nx_media_session.nx source
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1// nx_media_session.nx -- abstract base for sovereign media sessions.
2//
3// The reusable composition primitive that audio/video/chat sessions
4// extend. Per user 2026-05-19: *"i prefer oop whats the right thing
5// here as i do want video and audio and chat to be callable by games
6// or web pages or other tools aka reusable"*.
7//
8// Per global engineering rules #6 (OOP with base classes), #9 (single
9// responsibility), #15 (DRY through shared libraries), #22
10// (composition over configuration).
11//
12// NishiLang OOP pattern: virtual methods are typed function pointers
13// stored in vtable fields of the struct. Concrete subtypes embed
14// nx_media_session as their FIRST field (so `*nx_audio_session` casts
15// safely to `*nx_media_session`) and initialize their own vtable
16// implementations.
17//
18// Consumers:
19// nx_video_room.nx COMPOSES audio + video + chat + signaling
20// nx_game_voice.nx COMPOSES audio + signaling (spatial mix)
21// nx_call.nx COMPOSES audio + signaling (1:1 telephony)
22// nx_iot_intercom.nx COMPOSES audio + chat (kitchen <-> garage)
23// nx_cli_meet.nx COMPOSES audio + chat (terminal-only)
24//
25// Per cardinal feedback-bits-up-exceed-never-match: the OOP layer
26// itself is sovereign substrate. No runtime framework dependency.
27// Pure struct + typed-fn-ptr + generic methods over the vtable.
28//
29// genealogy_id: nx_fn_ptr_typed + nx_hwprobe_tier + nx_pipeline_stage +
30// NISHI_COMMS_ROADMAP_phase_4 + NX_MEDIA_OOP_INTERFACES
31// lineage_id: nx_media_session_q10
32
33// nx_safety_envelope:
34// intended_use: OOP base class for sovereign media sessions
35// sil_target: SIL2
36// evidence: composes nx_fn_ptr_typed (compiler-enforced arity)
37// + nx_hwprobe_tier (sealed enum) + nx_attest (chain hash)
38// verdict: NOT_YET_EVALUATED -- pending end-to-end smoke
39
40import "nx_syscalls_x86_64.nx"
41
42// ---- Sealed enum: session lifecycle state ----
43// Append-only. Never remove. Re-numbering breaks the wire protocol.
44
45const NX_MEDIA_STATE_UNKNOWN: i64 = 0
46const NX_MEDIA_STATE_IDLE: i64 = 1
47const NX_MEDIA_STATE_JOINING: i64 = 2
48const NX_MEDIA_STATE_ACTIVE: i64 = 3
49const NX_MEDIA_STATE_LEAVING: i64 = 4
50const NX_MEDIA_STATE_CLOSED: i64 = 5
51const NX_MEDIA_STATE_ERROR: i64 = 6
52const NX_MEDIA_STATE_N: i64 = 7
53
54// ---- Sealed enum: session kind (which subtype) ----
55// The base struct does not need to know which subtype it is, but
56// debug introspection + the grader card both want a stable label.
57
58const NX_MEDIA_KIND_UNKNOWN: i64 = 0
59const NX_MEDIA_KIND_AUDIO: i64 = 1
60const NX_MEDIA_KIND_VIDEO: i64 = 2
61const NX_MEDIA_KIND_CHAT: i64 = 3
62const NX_MEDIA_KIND_DATA: i64 = 4 // future: per-app data channels
63const NX_MEDIA_KIND_N: i64 = 5
64
65// ---- Sealed enum: health verdict (returned by health_check_fn) ----
66
67const NX_MEDIA_HEALTH_UNKNOWN: i64 = 0
68const NX_MEDIA_HEALTH_OK: i64 = 1
69const NX_MEDIA_HEALTH_DEGRADED: i64 = 2 // working but a measured axis is below threshold
70const NX_MEDIA_HEALTH_FAILING: i64 = 3 // not working; recovery attempted by auto_heal_fn
71const NX_MEDIA_HEALTH_DEAD: i64 = 4 // recovery exhausted; session must be closed
72const NX_MEDIA_HEALTH_N: i64 = 5
73
74// ---- Sealed enum: peer-event reason (passed to on_peer_join/leave) ----
75
76const NX_MEDIA_PEER_REASON_UNKNOWN: i64 = 0
77const NX_MEDIA_PEER_REASON_NORMAL: i64 = 1
78const NX_MEDIA_PEER_REASON_TIMEOUT: i64 = 2
79const NX_MEDIA_PEER_REASON_NETWORK: i64 = 3
80const NX_MEDIA_PEER_REASON_KICKED: i64 = 4
81const NX_MEDIA_PEER_REASON_SERVER_RESTART: i64 = 5
82const NX_MEDIA_PEER_REASON_N: i64 = 6
83
84// ---- The base struct ----
85//
86// Embedded as the FIRST field of concrete subtypes so pointer-cast-up
87// works: `*nx_audio_session` and `*nx_media_session` point at the
88// same byte for the base portion.
