code: public BlockInfo[] getSourceBlocks(BlockInfo[] blocks) {
      int numSourceBlocks = blocks.length - 
          (blocks.length / numStripeBlocks) * numParityBlocks - 
          ((blocks.length % numStripeBlocks == 0) ? 0 : numParityBlocks);
      BlockInfo[] sourceBlocks = new BlockInfo[numSourceBlocks];
      int pos = numParityBlocks;
      int stripeEnd = numStripeBlocks;
      for (int i = 0; i < numSourceBlocks; i++) {
        sourceBlocks[i] = blocks[pos];
        pos++;
        if (pos == stripeEnd) {
          pos += numParityBlocks;
          stripeEnd += numStripeBlocks;
        }
      }
      return sourceBlocks;
    }
docs: Return only the source blocks of the raided file