Remove function config allocations per invocation.

Cargo.toml

@@ -1,4 +1,5 @@
 [workspace]
+resolver = "2"
 members = [
     "lambda-http",
     "lambda-integration-tests",

lambda-runtime/Cargo.toml

@@ -32,7 +32,7 @@ hyper = { version = "0.14.20", features = [
     "server",
 ] }
 futures = "0.3"
-serde = { version = "1", features = ["derive"] }
+serde = { version = "1", features = ["derive", "rc"] }
 serde_json = "^1"
 bytes = "1.0"
 http = "0.2"

lambda-runtime/src/lib.rs

@@ -23,6 +23,7 @@ use std::{
     future::Future,
     marker::PhantomData,
     panic,
+    sync::Arc,
 };
 use tokio::io::{AsyncRead, AsyncWrite};
 use tokio_stream::{Stream, StreamExt};
@@ -58,6 +59,8 @@ pub struct Config {
     pub log_group: String,
 }
 
+type RefConfig = Arc<Config>;
+
 impl Config {
     /// Attempts to read configuration from environment variables.
     pub fn from_env() -> Result<Self, Error> {
@@ -86,7 +89,7 @@ where
 
 struct Runtime<C: Service<http::Uri> = HttpConnector> {
     client: Client<C>,
-    config: Config,
+    config: RefConfig,
 }
 
 impl<C> Runtime<C>
@@ -127,8 +130,7 @@ where
                 continue;
             }
 
-            let ctx: Context = Context::try_from(parts.headers)?;
-            let ctx: Context = ctx.with_config(&self.config);
+            let ctx: Context = Context::try_from((self.config.clone(), parts.headers))?;
             let request_id = &ctx.request_id.clone();
 
             let request_span = match &ctx.xray_trace_id {
@@ -263,7 +265,10 @@ where
     trace!("Loading config from env");
     let config = Config::from_env()?;
     let client = Client::builder().build().expect("Unable to create a runtime client");
-    let runtime = Runtime { client, config };
+    let runtime = Runtime {
+        client,
+        config: Arc::new(config),
+    };
 
     let client = &runtime.client;
     let incoming = incoming(client);
@@ -294,15 +299,15 @@ mod endpoint_tests {
         },
         simulated,
         types::Diagnostic,
-        Error, Runtime,
+        Config, Error, Runtime,
     };
     use futures::future::BoxFuture;
     use http::{uri::PathAndQuery, HeaderValue, Method, Request, Response, StatusCode, Uri};
     use hyper::{server::conn::Http, service::service_fn, Body};
     use lambda_runtime_api_client::Client;
     use serde_json::json;
     use simulated::DuplexStreamWrapper;
-    use std::{convert::TryFrom, env, marker::PhantomData};
+    use std::{convert::TryFrom, env, marker::PhantomData, sync::Arc};
     use tokio::{
         io::{self, AsyncRead, AsyncWrite},
         select,
@@ -531,9 +536,12 @@ mod endpoint_tests {
         if env::var("AWS_LAMBDA_LOG_GROUP_NAME").is_err() {
             env::set_var("AWS_LAMBDA_LOG_GROUP_NAME", "test_log");
         }
-        let config = crate::Config::from_env().expect("Failed to read env vars");
+        let config = Config::from_env().expect("Failed to read env vars");
 
-        let runtime = Runtime { client, config };
+        let runtime = Runtime {
+            client,
+            config: Arc::new(config),
+        };
         let client = &runtime.client;
         let incoming = incoming(client).take(1);
         runtime.run(incoming, f).await?;
@@ -568,13 +576,13 @@ mod endpoint_tests {
 
         let f = crate::service_fn(func);
 
-        let config = crate::Config {
+        let config = Arc::new(Config {
             function_name: "test_fn".to_string(),
             memory: 128,
             version: "1".to_string(),
             log_stream: "test_stream".to_string(),
             log_group: "test_log".to_string(),
-        };
+        });
 
         let runtime = Runtime { client, config };
         let client = &runtime.client;

