mirror of
https://github.com/tokio-rs/tracing.git
synced 2025-10-02 15:24:47 +00:00
1a9ee003ce
* ci: add `tracing_unstable` to CI Currently, the `valuable` support requires the `tracing_unstable` cfg to be set. Because none of our current CI jobs set this, we aren't currently testing that code, and have no way of even ensuring that it compiles. This is Bad. This PR adds a CI job to run tests with the unstable cfg enabled. * core: fix wrong `self` types with `valuable` This should fix the build. Signed-off-by: Eliza Weisman <eliza@buoyant.io>
1126 lines
35 KiB
Rust
1126 lines
35 KiB
Rust
//! `Span` and `Event` key-value data.
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//!
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//! Spans and events may be annotated with key-value data, referred to as known
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//! as _fields_. These fields consist of a mapping from a key (corresponding to
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//! a `&str` but represented internally as an array index) to a [`Value`].
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//!
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//! # `Value`s and `Subscriber`s
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//!
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//! `Subscriber`s consume `Value`s as fields attached to [span]s or [`Event`]s.
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//! The set of field keys on a given span or is defined on its [`Metadata`].
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//! When a span is created, it provides [`Attributes`] to the `Subscriber`'s
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//! [`new_span`] method, containing any fields whose values were provided when
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//! the span was created; and may call the `Subscriber`'s [`record`] method
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//! with additional [`Record`]s if values are added for more of its fields.
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//! Similarly, the [`Event`] type passed to the subscriber's [`event`] method
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//! will contain any fields attached to each event.
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//!
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//! `tracing` represents values as either one of a set of Rust primitives
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//! (`i64`, `u64`, `f64`, `bool`, and `&str`) or using a `fmt::Display` or
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//! `fmt::Debug` implementation. `Subscriber`s are provided these primitive
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//! value types as `dyn Value` trait objects.
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//!
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//! These trait objects can be formatted using `fmt::Debug`, but may also be
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//! recorded as typed data by calling the [`Value::record`] method on these
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//! trait objects with a _visitor_ implementing the [`Visit`] trait. This trait
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//! represents the behavior used to record values of various types. For example,
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//! an implementation of `Visit` might record integers by incrementing counters
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//! for their field names rather than printing them.
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//!
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//!
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//! # Using `valuable`
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//!
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//! `tracing`'s [`Value`] trait is intentionally minimalist: it supports only a small
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//! number of Rust primitives as typed values, and only permits recording
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//! user-defined types with their [`fmt::Debug`] or [`fmt::Display`]
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//! implementations. However, there are some cases where it may be useful to record
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//! nested values (such as arrays, `Vec`s, or `HashMap`s containing values), or
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//! user-defined `struct` and `enum` types without having to format them as
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//! unstructured text.
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//!
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//! To address `Value`'s limitations, `tracing` offers experimental support for
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//! the [`valuable`] crate, which provides object-safe inspection of structured
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//! values. User-defined types can implement the [`valuable::Valuable`] trait,
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//! and be recorded as a `tracing` field by calling their [`as_value`] method.
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//! If the [`Subscriber`] also supports the `valuable` crate, it can
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//! then visit those types fields as structured values using `valuable`.
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//!
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//! <pre class="ignore" style="white-space:normal;font:inherit;">
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//! <strong>Note</strong>: <code>valuable</code> support is an
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//! <a href = "../index.html#unstable-features">unstable feature</a>. See
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//! the documentation on unstable features for details on how to enable it.
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//! </pre>
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//!
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//! For example:
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//! ```ignore
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//! // Derive `Valuable` for our types:
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//! use valuable::Valuable;
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//!
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//! #[derive(Clone, Debug, Valuable)]
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//! struct User {
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//! name: String,
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//! age: u32,
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//! address: Address,
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//! }
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//!
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//! #[derive(Clone, Debug, Valuable)]
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//! struct Address {
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//! country: String,
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//! city: String,
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//! street: String,
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//! }
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//!
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//! let user = User {
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//! name: "Arwen Undomiel".to_string(),
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//! age: 3000,
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//! address: Address {
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//! country: "Middle Earth".to_string(),
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//! city: "Rivendell".to_string(),
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//! street: "leafy lane".to_string(),
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//! },
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//! };
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//!
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//! // Recording `user` as a `valuable::Value` will allow the `tracing` subscriber
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//! // to traverse its fields as a nested, typed structure:
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//! tracing::info!(current_user = user.as_value());
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//! ```
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//!
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//! Alternatively, the [`valuable()`] function may be used to convert a type
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//! implementing [`Valuable`] into a `tracing` field value.
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//!
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//! When the `valuable` feature is enabled, the [`Visit`] trait will include an
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//! optional [`record_value`] method. `Visit` implementations that wish to
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//! record `valuable` values can implement this method with custom behavior.
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//! If a visitor does not implement `record_value`, the [`valuable::Value`] will
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//! be forwarded to the visitor's [`record_debug`] method.
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//!
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//! [`valuable`]: https://crates.io/crates/valuable
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//! [`as_value`]: valuable::Valuable::as_value
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//! [`Subscriber`]: crate::Subscriber
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//! [`record_value`]: Visit::record_value
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//! [`record_debug`]: Visit::record_debug
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//!
