download method

Stream<DownloadEvent> download(String id)

Fetch id to disk, reporting progress until it is registered.

Emits a terminal DownloadFailed/DownloadCancelled event when the transfer fails or is cancelled; never fabricates a DownloadCompleted afterward.

Implementation

Stream<DownloadEvent> download(String id) async* {
  final operationId = id;
  var sequence = 0;
  yield DownloadStarted(operationId, sequence: sequence++);

  var extracting = false;
  var verifying = false;
  await for (final progress in RunAnywhereDownloads.shared.start(id)) {
    switch (progress.state) {
      case DownloadState.DOWNLOAD_STATE_FAILED:
        yield DownloadFailed(
          operationId,
          progress.hasError()
              ? SDKException.downloadFailed(id, progress.error.message)
              : SDKException.downloadFailed(id),
          sequence: sequence++,
        );
        return;
      case DownloadState.DOWNLOAD_STATE_CANCELLED:
        yield DownloadCancelled(operationId, sequence: sequence++);
        return;
      case DownloadState.DOWNLOAD_STATE_COMPLETED:
        final model = await get(id);
        if (model == null) {
          yield DownloadFailed(
            operationId,
            SDKException.modelNotFound(id),
            sequence: sequence++,
          );
          return;
        }
        yield DownloadCompleted(operationId, model, sequence: sequence++);
        return;
      default:
        // `DownloadStage` was deleted outright (idl/download_service.proto)
        // — it duplicated `DownloadState`; `state` is the single phase
        // field now.
        if (progress.state == DownloadState.DOWNLOAD_STATE_VALIDATING) {
          if (!verifying) {
            verifying = true;
            yield DownloadVerifying(operationId, sequence: sequence++);
          }
        } else if (progress.state == DownloadState.DOWNLOAD_STATE_EXTRACTING) {
          if (!extracting) {
            extracting = true;
            yield DownloadExtracting(
              operationId,
              sequence: sequence++,
              percent: progress.stageProgress > 0
                  ? progress.stageProgress
                  : null,
            );
          }
        } else {
          yield DownloadProgressEvent(
            operationId: operationId,
            bytesDone: progress.bytesDownloaded.toInt(),
            bytesTotal: progress.totalBytes.toInt(),
            sequence: sequence++,
            file: progress.hasCurrentFileName() &&
                    progress.currentFileName.isNotEmpty
                ? progress.currentFileName
                : null,
            overallProgress: progress.overallProgress > 0
                ? progress.overallProgress
                : null,
          );
        }
    }
  }
}