lambda-runtime/src/types.rs

@@ -1,4 +1,4 @@
-use crate::{Config, Error};
+use crate::{Error, RefConfig};
 use base64::prelude::*;
 use bytes::Bytes;
 use http::{HeaderMap, HeaderValue, StatusCode};
@@ -97,7 +97,7 @@ pub struct CognitoIdentity {
 /// are populated using the [Lambda environment variables](https://docs.aws.amazon.com/lambda/latest/dg/current-supported-versions.html)
 /// and [the headers returned by the poll request to the Runtime APIs](https://docs.aws.amazon.com/lambda/latest/dg/runtimes-api.html#runtimes-api-next).
 #[non_exhaustive]
-#[derive(Clone, Debug, Eq, PartialEq, Default, Serialize, Deserialize)]
+#[derive(Clone, Debug, Deserialize, Eq, PartialEq, Serialize)]
 pub struct Context {
     /// The AWS request ID generated by the Lambda service.
     pub request_id: String,
@@ -117,12 +117,14 @@ pub struct Context {
     /// Lambda function configuration from the local environment variables.
     /// Includes information such as the function name, memory allocation,
     /// version, and log streams.
-    pub env_config: Config,
+    pub env_config: RefConfig,
 }
 
-impl TryFrom<HeaderMap> for Context {
+impl TryFrom<(RefConfig, HeaderMap)> for Context {
     type Error = Error;
-    fn try_from(headers: HeaderMap) -> Result<Self, Self::Error> {
+    fn try_from(data: (RefConfig, HeaderMap)) -> Result<Self, Self::Error> {
+        let env_config = data.0;
+        let headers = data.1;
         let client_context: Option<ClientContext> = if let Some(value) = headers.get("lambda-runtime-client-context") {
             serde_json::from_str(value.to_str()?)?
         } else {
@@ -158,13 +160,20 @@ impl TryFrom<HeaderMap> for Context {
                 .map(|v| String::from_utf8_lossy(v.as_bytes()).to_string()),
             client_context,
             identity,
-            ..Default::default()
+            env_config,
         };
 
         Ok(ctx)
     }
 }
 
+impl Context {
+    /// The execution deadline for the current invocation.
+    pub fn deadline(&self) -> SystemTime {
+        SystemTime::UNIX_EPOCH + Duration::from_millis(self.deadline)
+    }
+}
+
 /// Incoming Lambda request containing the event payload and context.
 #[derive(Clone, Debug)]
 pub struct LambdaEvent<T> {
@@ -273,6 +282,8 @@ where
 #[cfg(test)]
 mod test {
     use super::*;
+    use crate::Config;
+    use std::sync::Arc;
 
     #[test]
     fn round_trip_lambda_error() {
@@ -292,6 +303,8 @@ mod test {
 
     #[test]
     fn context_with_expected_values_and_types_resolves() {
+        let config = Arc::new(Config::default());
+
         let mut headers = HeaderMap::new();
         headers.insert("lambda-runtime-aws-request-id", HeaderValue::from_static("my-id"));
         headers.insert("lambda-runtime-deadline-ms", HeaderValue::from_static("123"));
@@ -300,16 +313,18 @@ mod test {
             HeaderValue::from_static("arn::myarn"),
         );
         headers.insert("lambda-runtime-trace-id", HeaderValue::from_static("arn::myarn"));
-        let tried = Context::try_from(headers);
+        let tried = Context::try_from((config, headers));
         assert!(tried.is_ok());
     }
 
     #[test]
     fn context_with_certain_missing_headers_still_resolves() {
+        let config = Arc::new(Config::default());
+
         let mut headers = HeaderMap::new();
         headers.insert("lambda-runtime-aws-request-id", HeaderValue::from_static("my-id"));
         headers.insert("lambda-runtime-deadline-ms", HeaderValue::from_static("123"));
-        let tried = Context::try_from(headers);
+        let tried = Context::try_from((config, headers));
         assert!(tried.is_ok());
     }
 
@@ -338,7 +353,9 @@ mod test {
             "lambda-runtime-client-context",
             HeaderValue::from_str(&client_context_str).unwrap(),
         );
-        let tried = Context::try_from(headers);
+
+        let config = Arc::new(Config::default());
+        let tried = Context::try_from((config, headers));
         assert!(tried.is_ok());
         let tried = tried.unwrap();
         assert!(tried.client_context.is_some());
@@ -347,17 +364,20 @@ mod test {
 
     #[test]
     fn context_with_empty_client_context_resolves() {
+        let config = Arc::new(Config::default());
         let mut headers = HeaderMap::new();
         headers.insert("lambda-runtime-aws-request-id", HeaderValue::from_static("my-id"));
         headers.insert("lambda-runtime-deadline-ms", HeaderValue::from_static("123"));
         headers.insert("lambda-runtime-client-context", HeaderValue::from_static("{}"));
-        let tried = Context::try_from(headers);
+        let tried = Context::try_from((config, headers));
         assert!(tried.is_ok());
         assert!(tried.unwrap().client_context.is_some());
     }
 
