th.send(this.req, this.rsp);
                    long cnt = this.rsp.getCount();
                    this.fp += cnt;
                    len -= cnt;
                    off += cnt;
                    if ( log.isTraceEnabled() ) {
                        log.trace(String.format("Wrote at %d remain %d off %d len %d", this.fp, len - w, off, w));
                    }
                }

                final FileConfig fileConfig = new FileConfig();
                fileConfig.setId(id);
                if (id.endsWith("P")) {
                    fileConfig.setConfigParameter("config.pipeline=fp");
                }
                return OptionalEntity.of(fileConfig);
            }

            @Override
            public OptionalEntity<FileConfig> getFileConfigByName(String name) {

   * Computes the optimal k (number of hashes per element inserted in Bloom filter), given the
   * expected insertions and total number of bits in the Bloom filter.
   *
   * <p>See http://en.wikipedia.org/wiki/File:Bloom_filter_fp_probability.svg for the formula.
   *
   * @param n expected insertions (must be positive)
   * @param m total number of bits in Bloom filter (must be positive)
   */
  @VisibleForTesting