src/util/Hash.ts


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import * as sha1 from 'js-sha1';

export default class Hash {
   public static String(value: string) {
      let hash = 0;

      if (value.length === 0) {
         return hash;
      }

      for (let i = 0; i < value.length; i++) {
         hash = (hash << 5) - hash + value.charCodeAt(i);
         hash |= 0; // Convert to 32bit integer
      }

      return hash;
   }

   public static SHA1FromBase64(data: string): string {
      let base64 = data.replace(/^.+;base64,/, '');
      let buffer = base64ToArrayBuffer(base64);

      return sha1(buffer);
   }
}

function base64ToArrayBuffer(base64String: string) {
   let binaryString = window.atob(base64String);
   let bytes = new Uint8Array(binaryString.length);

   for (let i = 0; i < binaryString.length; i++) {
      bytes[i] = binaryString.charCodeAt(i);
   }

   return bytes.buffer;
}