opentelemetry-contrib api enhancements with new_span benchmark (#1232)

Author: shaun-cox

.cspell.json

@@ -25,6 +25,7 @@
     // these are words that are always correct and can be thought of as our
     // workspace dictionary.
     "words": [
+        "hasher",
         "opentelemetry",
         "OTLP",
         "quantile",

.gitignore

@@ -1,3 +1,4 @@
+/.vscode/
 /target/
 */target/
 **/*.rs.bk

opentelemetry-contrib/Cargo.toml

@@ -19,6 +19,7 @@ all-features = true
 rustdoc-args = ["--cfg", "docsrs"]
 
 [features]
+api = []
 default = []
 base64_format = ["base64", "binary_propagator"]
 binary_propagator = []
@@ -31,17 +32,24 @@ rt-async-std = ["async-std", "opentelemetry_sdk/rt-async-std"]
 async-std = { version = "1.10", optional = true }
 async-trait = { version = "0.1", optional = true }
 base64 = { version = "0.13", optional = true }
+futures-core = { version = "0.3", optional = true }
+futures-util = { version = "0.3", optional = true, default-features = false }
 once_cell = "1.17.1"
 opentelemetry = { version = "0.21", path = "../opentelemetry" }
-opentelemetry_sdk = { version = "0.20", path = "../opentelemetry-sdk" }
-opentelemetry-semantic-conventions = { version = "0.12", path = "../opentelemetry-semantic-conventions", optional = true }
+opentelemetry_sdk = { version = "0.20", optional = true, path = "../opentelemetry-sdk" }
+opentelemetry-semantic-conventions = { version = "0.12", optional = true, path = "../opentelemetry-semantic-conventions" }
 serde_json = { version = "1", optional = true }
 tokio = { version = "1.0", features = ["fs", "io-util"], optional = true }
 
-# futures
-futures-core = { version = "0.3", optional = true }
-futures-util = { version = "0.3", optional = true, default-features = false }
-
 [dev-dependencies]
 base64 = "0.13"
+criterion = { version = "0.5", features = ["html_reports"] }
+futures-util = { version = "0.3", default-features = false, features = ["std"] }
 opentelemetry_sdk = { path = "../opentelemetry-sdk", features = ["trace", "testing"] }
+[target.'cfg(not(target_os = "windows"))'.dev-dependencies]
+pprof = { version = "0.12", features = ["flamegraph", "criterion"] }
+
+[[bench]]
+name = "new_span"
+harness = false
+required-features = ["api"]

