feat: add module experimental::kxio with backoff macro

src/experimental/kxio/backoff.rs

@@ -0,0 +1,36 @@
+//
+#[macro_export]
+macro_rules! backoff {
+    ($backoff_secs:expr) => {{
+        $backoff_secs *= 2;
+        let jitter = rand::random::<u64>() % 10;
+        let backoff_secs = 60.min($backoff_secs + jitter);
+        tracing::debug(?backoff_secs, "Too many requests, backing off for {}s");
+        tokio::time::sleep(tokio::time::Duration::from_secs(backoff_secs)).await;
+    }};
+}
+
+#[macro_export]
+macro_rules! with_exponential_backoff {
+    ($operation:expr) => {{
+        let mut backoff_secs = 1;
+        loop {
+            match $operation {
+                Err(kxio::net::Error::Reqwest(err))
+                    if err.status() == Some(kxio::net::StatusCode::TOO_MANY_REQUESTS) =>
+                {
+                    $crate::backoff!(backoff_secs)
+                }
+                Err(kxio::net::Error::ResponseError { response })
+                    if response.status() == kxio::net::StatusCode::TOO_MANY_REQUESTS =>
+                {
+                    $crate::backoff!(backoff_secs)
+                }
+                Ok(response) if response.status() == kxio::net::StatusCode::TOO_MANY_REQUESTS => {
+                    $crate::backoff!(backoff_secs)
+                }
+                result => break result,
+            }
+        }
+    }};
+}

src/experimental/kxio/mod.rs

@@ -0,0 +1 @@
+mod backoff;

src/experimental/mod.rs

@@ -1,3 +1,6 @@
 //
 
+#[cfg(feature = "use-kxio")]
+mod kxio;
+
 mod to_string;