feat: extend hotpath coverage across crates

Add opt-in hotpath feature surfaces to every workspace crate and wire the root rustfs feature passthrough for function, allocation, and CPU profiling.

Add a focused set of function-level measurements for scanner, heal, lock, target replay, IAM, KMS, Keystone, trusted proxy, and capacity paths without adding request-scoped primitive wrappers.

Co-Authored-By: heihutu <heihutu@gmail.com>

crates/keystone/Cargo.toml

@@ -28,7 +28,34 @@ authors.workspace = true
 [lints]
 workspace = true
 
+[features]
+default = []
+hotpath = [
+    "hotpath/hotpath",
+    "hotpath/tokio",
+    "hotpath/futures",
+    "hotpath/reqwest-0-13",
+    "rustfs-credentials/hotpath",
+    "rustfs-policy/hotpath",
+    "rustfs-utils/hotpath",
+]
+hotpath-alloc = [
+    "hotpath",
+    "hotpath/hotpath-alloc",
+    "rustfs-credentials/hotpath-alloc",
+    "rustfs-policy/hotpath-alloc",
+    "rustfs-utils/hotpath-alloc",
+]
+hotpath-cpu = [
+    "hotpath",
+    "hotpath/hotpath-cpu",
+    "rustfs-credentials/hotpath-cpu",
+    "rustfs-policy/hotpath-cpu",
+    "rustfs-utils/hotpath-cpu",
+]
+
 [dependencies]
+hotpath.workspace = true
 tokio = { workspace = true, features = ["rt", "sync"] }
 reqwest = { workspace = true, features = ["json"] }
 serde = { workspace = true, features = ["derive"] }

crates/keystone/src/client.rs

@@ -95,6 +95,7 @@ impl KeystoneClient {
     }
 
     /// Validate a Keystone token
+    #[hotpath::measure]
     pub async fn validate_token(&self, token: &str) -> Result<KeystoneToken> {
         match self.version {
             KeystoneVersion::V3 => self.validate_token_v3(token).await,
@@ -238,6 +239,7 @@ impl KeystoneClient {
     }
 
     /// Get EC2 credentials for a user
+    #[hotpath::measure]
     pub async fn get_ec2_credentials(&self, user_id: &str, project_id: Option<&str>) -> Result<Vec<EC2Credential>> {
         let admin_token = self.get_admin_token().await?;