Remove Context from sync instruments (#1076)

Author: cijothomas

examples/metrics-basic/src/main.rs

@@ -1,5 +1,5 @@
 use opentelemetry_api::metrics::Unit;
-use opentelemetry_api::{metrics::MeterProvider as _, Context, KeyValue};
+use opentelemetry_api::{metrics::MeterProvider as _, KeyValue};
 use opentelemetry_sdk::metrics::{MeterProvider, PeriodicReader};
 use opentelemetry_sdk::{runtime, Resource};
 use std::error::Error;
@@ -29,7 +29,6 @@ async fn main() -> Result<(), Box<dyn Error + Send + Sync + 'static>> {
 
     // Record measurements using the Counter instrument.
     counter.add(
-        &Context::current(),
         10,
         [
             KeyValue::new("mykey1", "myvalue1"),
@@ -62,7 +61,6 @@ async fn main() -> Result<(), Box<dyn Error + Send + Sync + 'static>> {
 
     // Record measurements using the UpCounter instrument.
     updown_counter.add(
-        &Context::current(),
         -10,
         [
             KeyValue::new("mykey1", "myvalue1"),
@@ -98,7 +96,6 @@ async fn main() -> Result<(), Box<dyn Error + Send + Sync + 'static>> {
 
     // Record measurements using the histogram instrument.
     histogram.record(
-        &Context::current(),
         10.5,
         [
             KeyValue::new("mykey1", "myvalue1"),

opentelemetry-api/CHANGELOG.md

@@ -2,6 +2,11 @@
 
 ## Unreleased
 
+### Removed
+
+- Synchronous instruments no longer accepts `Context` while reporting
+  measurements. [#1076](https://github.com/open-telemetry/opentelemetry-rust/pull/1076).
+
 ### Fixed
 
 - Fix `SpanRef::set_attributes` mutability requirement. [#1038](https://github.com/open-telemetry/opentelemetry-rust/pull/1038)

opentelemetry-api/src/global/mod.rs

@@ -92,7 +92,7 @@
 //! # #[cfg(feature="metrics")]
 //! # {
 //! use opentelemetry_api::metrics::{Meter, noop::NoopMeterProvider};
-//! use opentelemetry_api::{global, Context, KeyValue};
+//! use opentelemetry_api::{global, KeyValue};
 //!
 //! fn init_meter() {
 //!     let provider = NoopMeterProvider::new();
@@ -106,10 +106,9 @@
 //!     // Then you can get a named tracer instance anywhere in your codebase.
 //!     let meter = global::meter("my-component");
 //!     let counter = meter.u64_counter("my_counter").init();
-//!     let cx = Context::current();
 //!
 //!     // record metrics
-//!     counter.add(&cx, 1, &[KeyValue::new("mykey", "myvalue")]);
+//!     counter.add(1, &[KeyValue::new("mykey", "myvalue")]);
 //! }
 //!
 //! // in main or other app start
@@ -123,17 +122,16 @@
 //! ```
 //! # #[cfg(feature="metrics")]
 //! # {
-//! use opentelemetry_api::{global, Context, KeyValue};
+//! use opentelemetry_api::{global, KeyValue};
 //!
 //! pub fn my_traced_library_function() {
 //!     // End users of your library will configure their global meter provider
 //!     // so you can use the global meter without any setup
 //!     let tracer = global::meter("my-library-name");
 //!     let counter = tracer.u64_counter("my_counter").init();
-//!     let cx = Context::current();
 //!
 //!     // record metrics
-//!     counter.add(&cx, 1, &[KeyValue::new("mykey", "myvalue")]);
+//!     counter.add(1, &[KeyValue::new("mykey", "myvalue")]);
 //! }
 //! # }
 //! ```

opentelemetry-api/src/metrics/instruments/counter.rs

@@ -1,6 +1,6 @@
 use crate::{
     metrics::{AsyncInstrument, AsyncInstrumentBuilder, InstrumentBuilder, MetricsError},
-    Context, KeyValue,
+    KeyValue,
 };
 use core::fmt;
 use std::sync::Arc;
@@ -9,7 +9,7 @@ use std::{any::Any, convert::TryFrom};
 /// An SDK implemented instrument that records increasing values.
 pub trait SyncCounter<T> {
     /// Records an increment to the counter.
-    fn add(&self, cx: &Context, value: T, attributes: &[KeyValue]);
+    fn add(&self, value: T, attributes: &[KeyValue]);
 }
 
 /// An instrument that records increasing values.
@@ -32,8 +32,8 @@ impl<T> Counter<T> {
     }
 
