mirror of
https://github.com/tokio-rs/tracing.git
synced 2025-09-30 22:40:34 +00:00
docs: document valuable support (#1887)
Depends on #1881 Right now, the `valuable` stuff isn't very discoverable --- enabling the feature just adds some trait impls and stuff that aren't particularly visible in the documentation. This PR adds some top-level docs on using `valuable`. In particular: - Added a section to the `tracing` and `tracing-core` lib.rs docs explaining the unstable features versioning policy and how to turn on unstable features - Added a section in the `field` module that explains how to use `valuable` to record fields. - It turns out the `tracing::field` module didn't really have docs, since it doesn't re-export the `tracing_core::field` module but re-exports its _types_ in a new module (because it adds a trait). It had a single line of docs that just said something about "structured key-value data". I fixed this by coping the docs from `tracing-core`. :/ - Enabled unstable features in the documentation on docs.rs and netlify.
This commit is contained in:
Eliza Weisman
GitHub
parent
67d45477f8
commit
3d96c0fe97
@ -8,8 +8,10 @@
|
||||
[build.environment]
|
||||
RUSTDOCFLAGS="""
|
||||
-D warnings \
|
||||
--cfg docsrs
|
||||
--cfg docsrs \
|
||||
--cfg tracing_unstable
|
||||
"""
|
||||
RUSTFLAGS="--cfg tracing_unstable"
|
||||
|
||||
[[redirects]]
|
||||
from = "/"
|
||||
|
||||
@ -8,7 +8,7 @@ name = "tracing-core"
|
||||
# - README.md
|
||||
# - Update CHANGELOG.md.
|
||||
# - Create "v0.1.x" git tag.
|
||||
version = "0.1.21"
|
||||
version = "0.1.22"
|
||||
authors = ["Tokio Contributors <team@tokio.rs>"]
|
||||
license = "MIT"
|
||||
readme = "README.md"
|
||||
@ -41,4 +41,8 @@ valuable = { version = "0.1.0", optional = true, default_features = false }
|
||||
|
||||
[package.metadata.docs.rs]
|
||||
all-features = true
|
||||
rustdoc-args = ["--cfg", "docsrs"]
|
||||
# enable unstable features in the documentation
|
||||
rustdoc-args = ["--cfg", "docsrs", "--cfg", "tracing_unstable"]
|
||||
# it's necessary to _also_ pass `--cfg tracing_unstable` to rustc, or else
|
||||
# dependencies will not be enabled, and the docs build will fail.
|
||||
rustc-args = ["--cfg", "tracing_unstable"]
|
||||
@ -1,4 +1,4 @@
|
||||
//! Span and `Event` key-value data.
|
||||
//! `Span` and `Event` key-value data.
|
||||
//!
|
||||
//! Spans and events may be annotated with key-value data, referred to as known
|
||||
//! as _fields_. These fields consist of a mapping from a key (corresponding to
|
||||
@ -24,8 +24,81 @@
|
||||
//! recorded as typed data by calling the [`Value::record`] method on these
|
||||
//! trait objects with a _visitor_ implementing the [`Visit`] trait. This trait
|
||||
//! represents the behavior used to record values of various types. For example,
|
||||
//! we might record integers by incrementing counters for their field names,
|
||||
//! rather than printing them.
|
||||
//! an implementation of `Visit` might record integers by incrementing counters
|
||||
//! for their field names rather than printing them.
|
||||
//!
|
||||
//!
|
||||
//! # Using `valuable`
|
||||
//!
|
||||
//! `tracing`'s [`Value`] trait is intentionally minimalist: it supports only a small
|
||||
//! number of Rust primitives as typed values, and only permits recording
|
||||
//! user-defined types with their [`fmt::Debug`] or [`fmt::Display`]
|
||||
//! implementations. However, there are some cases where it may be useful to record
|
||||
//! nested values (such as arrays, `Vec`s, or `HashMap`s containing values), or
|
||||
//! user-defined `struct` and `enum` types without having to format them as
|
||||
//! unstructured text.
|
||||
//!
