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river_data_core/models/
backend.rs

1use chrono::{DateTime, Utc};
2use uuid::Uuid;
3
4use crate::models::annotations::AnnotationUpsert;
5use crate::models::replicates::{GroupAudit, ReplicateSpec};
6use crate::models::streams::{IngestReading, IngestStatusEvent};
7
8/// Describes a data stream to register with river-data.
9#[derive(Debug, Clone)]
10pub struct StreamDescriptor {
11    /// Unique key within the source system (ie. a location id or column name).
12    pub source_key: String,
13    /// Human-readable name shown in the dashboard.
14    pub source_name: String,
15    /// Hierarchy path (ie. "cnet/VAD/WTW_DO_mgL_1"), parsed server-side for site discovery.
16    pub source_path: String,
17    pub metadata: serde_json::Value,
18    /// Stream classification ('spot' or 'continuous'); None defers to the API's resolution chain.
19    pub measurement_type: Option<String>,
20    /// Owning sensor; required for streams whose readings carry curve claims.
21    pub sensor_id: Option<Uuid>,
22    /// Replicate-family declaration; requires `measurement_type: "spot"`.
23    pub replicates: Option<ReplicateSpec>,
24    /// The decimal places the source stores or presents this channel at. Pairing writes it onto
25    /// the slot where none is declared, and the public API expresses served values at it. None
26    /// leaves the slot undeclared, which is served unrounded.
27    pub decimal_places: Option<i16>,
28}
29
30/// Asks a backend for readings for one stream since a cursor.
31#[derive(Debug, Clone)]
32pub struct StreamFetchRequest {
33    pub stream_id: Uuid,
34    pub source_key: String,
35    /// Last known reading time. None on a new stream or a full sync.
36    pub since: Option<DateTime<Utc>>,
37}
38
39/// A completeness claim over one stream: the readings sent alongside are the COMPLETE content of
40/// the source for this stream over `[from, to)`, read from `source_rows_read` source rows. The
41/// server diffs stored content against the payload and converges (new / changed / withdrawn);
42/// without a window the request is a bare append, exactly the old semantics.
43#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
44#[cfg_attr(feature = "openapi", derive(utoipa::ToSchema))]
45pub struct SourceWindow {
46    pub from: DateTime<Utc>,
47    pub to: DateTime<Utc>,
48    /// Source rows scanned to produce the payload. An empty payload over a window the store holds
49    /// readings for is refused server-side, so a decode failure cannot read as a source deletion.
50    pub source_rows_read: u64,
51    /// Instants the backend saw but could not carry (cell decode failures). The server retains
52    /// stored rows at these keys rather than withdrawing them.
53    #[serde(default, skip_serializing_if = "Vec::is_empty")]
54    pub dropped_times: Vec<DateTime<Utc>>,
55    /// Digest of the canonical payload, stamped by the driver before send. The server persists
56    /// it on a cleanly-applied pass and echoes it on the stream list, so the next cycle can skip
57    /// re-sending unchanged content. Opaque to the server; never computed server-side.
58    #[serde(default, skip_serializing_if = "Option::is_none")]
59    pub content_digest: Option<String>,
60}
61
62/// Readings fetched for one stream, ready to ingest.
63#[derive(Debug)]
64pub struct StreamReadings {
65    pub stream_id: Uuid,
66    pub source_key: String,
67    pub readings: Vec<IngestReading>,
68    /// Portal-precomputed mean/sd per replicate group, for server-side comparison.
69    pub audits: Vec<GroupAudit>,
70    /// Marks the readings as replicate collections; the API groups them per instant.
71    pub collection: bool,
72    /// The completeness claim, when this fetch read the source's full content for the stream.
73    pub window: Option<SourceWindow>,
74    /// Source-authored annotations riding this stream's payload (e.g. the standard curve the
75    /// source applied while producing a stored value). The driver registers them after the
76    /// stream's readings ingest; idempotent per (source_system, source_key).
77    pub annotations: Vec<AnnotationUpsert>,
78}
79
80impl StreamReadings {
81    /// Plain single-series readings: no audits, not a collection, no completeness claim.
