[−][src]Crate tracing_core
Core primitives for tracing
.
tracing
is a framework for instrumenting Rust programs to collect
structured, event-based diagnostic information. This crate defines the core
primitives of tracing
.
This crate provides:
-
span::Id
identifies a span within the execution of a program. -
Event
represents a single event within a trace. -
Subscriber
, the trait implemented to collect trace data. -
Metadata
andCallsite
provide information describing spans andEvent
s. -
Field
,FieldSet
,Value
, andValueSet
represent the structured data attached to a span. -
Dispatch
allows spans and events to be dispatched toSubscriber
s.
In addition, it defines the global callsite registry and per-thread current dispatcher which other components of the tracing system rely on.
Usage
Application authors will typically not use this crate directly. Instead,
they will use the tracing
crate, which provides a much more
fully-featured API. However, this crate's API will change very infrequently,
so it may be used when dependencies must be very stable.
Subscriber
implementations may depend on tracing-core
rather than
tracing
, as the additional APIs provided by tracing
are primarily useful
for instrumenting libraries and applications, and are generally not
necessary for Subscriber
implementations.
The tokio-rs/tracing
repository contains less stable crates designed to
be used with the tracing
ecosystem. It includes a collection of
Subscriber
implementations, as well as utility and adapter crates.
Crate Feature Flags
The following crate feature flags are available:
-
std
: Depend on the Rust standard library (enabled by default).no_std
users may disable this feature withdefault-features = false
:[dependencies] tracing-core = { version = "0.1.9", default-features = false }
Compiler support: requires rustc 1.39+
Note:
tracing-core
'sno_std
support requiresliballoc
.
Re-exports
pub use self::metadata::Kind; |
pub use self::subscriber::Interest; |
Modules
callsite | Callsites represent the source locations from which spans or events originate. |
dispatcher | Dispatches trace events to |
event | Events represent single points in time during the execution of a program. |
field | Span and |
metadata | Metadata describing trace data. |
span | Spans represent periods of time in the execution of a program. |
subscriber | Subscribers collect and record trace data. |
Macros
identify_callsite | Statically constructs an |
metadata | Statically constructs new span metadata. |
Structs
Dispatch |
|
Event |
|
Field | An opaque key allowing O(1) access to a field in a |
Level | Describes the level of verbosity of a span or event. |
Metadata |
Traits
Callsite | Trait implemented by callsites. |
Subscriber | Trait representing the functions required to collect trace data. |