time-graph provides always-on profiling for your code, allowing to record the execution time of functions, spans inside these functions and the full call graph of spans and functions at run-time.

Core concepts

There are two main concepts in this crate: [CallSite] identify a single call site in the source, usually a full function. One can then create a [Span] from any callsite, representing a single execution of the code. When executed, the [Span] will its elapsed time, and store it in the global call graph.

Controlling data collection

By default, no data is collected until you call [enable_data_collection] to start collecting timing data. Once you are done running your code, you can extract collected data with [get_full_graph], and possibly clear all collected data using [clear_collected_data].

Overhead and limitations

When data collection is disabled, this crate adds an overheard around 10 ns when calling a function or entering a span. With data collection enabled, this crate adds an overhead around 100 ns when calling a function or entering a span.

This makes this crate only useful for gathering profiling data on function/spans taking at least 1 µs to execute.

Crate features

This crate has two cargo features:

• json: enables json output format for the full call graph
• table: enables pretty-printing the full call graph to a table using term-table