static int getNumChunksForBlobAndChunkSize(long blobSize, int chunkSize) {
    return (int) (blobSize == 0 ? 1 : (blobSize - 1) / chunkSize + 1);
  }
Return the number of data chunks for the given blob and chunk sizes.
@param blobSize the size of the overall blob.
@param chunkSize the size of each data chunk (except, possibly the last one).
@return the number of data chunks for the given blob and chunk sizes.
ambry-router/src/main/java/com/github/ambry/router/RouterUtils.java