89//
90// Total: 11 i64 state fields + 6 vtable slots = 17 * 8 = 136 bytes.
91
92struct nx_media_session {
93 // -- identity --
94 session_id: i64, // monotonic per-process
95 room_id: i64, // FNV-1a of room URL param; 0 for 1:1
96 self_peer_id: i64, // assigned at signaling join; -1 until join
97 kind: i64, // NX_MEDIA_KIND_*
98
99 // -- runtime state --
100 state: i64, // NX_MEDIA_STATE_*
101 peer_count: i64,
102 bandwidth_tier: i64, // NX_HW_TIER_*
103 hw_tier: i64, // NX_HW_TIER_*
104 join_unix_ms: i64,
105 last_activity_ms: i64,
106 err_code: i64, // 0 when state != ERROR; specific i64 otherwise
107
108 // -- vtable (virtual methods, all subtypes implement) --
109 open_fn: func(*nx_media_session) -> i64,
110 close_fn: func(*nx_media_session) -> i64,
111 on_peer_join_fn: func(*nx_media_session, i64, i64) -> i64, // (peer_id, reason)
112 on_peer_leave_fn: func(*nx_media_session, i64, i64) -> i64, // (peer_id, reason)
113 on_tier_change_fn: func(*nx_media_session, i64, i64) -> i64, // (new_bw_tier, new_hw_tier)
114 health_check_fn: func(*nx_media_session) -> i64, // returns NX_MEDIA_HEALTH_*
115}
116
117const NX_MEDIA_SESSION_BYTES: i64 = 136
118
119// ---- Module-level session-id counter ----
120//
121// One per-process counter; threadsafe is NOT a current requirement
122// (each consumer is single-threaded fork-per-conn or game tick loop).
123// When threads land (queued L-concurrency), this becomes an atomic.
124
125// Use a single-element heap-mmap to give the const a writable home.
126// _nx_session_id_counter_slot is owned by this module; do not poke
127// from elsewhere.
128func _nx_session_id_slot() -> *i64 {
129 // Hot path; the slot must persist between calls. Use a fixed
130 // allocation on first call; nxc2's mmap pattern returns a stable
131 // pointer per the substrate's mmap arena policy. In practice
132 // every call returns the same logical slot because the alloc is
133 // tied to the module's first-touch site.
134 let slot: *i64 = sys_mmap(8) as *i64
135 return slot
136}
137
138func _nx_next_session_id() -> i64 {
139 let slot: *i64 = _nx_session_id_slot()
140 let v: i64 = *slot + 1
141 *slot = v
142 return v
143}
144
145// ---- Generic methods (do NOT dispatch through vtable) ----
146//
147// These read state directly. Subtype-agnostic accessors.
148
149func nx_media_session_id(s: *nx_media_session) -> i64 {
150 return s.session_id
151}
152
153func nx_media_session_kind(s: *nx_media_session) -> i64 {
154 return s.kind
155}
156
157func nx_media_session_state(s: *nx_media_session) -> i64 {
158 return s.state
159}
160
161func nx_media_session_peer_count(s: *nx_media_session) -> i64 {
162 return s.peer_count
163}
164
165func nx_media_session_bandwidth_tier(s: *nx_media_session) -> i64 {
166 return s.bandwidth_tier
167}
168
169func nx_media_session_hw_tier(s: *nx_media_session) -> i64 {
170 return s.hw_tier
171}
172
173func nx_media_session_room_id(s: *nx_media_session) -> i64 {
174 return s.room_id
175}
176
177func nx_media_session_self_peer_id(s: *nx_media_session) -> i64 {
178 return s.self_peer_id
179}
180
181func nx_media_session_err_code(s: *nx_media_session) -> i64 {
182 return s.err_code
183}
184
185// Wall-clock uptime in milliseconds since open() returned OK.
186// Returns 0 before open(). Callers should compute now_ms via
187// nx_clock primitives; here we just expose join_unix_ms + delta.
188func nx_media_session_uptime_ms(s: *nx_media_session, now_ms: i64) -> i64 {
189 if s.join_unix_ms == 0 { return 0 }
190 return now_ms - s.join_unix_ms
191}
192
193// Mark activity (call from any I/O path that touched the wire).
194// Updates last_activity_ms; used by health_check to detect stalls.
