Crate sp_tracing

Substrate tracing primitives and macros.

To trace functions or invidual code in Substrate, this crate provides within_span and enter_span. See the individual docs for how to use these macros.

Note that to allow traces from wasm execution environment there are 2 reserved identifiers for tracing Field recording, stored in the consts: WASM_TARGET_KEY and WASM_NAME_KEY - if you choose to record fields, you must ensure that your identifiers do not clash with either of these.

Additionally, we have a const: WASM_TRACE_IDENTIFIER, which holds a span name used to signal that the ‘actual’ span name and target should be retrieved instead from the associated Fields mentioned above.

Modules

event	Events represent single points in time during the execution of a program.
span	Spans represent periods of time in which a program was executing in a particular context.

Macros

debug	Constructs an event at the debug level.
debug_span	Constructs a span at the debug level.
enter_span	Enter a span.
error	Constructs an event at the error level.
error_span	Constructs a span at the error level.
event	Constructs a new Event.
info	Constructs an event at the info level.
info_span	Constructs a span at the info level.
span	Constructs a new span.
trace	Constructs an event at the trace level.
trace_span	Constructs a span at the trace level.
warn	Constructs an event at the warn level.
warn_span	Constructs a span at the warn level.
within_span	Runs given code within a tracing span, measuring it’s execution time.

Structs

Level	Describes the level of verbosity of a span or event.
Span	A handle representing a span, with the capability to enter the span if it exists.
WasmEntryAttributes	Span or Event Attributes
WasmFieldName	The name of a field provided as the argument name when contstructing an event! or span!. Generally generated automaticaly via stringify from an 'static &str. Likely print-able.
WasmFields	A list of WasmFieldNames in the order provided
WasmMetadata	Metadata provides generic information about the specifc location of the span! or event! call on the wasm-side.
WasmValuesSet	A list of WasmFieldNames with the given WasmValue (if provided) in the order specified.

Enums

WasmLevel	The Tracing Level – the user can filter by this
WasmValue	A paramter value provided to the span/event

Statics

WASM_NAME_KEY	The fieldname for the wasm-originated name
WASM_TARGET_KEY	The fieldname for the wasm-originated target
WASM_TRACE_IDENTIFIER	The identifier we are using to inject the wasm events in the generic tracing system

Functions

try_init_simple

Try to init a simple tracing subscriber with log compatibility layer. Ignores any error. Useful for testing.