValue.Xor(dbwrapper_private::GetObfuscateKey(parent));
-        leveldb::Slice slValue(&ssValue[0], ssValue.size());
+        leveldb::Slice slValue(ssValue.data(), ssValue.size());
 
         batch.Put(slKey, slValue);
         ssKey.clear();
@@ -84,7 +84,7 @@ public:
     {
         ssKey.reserve(DBWRAPPER_PREALLOC_KEY_SIZE);
         ssKey << key;
-        leveldb::Slice slKey(&ssKey[0], ssKey.size());
+        leveldb::Slice slKey(ssKey.data(), ssKey.size());
 
         batch.Delete(slKey);
         ssKey.clear();
@@ -115,7 +115,7 @@ public:
         CDataStream ssKey(SER_DISK, CLIENT_VERSION);
         ssKey.reserve(DBWRAPPER_PREALLOC_KEY_SIZE);
         ssKey << key;
-        leveldb::Slice slKey(&ssKey[0], ssKey.size());
+        leveldb::Slice slKey(ssKey.data(), ssKey.size());
         piter->Seek(slKey);
     }
 
@@ -208,7 +208,7 @@ public:
         CDataStream ssKey(SER_DISK, CLIENT_VERSION);
         ssKey.reserve(DBWRAPPER_PREALLOC_KEY_SIZE);
         ssKey << key;
-        leveldb::Slice slKey(&ssKey[0], ssKey.size());
+        leveldb::Slice slKey(ssKey.data(), ssKey.size());
 
         std::string strValue;
         leveldb::Status status = pdb->Get(readoptions, slKey, &strValue);
@@ -242,7 +242,7 @@ public:
         CDataStream ssKey(SER_DISK, CLIENT_VERSION);
         ssKey.reserve(DBWRAPPER_PREALLOC_KEY_SIZE);
         ssKey << key;
-        leveldb::Slice slKey(&ssKey[0], ssKey.size());
+        leveldb::Slice slKey(ssKey.data(), ssKey.size());
 
         std::string strValue;
         leveldb::Status status = pdb->Get(readoptions, slKey, &strValue);

src/streams.h

@@ -174,12 +174,10 @@ public:
         Init(nTypeIn, nVersionIn);
     }
 
-#if !defined(_MSC_VER) || _MSC_VER >= 1300
     CDataStream(const char* pbegin, const char* pend, int nTypeIn, int nVersionIn) : vch(pbegin, pend)
     {
         Init(nTypeIn, nVersionIn);
     }
-#endif
 
     CDataStream(const vector_type& vchIn, int nTypeIn, int nVersionIn) : vch(vchIn.begin(), vchIn.end())
     {
@@ -245,6 +243,8 @@ public:
     void clear()                                     { vch.clear(); nReadPos = 0; }
     iterator insert(iterator it, const char& x=char()) { return vch.insert(it, x); }
     void insert(iterator it, size_type n, const char& x) { vch.insert(it, n, x); }
+    value_type* data()                               { return vch.data() + nReadPos; }
+    const value_type* data() const                   { return vch.data() + nReadPos; }
 
     void insert(iterator it, std::vector<char>::const_iterator first, std::vector<char>::const_iterator last)
     {
@@ -259,7 +259,6 @@ public:
             vch.insert(it, first, last);
     }
 
-#if !defined(_MSC_VER) || _MSC_VER >= 1300
     void insert(iterator it, const char* first, const char* last)
     {
         assert(last - first >= 0);
@@ -272,7 +271,6 @@ public:
         else
             vch.insert(it, first, last);
     }
-#endif
 
     iterator erase(iterator it)
     {

src/wallet/db.cpp

@@ -397,15 +397,15 @@ bool CDB::Rewrite(const string& strFile, const char* pszSkip)
                                 break;
                             }
                             if (pszSkip &&
-                                strncmp(&ssKey[0], pszSkip, std::min(ssKey.size(), strlen(pszSkip))) == 0)
+                                strncmp(ssKey.data(), pszSkip, std::min(ssKey.size(), strlen(pszSkip))) == 0)
                                 continue;
-                            if (strncmp(&ssKey[0], "\x07version", 8) == 0) {
+                            if (strncmp(ssKey.data(), "\x07version", 8) == 0) {
                                 // Update version:
                                 ssValue.clear();
                                 ssValue << CLIENT_VERSION;
                             }
-                            Dbt datKey(&ssKey[0], ssKey.size());
-                            Dbt datValue(&ssValue[0], ssValue.size());
+                            Dbt datKey(ssKey.data(), ssKey.size());
+                            Dbt datValue(ssValue.data(), ssValue.size());
                             int ret2 = pdbCopy->put(NULL, &datKey, &datValue, DB_NOOVERWRITE);
                             if (ret2 > 0)
                                 fSuccess = false;

src/wallet/db.h

@@ -122,7 +122,7 @@ protected:
         CDataStream ssKey(SER_DISK, CLIENT_VERSION);
         ssKey.reserve(1000);
         ssKey << key;
-        Dbt datKey(&ssKey[0], ssKey.size());
+        Dbt datKey(ssKey.data(), ssKey.size());
 
         // Read
         Dbt datValue;
@@ -158,13 +158,13 @@ protected:
         CDataStream ssKey(SER_DISK, CLIENT_VERSION);
         ssKey.reserve(1000);
         ssKey << key;
-        Dbt datKey(&ssKey[0], ssKey.size());
+        Dbt datKey(ssKey.data(), ssKey.size());
 
         // Value
         CDataStream ssValue(SER_DISK, CLIENT_VERSION);
         ssValue.reserve(10000);
         ssValue << value;
-        Dbt datValue(&ssValue[0], ssValue.size());
+        Dbt datValue(ssValue.data(), ssValue.size());
 
         // Write
         int ret = pdb->put(activeTxn, &datKey, &datValue, (fOverwrite ? 0 : DB_NOOVERWRITE));
@@ -187,7 +187,7 @@ protected:
         CDataStream ssKey(SER_DISK, CLIENT_VERSION);
         ssKey.reserve(1000);
         ssKey << key;
-        Dbt datKey(&ssKey[0], ssKey.size());
+        Dbt datKey(ssKey.data(), ssKey.size());
 
         // Erase
         int ret = pdb->del(activeTxn, &datKey, 0);
@@ -207,7 +207,7 @@ protected:
         CDataStream ssKey(SER_DISK, CLIENT_VERSION);
         ssKey.reserve(1000);
         ssKey << key;
-        Dbt datKey(&ssKey[0], ssKey.size());
+        Dbt datKey(ssKey.data(), ssKey.size());
 
         // Exists
         int ret = pdb->exists(activeTxn, &datKey, 0);
@@ -234,7 +234,7 @@ protected:
         Dbt datKey;
         unsigned int fFlags = DB_NEXT;
         if (setRange) {
-            datKey.set_data(&ssKey[0]);
+            datKey.set_data(ssKey.data());
             datKey.set_size(ssKey.size());
             fFlags = DB_SET_RANGE;
         }