Rename Correlation Context into Baggage (#208)

examples/basic-otlp/src/main.rs

@@ -1,6 +1,6 @@
 use futures::stream::{Stream, StreamExt};
 use opentelemetry::api::metrics::{self, MetricsError, ObserverResult};
-use opentelemetry::api::{Context, CorrelationContextExt, Key, KeyValue, TraceContextExt, Tracer};
+use opentelemetry::api::{Context, BaggageExt, Key, KeyValue, TraceContextExt, Tracer};
 use opentelemetry::exporter;
 use opentelemetry::sdk::metrics::PushController;
 use opentelemetry::{global, sdk};
@@ -68,7 +68,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
     let value_recorder_two = meter.f64_value_recorder("ex.com.two").init();
 
     let _correlations =
-        Context::current_with_correlations(vec![FOO_KEY.string("foo1"), BAR_KEY.string("bar1")])
+        Context::current_with_baggage(vec![FOO_KEY.string("foo1"), BAR_KEY.string("bar1")])
             .attach();
 
     let value_recorder = value_recorder_two.bind(COMMON_LABELS.as_ref());
@@ -83,7 +83,7 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
 
         meter.record_batch_with_context(
             // Note: call-site variables added as context Entries:
-            &Context::current_with_correlations(vec![ANOTHER_KEY.string("xyz")]),
+            &Context::current_with_baggage(vec![ANOTHER_KEY.string("xyz")]),
             COMMON_LABELS.as_ref(),
             vec![value_recorder_two.measurement(2.0)],
         );

examples/basic/src/main.rs

@@ -1,6 +1,6 @@
 use futures::stream::{Stream, StreamExt};
 use opentelemetry::api::metrics::{self, MetricsError, ObserverResult};
-use opentelemetry::api::{Context, CorrelationContextExt, Key, KeyValue, TraceContextExt, Tracer};
+use opentelemetry::api::{Context, BaggageExt, Key, KeyValue, TraceContextExt, Tracer};
 use opentelemetry::exporter;
 use opentelemetry::sdk::metrics::PushController;
 use opentelemetry::{global, sdk};
@@ -64,7 +64,7 @@ async fn main() -> Result<(), Box<dyn Error>> {
     let value_recorder_two = meter.f64_value_recorder("ex.com.two").init();
 
     let _correlations =
-        Context::current_with_correlations(vec![FOO_KEY.string("foo1"), BAR_KEY.string("bar1")])
+        Context::current_with_baggage(vec![FOO_KEY.string("foo1"), BAR_KEY.string("bar1")])
             .attach();
 
     let value_recorder = value_recorder_two.bind(COMMON_LABELS.as_ref());
@@ -79,7 +79,7 @@ async fn main() -> Result<(), Box<dyn Error>> {
 
         meter.record_batch_with_context(
             // Note: call-site variables added as context Entries:
-            &Context::current_with_correlations(vec![ANOTHER_KEY.string("xyz")]),
+            &Context::current_with_baggage(vec![ANOTHER_KEY.string("xyz")]),
             COMMON_LABELS.as_ref(),
             vec![value_recorder_two.measurement(2.0)],
         );

src/api/correlation/mod.rs → src/api/baggage/mod.rs

@@ -1,40 +1,40 @@
-//! # OpenTelemetry Correlation Context API
+//! # OpenTelemetry Baggage API
 //!
-//! A Correlation Context is used to annotate telemetry, adding context and
+//! Baggage is used to annotate telemetry, adding context and
 //! information to metrics, traces, and logs. It is an abstract data type
 //! represented by a set of name/value pairs describing user-defined properties.
-//! Each name in a [`CorrelationContext`] is associated with exactly one value.
-//! `CorrelationContext`s are serialized according to the editor's draft of
-//! the [W3C Correlation Context] specification.
+//! Each name in a [`Baggage`] is associated with exactly one value.
+//! `Baggage`s are serialized according to the editor's draft of
+//! the [W3C Baggage] specification.
 //!
-//! [`CorrelationContext`]: struct.CorrelationContext.html
-//! [W3C Correlation Context]: https://w3c.github.io/correlation-context/
+//! [`CorrelationContext`]: struct.Baggage.html
+//! [W3C Baggage]: https://w3c.github.io/baggage/
 //!
 //! # Examples
 //!
 //! ```
 //! use opentelemetry::api::{
-//!     CorrelationContextExt, CorrelationContextPropagator, TextMapFormat, Key
+//!     BaggageExt, BaggagePropagator, TextMapFormat, Key
 //! };
 //! use std::collections::HashMap;
 //!
-//! // Example correlation value passed in externally via http headers
+//! // Example baggage value passed in externally via http headers
 //! let mut headers = HashMap::new();
 //! headers.insert("otcorrelations".to_string(), "user_id=1".to_string());
 //!
-//! let propagator = CorrelationContextPropagator::new();
+//! let propagator = BaggagePropagator::new();
 //! // can extract from any type that impls `Extractor`, usually an HTTP header map
 //! let cx = propagator.extract(&headers);
 //!
 //! // Iterate over extracted name / value pairs
-//! for (name, value) in cx.correlation_context() {
+//! for (name, value) in cx.baggage() {
 //!   // ...
 //! }
 //!
-//! // Add new correlations
-//! let cx_with_additions = cx.with_correlations(vec![Key::new("server_id").u64(42)]);
+//! // Add new baggage
+//! let cx_with_additions = cx.with_baggage(vec![Key::new("server_id").u64(42)]);
 //!
-//! // Inject correlations into http request
+//! // Inject aggage into http request
 //! propagator.inject_context(&cx_with_additions, &mut headers);
 //!
 //! let header_value = headers.get("otcorrelations").expect("header is injected");
@@ -48,18 +48,18 @@ use std::iter::FromIterator;
 mod propagation;
 