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//! [`Value`]: trait.Value.html
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//! [span]: ../span/
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//! [`Event`]: ../event/struct.Event.html
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//! [`Metadata`]: ../metadata/struct.Metadata.html
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//! [`Attributes`]: ../span/struct.Attributes.html
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//! [`Record`]: ../span/struct.Record.html
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//! [`new_span`]: ../subscriber/trait.Subscriber.html#method.new_span
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//! [`record`]: ../subscriber/trait.Subscriber.html#method.record
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//! [`event`]: ../subscriber/trait.Subscriber.html#method.event
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//! [`Value::record`]: trait.Value.html#method.record
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//! [`Visit`]: trait.Visit.html
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use crate::callsite;
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use crate::stdlib::{
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borrow::Borrow,
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fmt,
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hash::{Hash, Hasher},
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num,
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ops::Range,
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};
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use self::private::ValidLen;
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/// An opaque key allowing _O_(1) access to a field in a `Span`'s key-value
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/// data.
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///
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/// As keys are defined by the _metadata_ of a span, rather than by an
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/// individual instance of a span, a key may be used to access the same field
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/// across all instances of a given span with the same metadata. Thus, when a
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/// subscriber observes a new span, it need only access a field by name _once_,
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/// and use the key for that name for all other accesses.
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#[derive(Debug)]
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pub struct Field {
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i: usize,
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fields: FieldSet,
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}
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/// An empty field.
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///
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/// This can be used to indicate that the value of a field is not currently
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/// present but will be recorded later.
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///
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/// When a field's value is `Empty`. it will not be recorded.
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#[derive(Debug, Eq, PartialEq)]
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pub struct Empty;
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/// Describes the fields present on a span.
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pub struct FieldSet {
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/// The names of each field on the described span.
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names: &'static [&'static str],
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/// The callsite where the described span originates.
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callsite: callsite::Identifier,
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}
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/// A set of fields and values for a span.
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pub struct ValueSet<'a> {
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values: &'a [(&'a Field, Option<&'a (dyn Value + 'a)>)],
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fields: &'a FieldSet,
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}
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/// An iterator over a set of fields.
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#[derive(Debug)]
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pub struct Iter {
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idxs: Range<usize>,
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fields: FieldSet,
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}
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/// Visits typed values.
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///
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/// An instance of `Visit` ("a visitor") represents the logic necessary to
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/// record field values of various types. When an implementor of [`Value`] is
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/// [recorded], it calls the appropriate method on the provided visitor to
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/// indicate the type that value should be recorded as.
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///
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/// When a [`Subscriber`] implementation [records an `Event`] or a
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/// [set of `Value`s added to a `Span`], it can pass an `&mut Visit` to the
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/// `record` method on the provided [`ValueSet`] or [`Event`]. This visitor
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/// will then be used to record all the field-value pairs present on that
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/// `Event` or `ValueSet`.
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///
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/// # Examples
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///
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/// A simple visitor that writes to a string might be implemented like so:
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/// ```
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/// # extern crate tracing_core as tracing;
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/// use std::fmt::{self, Write};
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/// use tracing::field::{Value, Visit, Field};
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/// pub struct StringVisitor<'a> {
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/// string: &'a mut String,
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/// }
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///
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/// impl<'a> Visit for StringVisitor<'a> {
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/// fn record_debug(&mut self, field: &Field, value: &dyn fmt::Debug) {
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/// write!(self.string, "{} = {:?}; ", field.name(), value).unwrap();
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/// }
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/// }
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/// ```
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/// This visitor will format each recorded value using `fmt::Debug`, and
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/// append the field name and formatted value to the provided string,
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/// regardless of the type of the recorded value. When all the values have
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/// been recorded, the `StringVisitor` may be dropped, allowing the string
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/// to be printed or stored in some other data structure.
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///
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/// The `Visit` trait provides default implementations for `record_i64`,
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/// `record_u64`, `record_bool`, `record_str`, and `record_error`, which simply
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/// forward the recorded value to `record_debug`. Thus, `record_debug` is the
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/// only method which a `Visit` implementation *must* implement. However,
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/// visitors may override the default implementations of these functions in
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/// order to implement type-specific behavior.
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///
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/// Additionally, when a visitor receives a value of a type it does not care
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/// about, it is free to ignore those values completely. For example, a
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/// visitor which only records numeric data might look like this:
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///
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/// ```
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/// # extern crate tracing_core as tracing;
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/// # use std::fmt::{self, Write};
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/// # use tracing::field::{Value, Visit, Field};
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/// pub struct SumVisitor {
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/// sum: i64,
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/// }
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///
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/// impl Visit for SumVisitor {
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/// fn record_i64(&mut self, _field: &Field, value: i64) {
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/// self.sum += value;
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/// }
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///
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/// fn record_u64(&mut self, _field: &Field, value: u64) {
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/// self.sum += value as i64;
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/// }
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///
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/// fn record_debug(&mut self, _field: &Field, _value: &fmt::Debug) {
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/// // Do nothing
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/// }
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/// }
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/// ```
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///
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/// This visitor (which is probably not particularly useful) keeps a running
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/// sum of all the numeric values it records, and ignores all other values. A
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/// more practical example of recording typed values is presented in
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/// `examples/counters.rs`, which demonstrates a very simple metrics system
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/// implemented using `tracing`.
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///
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/// <div class="example-wrap" style="display:inline-block">
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/// <pre class="ignore" style="white-space:normal;font:inherit;">
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/// <strong>Note</strong>: The <code>record_error</code> trait method is only
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/// available when the Rust standard library is present, as it requires the
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/// <code>std::error::Error</code> trait.