|
||||
//! To address `Value`'s limitations, `tracing` offers experimental support for
|
||||
//! the [`valuable`] crate, which provides object-safe inspection of structured
|
||||
//! values. User-defined types can implement the [`valuable::Valuable`] trait,
|
||||
//! and be recorded as a `tracing` field by calling their [`as_value`] method.
|
||||
//! If the [`Subscriber`] also supports the `valuable` crate, it can
|
||||
//! then visit those types fields as structured values using `valuable`.
|
||||
//!
|
||||
//! <pre class="ignore" style="white-space:normal;font:inherit;">
|
||||
//! <strong>Note</strong>: <code>valuable</code> support is an
|
||||
//! <a href = "../index.html#unstable-features">unstable feature</a>. See
|
||||
//! the documentation on unstable features for details on how to enable it.
|
||||
//! </pre>
|
||||
//!
|
||||
//! For example:
|
||||
//! ```ignore
|
||||
//! // Derive `Valuable` for our types:
|
||||
//! use valuable::Valuable;
|
||||
//!
|
||||
//! #[derive(Clone, Debug, Valuable)]
|
||||
//! struct User {
|
||||
//! name: String,
|
||||
//! age: u32,
|
||||
//! address: Address,
|
||||
//! }
|
||||
//!
|
||||
//! #[derive(Clone, Debug, Valuable)]
|
||||
//! struct Address {
|
||||
//! country: String,
|
||||
//! city: String,
|
||||
//! street: String,
|
||||
//! }
|
||||
//!
|
||||
//! let user = User {
|
||||
//! name: "Arwen Undomiel".to_string(),
|
||||
//! age: 3000,
|
||||
//! address: Address {
|
||||
//! country: "Middle Earth".to_string(),
|
||||
//! city: "Rivendell".to_string(),
|
||||
//! street: "leafy lane".to_string(),
|
||||
//! },
|
||||
//! };
|
||||
//!
|
||||
//! // Recording `user` as a `valuable::Value` will allow the `tracing` subscriber
|
||||
//! // to traverse its fields as a nested, typed structure:
|
||||
//! tracing::info!(current_user = user.as_value());
|
||||
//! ```
|
||||
//!
|
||||
//! Alternatively, the [`valuable()`] function may be used to convert a type
|
||||
//! implementing [`Valuable`] into a `tracing` field value.
|
||||
//!
|
||||
//! When the `valuable` feature is enabled, the [`Visit`] trait will include an
|
||||
//! optional [`record_value`] method. `Visit` implementations that wish to
|
||||
//! record `valuable` values can implement this method with custom behavior.
|
||||
//! If a visitor does not implement `record_value`, the [`valuable::Value`] will
|
||||
//! be forwarded to the visitor's [`record_debug`] method.
|
||||
//!
|
||||
//! [`valuable`]: https://crates.io/crates/valuable
|
||||
//! [`as_value`]: valuable::Valuable::as_value
|
||||
//! [`Subscriber`]: crate::Subscriber
|
||||
//! [`record_value`]: Visit::record_value
|
||||
//! [`record_debug`]: Visit::record_debug
|
||||
//!
|
||||
//! [`Value`]: trait.Value.html
|
||||
//! [span]: ../span/
|
||||
|
||||
@ -43,9 +43,9 @@
|
||||
//! be used with the `tracing` ecosystem. It includes a collection of
|
||||
//! `Subscriber` implementations, as well as utility and adapter crates.
|
||||
//!
|
||||
//! ### Crate Feature Flags
|
||||
//! ## Crate Feature Flags
|
||||
//!
|
||||
//! The following crate feature flags are available:
|
||||
//! The following crate [feature flags] are available:
|
||||
//!
|
||||
//! * `std`: Depend on the Rust standard library (enabled by default).
|
||||
//!
|
||||
@ -58,6 +58,37 @@
|
||||
//!
|
||||
//! **Note**:`tracing-core`'s `no_std` support requires `liballoc`.
|
||||
//!
|
||||
//! ### Unstable Features
|
||||
//!