     /// Records an increment to the counter.
-    pub fn add(&self, cx: &Context, value: T, attributes: &[KeyValue]) {
-        self.0.add(cx, value, attributes)
+    pub fn add(&self, value: T, attributes: &[KeyValue]) {
+        self.0.add(value, attributes)
     }
 }
 

opentelemetry-api/src/metrics/instruments/histogram.rs

@@ -1,6 +1,6 @@
 use crate::{
     metrics::{InstrumentBuilder, MetricsError},
-    Context, KeyValue,
+    KeyValue,
 };
 use core::fmt;
 use std::convert::TryFrom;
@@ -9,7 +9,7 @@ use std::sync::Arc;
 /// An SDK implemented instrument that records a distribution of values.
 pub trait SyncHistogram<T> {
     /// Adds an additional value to the distribution.
-    fn record(&self, cx: &Context, value: T, attributes: &[KeyValue]);
+    fn record(&self, value: T, attributes: &[KeyValue]);
 }
 
 /// An instrument that records a distribution of values.
@@ -32,8 +32,8 @@ impl<T> Histogram<T> {
     }
 
     /// Adds an additional value to the distribution.
-    pub fn record(&self, cx: &Context, value: T, attributes: &[KeyValue]) {
-        self.0.record(cx, value, attributes)
+    pub fn record(&self, value: T, attributes: &[KeyValue]) {
+        self.0.record(value, attributes)
     }
 }
 

opentelemetry-api/src/metrics/instruments/up_down_counter.rs

@@ -1,6 +1,6 @@
 use crate::{
     metrics::{InstrumentBuilder, MetricsError},
-    Context, KeyValue,
+    KeyValue,
 };
 use core::fmt;
 use std::sync::Arc;
@@ -11,7 +11,7 @@ use super::{AsyncInstrument, AsyncInstrumentBuilder};
 /// An SDK implemented instrument that records increasing or decreasing values.
 pub trait SyncUpDownCounter<T> {
     /// Records an increment or decrement to the counter.
-    fn add(&self, cx: &Context, value: T, attributes: &[KeyValue]);
+    fn add(&self, value: T, attributes: &[KeyValue]);
 }
 
 /// An instrument that records increasing or decreasing values.
@@ -37,8 +37,8 @@ impl<T> UpDownCounter<T> {
     }
 
     /// Records an increment or decrement to the counter.
-    pub fn add(&self, cx: &Context, value: T, attributes: &[KeyValue]) {
-        self.0.add(cx, value, attributes)
+    pub fn add(&self, value: T, attributes: &[KeyValue]) {
+        self.0.add(value, attributes)
     }
 }
 

opentelemetry-api/src/metrics/noop.rs

@@ -8,7 +8,7 @@ use crate::{
         AsyncInstrument, CallbackRegistration, InstrumentProvider, Meter, MeterProvider, Observer,
         Result, SyncCounter, SyncHistogram, SyncUpDownCounter,
     },
-    Context, KeyValue,
+    KeyValue,
 };
 use std::{any::Any, borrow::Cow, sync::Arc};
 
@@ -93,19 +93,19 @@ impl NoopSyncInstrument {
 }
 
 impl<T> SyncCounter<T> for NoopSyncInstrument {
-    fn add(&self, _cx: &Context, _value: T, _attributes: &[KeyValue]) {
+    fn add(&self, _value: T, _attributes: &[KeyValue]) {
         // Ignored
     }
 }
 
 impl<T> SyncUpDownCounter<T> for NoopSyncInstrument {
-    fn add(&self, _cx: &Context, _value: T, _attributes: &[KeyValue]) {
+    fn add(&self, _value: T, _attributes: &[KeyValue]) {
         // Ignored
     }
 }
 
 impl<T> SyncHistogram<T> for NoopSyncInstrument {
-    fn record(&self, _cx: &Context, _value: T, _attributes: &[KeyValue]) {
+    fn record(&self, _value: T, _attributes: &[KeyValue]) {
         // Ignored
     }
 }

opentelemetry-otlp/examples/basic-otlp-http/src/main.rs

@@ -4,7 +4,7 @@ use opentelemetry_api::trace::TraceError;
 use opentelemetry_api::{
     metrics,
     trace::{TraceContextExt, Tracer},
-    Context, Key, KeyValue,
+    Key, KeyValue,
 };
 use opentelemetry_otlp::WithExportConfig;
 use opentelemetry_sdk::metrics as sdkmetrics;
@@ -58,8 +58,7 @@ async fn main() -> Result<(), Box<dyn Error + Send + Sync + 'static>> {
     let meter = global::meter("ex.com/basic");
 
     let histogram = meter.f64_histogram("ex.com.two").init();
-    let cx = Context::new();
-    histogram.record(&cx, 5.5, COMMON_ATTRIBUTES.as_ref());
+    histogram.record(5.5, COMMON_ATTRIBUTES.as_ref());
 
     tracer.in_span("operation", |cx| {
         let span = cx.span();

opentelemetry-otlp/examples/basic-otlp/src/main.rs

@@ -5,7 +5,7 @@ use opentelemetry_api::trace::TraceError;
 use opentelemetry_api::{
     metrics,
     trace::{TraceContextExt, Tracer},
-    Context, Key, KeyValue,
+    Key, KeyValue,
 };
 use opentelemetry_otlp::{ExportConfig, WithExportConfig};
 use opentelemetry_sdk::{metrics::MeterProvider, runtime, trace as sdktrace, Resource};
@@ -62,7 +62,6 @@ async fn main() -> Result<(), Box<dyn Error + Send + Sync + 'static>> {
     // execution.
     let _ = init_tracer()?;
     let meter_provider = init_metrics()?;
-    let cx = Context::new();
 