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/// </pre></div>
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///
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/// [`Value`]: trait.Value.html
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/// [recorded]: trait.Value.html#method.record
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/// [`Subscriber`]: ../subscriber/trait.Subscriber.html
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/// [records an `Event`]: ../subscriber/trait.Subscriber.html#method.event
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/// [set of `Value`s added to a `Span`]: ../subscriber/trait.Subscriber.html#method.record
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/// [`Event`]: ../event/struct.Event.html
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/// [`ValueSet`]: struct.ValueSet.html
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pub trait Visit {
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/// Visits an arbitrary type implementing the [`valuable`] crate's `Valuable` trait.
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///
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/// [`valuable`]: https://docs.rs/valuable
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#[cfg(all(tracing_unstable, feature = "valuable"))]
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#[cfg_attr(docsrs, doc(cfg(all(tracing_unstable, feature = "valuable"))))]
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fn record_value(&mut self, field: &Field, value: valuable::Value<'_>) {
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self.record_debug(field, &value)
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}
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/// Visit a double-precision floating point value.
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fn record_f64(&mut self, field: &Field, value: f64) {
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self.record_debug(field, &value)
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}
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/// Visit a signed 64-bit integer value.
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fn record_i64(&mut self, field: &Field, value: i64) {
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self.record_debug(field, &value)
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}
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/// Visit an unsigned 64-bit integer value.
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fn record_u64(&mut self, field: &Field, value: u64) {
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self.record_debug(field, &value)
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}
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/// Visit a boolean value.
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fn record_bool(&mut self, field: &Field, value: bool) {
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self.record_debug(field, &value)
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}
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/// Visit a string value.
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fn record_str(&mut self, field: &Field, value: &str) {
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self.record_debug(field, &value)
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}
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/// Records a type implementing `Error`.
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///
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/// <div class="example-wrap" style="display:inline-block">
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/// <pre class="ignore" style="white-space:normal;font:inherit;">
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/// <strong>Note</strong>: This is only enabled when the Rust standard library is
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/// present.
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/// </pre>
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#[cfg(feature = "std")]
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#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
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fn record_error(&mut self, field: &Field, value: &(dyn std::error::Error + 'static)) {
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self.record_debug(field, &format_args!("{}", value))
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}
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/// Visit a value implementing `fmt::Debug`.
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fn record_debug(&mut self, field: &Field, value: &dyn fmt::Debug);
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}
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/// A field value of an erased type.
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///
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/// Implementors of `Value` may call the appropriate typed recording methods on
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/// the [visitor] passed to their `record` method in order to indicate how
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/// their data should be recorded.
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///
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/// [visitor]: trait.Visit.html
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pub trait Value: crate::sealed::Sealed {
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/// Visits this value with the given `Visitor`.
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fn record(&self, key: &Field, visitor: &mut dyn Visit);
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}
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/// A `Value` which serializes using `fmt::Display`.
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///
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/// Uses `record_debug` in the `Value` implementation to
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/// avoid an unnecessary evaluation.
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#[derive(Clone)]
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pub struct DisplayValue<T: fmt::Display>(T);
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/// A `Value` which serializes as a string using `fmt::Debug`.
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#[derive(Clone)]
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pub struct DebugValue<T: fmt::Debug>(T);
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/// Wraps a type implementing `fmt::Display` as a `Value` that can be
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/// recorded using its `Display` implementation.
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pub fn display<T>(t: T) -> DisplayValue<T>
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where
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T: fmt::Display,
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{
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DisplayValue(t)
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}
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/// Wraps a type implementing `fmt::Debug` as a `Value` that can be
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/// recorded using its `Debug` implementation.
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pub fn debug<T>(t: T) -> DebugValue<T>
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where
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T: fmt::Debug,
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{
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DebugValue(t)
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}
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/// Wraps a type implementing [`Valuable`] as a `Value` that
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/// can be recorded using its `Valuable` implementation.
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///
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/// [`Valuable`]: https://docs.rs/valuable/latest/valuable/trait.Valuable.html
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#[cfg(all(tracing_unstable, feature = "valuable"))]
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#[cfg_attr(docsrs, doc(cfg(all(tracing_unstable, feature = "valuable"))))]
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pub fn valuable<T>(t: &T) -> valuable::Value<'_>
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where
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T: valuable::Valuable,
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{
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t.as_value()