|
||||
//! These feature flags enable **unstable** features. The public API may break in 0.1.x
|
||||
//! releases. To enable these features, the `--cfg tracing_unstable` must be passed to
|
||||
//! `rustc` when compiling.
|
||||
//!
|
||||
//! The following unstable feature flags are currently available:
|
||||
//!
|
||||
//! * `valuable`: Enables support for recording [field values] using the
|
||||
//! [`valuable`] crate.
|
||||
//!
|
||||
//! #### Enabling Unstable Features
|
||||
//!
|
||||
//! The easiest way to set the `tracing_unstable` cfg is to use the `RUSTFLAGS`
|
||||
//! env variable when running `cargo` commands:
|
||||
//!
|
||||
//! ```shell
|
||||
//! RUSTFLAGS="--cfg tracing_unstable" cargo build
|
||||
//! ```
|
||||
//! Alternatively, the following can be added to the `.cargo/config` file in a
|
||||
//! project to automatically enable the cfg flag for that project:
|
||||
//!
|
||||
//! ```toml
|
||||
//! [build]
|
||||
//! rustflags = ["--cfg", "tracing_unstable"]
|
||||
//! ```
|
||||
//!
|
||||
//! [feature flags]: https://doc.rust-lang.org/cargo/reference/manifest.html#the-features-section
|
||||
//! [field values]: crate::field
|
||||
//! [`valuable`]: https://crates.io/crates/valuable
|
||||
//!
|
||||
//! ## Supported Rust Versions
|
||||
//!
|
||||
//! Tracing is built against the latest stable release. The minimum supported
|
||||
|
||||
@ -28,7 +28,7 @@ edition = "2018"
|
||||
rust-version = "1.42.0"
|
||||
|
||||
[dependencies]
|
||||
tracing-core = { path = "../tracing-core", version = "0.1.21", default-features = false }
|
||||
tracing-core = { path = "../tracing-core", version = "0.1.22", default-features = false }
|
||||
log = { version = "0.4", optional = true }
|
||||
tracing-attributes = { path = "../tracing-attributes", version = "0.1.18", optional = true }
|
||||
cfg-if = "1.0.0"
|
||||
@ -81,4 +81,8 @@ maintenance = { status = "actively-developed" }
|
||||
|
||||
[package.metadata.docs.rs]
|
||||
all-features = true
|
||||
rustdoc-args = ["--cfg", "docsrs"]
|
||||
# enable unstable features in the documentation
|
||||
rustdoc-args = ["--cfg", "docsrs", "--cfg", "tracing_unstable"]
|
||||
# it's necessary to _also_ pass `--cfg tracing_unstable` to rustc, or else
|
||||
# dependencies will not be enabled, and the docs build will fail.
|
||||
rustc-args = ["--cfg", "tracing_unstable"]
|
||||
@ -1,4 +1,116 @@
|
||||
//! Structured data associated with `Span`s and `Event`s.
|
||||
//! `Span` and `Event` key-value data.
|
||||
//!
|
||||
//! Spans and events may be annotated with key-value data, referred to as known
|
||||
//! as _fields_. These fields consist of a mapping from a key (corresponding to
|
||||
//! a `&str` but represented internally as an array index) to a [`Value`].
|
||||
//!
|
||||
//! # `Value`s and `Subscriber`s
|
||||
//!
|
||||
//! `Subscriber`s consume `Value`s as fields attached to [span]s or [`Event`]s.
|
||||
//! The set of field keys on a given span or is defined on its [`Metadata`].
|
||||
//! When a span is created, it provides [`Attributes`] to the `Subscriber`'s
|
||||
//! [`new_span`] method, containing any fields whose values were provided when
|
||||
//! the span was created; and may call the `Subscriber`'s [`record`] method
|
||||
//! with additional [`Record`]s if values are added for more of its fields.
|
||||
//! Similarly, the [`Event`] type passed to the subscriber's [`event`] method
|
||||
//! will contain any fields attached to each event.
|
||||
//!