 #[cfg(feature = "trace")]
-pub use propagation::{CorrelationContextExt, CorrelationContextPropagator};
+pub use propagation::{BaggageExt, BaggagePropagator};
 
 /// A set of name/value pairs describing user-defined properties across systems.
 #[derive(Debug, Default)]
-pub struct CorrelationContext {
+pub struct Baggage {
     inner: HashMap<api::Key, api::Value>,
 }
 
-impl CorrelationContext {
-    /// Creates an empty `CorrelationContext`.
+impl Baggage {
+    /// Creates an empty `Baggage`.
     pub fn new() -> Self {
-        CorrelationContext {
+        Baggage {
             inner: HashMap::default(),
         }
     }
@@ -69,9 +69,9 @@ impl CorrelationContext {
     /// # Examples
     ///
     /// ```
-    /// use opentelemetry::api::{CorrelationContext, Value};
+    /// use opentelemetry::api::{Baggage, Value};
     ///
-    /// let mut cc = CorrelationContext::new();
+    /// let mut cc = Baggage::new();
     /// let _ = cc.insert("my-name", "my-value");
     ///
     /// assert_eq!(cc.get("my-name"), Some(&Value::String("my-value".to_string())))
@@ -80,17 +80,17 @@ impl CorrelationContext {
         self.inner.get(&key.into())
     }
 
-    /// Inserts a name-value pair into the correlation context.
+    /// Inserts a name-value pair into the baggage.
     ///
     /// If the name was not present, [`None`] is returned. If the name was present,
     /// the value is updated, and the old value is returned.
     ///
     /// # Examples
     ///
     /// ```
-    /// use opentelemetry::api::{CorrelationContext, Value};
+    /// use opentelemetry::api::{Baggage, Value};
     ///
-    /// let mut cc = CorrelationContext::new();
+    /// let mut cc = Baggage::new();
     /// let _ = cc.insert("my-name", "my-value");
     ///
     /// assert_eq!(cc.get("my-name"), Some(&Value::String("my-value".to_string())))
@@ -103,29 +103,29 @@ impl CorrelationContext {
         self.inner.insert(key.into(), value.into())
     }
 
-    /// Removes a name from the correlation context, returning the value
+    /// Removes a name from the baggage, returning the value
     /// corresponding to the name if the pair was previously in the map.
     pub fn remove<K: Into<api::Key>>(&mut self, key: K) -> Option<api::Value> {
         self.inner.remove(&key.into())
     }
 
-    /// Returns the number of attributes for this correlation context
+    /// Returns the number of attributes for this baggage
     pub fn len(&self) -> usize {
         self.inner.len()
     }
 
-    /// Returns `true` if the correlation context contains no items.
+    /// Returns `true` if the baggage contains no items.
     pub fn is_empty(&self) -> bool {
         self.inner.is_empty()
     }
 
-    /// Gets an iterator over the correlation context items, sorted by name.
+    /// Gets an iterator over the baggage items, sorted by name.
     pub fn iter(&self) -> Iter {
         self.into_iter()
     }
 }
 
-/// An iterator over the entries of a `CorrelationContext`.
+/// An iterator over the entries of a `Baggage`.
 #[derive(Debug)]
 pub struct Iter<'a>(hash_map::Iter<'a, api::Key, api::Value>);
 impl<'a> Iterator for Iter<'a> {
@@ -136,7 +136,7 @@ impl<'a> Iterator for Iter<'a> {
     }
 }
 
-impl<'a> IntoIterator for &'a CorrelationContext {
+impl<'a> IntoIterator for &'a Baggage {
     type Item = (&'a api::Key, &'a api::Value);
     type IntoIter = Iter<'a>;
 
@@ -145,17 +145,17 @@ impl<'a> IntoIterator for &'a CorrelationContext {
     }
 }
 
-impl FromIterator<(api::Key, api::Value)> for CorrelationContext {
+impl FromIterator<(api::Key, api::Value)> for Baggage {
     fn from_iter<I: IntoIterator<Item = (api::Key, api::Value)>>(iter: I) -> Self {
-        CorrelationContext {
+        Baggage {
             inner: iter.into_iter().collect(),
         }
     }
 }
 
-impl FromIterator<api::KeyValue> for CorrelationContext {
+impl FromIterator<api::KeyValue> for Baggage {
     fn from_iter<I: IntoIterator<Item = api::KeyValue>>(iter: I) -> Self {
-        CorrelationContext {
+        Baggage {
             inner: iter.into_iter().map(|kv| (kv.key, kv.value)).collect(),
         }
     }