gregg-protocol 1.0.7

Versioned JSON wire types, metric capabilities, and identity structures shared by the gregg daemon and client.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152

//! `gregg-protocol` defines the versioned JSON wire contract shared by the
//! `greggd` daemon and the `gregg` client.
//!
//! The crate is intentionally dependency-light (only `serde`, `serde_json`, and
//! `thiserror`) so it can be consumed by collectors, the HTTP server, the
//! polling engine, and tests without dragging in larger stacks.
//!
//! # Schema versions
//!
//! ## Version 1
//!
//! Every snapshot carries an explicit
//! [`SCHEMA_VERSION_V1`](constant.SCHEMA_VERSION_V1) so clients can reject
//! incompatible payloads per host without terminating the whole TUI.
//!
//! Numeric values are transported as raw units — bytes for memory and swap,
//! percentages in the closed interval `0.0..=100.0` for utilization, and
//! milliseconds since the Unix epoch for timestamps. No human-formatted
//! strings cross the wire.
//!
//! ## Version 2
//!
//! Schema version 2 ([`SCHEMA_VERSION_V2`](constant.SCHEMA_VERSION_V2))
//! extends v1 with explicit capability flags for load average, swap, and
//! memory commit. This allows the protocol to truthfully represent Linux,
//! macOS, and Windows metric differences without fabricating unsupported
//! values.
//!
//! V2 snapshots use `Option` for metrics that are unsupported on some
//! platforms. Capability flags determine which `Option` values must be
//! `Some` (supported) vs `None` (unsupported).
//!
//! The `/v2/status` response is a flat [`v2::StatusPayloadV2`] wrapper. Its
//! optional `drives` field is additive and does not change the public Rust
//! struct-literal compatibility of [`v2::StatusSnapshotV2`].
//!
//! # Compatibility policy
//!
//! Within each schema version:
//!
//! - Unknown additive JSON fields are ignored by default.
//! - Required version-1 fields remain required unless explicitly changed to
//!   optional under an additive compatibility decision.
//! - Capability flags control interpretation of optional metrics. A `None`
//!   value paired with a `false` capability is expected; a `None` value
//!   paired with a `true` capability indicates a missing or still-warming
//!   sample.
//!
//! # Examples
//!
//! ## Version 1
//!
//! ```
//! use gregg_protocol::{StatusSnapshot, HealthResponse, ReadinessState, SCHEMA_VERSION_V1};
//!
//! let json = format!(r#"{{
//!     "schema_version": {sv},
//!     "observed_at_unix_ms": 1,
//!     "sample_interval_ms": 1000,
//!     "capabilities": {{ "cpu_iowait": false }},
//!     "system": {{
//!         "name": "mac-mini",
//!         "hostname": "mac-mini.local",
//!         "os_name": "macos",
//!         "os_version": "15.0",
//!         "kernel_name": "Darwin",
//!         "kernel_release": "24.0.0",
//!         "architecture": "arm64"
//!     }},
//!     "cpu": {{ "logical_cores": 8, "usage_pct": 12.5, "iowait_pct": null }},
//!     "load": {{ "one": 1.1, "five": 0.9, "fifteen": 0.6 }},
//!     "memory": {{ "used_bytes": 1, "total_bytes": 2, "usage_pct": 50.0 }},
//!     "swap": {{ "used_bytes": 0, "total_bytes": 0, "usage_pct": 0.0 }}
//! }}"#, sv = SCHEMA_VERSION_V1);
//!
//! let snap: StatusSnapshot = serde_json::from_str(&json).expect("valid snapshot");
//! snap.validate().expect("snapshot validates");
//!
//! let health = HealthResponse::warming();
//! assert_eq!(health.state, ReadinessState::Warming);
//! ```
//!
//! ## Version 2
//!
//! ```
//! use gregg_protocol::v2::{
//!     StatusSnapshotV2, MetricCapabilitiesV2, CpuMetricsV2, CommitMetrics,
//!     HealthResponseV2, SCHEMA_VERSION_V2,
//! };
//! use gregg_protocol::{ReadinessState, HealthCategory};
//!
//! let json = r#"{
//!     "schema_version": 2,
//!     "observed_at_unix_ms": 1,
//!     "sample_interval_ms": 1000,
//!     "capabilities": {
//!         "cpu_iowait": false,
//!         "load_average": false,
//!         "swap": false,
//!         "memory_commit": true
//!     },
//!     "system": {
//!         "name": "win-pc",
//!         "hostname": "win-pc.local",
//!         "os_name": "windows",
//!         "os_version": "10.0",
//!         "kernel_name": "Windows",
//!         "kernel_release": "10.0.19045",
//!         "architecture": "x86_64"
//!     },
//!     "cpu": { "logical_cores": 4, "usage_pct": 12.5, "iowait_pct": null },
//!     "memory": { "used_bytes": 2000000000, "total_bytes": 8000000000, "usage_pct": 25.0 },
//!     "commit": { "used_bytes": 3000000000, "limit_bytes": 8000000000, "usage_pct": 37.5 }
//! }"#;
//!
//! let snap: StatusSnapshotV2 = serde_json::from_str(json).expect("valid v2 snapshot");
//! gregg_protocol::validate_v2(&snap).expect("v2 validates");
//!
//! let health = HealthResponseV2::ready(snap);
//! assert_eq!(health.state, ReadinessState::Ready);
//! ```

#![forbid(unsafe_code)]

pub mod v2;

mod health;
mod snapshot;
mod validate;
mod validate_v2;

#[cfg(feature = "test_support")]
pub mod test_support;

pub use health::{HealthCategory, HealthResponse, ReadinessState};
pub use snapshot::{
    CpuMetrics, LoadAverage, MemoryMetrics, MetricCapabilities, StatusSnapshot, SwapMetrics,
    SystemIdentity,
};
pub use validate::{ValidationViolation, ViolationKind};
pub use validate_v2::{validate_payload_v2, validate_v2, ValidationViolationV2, ViolationKindV2};

/// Schema major version implemented by this crate (version 1).
///
/// Wire payloads whose `schema_version` does not match this value are
/// rejected by [`StatusSnapshot::validate`]. Additive changes within version 1
/// are allowed by the compatibility policy; breaking changes require a new
/// schema major and explicit migration handling.
pub const SCHEMA_VERSION_V1: u16 = 1;

/// Maximum sampling cadence accepted by the wire validation rules.
pub const MAX_SAMPLE_INTERVAL_MS: u64 = 86_400_000;