Method Open

src/wallet/sqlite.cpp:201–284

}

void SQLiteDatabase::Open()
{
    int flags = SQLITE_OPEN_FULLMUTEX | SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE;
    if (m_mock) {
        flags |= SQLITE_OPEN_MEMORY; // In memory database for mock db
    }

    if (m_db == nullptr) {
        if (!m_mock) {
            TryCreateDirectories(fs::PathFromString(m_dir_path));
        }
        int ret = sqlite3_open_v2(m_file_path.c_str(), &m_db, flags, nullptr);
        if (ret != SQLITE_OK) {
            throw std::runtime_error(strprintf("SQLiteDatabase: Failed to open database: %s\n", sqlite3_errstr(ret)));
        }
        ret = sqlite3_extended_result_codes(m_db, 1);
        if (ret != SQLITE_OK) {
            throw std::runtime_error(strprintf("SQLiteDatabase: Failed to enable extended result codes: %s\n", sqlite3_errstr(ret)));
        }
    }

    if (sqlite3_db_readonly(m_db, "main") != 0) {
        throw std::runtime_error("SQLiteDatabase: Database opened in readonly mode but read-write permissions are needed");
    }

    // Acquire an exclusive lock on the database
    // First change the locking mode to exclusive
    SetPragma(m_db, "locking_mode", "exclusive", "Unable to change database locking mode to exclusive");
    // Now begin a transaction to acquire the exclusive lock. This lock won't be released until we close because of the exclusive locking mode.
    int ret = sqlite3_exec(m_db, "BEGIN EXCLUSIVE TRANSACTION", nullptr, nullptr, nullptr);
    if (ret != SQLITE_OK) {
        throw std::runtime_error("SQLiteDatabase: Unable to obtain an exclusive lock on the database, is it being used by another instance of " PACKAGE_NAME "?\n");
    }
    ret = sqlite3_exec(m_db, "COMMIT", nullptr, nullptr, nullptr);
    if (ret != SQLITE_OK) {
        throw std::runtime_error(strprintf("SQLiteDatabase: Unable to end exclusive lock transaction: %s\n", sqlite3_errstr(ret)));
    }

    // Enable fullfsync for the platforms that use it
    SetPragma(m_db, "fullfsync", "true", "Failed to enable fullfsync");

    if (gArgs.GetBoolArg("-unsafesqlitesync", false)) {
        // Use normal synchronous mode for the journal
        LogPrintf("WARNING SQLite is configured to not wait for data to be flushed to disk. Data loss and corruption may occur.\n");
        SetPragma(m_db, "synchronous", "OFF", "Failed to set synchronous mode to OFF");
    }

    // Make the table for our key-value pairs
    // First check that the main table exists
    sqlite3_stmt* check_main_stmt{nullptr};
    ret = sqlite3_prepare_v2(m_db, "SELECT name FROM sqlite_master WHERE type='table' AND name='main'", -1, &check_main_stmt, nullptr);
    if (ret != SQLITE_OK) {
        throw std::runtime_error(strprintf("SQLiteDatabase: Failed to prepare statement to check table existence: %s\n", sqlite3_errstr(ret)));
    }
    ret = sqlite3_step(check_main_stmt);
    if (sqlite3_finalize(check_main_stmt) != SQLITE_OK) {
        throw std::runtime_error(strprintf("SQLiteDatabase: Failed to finalize statement checking table existence: %s\n", sqlite3_errstr(ret)));
    }