fast_telemetry/
lib.rs

1//! Fast, thread-sharded counters and histograms for high-performance telemetry.
2//!
3//! OpenTelemetry counters use atomic operations with global synchronization,
4//! which causes cache-line bouncing across cores. This crate provides
5//! thread-local sharded counters that:
6//!
7//! - Increment with no cross-thread contention (just a thread-local write)
8//! - Are cache-line padded to avoid false sharing (using crossbeam's CachePadded)
9//! - Aggregate on read (sum all shards)
10//!
11//! # Labeled Metrics
12//!
13//! For dimensional metrics (counters/gauges/histograms broken down by label),
14//! use the `Labeled*` types with a `LabelEnum` implementation. These provide
15//! O(1) lookup via array indexing instead of HashMap lookups.
16//!
17//! ```ignore
18//! use fast_telemetry::{LabeledCounter, LabelEnum};
19//!
20//! #[derive(Copy, Clone, Debug)]
21//! enum HttpMethod { Get, Post, Put, Delete }
22//!
23//! impl LabelEnum for HttpMethod { /* ... */ }
24//!
25//! let counter: LabeledCounter<HttpMethod> = LabeledCounter::new(4);
26//! counter.inc(HttpMethod::Get);  // O(1) array index, no hashing
27//! ```
28
29mod export;
30pub(crate) mod internal;
31mod metric;
32#[cfg(feature = "runtime")]
33mod runtime;
34pub mod span;
35mod temporality;
36
37pub use export::text::{DogStatsDExport, PrometheusExport};
38
39// These helpers are public only because the ExportMetrics proc macro generates
40// code that calls them. They are not part of the public API and may change
41// without notice.
42#[doc(hidden)]
43pub mod __macro_support {
44    pub use crate::export::text::{
45        __write_dogstatsd, __write_dogstatsd_distribution, __write_dogstatsd_distribution_delta,
46        __write_dogstatsd_distribution_delta_dynamic,
47        __write_dogstatsd_distribution_delta_dynamic_pairs, __write_dogstatsd_distribution_dynamic,
48        __write_dogstatsd_dynamic, __write_dogstatsd_dynamic_pairs, __write_dogstatsd_with_label,
49        FastFormat,
50    };
51}
52pub use metric::ExportMetrics;
53pub use metric::{
54    Counter, Distribution, DistributionSnapshot, DynamicCounter, DynamicCounterSeries,
55    DynamicDistribution, DynamicDistributionSeries, DynamicGauge, DynamicGaugeI64,
56    DynamicGaugeI64Series, DynamicGaugeSeries, DynamicHistogram, DynamicHistogramSeries,
57    DynamicHistogramSeriesView, DynamicLabelSet, Gauge, GaugeF64, Histogram, HistogramSnapshot,
58    LabelEnum, LabeledCounter, LabeledGauge, LabeledHistogram, LabeledSampledTimer, MaxGauge,
59    MaxGaugeF64, MetricKind, MetricLabel, MetricLabels, MetricLabelsIter, MetricMeta,
60    MetricVisitor, MinGauge, MinGaugeF64, SampledTimer, SampledTimerGuard,
61};
62#[cfg(feature = "bench-tools")]
63#[doc(hidden)]
64pub use metric::{CounterSet, CounterSetBuffer};
65#[cfg(feature = "eviction")]
66pub use metric::{advance_cycle, current_cycle};
67#[cfg(feature = "runtime")]
68pub use runtime::{MetricScope, RegisteredMetrics, Runtime, RuntimeConfig};
69pub use span::{
70    CompletedSpan, Span, SpanAttribute, SpanCollector, SpanEvent, SpanId, SpanKind, SpanStatus,
71    SpanValue, TraceId, current_span_id, current_trace_id,
72};
73pub use temporality::Temporality;
74
75#[cfg(feature = "otlp")]
76pub use export::otlp::OtlpExport;
77
78#[cfg(feature = "clickhouse")]
79pub use export::clickhouse::{ClickHouseExport, ClickHouseMetricBatch};
80
81#[cfg(feature = "macros")]
82pub use fast_telemetry_macros::{ExportMetrics, LabelEnum as DeriveLabel};
83
84// Internal compatibility aliases for moved modules.
85pub(crate) use internal::exp_buckets;
86pub(crate) use internal::thread_id;
87pub(crate) use metric::label;
88
89#[cfg(feature = "otlp")]
90pub mod otlp {
91    pub use crate::export::otlp::*;
92}
93
94#[cfg(feature = "clickhouse")]
95pub mod clickhouse {
96    pub use crate::export::clickhouse::*;
97}
fast_telemetry/lib.rs

fast_telemetry/
lib.rs