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}
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// ===== impl Visit =====
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impl<'a, 'b> Visit for fmt::DebugStruct<'a, 'b> {
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fn record_debug(&mut self, field: &Field, value: &dyn fmt::Debug) {
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self.field(field.name(), value);
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}
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}
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impl<'a, 'b> Visit for fmt::DebugMap<'a, 'b> {
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fn record_debug(&mut self, field: &Field, value: &dyn fmt::Debug) {
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self.entry(&format_args!("{}", field), value);
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}
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}
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impl<F> Visit for F
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where
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F: FnMut(&Field, &dyn fmt::Debug),
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{
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fn record_debug(&mut self, field: &Field, value: &dyn fmt::Debug) {
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(self)(field, value)
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}
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}
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|
// ===== impl Value =====
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macro_rules! impl_values {
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( $( $record:ident( $( $whatever:tt)+ ) ),+ ) => {
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$(
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impl_value!{ $record( $( $whatever )+ ) }
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)+
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}
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}
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|
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|
macro_rules! ty_to_nonzero {
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|
(u8) => {
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|
NonZeroU8
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|
};
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|
(u16) => {
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|
NonZeroU16
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|
};
|
|
(u32) => {
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|
NonZeroU32
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|
};
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|
(u64) => {
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|
NonZeroU64
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|
};
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|
(u128) => {
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|
NonZeroU128
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|
};
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|
(usize) => {
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|
NonZeroUsize
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|
};
|
|
(i8) => {
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|
NonZeroI8
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|
};
|
|
(i16) => {
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|
NonZeroI16
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|
};
|
|
(i32) => {
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|
NonZeroI32
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|
};
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|
(i64) => {
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|
NonZeroI64
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|
};
|
|
(i128) => {
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|
NonZeroI128
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|
};
|
|
(isize) => {
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|
NonZeroIsize
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|
};
|
|
}
|
|
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|
macro_rules! impl_one_value {
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|
(f32, $op:expr, $record:ident) => {
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impl_one_value!(normal, f32, $op, $record);
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|
};
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|
(f64, $op:expr, $record:ident) => {
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|
impl_one_value!(normal, f64, $op, $record);
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|
};
|
|
(bool, $op:expr, $record:ident) => {
|
|
impl_one_value!(normal, bool, $op, $record);
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|
};
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|
($value_ty:tt, $op:expr, $record:ident) => {
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|
impl_one_value!(normal, $value_ty, $op, $record);
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|
impl_one_value!(nonzero, $value_ty, $op, $record);
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|
};
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|
(normal, $value_ty:tt, $op:expr, $record:ident) => {
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|
impl $crate::sealed::Sealed for $value_ty {}
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|
impl $crate::field::Value for $value_ty {
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|
fn record(&self, key: &$crate::field::Field, visitor: &mut dyn $crate::field::Visit) {
|
|
visitor.$record(key, $op(*self))
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|
}
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|
}
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|
};
|
|
(nonzero, $value_ty:tt, $op:expr, $record:ident) => {
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|
// This `use num::*;` is reported as unused because it gets emitted
|
|
// for every single invocation of this macro, so there are multiple `use`s.
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|
// All but the first are useless indeed.
|
|
// We need this import because we can't write a path where one part is
|
|
// the `ty_to_nonzero!($value_ty)` invocation.
|
|
#[allow(clippy::useless_attribute, unused)]
|
|
use num::*;
|
|
impl $crate::sealed::Sealed for ty_to_nonzero!($value_ty) {}
|
|
impl $crate::field::Value for ty_to_nonzero!($value_ty) {
|
|
fn record(&self, key: &$crate::field::Field, visitor: &mut dyn $crate::field::Visit) {
|
|
visitor.$record(key, $op(self.get()))
|
|
}
|
|
}
|
|
};
|
|
}
|
|
|
|
macro_rules! impl_value {
|
|
( $record:ident( $( $value_ty:tt ),+ ) ) => {
|
|
$(
|
|
impl_one_value!($value_ty, |this: $value_ty| this, $record);
|
|
)+
|
|
};
|
|
( $record:ident( $( $value_ty:tt ),+ as $as_ty:ty) ) => {
|
|
$(
|
|
impl_one_value!($value_ty, |this: $value_ty| this as $as_ty, $record);
|
|
)+
|
|
};
|
|
}
|
|
|
|
// ===== impl Value =====
|
|
|
|
impl_values! {
|
|
record_u64(u64),
|
|
record_u64(usize, u32, u16, u8 as u64),
|
|
record_i64(i64),
|
|
record_i64(isize, i32, i16, i8 as i64),
|
|
record_bool(bool),
|
|
record_f64(f64, f32 as f64)
|
|
}
|
|
|
|
impl<T: crate::sealed::Sealed> crate::sealed::Sealed for Wrapping<T> {}
|
|
impl<T: crate::field::Value> crate::field::Value for Wrapping<T> {
|
|
fn record(&self, key: &crate::field::Field, visitor: &mut dyn crate::field::Visit) {
|
|
self.0.record(key, visitor)
|
|
}
|
|
}
|
|
|
|
impl crate::sealed::Sealed for str {}
|
|
|
|
impl Value for str {
|
|
fn record(&self, key: &Field, visitor: &mut dyn Visit) {
|
|
visitor.record_str(key, self)
|
|
}
|
|
}
|
|
|
|
#[cfg(feature = "std")]
|
|
impl crate::sealed::Sealed for dyn std::error::Error + 'static {}
|
|
|
|
#[cfg(feature = "std")]
|
|
#[cfg_attr(docsrs, doc(cfg(feature = "std")))]
|
|
impl Value for dyn std::error::Error + 'static {
|
|
fn record(&self, key: &Field, visitor: &mut dyn Visit) {
|
|
visitor.record_error(key, self)
|
|
}
|
|
}
|
|
|
|
impl<'a, T: ?Sized> crate::sealed::Sealed for &'a T where T: Value + crate::sealed::Sealed + 'a {}
|
|
|
|
impl<'a, T: ?Sized> Value for &'a T
|
|
where
|
|
T: Value + 'a,
|
|
{
|
|
fn record(&self, key: &Field, visitor: &mut dyn Visit) {
|
|
(*self).record(key, visitor)
|
|
}
|
|
}
|
|
|
|
impl<'a, T: ?Sized> crate::sealed::Sealed for &'a mut T where T: Value + crate::sealed::Sealed + 'a {}
|
|
|
|
impl<'a, T: ?Sized> Value for &'a mut T
|
|
where
|
|
T: Value + 'a,
|
|
{
|
|
fn record(&self, key: &Field, visitor: &mut dyn Visit) {
|
|
// Don't use `(*self).record(key, visitor)`, otherwise would
|
|
// cause stack overflow due to `unconditional_recursion`.
