学步园

从后往前加

：getSpilit源码

        while (((double) bytesRemaining)/splitSize > SPLIT_SLOP) {
          String[] splitHosts = getSplitHosts(blkLocations,
              length-bytesRemaining, splitSize, clusterMap);
          splits.add(new FileSplit(path, length-bytesRemaining, splitSize,
              splitHosts));
          bytesRemaining -= splitSize;
        }