1 files changed, 16 insertions, 10 deletions

diff --git a/src/txdb.cpp b/src/txdb.cpp
index 52cd96283..79838b611 100644
--- a/src/txdb.cpp
+++ b/src/txdb.cpp
@@ -11,6 +11,8 @@
 
 #include <stdint.h>
 
+#include <boost/thread.hpp>
+
 using namespace std;
 
 void static BatchWriteCoins(CLevelDBBatch &batch, const uint256 &hash, const CCoins &coins) {
@@ -27,7 +29,7 @@ void static BatchWriteHashBestChain(CLevelDBBatch &batch, const uint256 &hash) {
 CCoinsViewDB::CCoinsViewDB(size_t nCacheSize, bool fMemory, bool fWipe) : db(GetDataDir() / "chainstate", nCacheSize, fMemory, fWipe) {
 }
 
-bool CCoinsViewDB::GetCoins(const uint256 &txid, CCoins &coins) {
+bool CCoinsViewDB::GetCoins(const uint256 &txid, CCoins &coins) const {
     return db.Read(make_pair('c', txid), coins);
 }
 
@@ -37,11 +39,11 @@ bool CCoinsViewDB::SetCoins(const uint256 &txid, const CCoins &coins) {
     return db.WriteBatch(batch);
 }
 
-bool CCoinsViewDB::HaveCoins(const uint256 &txid) {
+bool CCoinsViewDB::HaveCoins(const uint256 &txid) const {
     return db.Exists(make_pair('c', txid));
 }
 
-uint256 CCoinsViewDB::GetBestBlock() {
+uint256 CCoinsViewDB::GetBestBlock() const {
     uint256 hashBestChain;
     if (!db.Read('B', hashBestChain))
         return uint256(0);
@@ -54,12 +56,15 @@ bool CCoinsViewDB::SetBestBlock(const uint256 &hashBlock) {
     return db.WriteBatch(batch);
 }
 
-bool CCoinsViewDB::BatchWrite(const CCoinsMap &mapCoins, const uint256 &hashBlock) {
+bool CCoinsViewDB::BatchWrite(CCoinsMap &mapCoins, const uint256 &hashBlock) {
     LogPrint("coindb", "Committing %u changed transactions to coin database...\n", (unsigned int)mapCoins.size());
 
     CLevelDBBatch batch;
-    for (CCoinsMap::const_iterator it = mapCoins.begin(); it != mapCoins.end(); it++)
+    for (CCoinsMap::iterator it = mapCoins.begin(); it != mapCoins.end();) {
         BatchWriteCoins(batch, it->first, it->second);
+        CCoinsMap::iterator itOld = it++;
+        mapCoins.erase(itOld);
+    }
     if (hashBlock != uint256(0))
         BatchWriteHashBestChain(batch, hashBlock);
 
@@ -102,8 +107,11 @@ bool CBlockTreeDB::ReadLastBlockFile(int &nFile) {
     return Read('l', nFile);
 }
 
-bool CCoinsViewDB::GetStats(CCoinsStats &stats) {
-    leveldb::Iterator *pcursor = db.NewIterator();
+bool CCoinsViewDB::GetStats(CCoinsStats &stats) const {
+    /* It seems that there are no "const iterators" for LevelDB.  Since we
+       only need read operations on it, use a const-cast to get around
+       that restriction.  */
+    leveldb::Iterator *pcursor = const_cast<CLevelDBWrapper*>(&db)->NewIterator();
     pcursor->SeekToFirst();
 
     CHashWriter ss(SER_GETHASH, PROTOCOL_VERSION);
@@ -146,7 +154,6 @@ bool CCoinsViewDB::GetStats(CCoinsStats &stats) {
             return error("%s : Deserialize or I/O error - %s", __func__, e.what());
         }
     }
-    delete pcursor;
     stats.nHeight = mapBlockIndex.find(GetBestBlock())->second->nHeight;
     stats.hashSerialized = ss.GetHash();
     stats.nTotalAmount = nTotalAmount;
@@ -178,7 +185,7 @@ bool CBlockTreeDB::ReadFlag(const std::string &name, bool &fValue) {
 
 bool CBlockTreeDB::LoadBlockIndexGuts()
 {
-    leveldb::Iterator *pcursor = NewIterator();
+    boost::scoped_ptr<leveldb::Iterator> pcursor(NewIterator());
 
     CDataStream ssKeySet(SER_DISK, CLIENT_VERSION);
     ssKeySet << make_pair('b', uint256(0));
@@ -224,7 +231,6 @@ bool CBlockTreeDB::LoadBlockIndexGuts()
             return error("%s : Deserialize or I/O error - %s", __func__, e.what());
         }
     }
-    delete pcursor;
 
     return true;
 }