|
|
T::record(self, key, visitor)
|
|
}
|
|
}
|
|
|
|
impl<'a> crate::sealed::Sealed for fmt::Arguments<'a> {}
|
|
|
|
impl<'a> Value for fmt::Arguments<'a> {
|
|
fn record(&self, key: &Field, visitor: &mut dyn Visit) {
|
|
visitor.record_debug(key, self)
|
|
}
|
|
}
|
|
|
|
impl fmt::Debug for dyn Value {
|
|
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
|
|
// We are only going to be recording the field value, so we don't
|
|
// actually care about the field name here.
|
|
struct NullCallsite;
|
|
static NULL_CALLSITE: NullCallsite = NullCallsite;
|
|
impl crate::callsite::Callsite for NullCallsite {
|
|
fn set_interest(&self, _: crate::subscriber::Interest) {
|
|
unreachable!("you somehow managed to register the null callsite?")
|
|
}
|
|
|
|
fn metadata(&self) -> &crate::Metadata<'_> {
|
|
unreachable!("you somehow managed to access the null callsite?")
|
|
}
|
|
}
|
|
|
|
static FIELD: Field = Field {
|
|
i: 0,
|
|
fields: FieldSet::new(&[], crate::identify_callsite!(&NULL_CALLSITE)),
|
|
};
|
|
|
|
let mut res = Ok(());
|
|
self.record(&FIELD, &mut |_: &Field, val: &dyn fmt::Debug| {
|
|
res = write!(f, "{:?}", val);
|
|
});
|
|
res
|
|
}
|
|
}
|
|
|
|
impl fmt::Display for dyn Value {
|
|
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
|
|
fmt::Debug::fmt(self, f)
|
|
}
|
|
}
|
|
|
|
// ===== impl DisplayValue =====
|
|
|
|
impl<T: fmt::Display> crate::sealed::Sealed for DisplayValue<T> {}
|
|
|
|
impl<T> Value for DisplayValue<T>
|
|
where
|
|
T: fmt::Display,
|
|
{
|
|
fn record(&self, key: &Field, visitor: &mut dyn Visit) {
|
|
visitor.record_debug(key, &format_args!("{}", self.0))
|
|
}
|
|
}
|
|
|
|
impl<T: fmt::Display> fmt::Debug for DisplayValue<T> {
|
|
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
|
|
write!(f, "{}", self.0)
|
|
}
|
|
}
|
|
|
|
impl<T: fmt::Display> fmt::Display for DisplayValue<T> {
|
|
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
|
|
fmt::Display::fmt(&self.0, f)
|
|
}
|
|
}
|
|
|
|
// ===== impl DebugValue =====
|
|
|
|
impl<T: fmt::Debug> crate::sealed::Sealed for DebugValue<T> {}
|
|
|
|
impl<T> Value for DebugValue<T>
|
|
where
|
|
T: fmt::Debug,
|
|
{
|
|
fn record(&self, key: &Field, visitor: &mut dyn Visit) {
|
|
visitor.record_debug(key, &self.0)
|
|
}
|
|
}
|
|
|
|
impl<T: fmt::Debug> fmt::Debug for DebugValue<T> {
|
|
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
|
|
write!(f, "{:?}", self.0)
|
|
}
|
|
}
|
|
|
|
// ===== impl ValuableValue =====
|
|
|
|
#[cfg(all(tracing_unstable, feature = "valuable"))]
|
|
impl crate::sealed::Sealed for valuable::Value<'_> {}
|
|
|
|
#[cfg(all(tracing_unstable, feature = "valuable"))]
|
|
#[cfg_attr(docsrs, doc(cfg(all(tracing_unstable, feature = "valuable"))))]
|
|
impl Value for valuable::Value<'_> {
|
|
fn record(&self, key: &Field, visitor: &mut dyn Visit) {
|
|
visitor.record_value(key, *self)
|
|
}
|
|
}
|
|
|
|
#[cfg(all(tracing_unstable, feature = "valuable"))]
|
|
impl crate::sealed::Sealed for &'_ dyn valuable::Valuable {}
|
|
|
|
#[cfg(all(tracing_unstable, feature = "valuable"))]
|
|
#[cfg_attr(docsrs, doc(cfg(all(tracing_unstable, feature = "valuable"))))]
|
|
impl Value for &'_ dyn valuable::Valuable {
|
|
fn record(&self, key: &Field, visitor: &mut dyn Visit) {
|
|
visitor.record_value(key, self.as_value())
|
|
}
|
|
}
|
|
|
|
impl crate::sealed::Sealed for Empty {}
|
|
impl Value for Empty {
|
|
#[inline]
|
|
fn record(&self, _: &Field, _: &mut dyn Visit) {}
|
|
}
|
|
|
|
impl<T: Value> crate::sealed::Sealed for Option<T> {}
|
|
|
|
impl<T: Value> Value for Option<T> {
|
|
fn record(&self, key: &Field, visitor: &mut dyn Visit) {
|
|
if let Some(v) = &self {
|
|
v.record(key, visitor)
|
|
}
|
|
}
|
|
}
|
|
|
|
// ===== impl Field =====
|
|
|
|
impl Field {
|
|
/// Returns an [`Identifier`] that uniquely identifies the [`Callsite`]
|
|
/// which defines this field.
