index: Remove TxIndexDB from public interface of TxIndex.

src/index/txindex.cpp

@@ -8,7 +8,9 @@
 
 std::unique_ptr<TxIndex> g_txindex;
 
-TxIndex::TxIndex(std::unique_ptr<TxIndexDB> db) : m_db(std::move(db)) {}
+TxIndex::TxIndex(size_t n_cache_size, bool f_memory, bool f_wipe)
+    : m_db(MakeUnique<TxIndex::DB>(n_cache_size, f_memory, f_wipe))
+{}
 
 bool TxIndex::Init()
 {

src/index/txindex.h

@@ -29,7 +29,7 @@ protected:
 
 public:
     /// Constructs the index, which becomes available to be queried.
-    explicit TxIndex(std::unique_ptr<TxIndexDB> db);
+    explicit TxIndex(size_t n_cache_size, bool f_memory = false, bool f_wipe = false);
 
     /// Look up a transaction by hash.
     ///