Make appropriate getter-routines "const" in CCoinsView.

Mark the "Get"/"Have" routines in CCoinsView and subclasses as "const".

1 files changed, 8 insertions, 5 deletions

diff --git a/src/txdb.cpp b/src/txdb.cpp
index 7c0683aaf3..2349514def 100644
--- a/src/txdb.cpp
+++ b/src/txdb.cpp
@@ -27,7 +27,7 @@ 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 +37,11 @@ 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);
@@ -105,8 +105,11 @@ bool CBlockTreeDB::ReadLastBlockFile(int &nFile) {
     return Read('l', nFile);
 }
 
-bool CCoinsViewDB::GetStats(CCoinsStats &stats) {
-    boost::scoped_ptr<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);