egui_charts/data/
metrics.rs

1//! Instrument metrics published by a host, independent of its price bars.
2
3use super::{Sink, SubscriptionId};
4use crate::model::Bar;
5use crate::scales::StudyFormat;
6use chrono::{DateTime, Utc};
7
8/// One metric offered for an instrument, identified by a host-owned key.
9#[derive(Clone, Debug, PartialEq, Eq)]
10pub struct MetricSeries {
11    /// Key used in metric history and subscription requests.
12    pub id: String,
13    /// Display name, such as "Open interest".
14    pub name: String,
15    /// Display unit, such as "contracts", "USD" or "%".
16    pub unit: String,
17    /// Numeric format used in legends, axes and tooltips.
18    pub format: StudyFormat,
19}
20
21/// A metric's value from this instant until the next published point.
22/// Non-finite values are rejected, like invalid price bars.
23#[derive(Clone, Copy, Debug, PartialEq)]
24pub struct MetricPoint {
25    /// UTC instant at which this observation takes effect.
26    pub time: DateTime<Utc>,
27    /// Metric value in the units declared by `MetricSeries`.
28    pub value: f64,
29}
30
31impl From<MetricPoint> for Bar {
32    fn from(point: MetricPoint) -> Self {
33        Self::new(
34            point.time,
35            point.value,
36            point.value,
37            point.value,
38            point.value,
39            0.0,
40        )
41    }
42}
43
44/// Up to `count` metric points strictly before `before`, or the latest when absent.
45/// Include the point in effect before the chart's first bar when paging back.
46#[derive(Clone, Debug, PartialEq, Eq)]
47pub struct MetricRequest {
48    /// Instrument identifier used by the host.
49    pub symbol: String,
50    /// [`MetricSeries::id`] for this instrument.
51    pub metric: String,
52    /// Exclusive upper time bound, or `None` for the latest points.
53    pub before: Option<DateTime<Utc>>,
54    /// Maximum number of points to return.
55    pub count: usize,
56}
57
58/// A page of metric history, in any order. The chart sorts and deduplicates by timestamp.
59/// A live correction of the same timestamp takes precedence over history.
60#[derive(Clone, Debug, Default, PartialEq)]
61pub struct MetricPage {
62    /// Metric observations in this page.
63    pub points: Vec<MetricPoint>,
64    /// Whether this page reaches the beginning of the available history.
65    pub end_of_history: bool,
66}
67
68/// A live metric stream, stopped through [`super::Datafeed::unsubscribe`].
69/// Push with [`Sink::push_metric`]; timestamps are retained without price-bar aggregation.
70#[derive(Clone)]
71pub struct MetricSubscription {
72    /// Identifier used to unsubscribe this metric stream.
73    pub id: SubscriptionId,
74    /// Instrument identifier used by the host.
75    pub symbol: String,
76    /// Host-owned metric identifier for this instrument.
77    pub metric: String,
78    /// Destination for updates; stop publishing when it becomes inactive.
79    pub sink: Sink,
80}
81
82impl Sink {
83    /// Publish or correct a metric point. Its value is held until the next point;
84    /// an inactive subscription ignores pushes, like [`Self::push_bar`].
85    pub fn push_metric(&self, point: MetricPoint) {
86        self.push_bar(point.into());
87    }
88}
egui_charts/data/metrics.rs

egui_charts/data/
metrics.rs
