1 files changed, 154 insertions, 0 deletions
diff --git a/src/wallet/test/db_tests.cpp b/src/wallet/test/db_tests.cpp
index d341e84d9b..f783424df8 100644
--- a/src/wallet/test/db_tests.cpp
+++ b/src/wallet/test/db_tests.cpp
@@ -2,6 +2,10 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
+#if defined(HAVE_CONFIG_H)
+#include <config/bitcoin-config.h>
+#endif
+
 #include <boost/test/unit_test.hpp>
 
 #include <test/util/setup_common.h>
@@ -205,5 +209,155 @@ BOOST_AUTO_TEST_CASE(db_cursor_prefix_byte_test)
     }
 }
 
+BOOST_AUTO_TEST_CASE(db_availability_after_write_error)
+{
+    // Ensures the database remains accessible without deadlocking after a write error.
+    // To simulate the behavior, record overwrites are disallowed, and the test verifies
+    // that the database remains active after failing to store an existing record.
+    for (const auto& database : TestDatabases(m_path_root)) {
+        // Write original record
+        std::unique_ptr<DatabaseBatch> batch = database->MakeBatch();
+        std::string key = "key";
+        std::string value = "value";
+        std::string value2 = "value_2";
+        BOOST_CHECK(batch->Write(key, value));
+        // Attempt to overwrite the record (expect failure)
+        BOOST_CHECK(!batch->Write(key, value2, /*fOverwrite=*/false));
+        // Successfully overwrite the record
+        BOOST_CHECK(batch->Write(key, value2, /*fOverwrite=*/true));
+        // Sanity-check; read and verify the overwritten value
+        std::string read_value;
+        BOOST_CHECK(batch->Read(key, read_value));
+        BOOST_CHECK_EQUAL(read_value, value2);
+    }
+}
+
+// Verify 'ErasePrefix' functionality using db keys similar to the ones used by the wallet.
+// Keys are in the form of std::pair<TYPE, ENTRY_ID>
+BOOST_AUTO_TEST_CASE(erase_prefix)
+{
+    const std::string key = "key";
+    const std::string key2 = "key2";
+    const std::string value = "value";
+    const std::string value2 = "value_2";
+    auto make_key = [](std::string type, std::string id) { return std::make_pair(type, id); };
+
+    for (const auto& database : TestDatabases(m_path_root)) {
+        std::unique_ptr<DatabaseBatch> batch = database->MakeBatch();
+
+        // Write two entries with the same key type prefix, a third one with a different prefix
+        // and a fourth one with the type-id values inverted
+        BOOST_CHECK(batch->Write(make_key(key, value), value));
+        BOOST_CHECK(batch->Write(make_key(key, value2), value2));
+        BOOST_CHECK(batch->Write(make_key(key2, value), value));
+        BOOST_CHECK(batch->Write(make_key(value, key), value));
+
+        // Erase the ones with the same prefix and verify result
+        BOOST_CHECK(batch->TxnBegin());
+        BOOST_CHECK(batch->ErasePrefix(DataStream() << key));
+        BOOST_CHECK(batch->TxnCommit());
+
+        BOOST_CHECK(!batch->Exists(make_key(key, value)));
+        BOOST_CHECK(!batch->Exists(make_key(key, value2)));
+        // Also verify that entries with a different prefix were not erased
+        BOOST_CHECK(batch->Exists(make_key(key2, value)));
+        BOOST_CHECK(batch->Exists(make_key(value, key)));
+    }
+}
+
+#ifdef USE_SQLITE
+
+// Test-only statement execution error
+constexpr int TEST_SQLITE_ERROR = -999;
+
+class DbExecBlocker : public SQliteExecHandler
+{
+private:
+    SQliteExecHandler m_base_exec;
+    std::set<std::string> m_blocked_statements;
+public:
+    DbExecBlocker(std::set<std::string> blocked_statements) : m_blocked_statements(blocked_statements) {}
+    int Exec(SQLiteDatabase& database, const std::string& statement) override {
+        if (m_blocked_statements.contains(statement)) return TEST_SQLITE_ERROR;
+        return m_base_exec.Exec(database, statement);
+    }
+};
+
+BOOST_AUTO_TEST_CASE(txn_close_failure_dangling_txn)
+{
+    // Verifies that there is no active dangling, to-be-reversed db txn
+    // after the batch object that initiated it is destroyed.
