flood/client/source/scripts/reducers/clientReducer.js

const initialState = {
  torrentDetails: {},
  transfers: {
    updatedAt: 0,
    download: {
      rate: 0,
      total: 0
    },
    upload: {
      rate: 0,
      total: 0
    }
  }
};

export default function clientReducer(state = initialState, action) {
  switch (action.type) {

    case 'RECEIVE_TORRENT_DETAILS':
      let torrentDetails = {};
      torrentDetails[action.payload.hash] = action.payload.torrentDetails;

      return Object.assign(
          {},
          state,
          {
            ...state,
            torrentDetails
          }
        );

    case 'CLIENT_RECEIVE_TRANSFER_DATA':
      return Object.assign(
        {},
        state,
        {
          ...state,
          transfers: {
            ...state.transfers,
            updatedAt: Date.now(),
            download: {
              rate: action.payload.downloadRate,
              total: action.payload.downloadTotal
            },
            upload: {
              rate: action.payload.uploadRate,
              total: action.payload.uploadTotal
            }
          }
        }
      );

    default:
      return state;
  }
}