elfo_logger/
lib.rs

1//! Registers `tracing` subscriber and logs events. [Configuration].
2//!
3//! [Configuration]: config::Config
4
5#![cfg_attr(docsrs, feature(doc_cfg))]
6
7#[macro_use]
8extern crate elfo_utils;
9
10use std::sync::Arc;
11
12use dashmap::DashMap;
13use derive_more::Constructor;
14use futures_intrusive::{buffer::GrowingHeapBuf, channel::GenericChannel};
15use fxhash::FxBuildHasher;
16use parking_lot::RawMutex;
17use sharded_slab::Pool;
18use tracing::{span::Id as SpanId, Metadata};
19use tracing_subscriber::{prelude::*, registry::Registry};
20
21use elfo_core::{tracing::TraceId, ActorMeta, Blueprint};
22use elfo_utils::time::SystemTime;
23
24use crate::actor::Logger;
25
26pub use crate::{actor::ReopenLogFile, capture_layer::CaptureLayer, scope_filter::ScopeFilter};
27
28pub mod config;
29
30mod actor;
31mod capture_layer;
32mod formatters;
33mod scope_filter;
34mod stats;
35mod theme;
36
37mod line_buffer;
38mod line_transaction;
39
40const CHANNEL_CAPACITY: usize = 128 * 1024;
41
42type StringId = usize;
43
44struct Shared {
45    channel: GenericChannel<RawMutex, PreparedEvent, GrowingHeapBuf<PreparedEvent>>,
46    pool: Pool<String>,
47    spans: DashMap<SpanId, SpanData, FxBuildHasher>,
48}
49
50// TODO: store once instead of here and `Registry`.
51#[derive(Constructor)]
52struct SpanData {
53    parent_id: Option<SpanId>,
54    payload_id: StringId,
55}
56
57struct PreparedEvent {
58    timestamp: SystemTime,
59    trace_id: Option<TraceId>,
60    metadata: &'static Metadata<'static>,
61    object: Option<Arc<ActorMeta>>,
62    span_id: Option<SpanId>,
63    payload_id: StringId,
64}
65
66/// Creates a new logger blueprint and returns [`ScopeFilter`] and
67/// [`CaptureLayer`] to install on a tracing subscriber.
68///
69/// It's useful when you want to set a tracing subscriber on your own, for
70/// example, to integrate with `console-subscriber` or to use custom layers.
71///
72/// # Example
73/// ```
74/// # use elfo_core as elfo;
75/// # mod console_subscriber { pub fn spawn() -> Option<elfo_logger::CaptureLayer> { None } }
76/// use tracing_subscriber::prelude::*;
77///
78/// // Usually, it's `elfo::batteries::logger::new`.
79/// let (logger, scope_filter, capture_layer) = elfo_logger::new();
80///
81/// tracing_subscriber::registry()
82///     .with(console_subscriber::spawn())
83///     .with(capture_layer.with_filter(scope_filter))
84///     .init();
85///
86/// let topology = elfo::Topology::empty();
87/// let loggers = topology.local("system.loggers");
88///
89/// loggers.mount(logger);
90/// ```
91pub fn new() -> (Blueprint, ScopeFilter, CaptureLayer) {
92    let shared = Shared {
93        channel: GenericChannel::with_capacity(CHANNEL_CAPACITY),
94        pool: Pool::default(),
95        spans: DashMap::default(),
96    };
97
98    let shared = Arc::new(shared);
99    let scope_filter = ScopeFilter::new();
100    let capture_layer = CaptureLayer::new(shared.clone());
101    let blueprint = Logger::blueprint(shared, scope_filter.clone());
102
103    (blueprint, scope_filter, capture_layer)
104}
105
106/// Initializes `tracing` subscriber and returns a blueprint.
107///
108/// It install a subscriber with following layers:
109/// * [`EnvFilter`], if `RUST_LOG` is set and the `env-filter` feature is
110///   enabled (it's by default).
111/// * [`ScopeFilter`] to filter events based on [elfo configuration].
112/// * [`CaptureLayer`] to send events to the logger actor.
113///
114/// # Example
115/// ```
116/// # use elfo_core as elfo;
117///
118/// // Usually, it's `elfo::batteries::logger::init`.
119/// let logger = elfo_logger::init();
120///
121/// let topology = elfo::Topology::empty();
122/// let loggers = topology.local("system.loggers");
123///
124/// loggers.mount(logger);
125/// ```
126///
127/// [`EnvFilter`]: tracing_subscriber::EnvFilter
128/// [elfo configuration]: elfo_core::config::system::logging::LoggingConfig
129pub fn init() -> Blueprint {
130    let (blueprint, scope_filter, capture_layer) = new();
131
132    let subscriber = Registry::default().with(capture_layer).with(scope_filter);
133
134    #[cfg(feature = "env-filter")]
135    let subscriber = {
136        use tracing_subscriber::EnvFilter;
137
138        let env_filter = std::env::var(EnvFilter::DEFAULT_ENV)
139            .ok()
140            .map(|_| EnvFilter::try_from_default_env().expect("invalid env"));
141
142        subscriber.with(env_filter)
143    };
144
145    tracing::subscriber::set_global_default(subscriber).expect("cannot set global subscriber");
146
147    // TODO: remove test log at all?
148    #[cfg(feature = "tracing-log")]
149    {
150        if let Err(e) = tracing_log::LogTracer::init() {
151            tracing::error!(
152                error = &*e.to_string(),
153                "can't integrate with log adapter, logs produced via `log` crate might be not available",
154            );
155        } else {
156            // Required to initialize `tracing-log` logs detection in `scope_filter`.
157            log::error!("initialized tracing_log adapter");
158        }
159    }
160
161    blueprint
162}
elfo_logger/lib.rs

elfo_logger/
lib.rs
