deserialize()

in gremlin-javascript/src/main/javascript/gremlin-javascript/lib/structure/io/binary/internals/PSerializer.js [80:150]

• 63 lines of code
• 15 McCabe index (conditional complexity)

  deserialize(buffer, fullyQualifiedFormat = true) {
    let len = 0;
    let cursor = buffer;

    try {
      if (buffer === undefined || buffer === null || !(buffer instanceof Buffer)) {
        throw new Error('buffer is missing');
      }
      if (buffer.length < 1) {
        throw new Error('buffer is empty');
      }

      if (fullyQualifiedFormat) {
        const type_code = cursor.readUInt8();
        len++;
        if (type_code !== this.ioc.DataType.P) {
          throw new Error('unexpected {type_code}');
        }
        cursor = cursor.slice(1);

        if (cursor.length < 1) {
          throw new Error('{value_flag} is missing');
        }
        const value_flag = cursor.readUInt8();
        len++;
        if (value_flag === 1) {
          return { v: null, len };
        }
        if (value_flag !== 0) {
          throw new Error('unexpected {value_flag}');
        }
        cursor = cursor.slice(1);
      }

      let name, name_len;
      try {
        ({ v: name, len: name_len } = this.ioc.stringSerializer.deserialize(cursor, false));
        len += name_len;
      } catch (err) {
        err.message = '{name}: ' + err.message;
        throw err;
      }
      cursor = cursor.slice(name_len);

      let values, values_len;
      try {
        ({ v: values, len: values_len } = this.ioc.listSerializer.deserialize(cursor, false));
        len += values_len;
      } catch (err) {
        err.message = '{values}: ' + err.message;
        throw err;
      }
      cursor = cursor.slice(values_len);

      if (values.length < 1) {
        return { v: new P(''), len };
      }

      let v;
      const P_static = P[name];
      if (typeof P_static === 'function') {
        v = P_static(...values); // it's better to follow existing logic which may depend on an operator name
      } else {
        v = new P(name, ...values);
      }

      return { v, len };
    } catch (err) {
      throw this.ioc.utils.des_error({ serializer: this, args: arguments, cursor, err });
    }
  }