Cache EventSet in User-Event exporter to avoid contention and other changes (#192)

Author: cijothomas

opentelemetry-user-events-logs/Cargo.toml

@@ -25,11 +25,17 @@ tracing = { version = "0.1", default-features = false, features = ["std"] }
 tracing-core = "0.1.31"
 tracing-subscriber = { version = "0.3.0", default-features = false, features = ["env-filter", "fmt", "registry", "std"] }
 ctrlc = "3.4"
+criterion = "0.5"
 
 [features]
 spec_unstable_logs_enabled = ["opentelemetry/spec_unstable_logs_enabled", "opentelemetry_sdk/spec_unstable_logs_enabled", "opentelemetry-appender-tracing/spec_unstable_logs_enabled"]
 internal-logs = ["tracing", "opentelemetry/internal-logs", "opentelemetry_sdk/internal-logs"]
 default = ["internal-logs"]
 
+[[bench]]
+name = "logs"
+harness = false
+required-features = ["spec_unstable_logs_enabled"]
+
 [lints]
 workspace = true

opentelemetry-user-events-logs/benches/logs.rs

@@ -0,0 +1,88 @@
+/*
+    The benchmark results:
+    criterion = "0.5.1"
+
+    Hardware: Apple M4 Pro
+    Total Number of Cores:	10
+    (Inside multipass vm running Ubuntu 22.04)
+    // When no listener
+    | Test                        | Average time|
+    |-----------------------------|-------------|
+    | User_Event_4_Attributes     | 10 ns       |
+    | User_Event_6_Attributes     | 10 ns       |
+
+    // When listener is enabled
+    // Run below to enable
+    //  echo 1 | sudo tee /sys/kernel/debug/tracing/events/user_events/myprovider_L2K1/enable
+    // Run below to disable
+    //  echo 0 | sudo tee /sys/kernel/debug/tracing/events/user_events/myprovider_L2K1/enable
+    | Test                        | Average time|
+    |-----------------------------|-------------|
+    | User_Event_4_Attributes     | 617 ns      |
+    | User_Event_6_Attributes     | 715 ns      |
+*/
+
+// running the following from the current directory
+// sudo -E ~/.cargo/bin/cargo bench --bench logs --all-features
+
+use criterion::{criterion_group, criterion_main, Criterion};
+use opentelemetry_appender_tracing::layer as tracing_layer;
+use opentelemetry_sdk::logs::SdkLoggerProvider;
+use opentelemetry_sdk::Resource;
+use opentelemetry_user_events_logs::UserEventsLoggerProviderBuilderExt;
+use tracing::error;
+use tracing_subscriber::prelude::*;
+use tracing_subscriber::Registry;
+
+fn benchmark_with_ot_layer(c: &mut Criterion, name: &str, num_attributes: usize) {
+    let provider = SdkLoggerProvider::builder()
+        .with_resource(
+            Resource::builder_empty()
+                .with_service_name("benchmark")
+                .build(),
+        )
+        .with_user_event_exporter("myprovider")
+        .build();
+    let ot_layer = tracing_layer::OpenTelemetryTracingBridge::new(&provider);
+    let subscriber = Registry::default().with(ot_layer);
+
+    tracing::subscriber::with_default(subscriber, || {
+        c.bench_function(name, |b| {
+            b.iter(|| {
+                if num_attributes == 4 {
+                    error!(
+                        name : "CheckoutFailed",
+                        field1 = "field1",
+                        field2 = "field2",
+                        field3 = "field3",
+                        field4 = "field4",
+                        message = "Unable to process checkout."
+                    );
+                } else if num_attributes == 6 {
+                    error!(
+                        name : "CheckoutFailed",
+                        field1 = "field1",
+                        field2 = "field2",
+                        field3 = "field3",
+                        field4 = "field4",
+                        field5 = "field5",
+                        field6 = "field6",
+                        message = "Unable to process checkout."
+                    );
+                }
+            });
+        });
+    });
+}
+
+fn criterion_benchmark(c: &mut Criterion) {
+    benchmark_with_ot_layer(c, "User_Event_4_Attributes", 4);
+    benchmark_with_ot_layer(c, "User_Event_6_Attributes", 6)
+}
+
+criterion_group! {
+    name = benches;
+    config = Criterion::default();
+    targets = criterion_benchmark
+}
+criterion_main!(benches);