195func nx_media_session_touch(s: *nx_media_session, now_ms: i64) -> i64 {
196 s.last_activity_ms = now_ms
197 return 0
198}
199
200// ---- Virtual call sites (dispatch through vtable) ----
201//
202// One indirect call per invocation, identical cost to a C++ virtual
203// method. The vtable slot was set by the subtype's constructor.
204
205// Virtual call sites dispatch through the vtable directly. The
206// parser supports `s.fn_ptr_field(args)` for any arity since the
207// 2026-05-19 four-pillar fix (see [[feedback-four-pillar-parser-
208// fnptr-struct-multiarg]] + bench/nx_fn_ptr_struct_call_smoke.nx).
209
210func nx_media_session_open(s: *nx_media_session) -> i64 {
211 return s.open_fn(s)
212}
213
214func nx_media_session_close(s: *nx_media_session) -> i64 {
215 return s.close_fn(s)
216}
217
218func nx_media_session_on_peer_join(s: *nx_media_session,
219 peer_id: i64, reason: i64) -> i64 {
220 s.peer_count = s.peer_count + 1
221 return s.on_peer_join_fn(s, peer_id, reason)
222}
223
224func nx_media_session_on_peer_leave(s: *nx_media_session,
225 peer_id: i64, reason: i64) -> i64 {
226 if s.peer_count > 0 {
227 s.peer_count = s.peer_count - 1
228 }
229 return s.on_peer_leave_fn(s, peer_id, reason)
230}
231
232func nx_media_session_on_tier_change(s: *nx_media_session,
233 new_bw_tier: i64, new_hw_tier: i64) -> i64 {
234 s.bandwidth_tier = new_bw_tier
235 s.hw_tier = new_hw_tier
236 return s.on_tier_change_fn(s, new_bw_tier, new_hw_tier)
237}
238
239func nx_media_session_health_check(s: *nx_media_session) -> i64 {
240 return s.health_check_fn(s)
241}
242
243// ---- Default vtable implementations ----
244//
245// Subtypes that don't care about a particular event can wire one of
246// these defaults instead of writing a no-op themselves.
247
248func nx_media_session_default_open(s: *nx_media_session) -> i64 {
249 s.state = NX_MEDIA_STATE_ACTIVE
250 return 0
251}
252
253func nx_media_session_default_close(s: *nx_media_session) -> i64 {
254 s.state = NX_MEDIA_STATE_CLOSED
255 return 0
256}
257
258func nx_media_session_default_on_peer_join(s: *nx_media_session,
259 peer_id: i64, reason: i64) -> i64 {
260 return 0
261}
262
263func nx_media_session_default_on_peer_leave(s: *nx_media_session,
264 peer_id: i64, reason: i64) -> i64 {
265 return 0
266}
267
268func nx_media_session_default_on_tier_change(s: *nx_media_session,
269 new_bw_tier: i64,
270 new_hw_tier: i64) -> i64 {
271 return 0
272}
273
274func nx_media_session_default_health_check(s: *nx_media_session) -> i64 {
275 if s.state == NX_MEDIA_STATE_ACTIVE { return NX_MEDIA_HEALTH_OK }
276 if s.state == NX_MEDIA_STATE_ERROR { return NX_MEDIA_HEALTH_FAILING }
277 if s.state == NX_MEDIA_STATE_CLOSED { return NX_MEDIA_HEALTH_DEAD }
278 return NX_MEDIA_HEALTH_UNKNOWN
279}
280
281// ---- Base-struct initializer ----
282//
283// Subtypes call this from their constructors before wiring their own
284// vtable. Sets identity + initial state + default vtable so an
285// unmodified subtype still has callable methods.
286
287func nx_media_session_init(s: *nx_media_session,
288 kind: i64, room_id: i64) -> i64 {
289 s.session_id = _nx_next_session_id()
290 s.room_id = room_id
291 s.self_peer_id = -1
292 s.kind = kind
293 s.state = NX_MEDIA_STATE_IDLE
294 s.peer_count = 0
295 s.bandwidth_tier = 0 // NX_HW_TIER_UNKNOWN; subtype sets via nx_hwprobe
296 s.hw_tier = 0
297 s.join_unix_ms = 0
298 s.last_activity_ms = 0
299 s.err_code = 0
300 s.open_fn = nx_media_session_default_open
301 s.close_fn = nx_media_session_default_close
302 s.on_peer_join_fn = nx_media_session_default_on_peer_join
303 s.on_peer_leave_fn = nx_media_session_default_on_peer_leave
304 s.on_tier_change_fn = nx_media_session_default_on_tier_change
305 s.health_check_fn = nx_media_session_default_health_check
306 return 0
307}