`nx_gossip.nx` source

1// nx_gossip.nx -- LIB: EPIDEMIC / ANTI-ENTROPY gossip so the Napster index spreads across the mesh with NO central
2// bottleneck (operator: "lots of peers can share with lots of peers ... spoke to spoke or hub to hub"). Each node
3// holds a local content registry (nx_dist_index rows). A gossip round reconciles two nodes: exchange a compact
4// DIGEST (the set of cids each holds) -> each side selects the rows the other LACKS -> merge (idempotent by cid).
5// After a symmetric round both nodes hold the UNION -> run pairwise across the mesh and knowledge converges
6// epidemically. Composes nx_dist_index (row parsing, di_has_cid). No TLS. license_tier: ORIGINAL
7import "nx_dist_index.nx"
8import "nx_syscalls.nx"
9
10// DIGEST: newline-separated cids present in reg (the compact "I have these" summary sent to a peer).
11func gossip_digest(reg: *u8, rlen: i64, out: *u8) -> i64 {
12    var o: i64=0; var ls: i64=0
13    while ls<rlen {
14        let le: i64 = di_eol(reg, ls, rlen)
15        let t1: i64 = di_tab(reg, ls, le); let cs: i64 = t1+1; let ce: i64 = di_tab(reg, cs, le)
16        var k: i64=cs; while k<ce { out[o]=reg[k]; o=o+1; k=k+1 } out[o]=10 as u8; o=o+1
17        ls = le+1
18    }
19    out[o]=0 as u8; return o
20}
21// does a digest (newline cids) already list this cid?
22func gossip_digest_has(digest: *u8, dlen: i64, cid: *u8) -> i64 {
23    let cl: i64 = di_strlen(cid); var ls: i64=0
24    while ls<dlen {
25        let le: i64 = di_eol(digest, ls, dlen)
26        if le-ls==cl { if di_memeq((digest as i64 + ls) as *u8, cid, cl)==1 { return 1 } }
27        ls = le+1
28    }
29    return 0
30}
31// SELECT: append every row of my_reg whose cid is NOT in the peer's digest (what I can teach the peer). Returns len.
32func gossip_select(my_reg: *u8, mlen: i64, peer_digest: *u8, dlen: i64, out: *u8) -> i64 {
33    var o: i64=0; var ls: i64=0
34    while ls<mlen {
35        let le: i64 = di_eol(my_reg, ls, mlen)
36        let t1: i64 = di_tab(my_reg, ls, le); let cs: i64 = t1+1; let ce: i64 = di_tab(my_reg, cs, le)
37        let tmp: *u8 = sys_mmap(128); var j: i64=0; while cs+j<ce { tmp[j]=my_reg[cs+j]; j=j+1 } tmp[j]=0 as u8
38        if gossip_digest_has(peer_digest, dlen, tmp)==0 {
39            var k: i64=ls; while k<le { out[o]=my_reg[k]; o=o+1; k=k+1 } out[o]=10 as u8; o=o+1
40        }
41        ls = le+1
42    }
43    out[o]=0 as u8; return o
44}
45// MERGE: fold incoming rows into dst (idempotent by cid -- additive-only). Returns new dst length.
46func gossip_merge(dst: *u8, dlen: i64, incoming: *u8, ilen: i64) -> i64 {
47    var out: i64=dlen; var ls: i64=0
48    while ls<ilen {
49        let le: i64 = di_eol(incoming, ls, ilen)
50        if le>ls {
51            let t1: i64 = di_tab(incoming, ls, le); let cs: i64 = t1+1; let ce: i64 = di_tab(incoming, cs, le)
52            let tmp: *u8 = sys_mmap(128); var j: i64=0; while cs+j<ce { tmp[j]=incoming[cs+j]; j=j+1 } tmp[j]=0 as u8
53            if di_has_cid(dst, out, tmp)==0 {
54                var k: i64=ls; while k<le { dst[out]=incoming[k]; out=out+1; k=k+1 } dst[out]=10 as u8; out=out+1
55            }
56        }
57        ls = le+1
58    }
59    return out
60}
nx_gossip.nx source

`nx_gossip.nx` source
