nx_fec_stripe_test.nx source

1// nx_fec_stripe_test.nx -- 1:1 KAT for FEC-complementary striping 2// (nx_fec_stripe.nx). Proves the exceed over plain striping: a source 3// packet lost on its path with NO duplicate is reconstructed by repair 4// parity on the complementary path -- i.e. CORRELATED loss recovered. 5// EXHAUSTIVE: sweeps EVERY single-source-loss position (row FEC must 6// recover any 1-per-row loss). Plus a both-paths-lossy case, the honest 7// over-budget case, and the bandwidth-vs-duplication point. 8// 9// expect_exit: 0 10// license_tier: ORIGINAL 11 12import "nx_fec_stripe.nx" 13 14const SL: i64 = 4 // columns 15const SD: i64 = 3 // rows 16const SS: i64 = 4 // bytes/pkt (K = 12 source) 17 18func main() -> i64 { 19 let K: i64 = SL * SD 20 let golden: *u8 = sys_mmap(K * SS) 21 let src: *u8 = sys_mmap(K * SS) 22 let rows: *u8 = sys_mmap(SD * SS) 23 let cols: *u8 = sys_mmap(SL * SS) 24 let present: *i64 = sys_mmap(K * 8) as *i64 25 let rp: *i64 = sys_mmap(SD * 8) as *i64 26 let cp: *i64 = sys_mmap(SL * 8) as *i64 27 28 var i: i64 = 0 29 while i < K * SS { golden[i] = ((i * 11 + 3) & 0xff) as u8; i = i + 1 } 30 i = 0 31 while i < K * SS { src[i] = golden[i]; i = i + 1 } 32 fec_encode_rows(src, SL, SD, SS, rows) 33 fec_encode_cols(src, SL, SD, SS, cols) 34 35 // ---- T1 EXHAUSTIVE: every single source loss (no duplicate, source on 36 // path0 only) is reconstructed by the repair parity on path1 ---- 37 var lost: i64 = 0 38 while lost < K { 39 // reset clean grid + all repairs present (path1 intact) 40 var j: i64 = 0 41 while j < K * SS { src[j] = golden[j]; j = j + 1 } 42 j = 0 43 while j < K { present[j] = 1; j = j + 1 } 44 j = 0 45 while j < SD { rp[j] = 1; j = j + 1 } 46 j = 0 47 while j < SL { cp[j] = 1; j = j + 1 } 48 // simulate: source `lost` dropped on path0 (zeroed, no copy anywhere) 49 fec_zero(fec_pkt(src, lost, SS), SS) 50 present[lost] = 0 51 // verify path-plan: source on path0, repairs on path1 52 if fec_stripe_path_of(lost, K) != 0 { return 1 } 53 if fec_stripe_path_of(K + 1, K) != 1 { return 2 } 54 // recover from the complementary repair 55 if fec_stripe_recover(src, SL, SD, SS, present, rows, rp, cols, cp) != 0 { return 3 } 56 // bytes exact? 57 j = 0 58 while j < K * SS { if (src[j] & 0xff) != (golden[j] & 0xff) { return 4 } j = j + 1 } 59 lost = lost + 1 60 } 61 62 // ---- T2: BOTH paths lossy within budget -- source loss + a lost col 63 // repair, recovered via the surviving row repair (correlated loss) ---- 64 i = 0 65 while i < K * SS { src[i] = golden[i]; i = i + 1 } 66 i = 0 67 while i < K { present[i] = 1; i = i + 1 } 68 i = 0 69 while i < SD { rp[i] = 1; i = i + 1 } 70 i = 0 71 while i < SL { cp[i] = 1; i = i + 1 } 72 fec_zero(fec_pkt(src, 6, SS), SS); present[6] = 0 // source lost on path0 (row1) 73 cp[2] = 0 // a col repair lost on path1 74 if fec_stripe_recover(src, SL, SD, SS, present, rows, rp, cols, cp) != 0 { return 5 } 75 i = 0 76 while i < K * SS { if (src[i] & 0xff) != (golden[i] & 0xff) { return 6 } i = i + 1 } 77 78 // ---- T3: over-budget (2x2 block, both row+col parity insufficient) -> 79 // honestly unrecoverable, no corruption ---- 80 i = 0 81 while i < K { present[i] = 1; i = i + 1 } 82 i = 0 83 while i < SD { rp[i] = 1; i = i + 1 } 84 i = 0 85 while i < SL { cp[i] = 1; i = i + 1 } 86 present[5] = 0; present[6] = 0; present[9] = 0; present[10] = 0 87 if fec_stripe_recover(src, SL, SD, SS, present, rows, rp, cols, cp) != 4 { return 7 } 88 89 // ---- T4: bandwidth -- FEC stripe overhead < 100% (1+1 duplication) ---- 90 if fec_stripe_overhead_pct(FEC_ROW, SL, SD) != 25 { return 8 } // 3/12 = 25% vs 100% dup 91 if fec_stripe_overhead_pct(FEC_2D, SL, SD) != 58 { return 9 } // 7/12 = 58% vs 100% dup 92 93 sys_write(1, "FEC-STRIPE KAT PASS (every single source loss recovered by complementary parity; correlated-loss recovery at <100% overhead)\n", 124) 94 return 0 95}