|
|
///
|
|
/// [`Identifier`]: ../callsite/struct.Identifier.html
|
|
/// [`Callsite`]: ../callsite/trait.Callsite.html
|
|
#[inline]
|
|
pub fn callsite(&self) -> callsite::Identifier {
|
|
self.fields.callsite()
|
|
}
|
|
|
|
/// Returns a string representing the name of the field.
|
|
pub fn name(&self) -> &'static str {
|
|
self.fields.names[self.i]
|
|
}
|
|
}
|
|
|
|
impl fmt::Display for Field {
|
|
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
|
|
f.pad(self.name())
|
|
}
|
|
}
|
|
|
|
impl AsRef<str> for Field {
|
|
fn as_ref(&self) -> &str {
|
|
self.name()
|
|
}
|
|
}
|
|
|
|
impl PartialEq for Field {
|
|
fn eq(&self, other: &Self) -> bool {
|
|
self.callsite() == other.callsite() && self.i == other.i
|
|
}
|
|
}
|
|
|
|
impl Eq for Field {}
|
|
|
|
impl Hash for Field {
|
|
fn hash<H>(&self, state: &mut H)
|
|
where
|
|
H: Hasher,
|
|
{
|
|
self.callsite().hash(state);
|
|
self.i.hash(state);
|
|
}
|
|
}
|
|
|
|
impl Clone for Field {
|
|
fn clone(&self) -> Self {
|
|
Field {
|
|
i: self.i,
|
|
fields: FieldSet {
|
|
names: self.fields.names,
|
|
callsite: self.fields.callsite(),
|
|
},
|
|
}
|
|
}
|
|
}
|
|
|
|
// ===== impl FieldSet =====
|
|
|
|
impl FieldSet {
|
|
/// Constructs a new `FieldSet` with the given array of field names and callsite.
|
|
pub const fn new(names: &'static [&'static str], callsite: callsite::Identifier) -> Self {
|
|
Self { names, callsite }
|
|
}
|
|
|
|
/// Returns an [`Identifier`] that uniquely identifies the [`Callsite`]
|
|
/// which defines this set of fields..
|
|
///
|
|
/// [`Identifier`]: ../callsite/struct.Identifier.html
|
|
/// [`Callsite`]: ../callsite/trait.Callsite.html
|
|
pub(crate) fn callsite(&self) -> callsite::Identifier {
|
|
callsite::Identifier(self.callsite.0)
|
|
}
|
|
|
|
/// Returns the [`Field`] named `name`, or `None` if no such field exists.
|
|
///
|
|
/// [`Field`]: ../struct.Field.html
|
|
pub fn field<Q: ?Sized>(&self, name: &Q) -> Option<Field>
|
|
where
|
|
Q: Borrow<str>,
|
|
{
|
|
let name = &name.borrow();
|
|
self.names.iter().position(|f| f == name).map(|i| Field {
|
|
i,
|
|
fields: FieldSet {
|
|
names: self.names,
|
|
callsite: self.callsite(),
|
|
},
|
|
})
|
|
}
|
|
|
|
/// Returns `true` if `self` contains the given `field`.
|
|
///
|
|
/// <div class="example-wrap" style="display:inline-block">
|
|
/// <pre class="ignore" style="white-space:normal;font:inherit;">
|
|
/// <strong>Note</strong>: If <code>field</code> shares a name with a field
|
|
/// in this <code>FieldSet</code>, but was created by a <code>FieldSet</code>
|
|
/// with a different callsite, this <code>FieldSet</code> does <em>not</em>
|
|
/// contain it. This is so that if two separate span callsites define a field
|
|
/// named "foo", the <code>Field</code> corresponding to "foo" for each
|
|
/// of those callsites are not equivalent.
|
|
/// </pre></div>
|
|
pub fn contains(&self, field: &Field) -> bool {
|
|
field.callsite() == self.callsite() && field.i <= self.len()
|
|
}
|
|
|
|
/// Returns an iterator over the `Field`s in this `FieldSet`.
|
|
pub fn iter(&self) -> Iter {
|
|
let idxs = 0..self.len();
|
|
Iter {
|
|
idxs,
|
|
fields: FieldSet {
|
|
names: self.names,
|
|
callsite: self.callsite(),
|
|
},
|
|
}
|
|
}
|
|
|
|
/// Returns a new `ValueSet` with entries for this `FieldSet`'s values.
|
|
///
|
|
/// Note that a `ValueSet` may not be constructed with arrays of over 32
|
|
/// elements.
|
|
#[doc(hidden)]
|
|
pub fn value_set<'v, V>(&'v self, values: &'v V) -> ValueSet<'v>
|
|
where
|
|
V: ValidLen<'v>,
|
|
{
|
|
ValueSet {
|
|
fields: self,
|
|
values: values.borrow(),
|
|
}
|
|
}
|
|
|
|
/// Returns the number of fields in this `FieldSet`.
|
|
#[inline]
|
|
pub fn len(&self) -> usize {
|
|
self.names.len()
|
|
}
|
|
|
|
/// Returns whether or not this `FieldSet` has fields.