82    pub fn new(stream_id: Uuid, source_key: String, readings: Vec<IngestReading>) -> Self {
83        Self {
84            stream_id,
85            source_key,
86            readings,
87            audits: Vec::new(),
88            collection: false,
89            window: None,
90            annotations: Vec::new(),
91        }
92    }
93}
94
95/// Status events fetched for one stream.
96#[derive(Debug)]
97pub struct StreamStatusEvents {
98    pub stream_id: Uuid,
99    pub source_key: String,
100    pub events: Vec<IngestStatusEvent>,
101}
102
103/// Everything the source holds that could become a stream, whether or not the connector takes it.
104///
105/// `discover_streams` reports what a connector accepted, so a column it declined and a group it has
106/// not discovered yet are invisible to every downstream check: no completeness window covers them,
107/// no receipt names them, and reconciliation cannot speak about them at all. This is what a sign-off
108/// against a retiring source has to read.
109///
110/// Taken channels are listed per group because that is the question being asked (is this station,
111/// whole, here); declined channels are listed once, source-wide, because a source declines a
112/// channel by its own rules and not per group.
113#[derive(Debug, Clone, Default, serde::Serialize, serde::Deserialize)]
114pub struct SourceInventory {
115    /// One entry per channel the connector carries, keyed as it registers.
116    pub candidates: Vec<SourceCandidate>,
117    /// Channels the source holds and the connector does not carry, with the connector's reason.
118    #[serde(default)]
119    pub declined: Vec<DeclinedChannel>,
120    /// Every group the source holds, so one with no channel at all is still named.
121    #[serde(default)]
122    pub groups: Vec<String>,
123}
124
125/// One channel the connector carries.
126#[derive(Debug, Clone, PartialEq, serde::Serialize, serde::Deserialize)]
127pub struct SourceCandidate {
128    /// The key it registers under.
129    pub source_key: String,
130    /// The source's own grouping: the station, the location, whatever a report is read by.
131    #[serde(default, skip_serializing_if = "Option::is_none")]
132    pub group: Option<String>,
133}
134
135/// One channel the connector leaves behind, and why.
136#[derive(Debug, Clone, PartialEq, serde::Serialize, serde::Deserialize)]
137pub struct DeclinedChannel {
138    /// The source's own name for it: a column, a location id.
139    pub channel: String,
140    pub reason: String,
141}
142
143impl SourceInventory {
144    /// The inventory a backend that declines nothing has: every descriptor it discovered.
145    #[must_use]
146    pub fn of_discovered(descriptors: &[StreamDescriptor]) -> Self {
147        let candidates: Vec<SourceCandidate> = descriptors
148            .iter()
149            .map(|d| SourceCandidate {
150                source_key: d.source_key.clone(),
151                group: d.source_path.split('/').nth(1).map(ToString::to_string),
152            })
153            .collect();
154        let mut groups: Vec<String> = candidates
155            .iter()
156            .filter_map(|c| c.group.clone())
157            .collect::<std::collections::BTreeSet<_>>()
158            .into_iter()
159            .collect();
160        groups.sort();
161        Self {
162            candidates,
163            declined: Vec::new(),
164            groups,
165        }
166    }
167}
168
169#[cfg(test)]
170mod tests {
171    use super::*;
172
173    /// The completeness claim round-trips: the API echoes it back as `accepted_window` and the
174    /// client treats a missing echo as a hard error, so both sides read one shape.
175    #[test]
176    fn source_window_round_trips() {
177        let w = SourceWindow {
178            from: Utc::now(),
179            to: Utc::now(),
180            source_rows_read: 500,
181            dropped_times: vec![Utc::now()],
182            content_digest: Some("fnv:1".into()),
183        };
184        let back: SourceWindow = serde_json::from_value(serde_json::to_value(&w).unwrap()).unwrap();
185        assert_eq!(back.source_rows_read, 500);
186        assert_eq!(back.dropped_times.len(), 1);
187        assert_eq!(back.content_digest.as_deref(), Some("fnv:1"));
188    }
189}