opentelemetry-contrib/benches/new_span.rs

@@ -0,0 +1,183 @@
+use criterion::{criterion_group, criterion_main, BenchmarkId, Criterion, Throughput};
+use futures_util::future::BoxFuture;
+use opentelemetry::{
+    global::BoxedTracer,
+    trace::{
+        mark_span_as_active, noop::NoopTracer, SpanBuilder, SpanContext, SpanId,
+        TraceContextExt as _, TraceFlags, TraceId, TraceState, Tracer as _, TracerProvider as _,
+    },
+    Context, ContextGuard,
+};
+use opentelemetry_contrib::trace::{
+    new_span_if_parent_sampled, new_span_if_recording, TracerSource,
+};
+use opentelemetry_sdk::{
+    export::trace::{ExportResult, SpanData, SpanExporter},
+    trace::{config, Sampler, TracerProvider},
+};
+#[cfg(not(target_os = "windows"))]
+use pprof::criterion::{Output, PProfProfiler};
+use std::fmt::Display;
+
+fn criterion_benchmark(c: &mut Criterion) {
+    let mut group = c.benchmark_group("new_span");
+    group.throughput(Throughput::Elements(1));
+    for env in [
+        Environment::InContext,
+        Environment::NoContext,
+        Environment::NoSdk,
+    ] {
+        let (_provider, tracer, _guard) = env.setup();
+
+        for api in [Api::Alt, Api::Spec] {
+            let param = format!("{env}/{api}");
+            group.bench_function(
+                BenchmarkId::new("if_parent_sampled", param.clone()),
+                // m2max, in-cx/alt: 530ns
+                // m2max, no-cx/alt: 5.9ns
+                // m2max, no-sdk/alt: 5.9ns
+                // m2max, in-cx/spec: 505ns
+                // m2max, no-cx/spec: 255ns
+                // m2max, no-sdk/spec: 170ns
+                |b| match api {
+                    Api::Alt => b.iter(|| {
+                        new_span_if_parent_sampled(
+                            || SpanBuilder::from_name("new_span"),
+                            TracerSource::borrowed(&tracer),
+                        )
+                        .map(|cx| cx.attach())
+                    }),
+                    Api::Spec => b.iter(|| mark_span_as_active(tracer.start("new_span"))),
+                },
+            );
+            group.bench_function(
+                BenchmarkId::new("if_recording", param.clone()),
+                // m2max, in-cx/alt: 8ns
+                // m2max, no-cx/alt: 5.9ns
+                // m2max, no-sdk/alt: 5.9ns
+                // m2max, in-cx/spec: 31ns
+                // m2max, no-cx/spec: 5.8ns
+                // m2max, no-sdk/spec: 5.7ns
+                |b| match api {
+                    Api::Alt => b.iter(|| {
+                        new_span_if_recording(
+                            || SpanBuilder::from_name("new_span"),
+                            TracerSource::borrowed(&tracer),
+                        )
+                        .map(|cx| cx.attach())
+                    }),
+                    Api::Spec => b.iter(|| {
+                        Context::current()
+                            .span()
+                            .is_recording()
+                            .then(|| mark_span_as_active(tracer.start("new_span")))
+                    }),
+                },
+            );
+        }
+    }
+}
+
+#[derive(Copy, Clone)]
+enum Api {
+    /// An alternative way which may be faster than what the spec recommends.
+    Alt,
+    /// The recommended way as proposed by the current opentelemetry specification.
+    Spec,
+}
+
+impl Api {
+    const fn as_str(self) -> &'static str {
+        match self {
+            Api::Alt => "alt",
+            Api::Spec => "spec",
+        }
+    }
+}
+
+impl Display for Api {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.as_str())
+    }
+}
+
+#[derive(Copy, Clone)]
+enum Environment {
+    /// There is an active span being sampled in the current context.
+    InContext,
+    /// There is no span in context (or there is not context).
+    NoContext,
+    /// An SDK has not been configured, so instrumentation should be noop.
+    NoSdk,
+}
+
+impl Environment {
+    const fn as_str(self) -> &'static str {
+        match self {
+            Environment::InContext => "in-cx",
+            Environment::NoContext => "no-cx",
+            Environment::NoSdk => "no-sdk",
+        }
+    }
+
+    fn setup(&self) -> (Option<TracerProvider>, BoxedTracer, Option<ContextGuard>) {
+        match self {
+            Environment::InContext => {
+                let guard = Context::current()
+                    .with_remote_span_context(SpanContext::new(
+                        TraceId::from(0x09251969),
+                        SpanId::from(0x08171969),
+                        TraceFlags::SAMPLED,
+                        true,
+                        TraceState::default(),
+                    ))
+                    .attach();
+                let (provider, tracer) = parent_sampled_tracer(Sampler::AlwaysOff);
+                (Some(provider), tracer, Some(guard))
+            }
+            Environment::NoContext => {
+                let (provider, tracer) = parent_sampled_tracer(Sampler::AlwaysOff);
+                (Some(provider), tracer, None)
+            }
+            Environment::NoSdk => (None, BoxedTracer::new(Box::new(NoopTracer::new())), None),
+        }
+    }
+}
+
+impl Display for Environment {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.as_str())
+    }
+}
+
+fn parent_sampled_tracer(inner_sampler: Sampler) -> (TracerProvider, BoxedTracer) {
+    let provider = TracerProvider::builder()
+        .with_config(config().with_sampler(Sampler::ParentBased(Box::new(inner_sampler))))
+        .with_simple_exporter(NoopExporter)
+        .build();
+    let tracer = provider.tracer(module_path!());
+    (provider, BoxedTracer::new(Box::new(tracer)))
+}
+
+#[derive(Debug)]
+struct NoopExporter;
+
+impl SpanExporter for NoopExporter {
+    fn export(&mut self, _spans: Vec<SpanData>) -> BoxFuture<'static, ExportResult> {
+        Box::pin(futures_util::future::ready(Ok(())))
+    }
+}
+
+#[cfg(not(target_os = "windows"))]
+criterion_group! {
+    name = benches;
+    config = Criterion::default().with_profiler(PProfProfiler::new(100, Output::Flamegraph(None)));
+    targets = criterion_benchmark
+}
+#[cfg(target_os = "windows")]
+criterion_group! {
+    name = benches;
+    config = Criterion::default();
+    targets = criterion_benchmark
+}
+criterion_main!(benches);