     let tracer = global::tracer("ex.com/basic");
     let meter = global::meter("ex.com/basic");
@@ -77,7 +76,7 @@ async fn main() -> Result<(), Box<dyn Error + Send + Sync + 'static>> {
     })?;
 
     let histogram = meter.f64_histogram("ex.com.two").init();
-    histogram.record(&cx, 5.5, COMMON_ATTRIBUTES.as_ref());
+    histogram.record(5.5, COMMON_ATTRIBUTES.as_ref());
 
     tracer.in_span("operation", |cx| {
         let span = cx.span();
@@ -93,7 +92,7 @@ async fn main() -> Result<(), Box<dyn Error + Send + Sync + 'static>> {
 
             span.add_event("Sub span event", vec![]);
 
-            histogram.record(&cx, 1.3, &[]);
+            histogram.record(1.3, &[]);
         });
     });
 

opentelemetry-prometheus/examples/hyper.rs

@@ -6,7 +6,7 @@ use hyper::{
 use once_cell::sync::Lazy;
 use opentelemetry_api::{
     metrics::{Counter, Histogram, MeterProvider as _, Unit},
-    Context, KeyValue,
+    KeyValue,
 };
 use opentelemetry_sdk::metrics::MeterProvider;
 use prometheus::{Encoder, Registry, TextEncoder};
@@ -17,14 +17,13 @@ use std::time::SystemTime;
 static HANDLER_ALL: Lazy<[KeyValue; 1]> = Lazy::new(|| [KeyValue::new("handler", "all")]);
 
 async fn serve_req(
-    cx: Context,
     req: Request<Body>,
     state: Arc<AppState>,
 ) -> Result<Response<Body>, hyper::Error> {
     println!("Receiving request at path {}", req.uri());
     let request_start = SystemTime::now();
 
-    state.http_counter.add(&cx, 1, HANDLER_ALL.as_ref());
+    state.http_counter.add(1, HANDLER_ALL.as_ref());
 
     let response = match (req.method(), req.uri().path()) {
         (&Method::GET, "/metrics") => {
@@ -34,7 +33,7 @@ async fn serve_req(
             encoder.encode(&metric_families, &mut buffer).unwrap();
             state
                 .http_body_gauge
-                .record(&cx, buffer.len() as u64, HANDLER_ALL.as_ref());
+                .record(buffer.len() as u64, HANDLER_ALL.as_ref());
 
             Response::builder()
                 .status(200)
@@ -53,7 +52,6 @@ async fn serve_req(
     };
 
     state.http_req_histogram.record(
-        &cx,
         request_start.elapsed().map_or(0.0, |d| d.as_secs_f64()),
         &[],
     );
@@ -74,7 +72,6 @@ pub async fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
         .with_registry(registry.clone())
         .build()?;
     let provider = MeterProvider::builder().with_reader(exporter).build();
-    let cx = Context::new();
 
     let meter = provider.meter("hyper-example");
     let state = Arc::new(AppState {
@@ -99,15 +96,10 @@ pub async fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
     // incoming HTTP requests on said connection.
     let make_svc = make_service_fn(move |_conn| {
         let state = state.clone();
-        let cx = cx.clone();
         // This is the `Service` that will handle the connection.
         // `service_fn` is a helper to convert a function that
         // returns a Response into a `Service`.
-        async move {
-            Ok::<_, Infallible>(service_fn(move |req| {
-                serve_req(cx.clone(), req, state.clone())
-            }))
-        }
+        async move { Ok::<_, Infallible>(service_fn(move |req| serve_req(req, state.clone()))) }
     });
 
     let addr = ([127, 0, 0, 1], 3000).into();

opentelemetry-prometheus/src/lib.rs

@@ -3,12 +3,11 @@
 //! [Prometheus]: https://prometheus.io
 //!
 //! ```
-//! use opentelemetry_api::{metrics::MeterProvider as _, Context, KeyValue};
+//! use opentelemetry_api::{metrics::MeterProvider as _, KeyValue};
 //! use opentelemetry_sdk::metrics::MeterProvider;
 //! use prometheus::{Encoder, TextEncoder};
 //!
 //! # fn main() -> Result<(), Box<dyn std::error::Error>> {
-//! let cx = Context::current();
 //!
 //! // create a new prometheus registry
 //! let registry = prometheus::Registry::new();
@@ -32,8 +31,8 @@
 //!     .with_description("Records values")
 //!     .init();
 //!
-//! counter.add(&cx, 100, &[KeyValue::new("key", "value")]);
-//! histogram.record(&cx, 100, &[KeyValue::new("key", "value")]);
+//! counter.add(100, &[KeyValue::new("key", "value")]);
+//! histogram.record(100, &[KeyValue::new("key", "value")]);
 //!
 //! // Encode data as text or protobuf
 //! let encoder = TextEncoder::new();