|
|
#[inline]
|
|
pub fn is_empty(&self) -> bool {
|
|
self.names.is_empty()
|
|
}
|
|
}
|
|
|
|
impl<'a> IntoIterator for &'a FieldSet {
|
|
type IntoIter = Iter;
|
|
type Item = Field;
|
|
#[inline]
|
|
fn into_iter(self) -> Self::IntoIter {
|
|
self.iter()
|
|
}
|
|
}
|
|
|
|
impl fmt::Debug for FieldSet {
|
|
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
|
|
f.debug_struct("FieldSet")
|
|
.field("names", &self.names)
|
|
.field("callsite", &self.callsite)
|
|
.finish()
|
|
}
|
|
}
|
|
|
|
impl fmt::Display for FieldSet {
|
|
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
|
|
f.debug_set()
|
|
.entries(self.names.iter().map(display))
|
|
.finish()
|
|
}
|
|
}
|
|
|
|
// ===== impl Iter =====
|
|
|
|
impl Iterator for Iter {
|
|
type Item = Field;
|
|
fn next(&mut self) -> Option<Field> {
|
|
let i = self.idxs.next()?;
|
|
Some(Field {
|
|
i,
|
|
fields: FieldSet {
|
|
names: self.fields.names,
|
|
callsite: self.fields.callsite(),
|
|
},
|
|
})
|
|
}
|
|
}
|
|
|
|
// ===== impl ValueSet =====
|
|
|
|
impl<'a> ValueSet<'a> {
|
|
/// Returns an [`Identifier`] that uniquely identifies the [`Callsite`]
|
|
/// defining the fields this `ValueSet` refers to.
|
|
///
|
|
/// [`Identifier`]: ../callsite/struct.Identifier.html
|
|
/// [`Callsite`]: ../callsite/trait.Callsite.html
|
|
#[inline]
|
|
pub fn callsite(&self) -> callsite::Identifier {
|
|
self.fields.callsite()
|
|
}
|
|
|
|
/// Visits all the fields in this `ValueSet` with the provided [visitor].
|
|
///
|
|
/// [visitor]: ../trait.Visit.html
|
|
pub(crate) fn record(&self, visitor: &mut dyn Visit) {
|
|
let my_callsite = self.callsite();
|
|
for (field, value) in self.values {
|
|
if field.callsite() != my_callsite {
|
|
continue;
|
|
}
|
|
if let Some(value) = value {
|
|
value.record(field, visitor);
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Returns `true` if this `ValueSet` contains a value for the given `Field`.
|
|
pub(crate) fn contains(&self, field: &Field) -> bool {
|
|
field.callsite() == self.callsite()
|
|
&& self
|
|
.values
|
|
.iter()
|
|
.any(|(key, val)| *key == field && val.is_some())
|
|
}
|
|
|
|
/// Returns true if this `ValueSet` contains _no_ values.
|
|
pub(crate) fn is_empty(&self) -> bool {
|
|
let my_callsite = self.callsite();
|
|
self.values
|
|
.iter()
|
|
.all(|(key, val)| val.is_none() || key.callsite() != my_callsite)
|
|
}
|
|
|
|
pub(crate) fn field_set(&self) -> &FieldSet {
|
|
self.fields
|
|
}
|
|
}
|
|
|
|
impl<'a> fmt::Debug for ValueSet<'a> {
|
|
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
|
|
self.values
|
|
.iter()
|
|
.fold(&mut f.debug_struct("ValueSet"), |dbg, (key, v)| {
|
|
if let Some(val) = v {
|
|
val.record(key, dbg);
|
|
}
|
|
dbg
|
|
})
|
|
.field("callsite", &self.callsite())
|
|
.finish()
|
|
}
|
|
}
|
|
|
|
impl<'a> fmt::Display for ValueSet<'a> {
|
|
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
|
|
self.values
|
|
.iter()
|
|
.fold(&mut f.debug_map(), |dbg, (key, v)| {
|
|
if let Some(val) = v {
|
|
val.record(key, dbg);
|
|
}
|
|
dbg
|
|
})
|
|
.finish()
|
|
}
|
|
}
|
|
|
|
// ===== impl ValidLen =====
|
|
|
|
mod private {
|
|
use super::*;
|
|
|
|
/// Marker trait implemented by arrays which are of valid length to
|
|
/// construct a `ValueSet`.
|
|
///
|
|
/// `ValueSet`s may only be constructed from arrays containing 32 or fewer
|
|
/// elements, to ensure the array is small enough to always be allocated on the
|
|
/// stack. This trait is only implemented by arrays of an appropriate length,
|
|
/// ensuring that the correct size arrays are used at compile-time.
