Add ability to use a custom sampler

Author: cetra3

src/config.rs

@@ -12,7 +12,7 @@ use std::{
 use opentelemetry_sdk::{
     logs::LogProcessor,
     metrics::reader::MetricReader,
-    trace::{IdGenerator, SpanProcessor},
+    trace::{IdGenerator, ShouldSample, SpanProcessor, TracerProviderBuilder},
 };
 use regex::Regex;
 use tracing::{Level, level_filters::LevelFilter};
@@ -373,12 +373,12 @@ pub struct AdvancedOptions {
     pub(crate) resources: Vec<opentelemetry_sdk::Resource>,
     pub(crate) log_record_processors: Vec<BoxedLogProcessor>,
     pub(crate) enable_tracing_metrics: bool,
-    //
-    //
-    // TODO: arguments below supported by Python
+    pub(crate) trace_provider: TracerProviderBuilder, //
+                                                      //
+                                                      // TODO: arguments below supported by Python
 
-    // /// Generator for nanosecond start and end timestamps of spans.
-    // pub ns_timestamp_generator: Option,
+                                                      // /// Generator for nanosecond start and end timestamps of spans.
+                                                      // pub ns_timestamp_generator: Option,
 }
 
 impl AdvancedOptions {
@@ -418,6 +418,13 @@ impl AdvancedOptions {
         self
     }
 
+    /// Add a custom sampler implementation
+    #[must_use]
+    pub fn with_sampler<T: ShouldSample + 'static>(mut self, sampler: T) -> Self {
+        self.trace_provider = self.trace_provider.with_sampler(sampler);
+        self
+    }
+
     /// Support capturing tracing events as metrics as per [`tracing_opentelemetry::MetricsLayer`](https://docs.rs/tracing-opentelemetry/latest/tracing_opentelemetry/struct.MetricsLayer.html).
     #[must_use]
     pub fn with_tracing_metrics(mut self, enable: bool) -> Self {

src/logfire.rs

@@ -290,7 +290,7 @@ impl Logfire {
             SendToLogfire::No => false,
         };
 
-        let mut tracer_provider_builder = SdkTracerProvider::builder();
+        let mut tracer_provider_builder = advanced_options.trace_provider;
         let mut logger_provider_builder = SdkLoggerProvider::builder();
         let mut meter_provider_builder = SdkMeterProvider::builder();