openethereum/js/packages/shared/redux/providers/registry/reducer.js

// Copyright 2015-2017 Parity Technologies (UK) Ltd.
// This file is part of Parity.

// Parity is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// Parity is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with Parity.  If not, see <http://www.gnu.org/licenses/>.

const initialState = {
  reverse: {} // cache for reverse lookup
};

export default (state = initialState, action) => {
  if (action.type === 'setReverse') {
    if (state.reverse[action.address] === action.reverse) {
      return state;
    }

    return {
      reverse: {
        ...state.reverse, [ action.address ]: action.reverse
      }
    };
  }

  return state;
};