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/cryptonote_core/blockchain.cpp

@@ -39,7 +39,6 @@
 #include "tx_pool.h"
 #include "blockchain.h"
 #include "blockchain_db/blockchain_db.h"
-#include "blockchain_db/lmdb/db_lmdb.h"
 #include "cryptonote_format_utils.h"
 #include "cryptonote_boost_serialization.h"
 #include "cryptonote_config.h"
@@ -65,8 +64,7 @@ using epee::string_tools::pod_to_hex;
 DISABLE_VS_WARNINGS(4267)
 
 //------------------------------------------------------------------
-// TODO: initialize m_db with a concrete implementation of BlockchainDB
-Blockchain::Blockchain(tx_memory_pool& tx_pool):m_db(), m_tx_pool(tx_pool), m_current_block_cumul_sz_limit(0), m_is_in_checkpoint_zone(false), m_is_blockchain_storing(false), m_testnet(false), m_enforce_dns_checkpoints(false)
+Blockchain::Blockchain(tx_memory_pool& tx_pool):m_db(), m_tx_pool(tx_pool), m_current_block_cumul_sz_limit(0), m_is_in_checkpoint_zone(false), m_is_blockchain_storing(false), m_enforce_dns_checkpoints(false)
 {
   LOG_PRINT_L3("Blockchain::" << __func__);
 }
@@ -226,43 +224,24 @@ uint64_t Blockchain::get_current_blockchain_height() const
 //------------------------------------------------------------------
 //FIXME: possibly move this into the constructor, to avoid accidentally
 //       dereferencing a null BlockchainDB pointer
-bool Blockchain::init(const std::string& config_folder, const bool testnet, const int db_flags)
+bool Blockchain::init(BlockchainDB* db, const bool testnet)
 {
   LOG_PRINT_L3("Blockchain::" << __func__);
   CRITICAL_REGION_LOCAL(m_blockchain_lock);
 
-  // TODO: make this configurable
-  m_db = new BlockchainLMDB();
-
-  m_config_folder = config_folder;
-  m_testnet = testnet;
-
-  boost::filesystem::path folder(m_config_folder);
-
-  folder /= m_db->get_db_name();
-
-  LOG_PRINT_L0("Loading blockchain from folder " << folder.c_str() << " ...");
-
-  const std::string filename = folder.string();
-  try
+  if (db == nullptr)
   {
-    m_db->open(filename, db_flags);
+    LOG_ERROR("Attempted to init Blockchain with null DB");
+    return false;
   }
-  catch (const DB_OPEN_FAILURE& e)
+  if (!db->is_open())
   {
-    LOG_PRINT_L0("No blockchain file found, attempting to create one.");
-    try
-    {
-      m_db->create(filename);
-    }
-    catch (const DB_CREATE_FAILURE& db_create_error)
-    {
-      LOG_PRINT_L0("Unable to create BlockchainDB!  This is not good...");
-      //TODO: make sure whatever calls this handles the return value properly
-      return false;
-    }
+    LOG_ERROR("Attempted to init Blockchain with unopened DB");
+    return false;
   }
 
+  m_db = db;
+
   // if the blockchain is new, add the genesis block
   // this feels kinda kludgy to do it this way, but can be looked at later.
   // TODO: add function to create and store genesis block,

src/cryptonote_core/blockchain.h

@@ -81,7 +81,7 @@ namespace cryptonote
 
     Blockchain(tx_memory_pool& tx_pool);
 
-    bool init(const std::string& config_folder, const bool testnet = false, const int db_flags = 0);
+    bool init(BlockchainDB* db, const bool testnet = false);
     bool deinit();
 
     void set_checkpoints(checkpoints&& chk_pts) { m_checkpoints = chk_pts; }
@@ -180,11 +180,9 @@ namespace cryptonote
     outputs_container m_outputs;
 
 
-    std::string m_config_folder;
     checkpoints m_checkpoints;
     std::atomic<bool> m_is_in_checkpoint_zone;
     std::atomic<bool> m_is_blockchain_storing;
-    bool m_testnet;
     bool m_enforce_dns_checkpoints;
 
     bool switch_to_alternative_blockchain(std::list<blocks_ext_by_hash::iterator>& alt_chain, bool discard_disconnected_chain);

src/cryptonote_core/cryptonote_core.cpp

@@ -44,6 +44,9 @@ using namespace epee;
 #include <csignal>
 #include "daemon/command_line_args.h"
 #include "cryptonote_core/checkpoints_create.h"
+#include "blockchain_db/blockchain_db.h"
+#include "blockchain_db/lmdb/db_lmdb.h"
+#include "blockchain_db/berkeleydb/db_bdb.h"
 
 DISABLE_VS_WARNINGS(4355)
 
@@ -194,7 +197,45 @@ namespace cryptonote
     r = m_mempool.init(m_config_folder);
     CHECK_AND_ASSERT_MES(r, false, "Failed to initialize memory pool");
 
+#if BLOCKCHAIN_DB == DB_LMDB
+    std::string db_type = command_line::get_arg(vm, daemon_args::arg_db_type);
+
+    BlockchainDB* db = nullptr;
+    if (db_type == "lmdb")
+    {
+      db = new BlockchainLMDB();
+    }
+    else if (db_type == "berkeley")
+    {
+      db = new BlockchainBDB();
+    }
+    else
+    {
+      LOG_ERROR("Attempted to use non-existant database type");
+      return false;
+    }
+
+    boost::filesystem::path folder(m_config_folder);
+
+    folder /= db->get_db_name();
+
+    LOG_PRINT_L0("Loading blockchain from folder " << folder.c_str() << " ...");
+
+    const std::string filename = folder.string();
+    try
+    {
+      db->open(filename);
+    }
+    catch (const DB_ERROR& e)
+    {
+      LOG_PRINT_L0("Error opening database: " << e.what());
+      return false;
+    }
+
+    r = m_blockchain_storage.init(db, m_testnet);
+#else
     r = m_blockchain_storage.init(m_config_folder, m_testnet);
+#endif
     CHECK_AND_ASSERT_MES(r, false, "Failed to initialize blockchain storage");
 
     // load json & DNS checkpoints, and verify them