node/chainstate: Add options for in-memory DBs

[META] In a future commit, these options will be used in TestingSetup to
       ensure that the DBs are in-memory.

src/init.cpp

@@ -1415,6 +1415,8 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
                                 cache_sizes.block_tree_db,
                                 cache_sizes.coins_db,
                                 cache_sizes.coins,
+                                false,
+                                false,
                                 ShutdownRequested,
                                 []() {
                                     uiInterface.ThreadSafeMessageBox(

src/node/chainstate.cpp

@@ -17,6 +17,8 @@ std::optional<ChainstateLoadingError> LoadChainstate(bool fReset,
                                                      int64_t nBlockTreeDBCache,
                                                      int64_t nCoinDBCache,
                                                      int64_t nCoinCacheUsage,
+                                                     bool block_tree_db_in_memory,
+                                                     bool coins_db_in_memory,
                                                      std::function<bool()> shutdown_requested,
                                                      std::function<void()> coins_error_cb)
 {
@@ -36,7 +38,7 @@ std::optional<ChainstateLoadingError> LoadChainstate(bool fReset,
         // new CBlockTreeDB tries to delete the existing file, which
         // fails if it's still open from the previous loop. Close it first:
         pblocktree.reset();
-        pblocktree.reset(new CBlockTreeDB(nBlockTreeDBCache, false, fReset));
+        pblocktree.reset(new CBlockTreeDB(nBlockTreeDBCache, block_tree_db_in_memory, fReset));
 
         if (fReset) {
             pblocktree->WriteReindexing(true);
@@ -81,7 +83,7 @@ std::optional<ChainstateLoadingError> LoadChainstate(bool fReset,
         for (CChainState* chainstate : chainman.GetAll()) {
             chainstate->InitCoinsDB(
                 /* cache_size_bytes */ nCoinDBCache,
-                /* in_memory */ false,
+                /* in_memory */ coins_db_in_memory,
                 /* should_wipe */ fReset || fReindexChainState);
 
             if (coins_error_cb) {

src/node/chainstate.h

@@ -63,6 +63,8 @@ std::optional<ChainstateLoadingError> LoadChainstate(bool fReset,
                                                      int64_t nBlockTreeDBCache,
                                                      int64_t nCoinDBCache,
                                                      int64_t nCoinCacheUsage,
+                                                     bool block_tree_db_in_memory,
+                                                     bool coins_db_in_memory,
                                                      std::function<bool()> shutdown_requested = nullptr,
                                                      std::function<void()> coins_error_cb = nullptr);