data store.js

class DataStore {
  constructor(data, indexes) {
    this.data = data;
    this.indexes = indexes;
    this.indexedData = {};
    for (let i = 0; i < this.indexes.length; i++) {
      const index = this.indexes[i];
      this.indexedData[index] = [];
      for (let j = 0; j < this.data.length; j++) {
        const d = this.data[j];
        if (!this.indexedData[d[index]]) {
          this.indexedData[d[index]] = [];
        }
        this.indexedData[d[index]].push(d);
      }
    }
  }
  getByIndex(value) {
    const matched = [];
    for (let i = 0; i < this.indexes.length; i++) {
      const index = this.indexes[i];
      if (this.indexedData[index][value]) {
        matched.push(this.indexedData[index][value]);
      }
    }
    return matched;
  }
}