Method saturatedAdd

core/src/main/java/io/grpc/internal/JsonUtil.java:422–432

Returns the sum of a and b unless it would overflow or underflow in which case Long.MAX_VALUE or Long.MIN_VALUE is returned, respectively. Copy of com.google.common.math.LongMath#saturatedAdd.

(long a, long b)

   *
   */
  @SuppressWarnings("ShortCircuitBoolean")
  private static long saturatedAdd(long a, long b) {
    long naiveSum = a + b;
    if ((a ^ b) < 0 | (a ^ naiveSum) >= 0) {
      // If a and b have different signs or a has the same sign as the result then there was no
      // overflow, return.
      return naiveSum;
    }
    // we did over/under flow, if the sign is negative we should return MAX otherwise MIN
    return Long.MAX_VALUE + ((naiveSum >>> (Long.SIZE - 1)) ^ 1);
  }
}