|
||||
//! `tracing` represents values as either one of a set of Rust primitives
|
||||
//! (`i64`, `u64`, `f64`, `bool`, and `&str`) or using a `fmt::Display` or
|
||||
//! `fmt::Debug` implementation. `Subscriber`s are provided these primitive
|
||||
//! value types as `dyn Value` trait objects.
|
||||
//!
|
||||
//! These trait objects can be formatted using `fmt::Debug`, but may also be
|
||||
//! recorded as typed data by calling the [`Value::record`] method on these
|
||||
//! trait objects with a _visitor_ implementing the [`Visit`] trait. This trait
|
||||
//! represents the behavior used to record values of various types. For example,
|
||||
//! an implementation of `Visit` might record integers by incrementing counters
|
||||
//! for their field names rather than printing them.
|
||||
//!
|
||||
//!
|
||||
//! # Using `valuable`
|
||||
//!
|
||||
//! `tracing`'s [`Value`] trait is intentionally minimalist: it supports only a small
|
||||
//! number of Rust primitives as typed values, and only permits recording
|
||||
//! user-defined types with their [`fmt::Debug`] or [`fmt::Display`]
|
||||
//! implementations. However, there are some cases where it may be useful to record
|
||||
//! nested values (such as arrays, `Vec`s, or `HashMap`s containing values), or
|
||||
//! user-defined `struct` and `enum` types without having to format them as
|
||||
//! unstructured text.
|
||||
//!
|
||||
//! To address `Value`'s limitations, `tracing` offers experimental support for
|
||||
//! the [`valuable`] crate, which provides object-safe inspection of structured
|
||||
//! values. User-defined types can implement the [`valuable::Valuable`] trait,
|
||||
//! and be recorded as a `tracing` field by calling their [`as_value`] method.
|
||||
//! If the [`Subscriber`] also supports the `valuable` crate, it can
|
||||
//! then visit those types fields as structured values using `valuable`.
|
||||
//!
|
||||
//! <pre class="ignore" style="white-space:normal;font:inherit;">
|
||||
//! <strong>Note</strong>: <code>valuable</code> support is an
|
||||
//! <a href = "../index.html#unstable-features">unstable feature</a>. See
|
||||
//! the documentation on unstable features for details on how to enable it.
|
||||
//! </pre>
|
||||
//!
|
||||
//! For example:
|
||||
//! ```ignore
|
||||
//! // Derive `Valuable` for our types:
|
||||
//! use valuable::Valuable;
|
||||
//!
|
||||
//! #[derive(Clone, Debug, Valuable)]
|
||||
//! struct User {
|
||||
//! name: String,
|
||||
//! age: u32,
|
||||
//! address: Address,
|
||||
//! }
|
||||
//!
|
||||
//! #[derive(Clone, Debug, Valuable)]
|
||||
//! struct Address {
|
||||
//! country: String,
|
||||
//! city: String,
|
||||
//! street: String,
|
||||
//! }
|
||||
//!
|
||||
//! let user = User {
|
||||
//! name: "Arwen Undomiel".to_string(),
|
||||
//! age: 3000,
|
||||
//! address: Address {
|
||||
//! country: "Middle Earth".to_string(),
|
||||
//! city: "Rivendell".to_string(),
|
||||
//! street: "leafy lane".to_string(),
|
||||
//! },
|
||||
//! };
|
||||
//!
|
||||
//! // Recording `user` as a `valuable::Value` will allow the `tracing` subscriber
|
||||
//! // to traverse its fields as a nested, typed structure:
|
||||
//! tracing::info!(current_user = user.as_value());
|
||||
//! ```
|
||||
//!
|
||||
//! Alternatively, the [`valuable()`] function may be used to convert a type
|
||||
//! implementing [`Valuable`] into a `tracing` field value.
|
||||
//!
|
||||
//! When the `valuable` feature is enabled, the [`Visit`] trait will include an
|
||||
//! optional [`record_value`] method. `Visit` implementations that wish to
|
||||
//! record `valuable` values can implement this method with custom behavior.
|
||||
//! If a visitor does not implement `record_value`, the [`valuable::Value`] will
|
||||
//! be forwarded to the visitor's [`record_debug`] method.
