5 files changed, 103 insertions, 1 deletions
diff --git a/src/wallet/bdb.cpp b/src/wallet/bdb.cpp
index 24eb2ee34c..61463aaf5e 100644
--- a/src/wallet/bdb.cpp
+++ b/src/wallet/bdb.cpp
@@ -824,3 +824,35 @@ std::unique_ptr<DatabaseBatch> BerkeleyDatabase::MakeBatch(const char* mode, boo
 {
     return MakeUnique<BerkeleyBatch>(*this, mode, flush_on_close);
 }
+
+bool ExistsBerkeleyDatabase(const fs::path& path)
+{
+    fs::path env_directory;
+    std::string data_filename;
+    SplitWalletPath(path, env_directory, data_filename);
+    return IsBerkeleyBtree(env_directory / data_filename);
+}
+
+std::unique_ptr<BerkeleyDatabase> MakeBerkeleyDatabase(const fs::path& path, const DatabaseOptions& options, DatabaseStatus& status, bilingual_str& error)
+{
+    std::unique_ptr<BerkeleyDatabase> db;
+    {
+        LOCK(cs_db); // Lock env.m_databases until insert in BerkeleyDatabase constructor
+        std::string data_filename;
+        std::shared_ptr<BerkeleyEnvironment> env = GetWalletEnv(path, data_filename);
+        if (env->m_databases.count(data_filename)) {
+            error = Untranslated(strprintf("Refusing to load database. Data file '%s' is already loaded.", (env->Directory() / data_filename).string()));
+            status = DatabaseStatus::FAILED_ALREADY_LOADED;
+            return nullptr;
+        }
+        db = MakeUnique<BerkeleyDatabase>(std::move(env), std::move(data_filename));
+    }
+
+    if (options.verify && !db->Verify(error)) {
+        status = DatabaseStatus::FAILED_VERIFY;
+        return nullptr;
+    }
+
+    status = DatabaseStatus::SUCCESS;
+    return db;
+}
diff --git a/src/wallet/bdb.h b/src/wallet/bdb.h
index 75546924e8..82ad136649 100644
--- a/src/wallet/bdb.h
+++ b/src/wallet/bdb.h
@@ -90,6 +90,9 @@ std::shared_ptr<BerkeleyEnvironment> GetWalletEnv(const fs::path& wallet_path, s
 /** Return whether a BDB wallet database is currently loaded. */
 bool IsBDBWalletLoaded(const fs::path& wallet_path);
 
+/** Check format of database file */
+bool IsBerkeleyBtree(const fs::path& path);
+
 class BerkeleyBatch;
 
 /** An instance of this class represents one database.
@@ -224,4 +227,10 @@ public:
 
 std::string BerkeleyDatabaseVersion();
 
+//! Check if Berkeley database exists at specified path.
+bool ExistsBerkeleyDatabase(const fs::path& path);
+
+//! Return object giving access to Berkeley database at specified path.
+std::unique_ptr<BerkeleyDatabase> MakeBerkeleyDatabase(const fs::path& path, const DatabaseOptions& options, DatabaseStatus& status, bilingual_str& error);
+
 #endif // BITCOIN_WALLET_BDB_H
diff --git a/src/wallet/db.h b/src/wallet/db.h
index 0afaba5fd1..f0f6f03c43 100644
--- a/src/wallet/db.h
+++ b/src/wallet/db.h
@@ -195,4 +195,26 @@ public:
     std::unique_ptr<DatabaseBatch> MakeBatch(const char* mode = "r+", bool flush_on_close = true) override { return MakeUnique<DummyBatch>(); }
 };
 
+enum class DatabaseFormat {
+    BERKELEY,
+};
+
+struct DatabaseOptions {
+    bool require_existing = false;
+    bool require_create = false;
+    bool verify = true;
+};
+
+enum class DatabaseStatus {
+    SUCCESS,
+    FAILED_BAD_PATH,
+    FAILED_BAD_FORMAT,
+    FAILED_ALREADY_LOADED,
+    FAILED_ALREADY_EXISTS,
+    FAILED_NOT_FOUND,
+    FAILED_VERIFY,
+};
+
+std::unique_ptr<WalletDatabase> MakeDatabase(const fs::path& path, const DatabaseOptions& options, DatabaseStatus& status, bilingual_str& error);
+
 #endif // BITCOIN_WALLET_DB_H
diff --git a/src/wallet/walletdb.cpp b/src/wallet/walletdb.cpp
index 962ea66fa0..23c4b69777 100644
--- a/src/wallet/walletdb.cpp
+++ b/src/wallet/walletdb.cpp
@@ -13,6 +13,8 @@
 #include <util/bip32.h>
 #include <util/system.h>
 #include <util/time.h>
+#include <util/translation.h>
+#include <wallet/bdb.h>
 #include <wallet/wallet.h>
 
 #include <atomic>
@@ -993,6 +995,43 @@ bool WalletBatch::TxnAbort()
     return m_batch->TxnAbort();
 }
 
+std::unique_ptr<WalletDatabase> MakeDatabase(const fs::path& path, const DatabaseOptions& options, DatabaseStatus& status, bilingual_str& error)
+{
+    bool exists;
+    try {
+        exists = fs::symlink_status(path).type() != fs::file_not_found;
+    } catch (const fs::filesystem_error& e) {
+        error = Untranslated(strprintf("Failed to access database path '%s': %s", path.string(), fsbridge::get_filesystem_error_message(e)));
+        status = DatabaseStatus::FAILED_BAD_PATH;
+        return nullptr;
+    }
+
+    Optional<DatabaseFormat> format;
+    if (exists) {
+        if (ExistsBerkeleyDatabase(path)) {
+            format = DatabaseFormat::BERKELEY;
+        }
+    } else if (options.require_existing) {
+        error = Untranslated(strprintf("Failed to load database path '%s'. Path does not exist.", path.string()));
+        status = DatabaseStatus::FAILED_NOT_FOUND;
+        return nullptr;
+    }
+
+    if (!format && options.require_existing) {
+        error = Untranslated(strprintf("Failed to load database path '%s'. Data is not in recognized format.", path.string()));
+        status = DatabaseStatus::FAILED_BAD_FORMAT;
+        return nullptr;
+    }
+
+    if (format && options.require_create) {
+        error = Untranslated(strprintf("Failed to create database path '%s'. Database already exists.", path.string()));
+        status = DatabaseStatus::FAILED_ALREADY_EXISTS;
+        return nullptr;
+    }
+
+    return MakeBerkeleyDatabase(path, options, status, error);
+}
+
 bool IsWalletLoaded(const fs::path& wallet_path)
 {
     return IsBDBWalletLoaded(wallet_path);
diff --git a/src/wallet/walletutil.cpp b/src/wallet/walletutil.cpp
index d6a8ee9e02..e4c72aed98 100644
--- a/src/wallet/walletutil.cpp
+++ b/src/wallet/walletutil.cpp
@@ -29,7 +29,7 @@ fs::path GetWalletDir()
     return path;
 }
 
-static bool IsBerkeleyBtree(const fs::path& path)
+bool IsBerkeleyBtree(const fs::path& path)
 {
     if (!fs::exists(path)) return false;