Steps toward multiple dbs available -- working

There will need to be some more refactoring for these changes to be
considered complete/correct, but for now it's working.

new daemon cli argument "--db-type", works for LMDB and BerkeleyDB.

A good deal of refactoring is also present in this commit, namely
Blockchain no longer instantiates BlockchainDB, but rather is passed a
pointer to an already-instantiated BlockchainDB on init().

src/blockchain_db/berkeleydb/db_bdb.cpp

@@ -724,13 +724,6 @@ void BlockchainBDB::open(const std::string& filename, const int db_flags)
   m_open = true;
 }
 
-// unused for now, create will happen on open if doesn't exist
-void BlockchainBDB::create(const std::string& filename)
-{
-  LOG_PRINT_L3("BlockchainBDB::" << __func__);
-  throw DB_CREATE_FAILURE("create() is not implemented for this BlockchainDB, open() will create files if needed.");
-}
-
 void BlockchainBDB::close()
 {
   LOG_PRINT_L3("BlockchainBDB::" << __func__);

src/blockchain_db/berkeleydb/db_bdb.h

@@ -95,8 +95,6 @@ public:
 
   virtual void open(const std::string& filename, const int db_flags);
 
-  virtual void create(const std::string& filename);
-
   virtual void close();
 
   virtual void sync();
@@ -279,7 +277,6 @@ private:
 
   Db* m_spent_keys;
 
-  bool m_open;
   uint64_t m_height;
   uint64_t m_num_outputs;
   std::string m_folder;

src/blockchain_db/blockchain_db.cpp

@@ -129,6 +129,11 @@ void BlockchainDB::pop_block(block& blk, std::vector<transaction>& txs)
   }
 }
 
+bool BlockchainDB::is_open()
+{
+  return m_open;
+}
+
 void BlockchainDB::remove_transaction(const crypto::hash& tx_hash)
 {
   transaction tx = get_tx(tx_hash);

src/blockchain_db/blockchain_db.h

@@ -62,6 +62,7 @@
  *
  * General:
  *   open()
+ *   is_open()
  *   close()
  *   sync()
  *   reset()
@@ -328,8 +329,8 @@ public:
   // open the db at location <filename>, or create it if there isn't one.
   virtual void open(const std::string& filename, const int db_flags = 0) = 0;
 
-  // make sure implementation has a create function as well
-  virtual void create(const std::string& filename) = 0;
+  // returns true of the db is open/ready, else false
+  bool is_open();
 
   // close and sync the db
   virtual void close() = 0;
@@ -482,6 +483,7 @@ public:
   // returns true if key image <img> is present in spent key images storage
   virtual bool has_key_image(const crypto::key_image& img) const = 0;
 
+  bool m_open;
 };  // class BlockchainDB
 
 

src/blockchain_db/db_types.h

@@ -0,0 +1,40 @@
+// Copyright (c) 2015, The Monero Project
+//
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without modification, are
+// permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice, this list of
+//    conditions and the following disclaimer.
+//
+// 2. Redistributions in binary form must reproduce the above copyright notice, this list
+//    of conditions and the following disclaimer in the documentation and/or other
+//    materials provided with the distribution.
+//
+// 3. Neither the name of the copyright holder nor the names of its contributors may be
+//    used to endorse or promote products derived from this software without specific
+//    prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY
+// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+// THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+// STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
+// THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// Parts of this file are originally copyright (c) 2012-2013 The Cryptonote developers
+#pragma once
+
+namespace cryptonote
+{
+
+  const std::unordered_set<std::string> blockchain_db_types = 
+  { "lmdb"
+  , "berkeley"
+  };
+
+} // namespace cryptonote

src/blockchain_db/lmdb/db_lmdb.cpp

@@ -733,13 +733,6 @@ void BlockchainLMDB::open(const std::string& filename, const int mdb_flags)
   // from here, init should be finished
 }
 
-// unused for now, create will happen on open if doesn't exist
-void BlockchainLMDB::create(const std::string& filename)
-{
-  LOG_PRINT_L3("BlockchainLMDB::" << __func__);
-  throw DB_CREATE_FAILURE("create() is not implemented for this BlockchainDB, open() will create files if needed.");
-}
-
 void BlockchainLMDB::close()
 {
   LOG_PRINT_L3("BlockchainLMDB::" << __func__);

src/blockchain_db/lmdb/db_lmdb.h

@@ -24,6 +24,7 @@
 // INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 // STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
 // THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#pragma once
 
 #include "blockchain_db/blockchain_db.h"
 #include "cryptonote_protocol/blobdatatype.h" // for type blobdata
@@ -116,8 +117,6 @@ public:
 
   virtual void open(const std::string& filename, const int mdb_flags=0);
 
-  virtual void create(const std::string& filename);
-
   virtual void close();
 
   virtual void sync();
@@ -302,7 +301,6 @@ private:
 
   MDB_dbi m_spent_keys;
 
-  bool m_open;
   uint64_t m_height;
   uint64_t m_num_outputs;
   std::string m_folder;