|
||||
//!
|
||||
//! [`fmt::Debug`]: std::fmt::Debug
|
||||
//! [`fmt::Display`]: std::fmt::Debug
|
||||
//! [`valuable`]: https://crates.io/crates/valuable
|
||||
//! [`valuable::Valuable`]: https://docs.rs/valuable/latest/valuable/trait.Valuable.html
|
||||
//! [`as_value`]: https://docs.rs/valuable/latest/valuable/trait.Valuable.html#tymethod.as_value
|
||||
//! [`valuable::Value`]: https://docs.rs/valuable/latest/valuable/enum.Value.html
|
||||
//! [`Subscriber`]: crate::Subscriber
|
||||
//! [`record_value`]: Visit::record_value
|
||||
//! [`record_debug`]: Visit::record_debug
|
||||
//! [span]: mod@crate::span
|
||||
//! [`Event`]: crate::event::Event
|
||||
//! [`Metadata`]: crate::Metadata
|
||||
//! [`Attributes`]: crate::span::Attributes
|
||||
//! [`Record`]: crate::span::Record
|
||||
//! [`new_span`]: crate::Subscriber::new_span
|
||||
//! [`record`]: crate::Subscriber::record
|
||||
//! [`event`]: crate::Subscriber::event
|
||||
pub use tracing_core::field::*;
|
||||
|
||||
use crate::Metadata;
|
||||
|
||||
@ -124,7 +124,7 @@ pub trait Instrument: Sized {
|
||||
}
|
||||
|
||||
/// Extension trait allowing futures to be instrumented with
|
||||
/// a `tracing` [`Subscriber`].
|
||||
/// a `tracing` [`Subscriber`](crate::Subscriber).
|
||||
#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
|
||||
pub trait WithSubscriber: Sized {
|
||||
/// Attaches the provided [`Subscriber`] to this type, returning a
|
||||
|
||||
@ -781,7 +781,7 @@
|
||||
//!
|
||||
//! ## Crate Feature Flags
|
||||
//!
|
||||
//! The following crate feature flags are available:
|
||||
//! The following crate [feature flags] are available:
|
||||
//!
|
||||
//! * A set of features controlling the [static verbosity level].
|
||||
//! * `log`: causes trace instrumentation points to emit [`log`] records as well
|
||||
@ -810,6 +810,37 @@
|
||||
//! requires <code>liballoc</code>.
|
||||
//! </pre>
|
||||
//!
|
||||
//! ### Unstable Features
|
||||
//!
|
||||
//! These feature flags enable **unstable** features. The public API may break in 0.1.x
|
||||
//! releases. To enable these features, the `--cfg tracing_unstable` must be passed to
|
||||
//! `rustc` when compiling.
|
||||
//!
|
||||
//! The following unstable feature flags are currently available:
|
||||
//!
|
||||
//! * `valuable`: Enables support for recording [field values] using the
|
||||
//! [`valuable`] crate.
|
||||
//!
|
||||
//! #### Enabling Unstable Features
|
||||
//!
|
||||
//! The easiest way to set the `tracing_unstable` cfg is to use the `RUSTFLAGS`
|
||||
//! env variable when running `cargo` commands:
|
||||
//!
|
||||
//! ```shell
|
||||
//! RUSTFLAGS="--cfg tracing_unstable" cargo build
|
||||
//! ```
|
||||
//! Alternatively, the following can be added to the `.cargo/config` file in a
|
||||
//! project to automatically enable the cfg flag for that project:
|
||||
//!
|
||||
//! ```toml
|
||||
//! [build]
|
||||
//! rustflags = ["--cfg", "tracing_unstable"]
|
||||
//! ```
|
||||
//!
|
||||
//! [feature flags]: https://doc.rust-lang.org/cargo/reference/manifest.html#the-features-section
|
||||
//! [field values]: crate::field
|
||||
//! [`valuable`]: https://crates.io/crates/valuable
|
||||
//!
|
||||
//! ## Supported Rust Versions
|
||||
//!
|
||||
//! Tracing is built against the latest stable release. The minimum supported
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user