opentelemetry: dissolve api module in favor of top-level modules (#412)

This makes the source tree less nested and makes the internal API and
filesystem more similar to the public API exposed by the crate.

opentelemetry/src/global/error_handler.rs

@@ -1,11 +1,38 @@
-use crate::api::Error;
+use std::sync::PoisonError;
 use std::sync::RwLock;
 
+#[cfg(feature = "metrics")]
+use crate::metrics::MetricsError;
+#[cfg(feature = "trace")]
+use crate::trace::TraceError;
+
 lazy_static::lazy_static! {
     /// The global error handler.
     static ref GLOBAL_ERROR_HANDLER: RwLock<Option<ErrorHandler>> = RwLock::new(None);
 }
 
+/// Wrapper for error from both tracing and metrics part of open telemetry.
+#[derive(thiserror::Error, Debug)]
+#[non_exhaustive]
+pub enum Error {
+    #[cfg(feature = "trace")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "trace")))]
+    #[error(transparent)]
+    Trace(#[from] TraceError),
+    #[cfg(feature = "metrics")]
+    #[cfg_attr(docsrs, doc(cfg(feature = "metrics")))]
+    #[error(transparent)]
+    Metric(#[from] MetricsError),
+    #[error("{0}")]
+    Other(String),
+}
+
+impl<T> From<PoisonError<T>> for Error {
+    fn from(err: PoisonError<T>) -> Self {
+        Error::Other(err.to_string())
+    }
+}
+
 struct ErrorHandler(Box<dyn Fn(Error) + Send + Sync>);
 
 /// Handle error using the globally configured error handler.

opentelemetry/src/lib.rs

@@ -160,29 +160,34 @@
 )]
 #![cfg_attr(test, deny(warnings))]
 
-mod api;
 pub mod global;
 pub mod sdk;
 
 #[cfg(feature = "testing")]
 #[allow(missing_docs)]
 pub mod testing;
 
+pub mod baggage;
+
+mod context;
+pub use context::{Context, ContextGuard};
+
+mod core;
+pub use crate::core::{Array, Key, KeyValue, Unit, Value};
+
 #[cfg(feature = "metrics")]
 #[cfg_attr(docsrs, doc(cfg(feature = "metrics")))]
-pub use api::labels;
+pub mod labels;
+
 #[cfg(feature = "metrics")]
 #[cfg_attr(docsrs, doc(cfg(feature = "metrics")))]
-pub use api::metrics;
+pub mod metrics;
+
+pub mod propagation;
+
 #[cfg(feature = "trace")]
 #[cfg_attr(docsrs, doc(cfg(feature = "trace")))]
-pub use api::trace;
-pub use api::{
-    baggage,
-    context::{Context, ContextGuard},
-    core::{Array, Key, KeyValue, Unit, Value},
-    propagation,
-};
+pub mod trace;
 
 #[cfg(any(feature = "metrics", feature = "trace"))]
 pub(crate) mod time {

opentelemetry/src/sdk/export/trace/mod.rs

@@ -1,10 +1,9 @@
 //! Trace exporters
-use crate::api::trace::TraceError;
 #[cfg(all(feature = "http", any(feature = "surf", feature = "reqwest")))]
 use crate::sdk::export::ExportError;
 use crate::{
     sdk,
-    trace::{Event, Link, SpanContext, SpanId, SpanKind, StatusCode},
+    trace::{Event, Link, SpanContext, SpanId, SpanKind, StatusCode, TraceError},
 };
 use async_trait::async_trait;
 #[cfg(feature = "http")]

opentelemetry/src/sdk/trace/span.rs

@@ -9,7 +9,7 @@
 //! is possible to change its name, set its `Attributes`, and add `Links` and `Events`.
 //! These cannot be changed after the `Span`'s end time has been set.
 use crate::trace::{Event, SpanContext, SpanId, SpanKind, StatusCode};
-use crate::{api, sdk, KeyValue};
+use crate::{sdk, trace, KeyValue};
 use std::sync::{Arc, Mutex};
 use std::time::SystemTime;
 
@@ -42,9 +42,9 @@ pub(crate) struct SpanData {
     /// Span attributes
     pub(crate) attributes: sdk::trace::EvictedHashMap,
     /// Span Message events
-    pub(crate) message_events: sdk::trace::EvictedQueue<api::trace::Event>,
+    pub(crate) message_events: sdk::trace::EvictedQueue<trace::Event>,
     /// Span Links
-    pub(crate) links: sdk::trace::EvictedQueue<api::trace::Link>,
+    pub(crate) links: sdk::trace::EvictedQueue<trace::Link>,
     /// Span status code
     pub(crate) status_code: StatusCode,
     /// Span status message
@@ -223,7 +223,7 @@ fn build_export_data(
 #[cfg(test)]
 mod tests {
     use super::*;
-    use crate::{api, api::core::KeyValue, api::trace::Span as _, api::trace::TracerProvider};
+    use crate::{core::KeyValue, trace::Span as _, trace::TracerProvider};
     use std::time::Duration;
 
     fn init() -> (sdk::trace::Tracer, SpanData) {
@@ -232,7 +232,7 @@ mod tests {
         let tracer = provider.get_tracer("opentelemetry", Some(env!("CARGO_PKG_VERSION")));
         let data = SpanData {
             parent_span_id: SpanId::from_u64(0),
-            span_kind: api::trace::SpanKind::Internal,
+            span_kind: trace::SpanKind::Internal,
             name: "opentelemetry".to_string(),
             start_time: crate::time::now(),
             end_time: crate::time::now(),

opentelemetry/src/sdk/trace/span_processor.rs

@@ -40,11 +40,11 @@ use futures::{
     FutureExt, Stream, StreamExt,
 };
 
-use crate::api::trace::{TraceError, TraceResult};
 use crate::global;
 use crate::sdk::trace::Span;
 use crate::{
     sdk::export::trace::{ExportResult, SpanData, SpanExporter},
+    trace::{TraceError, TraceResult},
     Context,
 };