Remove once_cell as a dependency

tracing-core/Cargo.toml

@@ -29,13 +29,12 @@ rust-version = "1.63.0"
 [features]
 default = ["std"]
 alloc = []
-std = ["once_cell", "alloc"]
+std = ["alloc"]
 
 [badges]
 maintenance = { status = "actively-developed" }
 
 [dependencies]
-once_cell = { version = "1.13.0", optional = true }
 
 [package.metadata.docs.rs]
 all-features = true

tracing-core/src/callsite.rs

@@ -167,7 +167,6 @@ pub use self::inner::{rebuild_interest_cache, register};
 #[cfg(feature = "std")]
 mod inner {
     use super::*;
-    use once_cell::sync::Lazy;
     use std::sync::RwLock;
     use std::vec::Vec;
 
@@ -178,10 +177,10 @@ mod inner {
         dispatchers: RwLock<Dispatchers>,
     }
 
-    static REGISTRY: Lazy<Registry> = Lazy::new(|| Registry {
+    static REGISTRY: Registry = Registry {
         callsites: LinkedList::new(),
         dispatchers: RwLock::new(Vec::new()),
-    });
+    };
 
     /// Clear and reregister interest on every [`Callsite`]
     ///

tracing-flame/Cargo.toml

@@ -19,7 +19,7 @@ categories = [
     "asynchronous",
 ]
 keywords = ["tracing", "subscriber", "flamegraph", "profiling"]
-rust-version = "1.63.0"
+rust-version = "1.70.0"
 
 [features]
 default = ["smallvec"]
@@ -28,7 +28,6 @@ smallvec = ["tracing-subscriber/smallvec"]
 [dependencies]
 tracing-subscriber = { path = "../tracing-subscriber", version = "0.3", default-features = false, features = ["registry", "fmt"] }
 tracing = { path = "../tracing", version = "0.2", default-features = false, features = ["std"] }
-once_cell = "1.13.0"
 
 [dev-dependencies]
 tempfile = "3.3.0"

tracing-flame/src/lib.rs

@@ -10,7 +10,7 @@
 //! issues bottlenecks in an application. For more details, see Brendan Gregg's [post]
 //! on flamegraphs.
 //!
-//! *Compiler support: [requires `rustc` 1.63+][msrv]*
+//! *Compiler support: [requires `rustc` 1.70+][msrv]*
 //!
 //! [msrv]: #supported-rust-versions
 //! [post]: http://www.brendangregg.com/flamegraphs.html
@@ -95,7 +95,7 @@
 //! ## Supported Rust Versions
 //!
 //! Tracing is built against the latest stable release. The minimum supported
-//! version is 1.63. The current Tracing version is not guaranteed to build on
+//! version is 1.70. The current Tracing version is not guaranteed to build on
 //! Rust versions earlier than the minimum supported version.
 //!
 //! Tracing follows the same compiler support policies as the rest of the Tokio
@@ -136,7 +136,6 @@
 
 use error::Error;
 use error::Kind;
-use once_cell::sync::Lazy;
 use std::cell::Cell;
 use std::fmt;
 use std::fmt::Write as _;
@@ -147,6 +146,7 @@ use std::marker::PhantomData;
 use std::path::Path;
 use std::sync::Arc;
 use std::sync::Mutex;
+use std::sync::OnceLock;
 use std::time::{Duration, Instant};
 use tracing::span;
 use tracing::Collect;
@@ -157,10 +157,10 @@ use tracing_subscriber::Subscribe;
 
 mod error;
 