opentelemetry-contrib/src/trace/context.rs

@@ -0,0 +1,161 @@
+use super::TracerSource;
+use opentelemetry::{
+    trace::{SpanBuilder, TraceContextExt as _, Tracer as _},
+    Context,
+};
+use std::{
+    fmt::{Debug, Formatter},
+    ops::{Deref, DerefMut},
+};
+
+/// Lazily creates a new span only if the current context has an active span,
+/// which will used as the new span's parent.
+///
+/// This is useful for instrumenting library crates whose activities would be
+/// undesirable to see as root spans, by themselves, outside of any application
+/// context.
+///
+/// # Examples
+///
+/// ```
+/// use opentelemetry::trace::{SpanBuilder};
+/// use opentelemetry_contrib::trace::{new_span_if_parent_sampled, TracerSource};
+///
+/// fn my_lib_fn() {
+///     let _guard = new_span_if_parent_sampled(
+///         || SpanBuilder::from_name("my span"),
+///         TracerSource::lazy(&|| opentelemetry::global::tracer(module_path!())),
+///     )
+///     .map(|cx| cx.attach());
+/// }
+/// ```
+pub fn new_span_if_parent_sampled(
+    builder_fn: impl Fn() -> SpanBuilder,
+    tracer: TracerSource<'_>,
+) -> Option<Context> {
+    Context::map_current(|current| {
+        current.span().span_context().is_sampled().then(|| {
+            let builder = builder_fn();
+            let span = tracer.get().build_with_context(builder, current);
+            current.with_span(span)
+        })
+    })
+}
+
+/// Lazily creates a new span only if the current context has a recording span,
+/// which will used as the new span's parent.
+///
+/// This is useful for instrumenting library crates whose activities would be
+/// undesirable to see as root spans, by themselves, outside of any application
+/// context.
+///
+/// # Examples
+///
+/// ```
+/// use opentelemetry::trace::{SpanBuilder};
+/// use opentelemetry_contrib::trace::{new_span_if_recording, TracerSource};
+///
+/// fn my_lib_fn() {
+///     let _guard = new_span_if_recording(
+///         || SpanBuilder::from_name("my span"),
+///         TracerSource::lazy(&|| opentelemetry::global::tracer(module_path!())),
+///     )
+///     .map(|cx| cx.attach());
+/// }
+/// ```
+pub fn new_span_if_recording(
+    builder_fn: impl Fn() -> SpanBuilder,
+    tracer: TracerSource<'_>,
+) -> Option<Context> {
+    Context::map_current(|current| {
+        current.span().is_recording().then(|| {
+            let builder = builder_fn();
+            let span = tracer.get().build_with_context(builder, current);
+            current.with_span(span)
+        })
+    })
+}
+
+/// Carries anything with an optional `opentelemetry::Context`.
+///
+/// A `Contextualized<T>` is a smart pointer which owns and instance of `T` and
+/// dereferences to it automatically.  The instance of `T` and its associated
+/// optional `Context` can be reacquired using the `Into` trait for the associated
+/// tuple type.
+///
+/// This type is mostly useful when sending `T`'s through channels with logical
+/// context propagation.
+///
+/// # Examples
+///
+/// ```
+/// use opentelemetry::trace::{SpanBuilder, TraceContextExt as _};
+/// use opentelemetry_contrib::trace::{new_span_if_parent_sampled, Contextualized, TracerSource};
+
+/// enum Message{Command};
+/// let (tx, rx) = std::sync::mpsc::channel();
+///
+/// let cx = new_span_if_parent_sampled(
+///     || SpanBuilder::from_name("my command"),
+///     TracerSource::lazy(&|| opentelemetry::global::tracer(module_path!())),
+/// );
+/// tx.send(Contextualized::new(Message::Command, cx));
+///
+/// let msg = rx.recv().unwrap();
+/// let (msg, cx) = msg.into_inner();
+/// let _guard = cx.filter(|cx| cx.has_active_span()).map(|cx| {
+///     cx.span().add_event("command received", vec![]);
+///     cx.attach()
+/// });
+/// ```
+pub struct Contextualized<T>(T, Option<Context>);
+
+impl<T> Contextualized<T> {
+    /// Creates a new instance using the specified value and optional context.
+    pub fn new(value: T, cx: Option<Context>) -> Self {
+        Self(value, cx)
+    }
+
+    /// Creates a new instance using the specified value and current context if
+    /// it has an active span.
+    pub fn pass_thru(value: T) -> Self {
+        Self::new(
+            value,
+            Context::map_current(|current| current.has_active_span().then(|| current.clone())),
+        )
+    }
+
+    /// Convert self into its constituent parts, returning a tuple.
+    pub fn into_inner(self) -> (T, Option<Context>) {
+        (self.0, self.1)
+    }
+}
+
+impl<T: Clone> Clone for Contextualized<T> {
+    fn clone(&self) -> Self {
+        Self(self.0.clone(), self.1.clone())
+    }
+}
+
+impl<T: Debug> Debug for Contextualized<T> {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        f.debug_tuple("Contextualized")
+            .field(&self.0)
+            .field(&self.1)
+            .finish()
+    }
+}
+
+impl<T> Deref for Contextualized<T> {
+    type Target = T;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl<T> DerefMut for Contextualized<T> {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.0
+    }
+}