internalZcodeDBInit function

void internalZcodeDBInit({ String? dbUrl, String? sqlite3Url, })

init zcode word database for web.

Upload zcode_ime.db and sqlite3.wasm to your object server supporting CDN. These files are too large to maybe freeze your Web app server if you do not set dbUrl and sqlite3Url. If you not setting these parameters, this package will fetch these files from your Web app server.

dbUrl is the URL of the zcode_ime.db file you uploaded. sqlite3Url is the URL of the sqlite3.wasm file you uploaded.

Implementation

void internalZcodeDBInit({String? dbUrl, String? sqlite3Url}) async {
  final fs = await IndexedDbFileSystem.open(dbName: 'indexedDB');
  // do not ignore slash, use absolute path
  final wordDbName = "/${basename(dbUrl ?? "/zcode_ime.db")}";
  final exists = fs.exists(wordDbName);
  final int size;
  if (exists) {
    size = fs.sizeOfFile(wordDbName);
  } else {
    size = 0;
  }
  if (!exists || size != dbLength) {
    final Uint8List data;
    if (dbUrl == null) {
      final key = "packages/zcode_embed_ime_db/db$wordDbName";
      final byteData = await rootBundle.load(key);
      final offset = byteData.offsetInBytes;
      final length = byteData.lengthInBytes;
      data = byteData.buffer.asUint8List(offset, length);
    } else {
      final response = await get(Uri.parse(dbUrl));
      data = response.bodyBytes;
    }
    if (!exists) {
      fs.createFile(wordDbName);
    }
    fs.write(wordDbName, data, 0);
    await fs.flush();
  }
  final WasmSqlite3 sqlite;
  final env = SqliteEnvironment(fileSystem: fs);
  if (sqlite3Url == null) {
    const key = "packages/zcode_embed_ime_db/sqlite3.wasm";
    final byteData = await rootBundle.load(key);
    final offset = byteData.offsetInBytes;
    final length = byteData.lengthInBytes;
    final data = byteData.buffer.asUint8List(offset, length);
    sqlite = await WasmSqlite3.load(data, env);
  } else {
    final uri = Uri.parse(sqlite3Url);
    sqlite = await WasmSqlite3.loadFromUrl(uri, environment: env);
  }
  zcodeDB = sqlite.open(wordDbName);
}