-static START: Lazy<Instant> = Lazy::new(Instant::now);
+static START: OnceLock<Instant> = OnceLock::new();
 
 thread_local! {
-    static LAST_EVENT: Cell<Instant> = Cell::new(*START);
+    static LAST_EVENT: Cell<Instant> = Cell::new(*START.get_or_init(Instant::now));
 
     static THREAD_NAME: String = {
         let thread = std::thread::current();
@@ -264,7 +264,7 @@ where
     pub fn new(writer: W) -> Self {
         // Initialize the start used by all threads when initializing the
         // LAST_EVENT when constructing the subscriber
-        let _unused = *START;
+        let _unused = START.get_or_init(Instant::now);
         Self {
             out: Arc::new(Mutex::new(writer)),
             config: Default::default(),

tracing-log/Cargo.toml

@@ -15,7 +15,7 @@ categories = [
 keywords = ["logging", "tracing", "log"]
 license = "MIT"
 readme = "README.md"
-rust-version = "1.63.0"
+rust-version = "1.70.0"
 
 [features]
 default = ["log-tracer", "std"]
@@ -25,7 +25,6 @@ log-tracer = []
 [dependencies]
 tracing-core = { path = "../tracing-core", version = "0.2"}
 log = "0.4.17"
-once_cell = "1.13.0"
 env_logger = { version = "0.8.4", optional = true }
 
 [dev-dependencies]

tracing-log/src/lib.rs

@@ -16,7 +16,7 @@
 //! - An [`env_logger`] module, with helpers for using the [`env_logger` crate]
 //!   with `tracing` (optional, enabled by the `env-logger` feature).
 //!
-//! *Compiler support: [requires `rustc` 1.63+][msrv]*
+//! *Compiler support: [requires `rustc` 1.70+][msrv]*
 //!
 //! [msrv]: #supported-rust-versions
 //!
@@ -76,7 +76,7 @@
 //! ## Supported Rust Versions
 //!
 //! Tracing is built against the latest stable release. The minimum supported
-//! version is 1.63. The current Tracing version is not guaranteed to build on
+//! version is 1.70. The current Tracing version is not guaranteed to build on
 //! Rust versions earlier than the minimum supported version.
 //!
 //! Tracing follows the same compiler support policies as the rest of the Tokio
@@ -124,9 +124,8 @@
     unused_parens,
     while_true
 )]
-use once_cell::sync::Lazy;
 
-use std::{fmt, io};
+use std::{fmt, io, sync::OnceLock};
 
 use tracing_core::{
     callsite::{self, Callsite},
@@ -318,19 +317,28 @@ log_cs!(
     ErrorCallsite
 );
 
-static TRACE_FIELDS: Lazy<Fields> = Lazy::new(|| Fields::new(&TRACE_CS));
-static DEBUG_FIELDS: Lazy<Fields> = Lazy::new(|| Fields::new(&DEBUG_CS));
-static INFO_FIELDS: Lazy<Fields> = Lazy::new(|| Fields::new(&INFO_CS));
-static WARN_FIELDS: Lazy<Fields> = Lazy::new(|| Fields::new(&WARN_CS));
-static ERROR_FIELDS: Lazy<Fields> = Lazy::new(|| Fields::new(&ERROR_CS));
+static TRACE_FIELDS: OnceLock<Fields> = OnceLock::new();
+static DEBUG_FIELDS: OnceLock<Fields> = OnceLock::new();
+static INFO_FIELDS: OnceLock<Fields> = OnceLock::new();
+static WARN_FIELDS: OnceLock<Fields> = OnceLock::new();
+static ERROR_FIELDS: OnceLock<Fields> = OnceLock::new();
 
