use futures-util instead of futures and with no default features

opentelemetry-contrib/Cargo.toml

@@ -40,7 +40,7 @@ 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 }
+futures-util = { version = "0.3", optional = true, default-features = false }
 
 [dev-dependencies]
 base64 = "0.13"

opentelemetry-datadog/Cargo.toml

@@ -43,7 +43,7 @@ futures-core = "0.3"
 async-trait = "0.1"
 base64 = "0.13"
 bytes = "1"
-futures-util = { version = "0.3", features = ["io"] }
+futures-util = { version = "0.3", default-features = false, features = ["io"] }
 isahc = "1.4"
 opentelemetry_sdk = { path = "../opentelemetry-sdk", features = ["trace", "testing"] }
 

opentelemetry-dynatrace/Cargo.toml

@@ -36,11 +36,10 @@ surf-client = ["surf", "opentelemetry-http/surf"]
 isahc-client = ["isahc", "opentelemetry-http/isahc"]
 
 rt-tokio = ["tokio", "opentelemetry/rt-tokio"]
-rt-async-std = ["async-std"]
+rt-async-std = ["async-std", "futures-channel"]
 
 wasm = [
     "base64",
-    "futures-util",
     "getrandom/js",
     "js-sys",
     "wasm-bindgen",
@@ -51,8 +50,7 @@ wasm = [
 [dependencies]
 async-std = { version = "= 1.10.0", features = ["unstable"], optional = true }
 base64 = { version = "0.21", optional = true }
-futures = "0.3"
-futures-util = { version = "0.3", optional = true }
+futures-channel = { version = "0.3", optional = true }
 getrandom = { version = "0.2", optional = true }
 http = "0.2"
 isahc = { version = "1.4", default-features = false, optional = true }
@@ -82,5 +80,6 @@ optional = true
 
 [dev-dependencies]
 opentelemetry_sdk = { version = "0.19.0", features = ["rt-tokio"] }
+futures-util = { version = "0.3", default-features = false }
 tokio = { version = "1.0", default-features = false, features = ["macros", "rt-multi-thread", "sync", "test-util"] }
 hyper = { version = "0.14", default-features = false, features = ["server", "tcp", "http1"] }

opentelemetry-dynatrace/src/metric.rs

@@ -233,7 +233,7 @@ pub struct MetricsExporter {
     sender: Arc<Mutex<tokio::sync::mpsc::Sender<ClientMessage>>>,
 
     #[cfg(all(not(feature = "rt-tokio"), feature = "rt-async-std"))]
-    sender: Arc<Mutex<futures::channel::mpsc::Sender<ClientMessage>>>,
+    sender: Arc<Mutex<futures_channel::mpsc::Sender<ClientMessage>>>,
 
     endpoint: Uri,
 
@@ -292,7 +292,7 @@ impl MetricsExporter {
         }));
 
         #[cfg(all(not(feature = "rt-tokio"), feature = "rt-async-std"))]
-        let (sender, mut receiver) = futures::channel::mpsc::channel::<ClientMessage>(2);
+        let (sender, mut receiver) = futures_channel::mpsc::channel::<ClientMessage>(2);
 
         #[cfg(all(not(feature = "rt-tokio"), feature = "rt-async-std"))]
         async_std::task::spawn(Box::pin(async move {

opentelemetry-dynatrace/tests/http_test.rs

@@ -1,6 +1,6 @@
 #[cfg(all(feature = "metrics", feature = "rt-tokio"))]
 mod test {
-    use futures::future::BoxFuture;
+    use futures_util::future::BoxFuture;
     use http::header::{HeaderValue, AUTHORIZATION, USER_AGENT};
     use hyper::{
         body,
@@ -20,18 +20,18 @@ mod test {
         tick_rx: tokio::sync::watch::Receiver<usize>,
     }
     impl runtime::Runtime for TestRuntime {
-        type Interval = futures::stream::Once<BoxFuture<'static, ()>>;
+        type Interval = futures_util::stream::Once<BoxFuture<'static, ()>>;
 
         type Delay = Pin<Box<tokio::time::Sleep>>;
 
         fn interval(&self, _duration: Duration) -> Self::Interval {
             let mut tick_rx = self.tick_rx.clone();
-            futures::stream::once(Box::pin(async move {
+            futures_util::stream::once(Box::pin(async move {
                 let _ = tick_rx.changed().await.is_ok();
             }))
         }
 
-        fn spawn(&self, future: futures::future::BoxFuture<'static, ()>) {
+        fn spawn(&self, future: BoxFuture<'static, ()>) {
             tokio::spawn(future);
         }
 

opentelemetry-otlp/Cargo.toml

@@ -51,7 +51,7 @@ tokio-stream = { version = "0.1", features = ["net"] }
 opentelemetry_sdk = { features = ["trace", "rt-tokio", "testing"], path = "../opentelemetry-sdk" }
 time = { version = "0.3", features = ["macros"] }
 tokio = { version = "1.0", features = ["macros", "rt-multi-thread"] }
-futures = { version = "0.3", default-features = false, features = ["std"] }
+futures-util = { version = "0.3", default-features = false }
 
 [features]
 # telemetry pillars and functions

opentelemetry-otlp/tests/smoke.rs

@@ -1,4 +1,4 @@
-use futures::StreamExt;
+use futures_util::StreamExt;
 use opentelemetry::global::shutdown_tracer_provider;
 use opentelemetry::trace::{Span, SpanKind, Tracer};
 use opentelemetry_otlp::WithExportConfig;

opentelemetry-stackdriver/Cargo.toml

@@ -42,4 +42,4 @@ tempfile = "3.3.0"
 tokio = "1"
 tonic-build = "0.9.0"
 walkdir = "2.3.2"
-futures = "0.3"
+futures-util = {version = "0.3", default-features = false }