omni_dev/daemon/protocol.rs
1//! Wire types for the daemon's Unix-domain control socket.
2//!
3//! The control plane speaks newline-delimited JSON (NDJSON): one
4//! [`DaemonEnvelope`] request per line, one [`DaemonReply`] response per line.
5//! New optional fields use `#[serde(default, skip_serializing_if = ...)]` so
6//! older peers stay byte-compatible on the wire.
7
8use serde::{Deserialize, Serialize};
9use serde_json::Value;
10
11use super::service::ServiceStatus;
12
13/// The reserved service name for the daemon's own built-in operations
14/// (`ping`, `status`, `shutdown`). A `None` `service` targets the same.
15pub const DAEMON_SERVICE: &str = "daemon";
16
17/// Maximum length, in bytes, of a single NDJSON line on the control socket.
18///
19/// Applies to both requests and replies, capping the per-connection read buffer
20/// so a peer that never sends a newline can't exhaust memory. 1 MiB is far above
21/// any real envelope.
22pub const MAX_LINE_BYTES: usize = 1024 * 1024;
23
24/// A request sent to the daemon over the control socket.
25#[derive(Debug, Clone, Serialize, Deserialize)]
26pub struct DaemonEnvelope {
27 /// Target service [`name`](super::service::DaemonService::name). `None`
28 /// (or `"daemon"`) routes to the built-in daemon ops.
29 #[serde(default, skip_serializing_if = "Option::is_none")]
30 pub service: Option<String>,
31 /// Operation name, interpreted by the target service (or the daemon).
32 pub op: String,
33 /// Operation payload; `null` when the op takes no arguments.
34 #[serde(default, skip_serializing_if = "Value::is_null")]
35 pub payload: Value,
36}
37
38impl DaemonEnvelope {
39 /// Builds an envelope targeting a named service.
40 pub fn service(name: impl Into<String>, op: impl Into<String>, payload: Value) -> Self {
41 Self {
42 service: Some(name.into()),
43 op: op.into(),
44 payload,
45 }
46 }
47
48 /// Builds an envelope targeting the built-in daemon ops.
49 pub fn builtin(op: impl Into<String>) -> Self {
50 Self {
51 service: None,
52 op: op.into(),
53 payload: Value::Null,
54 }
55 }
56}
57
58/// A response returned by the daemon over the control socket.
59#[derive(Debug, Clone, Serialize, Deserialize)]
60pub struct DaemonReply {
61 /// Whether the operation succeeded.
62 pub ok: bool,
63 /// Success payload; `null` for ops that return nothing.
64 #[serde(default, skip_serializing_if = "Value::is_null")]
65 pub payload: Value,
66 /// Error message when [`ok`](Self::ok) is `false`.
67 #[serde(default, skip_serializing_if = "Option::is_none")]
68 pub error: Option<String>,
69}
70
71impl DaemonReply {
72 /// Builds a successful reply carrying `payload`.
73 pub fn ok(payload: Value) -> Self {
74 Self {
75 ok: true,
76 payload,
77 error: None,
78 }
79 }
80
81 /// Builds a failure reply carrying an error message.
82 pub fn err(message: impl Into<String>) -> Self {
83 Self {
84 ok: false,
85 payload: Value::Null,
86 error: Some(message.into()),
87 }
88 }
89}
90
91/// The payload of a built-in `status` reply: per-service status snapshots.
92#[derive(Debug, Clone, Serialize, Deserialize)]
93pub struct StatusReport {
94 /// One entry per registered service, in registration order.
95 pub services: Vec<ServiceStatus>,
96}