connect function

Implementation

QueryExecutor connect([UserId? userId]) {
  return DatabaseConnection.delayed(
    Future(() async {
      final String dbName = userId?.val ?? 'common';

      // TODO: Uncomment, when [WasmStorageImplementation.opfsLocks] doesn't throw
      //       file I/O errors in Chromium browsers.
      // final result = await WasmDatabase.open(
      //   databaseName: dbName,
      //   sqlite3Uri: Uri.parse('sqlite3.wasm'),
      //   driftWorkerUri: Uri.parse('drift_worker.js'),
      // );
      //
      // Log.info('Using ${result.chosenImplementation} for `drift` backend.');
      //
      // if (result.missingFeatures.isNotEmpty) {
      //   Log.warning(
      //     'Browser misses the following features in order for `drift` to be as performant as possible: ${result.missingFeatures}',
      //   );
      // }
      //
      // return result.resolvedExecutor;

      final WasmProbeResult probed = await WasmDatabase.probe(
        sqlite3Uri: Uri.parse('sqlite3.wasm'),
        driftWorkerUri: Uri.parse('drift_worker.js'),
        databaseName: dbName,
      );

      final List<WasmStorageImplementation> available =
          probed.availableStorages.toList();

      if (!WebUtils.isSafari && !WebUtils.isFirefox) {
        available.remove(WasmStorageImplementation.opfsLocks);
      }

      checkExisting:
      for (final (location, name) in probed.existingDatabases) {
        if (name == dbName) {
          final implementationsForStorage = switch (location) {
            WebStorageApi.indexedDb => const [
              WasmStorageImplementation.sharedIndexedDb,
              WasmStorageImplementation.unsafeIndexedDb,
            ],
            WebStorageApi.opfs => const [
              WasmStorageImplementation.opfsShared,
              WasmStorageImplementation.opfsLocks,
            ],
          };

          // If any of the implementations for this location is still available,
          // we want to use it instead of another location.
          if (implementationsForStorage.any(available.contains)) {
            available.removeWhere(
              (i) => !implementationsForStorage.contains(i),
            );
            break checkExisting;
          }
        }
      }

      // Enum values are ordered by preferability, so just pick the best option
      // left.
      available.sortBy<num>((element) => element.index);

      final best = available.firstOrNull ?? WasmStorageImplementation.inMemory;
      final DatabaseConnection connection = await probed.open(best, dbName);

      Log.info('Using $best for `drift` backend.');

      if (probed.missingFeatures.isNotEmpty) {
        Log.warning(
          'Browser misses the following features in order for `drift` to be as performant as possible: ${probed.missingFeatures}',
        );
      }

      return connection;
    }),
  );
}