 fn level_to_cs(level: Level) -> (&'static dyn Callsite, &'static Fields) {
     match level {
-        Level::TRACE => (&TRACE_CS, &*TRACE_FIELDS),
-        Level::DEBUG => (&DEBUG_CS, &*DEBUG_FIELDS),
-        Level::INFO => (&INFO_CS, &*INFO_FIELDS),
-        Level::WARN => (&WARN_CS, &*WARN_FIELDS),
-        Level::ERROR => (&ERROR_CS, &*ERROR_FIELDS),
+        Level::TRACE => (
+            &TRACE_CS,
+            TRACE_FIELDS.get_or_init(|| Fields::new(&TRACE_CS)),
+        ),
+        Level::DEBUG => (
+            &DEBUG_CS,
+            DEBUG_FIELDS.get_or_init(|| Fields::new(&DEBUG_CS)),
+        ),
+        Level::INFO => (&INFO_CS, INFO_FIELDS.get_or_init(|| Fields::new(&INFO_CS))),
+        Level::WARN => (&WARN_CS, WARN_FIELDS.get_or_init(|| Fields::new(&WARN_CS))),
+        Level::ERROR => (
+            &ERROR_CS,
+            ERROR_FIELDS.get_or_init(|| Fields::new(&ERROR_CS)),
+        ),
     }
 }
 
@@ -342,11 +350,31 @@ fn loglevel_to_cs(
     &'static Metadata<'static>,
 ) {
     match level {
-        log::Level::Trace => (&TRACE_CS, &*TRACE_FIELDS, &TRACE_META),
-        log::Level::Debug => (&DEBUG_CS, &*DEBUG_FIELDS, &DEBUG_META),
-        log::Level::Info => (&INFO_CS, &*INFO_FIELDS, &INFO_META),
-        log::Level::Warn => (&WARN_CS, &*WARN_FIELDS, &WARN_META),
-        log::Level::Error => (&ERROR_CS, &*ERROR_FIELDS, &ERROR_META),
+        log::Level::Trace => (
+            &TRACE_CS,
+            TRACE_FIELDS.get_or_init(|| Fields::new(&TRACE_CS)),
+            &TRACE_META,
+        ),
+        log::Level::Debug => (
+            &DEBUG_CS,
+            DEBUG_FIELDS.get_or_init(|| Fields::new(&DEBUG_CS)),
+            &DEBUG_META,
+        ),
+        log::Level::Info => (
+            &INFO_CS,
+            INFO_FIELDS.get_or_init(|| Fields::new(&INFO_CS)),
+            &INFO_META,
+        ),
+        log::Level::Warn => (
+            &WARN_CS,
+            WARN_FIELDS.get_or_init(|| Fields::new(&WARN_CS)),
+            &WARN_META,
+        ),
+        log::Level::Error => (
+            &ERROR_CS,
+            ERROR_FIELDS.get_or_init(|| Fields::new(&ERROR_CS)),
+            &ERROR_META,
+        ),
     }
 }
 

tracing-subscriber/Cargo.toml

@@ -20,14 +20,14 @@ categories = [
     "asynchronous",
 ]
 keywords = ["logging", "tracing", "metrics", "subscriber"]
-rust-version = "1.63.0"
+rust-version = "1.70.0"
 
 [features]
 
 default = ["smallvec", "fmt", "ansi", "tracing-log", "std"]
 alloc = ["tracing-core/alloc"]
 std = ["alloc", "tracing-core/std"]
-env-filter = ["matchers", "regex", "once_cell", "tracing", "std", "thread_local"]
+env-filter = ["matchers", "regex", "tracing", "std", "thread_local"]
 fmt = ["registry", "std"]
 ansi = ["fmt", "nu-ansi-term"]
 registry = ["sharded-slab", "thread_local", "std"]
@@ -45,7 +45,6 @@ tracing = { optional = true, path = "../tracing", version = "0.2", default-featu
 matchers = { optional = true, version = "0.1.0" }
 regex = { optional = true, version = "1.6.0", default-features = false, features = ["std", "unicode-case", "unicode-perl"] }
 smallvec = { optional = true, version = "1.9.0" }
-once_cell = { optional = true, version = "1.13.0" }
 
 # fmt
 tracing-log = { path = "../tracing-log", version = "0.2", optional = true, default-features = false, features = ["log-tracer", "std"] }

tracing-subscriber/src/filter/env/directive.rs

@@ -4,9 +4,8 @@ use crate::filter::{
     env::{field, FieldMap},
     level::LevelFilter,
 };
-use once_cell::sync::Lazy;
 use regex::Regex;
-use std::{cmp::Ordering, fmt, iter::FromIterator, str::FromStr};
+use std::{cmp::Ordering, fmt, iter::FromIterator, str::FromStr, sync::OnceLock};
 use tracing_core::{span, Level, Metadata};
 
