Can you explain the format of the SIFT file?

[wangq95]

Hi, I successfully run this code on Ubuntu 16.04 and I saved the result as a SIFT file which looks like:
5115 128
2.12 679.77 1.005 1.807
80 128 26 10 7 0 0 3 17 51 28 75 111 90 8 4 0 6 15 22
21 127 9 1 0 2 2 0 0 2 0 0 100 128 10 1 3 4 2 8
128 81 17 3 5 73 57 91 8 7 10 5 6 128 75 19 0 0 0 0
0 2 0 0 106 42 2 0 1 5 10 30 128 128 128 18 1 5 5 23
7 30 128 22 3 24 9 4 0 0 0 0 0 0 0 0 22 90 6 0
0 0 0 1 18 66 51 46 10 0 0 0 0 1 27 24 7 0 0 0
0 0 0 0 0 0 0 0

but I don't understand what it means, can you help me to explain it, thanks a lot!