|
|
pub trait ValidLen<'a>: Borrow<[(&'a Field, Option<&'a (dyn Value + 'a)>)]> {}
|
|
}
|
|
|
|
macro_rules! impl_valid_len {
|
|
( $( $len:tt ),+ ) => {
|
|
$(
|
|
impl<'a> private::ValidLen<'a> for
|
|
[(&'a Field, Option<&'a (dyn Value + 'a)>); $len] {}
|
|
)+
|
|
}
|
|
}
|
|
|
|
impl_valid_len! {
|
|
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20,
|
|
21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32
|
|
}
|
|
|
|
#[cfg(test)]
|
|
mod test {
|
|
use super::*;
|
|
use crate::metadata::{Kind, Level, Metadata};
|
|
use crate::stdlib::{borrow::ToOwned, string::String};
|
|
|
|
struct TestCallsite1;
|
|
static TEST_CALLSITE_1: TestCallsite1 = TestCallsite1;
|
|
static TEST_META_1: Metadata<'static> = metadata! {
|
|
name: "field_test1",
|
|
target: module_path!(),
|
|
level: Level::INFO,
|
|
fields: &["foo", "bar", "baz"],
|
|
callsite: &TEST_CALLSITE_1,
|
|
kind: Kind::SPAN,
|
|
};
|
|
|
|
impl crate::callsite::Callsite for TestCallsite1 {
|
|
fn set_interest(&self, _: crate::subscriber::Interest) {
|
|
unimplemented!()
|
|
}
|
|
|
|
fn metadata(&self) -> &Metadata<'_> {
|
|
&TEST_META_1
|
|
}
|
|
}
|
|
|
|
struct TestCallsite2;
|
|
static TEST_CALLSITE_2: TestCallsite2 = TestCallsite2;
|
|
static TEST_META_2: Metadata<'static> = metadata! {
|
|
name: "field_test2",
|
|
target: module_path!(),
|
|
level: Level::INFO,
|
|
fields: &["foo", "bar", "baz"],
|
|
callsite: &TEST_CALLSITE_2,
|
|
kind: Kind::SPAN,
|
|
};
|
|
|
|
impl crate::callsite::Callsite for TestCallsite2 {
|
|
fn set_interest(&self, _: crate::subscriber::Interest) {
|
|
unimplemented!()
|
|
}
|
|
|
|
fn metadata(&self) -> &Metadata<'_> {
|
|
&TEST_META_2
|
|
}
|
|
}
|
|
|
|
#[test]
|
|
fn value_set_with_no_values_is_empty() {
|
|
let fields = TEST_META_1.fields();
|
|
let values = &[
|
|
(&fields.field("foo").unwrap(), None),
|
|
(&fields.field("bar").unwrap(), None),
|
|
(&fields.field("baz").unwrap(), None),
|
|
];
|
|
let valueset = fields.value_set(values);
|
|
assert!(valueset.is_empty());
|
|
}
|
|
|
|
#[test]
|
|
fn empty_value_set_is_empty() {
|
|
let fields = TEST_META_1.fields();
|
|
let valueset = fields.value_set(&[]);
|
|
assert!(valueset.is_empty());
|
|
}
|
|
|
|
#[test]
|
|
fn value_sets_with_fields_from_other_callsites_are_empty() {
|
|
let fields = TEST_META_1.fields();
|
|
let values = &[
|
|
(&fields.field("foo").unwrap(), Some(&1 as &dyn Value)),
|
|
(&fields.field("bar").unwrap(), Some(&2 as &dyn Value)),
|
|
(&fields.field("baz").unwrap(), Some(&3 as &dyn Value)),
|
|
];
|
|
let valueset = TEST_META_2.fields().value_set(values);
|
|
assert!(valueset.is_empty())
|
|
}
|
|
|
|
#[test]
|
|
fn sparse_value_sets_are_not_empty() {
|
|
let fields = TEST_META_1.fields();
|
|
let values = &[
|
|
(&fields.field("foo").unwrap(), None),
|
|
(&fields.field("bar").unwrap(), Some(&57 as &dyn Value)),
|
|
(&fields.field("baz").unwrap(), None),
|
|
];
|
|
let valueset = fields.value_set(values);
|
|
assert!(!valueset.is_empty());
|
|
}
|
|
|
|
#[test]
|
|
fn fields_from_other_callsets_are_skipped() {
|
|
let fields = TEST_META_1.fields();
|
|
let values = &[
|
|
(&fields.field("foo").unwrap(), None),
|
|
(
|
|
&TEST_META_2.fields().field("bar").unwrap(),
|
|
Some(&57 as &dyn Value),
|
|
),
|
|
(&fields.field("baz").unwrap(), None),
|
|
];
|
|
|
|
struct MyVisitor;
|
|
impl Visit for MyVisitor {
|
|
fn record_debug(&mut self, field: &Field, _: &dyn (crate::stdlib::fmt::Debug)) {
|
|
assert_eq!(field.callsite(), TEST_META_1.callsite())
|
|
}
|
|
}
|
|
let valueset = fields.value_set(values);
|
|
valueset.record(&mut MyVisitor);
|
|
}
|
|
|
|
#[test]
|
|
fn empty_fields_are_skipped() {
|
|
let fields = TEST_META_1.fields();
|
|
let values = &[
|
|
(&fields.field("foo").unwrap(), Some(&Empty as &dyn Value)),
|
|
(&fields.field("bar").unwrap(), Some(&57 as &dyn Value)),
|
|
(&fields.field("baz").unwrap(), Some(&Empty as &dyn Value)),
|
|
];
|
|
|
|
struct MyVisitor;
|
|
impl Visit for MyVisitor {
|
|
fn record_debug(&mut self, field: &Field, _: &dyn (crate::stdlib::fmt::Debug)) {
|
|
assert_eq!(field.name(), "bar")
|
|
}
|
|
}
|
|
let valueset = fields.value_set(values);
|
|
valueset.record(&mut MyVisitor);
|
|
}
|
|
|
|
#[test]
|
|
fn record_debug_fn() {
|
|
let fields = TEST_META_1.fields();
|
|
let values = &[
|
|
(&fields.field("foo").unwrap(), Some(&1 as &dyn Value)),
|
|
(&fields.field("bar").unwrap(), Some(&2 as &dyn Value)),
|
|
(&fields.field("baz").unwrap(), Some(&3 as &dyn Value)),
|
|
];
|
|
let valueset = fields.value_set(values);
|
|
let mut result = String::new();
|
|
valueset.record(&mut |_: &Field, value: &dyn fmt::Debug| {
|
|
use crate::stdlib::fmt::Write;
|
|
write!(&mut result, "{:?}", value).unwrap();
|
|
});
|
|
assert_eq!(result, "123".to_owned());
|
|
}
|
|
}
|