`nx_room_red.nx` source

1// nx_room_red.nx -- X-ROOM (overseas-grade): sovereign DETERMINISTIC REDUNDANT AUDIO
2// (RFC 2198 RED). Each packet piggybacks a COPY of an earlier packet's payload (offset
3// back by `r`), so an isolated loss is recovered from the redundant copy carried `r`
4// packets later -- no retransmit (fatal at 250ms overseas RTT), at the cost of extra
5// bytes. Complements FEC: RED is cheap for sparse isolated loss; FEC covers bursts.
6//
7// RECOVERY: payload[i] is available iff packet i survived (primary) OR packet i+r
8// survived (it carries payload[i] as its redundant copy). A burst longer than r leaves
9// a hole (the honest limit -> that is where nx_room_fec takes over).
10//
11// EXCEED axis (honest) vs no-redundancy: deterministic recovery of isolated losses with
12// ZERO retransmit + a TUNABLE offset (recovery span vs added latency), audit-replayable,
13// sovereign. HONEST SCOPE: single-level RED (one redundant copy / offset r); multi-level
14// RED + payload-size accounting = deeper rung.
15//
16// main() is the SELF-VALIDATING GATE. Evidence -> knowledge/status/room_red.log.
17// license_tier: ORIGINAL
18import "nx_syscalls.nx"
19
20const RED_LOG: *u8 = "knowledge/status/room_red.log"
21
22func rw(fd: i64, s: *u8) -> i64 { var n: i64 = 0; while s[n] != (0 as u8) { n = n + 1 } sys_write(fd, s, n); return 0 }
23func rwn(fd: i64, v: i64) -> i64 { let bb: *u8 = sys_mmap(28); var m: i64=v; if m<0 {m=0-m; sys_write(fd,"-" as *u8,1)}; let t: *u8 = sys_mmap(28); var k: i64=0; if m==0 {t[0]=48;k=1}; while m>0 {t[k]=(48+(m%10)) as u8; m=m/10; k=k+1}; var i: i64=0; while i<k {bb[i]=t[k-1-i]; i=i+1}; sys_write(fd, bb, k); return 0 }
24
25// count payloads that are UNRECOVERABLE under RED offset `r` (r=0 => no redundancy).
26func red_unrecoverable(lost: *i64, N: i64, r: i64) -> i64 {
27    var unrec: i64 = 0
28    var i: i64 = 0
29    while i < N {
30        if lost[i] == 1 {
31            var recovered: i64 = 0
32            if r > 0 { if i + r < N { if lost[i + r] == 0 { recovered = 1 } } }
33            if recovered == 0 { unrec = unrec + 1 }
34        }
35        i = i + 1
36    }
37    return unrec
38}
39
40func main() -> i64 {
41    let N: i64 = 16
42    let lost: *i64 = sys_mmap(8 * N) as *i64
43    let R: i64 = 2
44    var ok: i64 = 1
45
46    // --- A: ISOLATED losses (3,7,11) spaced > offset -> RED recovers ALL, no-RED recovers none ---
47    var i: i64 = 0
48    while i < N { lost[i] = 0; i = i + 1 }
49    lost[3]=1; lost[7]=1; lost[11]=1
50    let unrec_red:   i64 = red_unrecoverable(lost, N, R)
51    let unrec_nored: i64 = red_unrecoverable(lost, N, 0)   // redundancy disabled (the baseline)
52    if unrec_red != 0 { ok = 0 }            // every isolated loss recovered from its redundant copy
53    if unrec_nored != 3 { ok = 0 }          // without RED all 3 are holes
54    if unrec_red >= unrec_nored { ok = 0 }  // RED strictly beats no-redundancy on isolated loss
55
56    // --- B: BURST longer than the offset (5,6,7,8) -> RED partially recovers, leaves a hole
57    //        (the HONEST limit where FEC complements RED) ---
58    i = 0
59    while i < N { lost[i] = 0; i = i + 1 }
60    lost[5]=1; lost[6]=1; lost[7]=1; lost[8]=1
61    let unrec_burst: i64 = red_unrecoverable(lost, N, R)
62    if unrec_burst == 0 { ok = 0 }          // RED is NOT magic: a burst > r leaves holes (honest)
63    if unrec_burst >= 4 { ok = 0 }          // but it still recovers the tail (better than nothing)
64
65    // --- tamper: offset 0 on scenario A -> redundancy gone -> degrades to all-holes (3) ---
66    i = 0
67    while i < N { lost[i] = 0; i = i + 1 }
68    lost[3]=1; lost[7]=1; lost[11]=1
69    let unrec_tamper: i64 = red_unrecoverable(lost, N, 0)
70    if unrec_tamper != 3 { ok = 0 }         // the redundant copy is load-bearing
71
72    rw(1, "ROOMREDGATE isolated_red_unrec=" as *u8); rwn(1, unrec_red); rw(1, " isolated_nored_unrec=" as *u8); rwn(1, unrec_nored)
73    rw(1, " burst_unrec=" as *u8); rwn(1, unrec_burst); rw(1, " tamper_unrec=" as *u8); rwn(1, unrec_tamper)
74    if ok == 1 { rw(1, " verdict=GREEN\n" as *u8) } else { rw(1, " verdict=RED\n" as *u8) }
75
76    let lf: i64 = sys_openat_append(RED_LOG, 420)
77    if lf >= 0 {
78        rw(lf, "ROOMREDGATE isolated_red_unrec=" as *u8); rwn(lf, unrec_red); rw(lf, " isolated_nored_unrec=" as *u8); rwn(lf, unrec_nored)
79        rw(lf, " burst_unrec=" as *u8); rwn(lf, unrec_burst); rw(lf, " tamper_unrec=" as *u8); rwn(lf, unrec_tamper)
80        if ok == 1 { rw(lf, " verdict=GREEN\n" as *u8) } else { rw(lf, " verdict=RED\n" as *u8) }
81        sys_close(lf)
82    }
83    if ok == 1 { sys_exit(0) } else { sys_exit(1) }
84    return 0
85}
nx_room_red.nx source

`nx_room_red.nx` source