 /// A single filtering directive.
@@ -120,7 +119,11 @@ impl Directive {
     }
 
     pub(super) fn parse(from: &str, regex: bool) -> Result<Self, ParseError> {
-        static DIRECTIVE_RE: Lazy<Regex> = Lazy::new(|| {
+        static DIRECTIVE_RE: OnceLock<Regex> = OnceLock::new();
+        static SPAN_PART_RE: OnceLock<Regex> = OnceLock::new();
+        static FIELD_FILTER_RE: OnceLock<Regex> = OnceLock::new();
+
+        fn directive_re() -> Regex {
             Regex::new(
                 r"(?x)
             ^(?P<global_level>(?i:trace|debug|info|warn|error|off|[0-5]))$ |
@@ -139,13 +142,15 @@ impl Directive {
             ",
             )
             .unwrap()
-        });
-        static SPAN_PART_RE: Lazy<Regex> =
-            Lazy::new(|| Regex::new(r"(?P<name>[^\]\{]+)?(?:\{(?P<fields>[^\}]*)\})?").unwrap());
-        static FIELD_FILTER_RE: Lazy<Regex> =
+        }
+
+        fn span_part_re() -> Regex {
+            Regex::new(r"(?P<name>[^\]\{]+)?(?:\{(?P<fields>[^\}]*)\})?").unwrap()
+        }
+
+        fn field_filter_re() -> Regex {
             // TODO(eliza): this doesn't _currently_ handle value matchers that include comma
             // characters. We should fix that.
-            Lazy::new(|| {
                 Regex::new(
                     r"(?x)
                 (
@@ -159,9 +164,11 @@ impl Directive {
             ",
                 )
                 .unwrap()
-            });
+        }
 
-        let caps = DIRECTIVE_RE.captures(from).ok_or_else(ParseError::new)?;
+        let caps = DIRECTIVE_RE
+            .get_or_init(directive_re)
+            .captures(from).ok_or_else(ParseError::new)?;
 
         if let Some(level) = caps
             .name("global_level")
@@ -186,12 +193,13 @@ impl Directive {
             .name("span")
             .and_then(|cap| {
                 let cap = cap.as_str().trim_matches(|c| c == '[' || c == ']');
-                let caps = SPAN_PART_RE.captures(cap)?;
+                let caps = SPAN_PART_RE.get_or_init(span_part_re).captures(cap)?;
                 let span = caps.name("name").map(|c| c.as_str().to_owned());
                 let fields = caps
                     .name("fields")
                     .map(|c| {
                         FIELD_FILTER_RE
+                            .get_or_init(field_filter_re)
                             .find_iter(c.as_str())
                             .map(|c| field::Match::parse(c.as_str(), regex))
                             .collect::<Result<Vec<_>, _>>()

tracing-subscriber/src/lib.rs

@@ -10,7 +10,7 @@
 //! `tracing-subscriber` is intended for use by both `Collector` authors and
 //! application authors using `tracing` to instrument their applications.
 //!
-//! *Compiler support: [requires `rustc` 1.63+][msrv]*
+//! *Compiler support: [requires `rustc` 1.70+][msrv]*
 //!
 //! [msrv]: #supported-rust-versions
 //!
@@ -106,7 +106,7 @@
 //! ## Supported Rust Versions
 //!
 //! Tracing is built against the latest stable release. The minimum supported
-//! version is 1.63. The current Tracing version is not guaranteed to build on
+//! version is 1.70. The current Tracing version is not guaranteed to build on
 //! Rust versions earlier than the minimum supported version.
 //!
 //! Tracing follows the same compiler support policies as the rest of the Tokio