+    DatabaseOptions options;
+    DatabaseStatus status;
+    bilingual_str error;
+    std::unique_ptr<SQLiteDatabase> database = MakeSQLiteDatabase(m_path_root / "sqlite", options, status, error);
+
+    std::string key = "key";
+    std::string value = "value";
+
+    std::unique_ptr<SQLiteBatch> batch = std::make_unique<SQLiteBatch>(*database);
+    BOOST_CHECK(batch->TxnBegin());
+    BOOST_CHECK(batch->Write(key, value));
+    // Set a handler to prevent txn abortion during destruction.
+    // Mimicking a db statement execution failure.
+    batch->SetExecHandler(std::make_unique<DbExecBlocker>(std::set<std::string>{"ROLLBACK TRANSACTION"}));
+    // Destroy batch
+    batch.reset();
+
+    // Ensure there is no dangling, to-be-reversed db txn
+    BOOST_CHECK(!database->HasActiveTxn());
+
+    // And, just as a sanity check; verify that new batchs only write what they suppose to write
+    // and nothing else.
+    std::string key2 = "key2";
+    std::unique_ptr<SQLiteBatch> batch2 = std::make_unique<SQLiteBatch>(*database);
+    BOOST_CHECK(batch2->Write(key2, value));
+    // The first key must not exist
+    BOOST_CHECK(!batch2->Exists(key));
+}
+
+BOOST_AUTO_TEST_CASE(concurrent_txn_dont_interfere)
+{
+    std::string key = "key";
+    std::string value = "value";
+    std::string value2 = "value_2";
+
+    DatabaseOptions options;
+    DatabaseStatus status;
+    bilingual_str error;
+    const auto& database = MakeSQLiteDatabase(m_path_root / "sqlite", options, status, error);
+
+    std::unique_ptr<DatabaseBatch> handler = Assert(database)->MakeBatch();
+
+    // Verify concurrent db transactions does not interfere between each other.
+    // Start db txn, write key and check the key does exist within the db txn.
+    BOOST_CHECK(handler->TxnBegin());
+    BOOST_CHECK(handler->Write(key, value));
+    BOOST_CHECK(handler->Exists(key));
+
+    // But, the same key, does not exist in another handler
+    std::unique_ptr<DatabaseBatch> handler2 = Assert(database)->MakeBatch();
+    BOOST_CHECK(handler2->Exists(key));
+
+    // Attempt to commit the handler txn calling the handler2 methods.
+    // Which, must not be possible.
+    BOOST_CHECK(!handler2->TxnCommit());
+    BOOST_CHECK(!handler2->TxnAbort());
+
+    // Only the first handler can commit the changes.
+    BOOST_CHECK(handler->TxnCommit());
+    // And, once commit is completed, handler2 can read the record
+    std::string read_value;
+    BOOST_CHECK(handler2->Read(key, read_value));
+    BOOST_CHECK_EQUAL(read_value, value);
+
+    // Also, once txn is committed, single write statements are re-enabled.
+    // Which means that handler2 can read the record changes directly.
+    BOOST_CHECK(handler->Write(key, value2, /*fOverwrite=*/true));
+    BOOST_CHECK(handler2->Read(key, read_value));
+    BOOST_CHECK_EQUAL(read_value, value2);
+}
+#endif // USE_SQLITE
+
 BOOST_AUTO_TEST_SUITE_END()
 } // namespace wallet