WASI support

I was attempting to use this library with a WASI target and it was not compiling. The cfg options in the Cargo.toml and the source files did not match.

Signed-off-by: Caleb Schoepp <caleb.schoepp@fermyon.com>

src/layer.rs

@@ -7,7 +7,7 @@ use opentelemetry::{
 use std::fmt;
 use std::marker;
 use std::thread;
-#[cfg(not(target_arch = "wasm32"))]
+#[cfg(not(all(target_arch = "wasm32", not(target_os = "wasi"))))]
 use std::time::Instant;
 use std::{any::TypeId, borrow::Cow};
 use tracing_core::span::{self, Attributes, Id, Record};
@@ -17,7 +17,7 @@ use tracing_log::NormalizeEvent;
 use tracing_subscriber::layer::Context;
 use tracing_subscriber::registry::LookupSpan;
 use tracing_subscriber::Layer;
-#[cfg(target_arch = "wasm32")]
+#[cfg(all(target_arch = "wasm32", not(target_os = "wasi")))]
 use web_time::Instant;
 
 const SPAN_NAME_FIELD: &str = "otel.name";

src/lib.rs

@@ -154,12 +154,12 @@ pub struct OtelData {
 pub(crate) mod time {
     use std::time::SystemTime;
 
-    #[cfg(not(target_arch = "wasm32"))]
+    #[cfg(not(all(target_arch = "wasm32", not(target_os = "wasi"))))]
     pub(crate) fn now() -> SystemTime {
         SystemTime::now()
     }
 
-    #[cfg(target_arch = "wasm32")]
+    #[cfg(all(target_arch = "wasm32", not(target_os = "wasi")))]
     pub(crate) fn now() -> SystemTime {
         SystemTime::UNIX_EPOCH + std::time::Duration::from_millis(js_sys::Date::now() as u64)
     }