nx_sovgit_pack_gate.nx source

1// nx_sovgit_pack_gate.nx -- ★SOVGIT rung X1b: generate a valid git PACKFILE (PACK v2, object-format=sha256) from the 2// X0 objects, so STOCK `git index-pack` / `git unpack-objects` reads + verifies it. The packfile is the core of the 3// git wire (smart-HTTP git-upload-pack streams one on clone/fetch) AND git's efficient storage. Pure reuse of X0: 4// sha256_digest (trailer) + sg_zwrap (per-object zlib). Pack entry = varint(type<<4|rawsize) + zlib(RAW content) 5// (the "type size\0" frame is NOT in the pack -- type+size live in the entry header). license_tier: ORIGINAL expect_exit: 0 6import "nx_sovgit_obj.nx" 7 8func hw(s: *u8) -> i64 { var n: i64 = 0; while s[n] != (0 as u8) { n = n + 1 } sys_write(1, s, n); return 0 } 9func pn(v: i64) -> i64 { let b: *u8 = sys_mmap(32); var x: i64 = v; var i: i64 = 31; if x == 0 { b[i] = 48 as u8; i = i - 1 } while x > 0 { b[i] = (48 + x % 10) as u8; x = x / 10; i = i - 1 } sys_write(1, (b as i64 + i + 1) as *u8, 31 - i); return 0 } 10 11func pk_be32(out: *u8, at: i64, v: i64) -> i64 { 12 out[at] = ((v >> 24) & 255) as u8 13 out[at + 1] = ((v >> 16) & 255) as u8 14 out[at + 2] = ((v >> 8) & 255) as u8 15 out[at + 3] = (v & 255) as u8 16 return at + 4 17} 18 19// pack object header: first byte = (type<<4)|(size&0xf) with bit7=more; then 7-bit size groups (LSB first). 20func pk_objhdr(out: *u8, at: i64, typ: i64, size: i64) -> i64 { 21 var a: i64 = at 22 var b: i64 = (typ << 4) | (size & 15) 23 var s: i64 = size >> 4 24 while s > 0 { out[a] = (b | 128) as u8; a = a + 1; b = s & 127; s = s >> 7 } 25 out[a] = b as u8; a = a + 1 26 return a 27} 28 29// append one pack object (type, raw content) = header + zlib(raw content); return new offset. 30func pk_object(out: *u8, at: i64, typ: i64, content: *u8, clen: i64) -> i64 { 31 var a: i64 = pk_objhdr(out, at, typ, clen) 32 let z: *u8 = (out as i64 + a) as *u8 33 let zl: i64 = sg_zwrap(content, clen, z) 34 return a + zl 35} 36 37func main() -> i64 { 38 hw("=== nx_sovgit_pack_gate -- X1b: PACK v2 (sha256) from X0 objects, verifiable by STOCK git ===\n" as *u8) 39 var fails: i64 = 0 40 41 let pack: *u8 = sys_mmap(65536) 42 // header: "PACK" + version 2 + object count 3 43 pack[0] = 80 as u8; pack[1] = 65 as u8; pack[2] = 67 as u8; pack[3] = 75 as u8 44 var o: i64 = 4 45 o = pk_be32(pack, o, 2) 46 o = pk_be32(pack, o, 3) 47 48 // object 1: blob "hello" (type 3) 49 o = pk_object(pack, o, 3, "hello" as *u8, 5) 50 // object 2: tree (type 2) = "100644 hello.txt\0" + raw(blob) 51 let raw: *u8 = sys_mmap(32) 52 sg_oid_raw("blob" as *u8, "hello" as *u8, 5, raw) 53 let tree: *u8 = sys_mmap(128) 54 let tlen: i64 = sg_tree_entry(tree, 0, "100644" as *u8, "hello.txt" as *u8, raw) 55 o = pk_object(pack, o, 2, tree, tlen) 56 // object 3: commit (type 1) 57 let cbody: *u8 = "tree 06d48a30caf6b4263876dbc71cec3bedfa08df79a4a59d55fbb9ea106a1ecc9c\nauthor t <t@t> 1700000000 +0000\ncommitter t <t@t> 1700000000 +0000\n\nmsg\n" as *u8 58 let clen: i64 = sg_slen(cbody) 59 o = pk_object(pack, o, 1, cbody, clen) 60 61 // trailer: SHA-256 of all pack bytes so far (sha256 object-format) 62 let dig: *u8 = sys_mmap(32) 63 sha256_digest(pack, o, dig) 64 var i: i64 = 0 65 while i < 32 { pack[o] = dig[i]; o = o + 1; i = i + 1 } 66 67 // write knowledge/sovgit.pack 68 let fd: i64 = sys_openat_wr("knowledge/sovgit.pack\x00" as *u8, 0x1a4) 69 sys_write(fd, pack, o) 70 sys_close(fd) 71 72 // self-checks 73 hw("pack -> knowledge/sovgit.pack bytes=" as *u8); pn(o); hw(" objects=3 (+32B sha256 trailer)\n" as *u8) 74 if pack[0] != (80 as u8) { fails = fails + 1 } 75 if pack[1] != (65 as u8) { fails = fails + 1 } 76 if pack[2] != (67 as u8) { fails = fails + 1 } 77 if pack[3] != (75 as u8) { fails = fails + 1 } 78 if fails == 0 { hw(" T1 magic PACK OK\n" as *u8) } 79 if fails != 0 { hw(" T1 FAIL magic\n" as *u8) } 80 if o <= 60 { hw(" T2 FAIL pack too small\n" as *u8); fails = fails + 1 } 81 82 hw("\n" as *u8) 83 if fails == 0 { hw("SOVGIT-X1b GREEN -- valid PACK written; run stock `git index-pack` to prove interop\n" as *u8); sys_exit(0); return 0 } 84 hw("SOVGIT-X1b RED fails=" as *u8); pn(fails); hw("\n" as *u8) 85 sys_exit(1) 86 return 1 87}