Crate tracing_ext_ffi_subscriber

A simple crate for passing spans generated by the tracing ecosystem to a C or C++ profiling system when Rust is integrated into an existing framework. To help with integration into other tools you can use the environment variable TRACING_FFI_RELATIVE_OUT_DIR to configure where the include file ends relative to the build output (OUT_DIR). For example, TRACING_FFI_RELATIVE_OUT_DIR = "../../../../../include" will normally lead to the files being generated in an include dir next to your Cargo.toml.

Example usage

#include <Profiling.h>
#include <tracing_ffi.h>
#include <myrustlib.h>

int main(int argc, const char* argv[]) {
    tracing_ffi_ReturnCode result = tracing_ffi_install_global_with_enable(
        profiling_begin_named_scope,
        profiling_end_named_scope,
        profiling_is_enabled,
    );

    if (result != tracing_ffi_ReturnCode_Success) {
        return (int)result;
    }

    myrustlib_execute(10, 20);

    profiling_write_file("profile.json");
}

You can of course also configure this from Rust code; and bypass the C-api. In that case, use subscriber::ExternFFISpanSubscriber directly, and install with your preferred tracing method.

Modules

subscriber

The subscriber implementation provided by tracing-ext-ffi-subscriber.

Enums

ReturnCode

Simple error codes used for FFI calls.

Functions

tracing_ffi_install_global^⚠

Install the tracing hook globally with the provided enter and exit functions.

tracing_ffi_install_global_with_enabled^⚠

Install the tracing hook globally with the provided enter, exit, and enabled functions.

Type Definitions

EndTraceScopeFn

Function to be called when exiting a tracing scope.

IsEnabledFn

Function to call to check whether tracing is enabled.

StartTraceScopeFn

Function to be called when entering a tracing scope.