     #[test]
     fn context_with_identity_resolves() {
+        let config = Arc::new(Config::default());
+
         let cognito_identity = CognitoIdentity {
             identity_id: String::new(),
             identity_pool_id: String::new(),
@@ -370,7 +390,7 @@ mod test {
             "lambda-runtime-cognito-identity",
             HeaderValue::from_str(&cognito_identity_str).unwrap(),
         );
-        let tried = Context::try_from(headers);
+        let tried = Context::try_from((config, headers));
         assert!(tried.is_ok());
         let tried = tried.unwrap();
         assert!(tried.identity.is_some());
@@ -379,6 +399,8 @@ mod test {
 
     #[test]
     fn context_with_bad_deadline_type_is_err() {
+        let config = Arc::new(Config::default());
+
         let mut headers = HeaderMap::new();
         headers.insert("lambda-runtime-aws-request-id", HeaderValue::from_static("my-id"));
         headers.insert(
@@ -390,86 +412,81 @@ mod test {
             HeaderValue::from_static("arn::myarn"),
         );
         headers.insert("lambda-runtime-trace-id", HeaderValue::from_static("arn::myarn"));
-        let tried = Context::try_from(headers);
+        let tried = Context::try_from((config, headers));
         assert!(tried.is_err());
     }
 
     #[test]
     fn context_with_bad_client_context_is_err() {
+        let config = Arc::new(Config::default());
+
         let mut headers = HeaderMap::new();
         headers.insert("lambda-runtime-aws-request-id", HeaderValue::from_static("my-id"));
         headers.insert("lambda-runtime-deadline-ms", HeaderValue::from_static("123"));
         headers.insert(
             "lambda-runtime-client-context",
             HeaderValue::from_static("BAD-Type,not JSON"),
         );
-        let tried = Context::try_from(headers);
+        let tried = Context::try_from((config, headers));
         assert!(tried.is_err());
     }
 
     #[test]
     fn context_with_empty_identity_is_err() {
+        let config = Arc::new(Config::default());
+
         let mut headers = HeaderMap::new();
         headers.insert("lambda-runtime-aws-request-id", HeaderValue::from_static("my-id"));
         headers.insert("lambda-runtime-deadline-ms", HeaderValue::from_static("123"));
         headers.insert("lambda-runtime-cognito-identity", HeaderValue::from_static("{}"));
-        let tried = Context::try_from(headers);
+        let tried = Context::try_from((config, headers));
         assert!(tried.is_err());
     }
 
     #[test]
     fn context_with_bad_identity_is_err() {
+        let config = Arc::new(Config::default());
+
         let mut headers = HeaderMap::new();
         headers.insert("lambda-runtime-aws-request-id", HeaderValue::from_static("my-id"));
         headers.insert("lambda-runtime-deadline-ms", HeaderValue::from_static("123"));
         headers.insert(
             "lambda-runtime-cognito-identity",
             HeaderValue::from_static("BAD-Type,not JSON"),
         );
-        let tried = Context::try_from(headers);
+        let tried = Context::try_from((config, headers));
         assert!(tried.is_err());
     }
 
     #[test]
     #[should_panic]
     #[allow(unused_must_use)]
     fn context_with_missing_request_id_should_panic() {
+        let config = Arc::new(Config::default());
+
         let mut headers = HeaderMap::new();
         headers.insert("lambda-runtime-aws-request-id", HeaderValue::from_static("my-id"));
         headers.insert(
             "lambda-runtime-invoked-function-arn",
             HeaderValue::from_static("arn::myarn"),
         );
         headers.insert("lambda-runtime-trace-id", HeaderValue::from_static("arn::myarn"));
-        Context::try_from(headers);
+        Context::try_from((config, headers));
     }
 
     #[test]
     #[should_panic]
     #[allow(unused_must_use)]
     fn context_with_missing_deadline_should_panic() {
+        let config = Arc::new(Config::default());
+
         let mut headers = HeaderMap::new();
         headers.insert("lambda-runtime-deadline-ms", HeaderValue::from_static("123"));
         headers.insert(
             "lambda-runtime-invoked-function-arn",
             HeaderValue::from_static("arn::myarn"),
         );
         headers.insert("lambda-runtime-trace-id", HeaderValue::from_static("arn::myarn"));
-        Context::try_from(headers);
-    }
-}
-
-impl Context {
-    /// Add environment details to the context by setting `env_config`.
-    pub fn with_config(self, config: &Config) -> Self {
-        Self {
-            env_config: config.clone(),
-            ..self
-        }
-    }
-
-    /// The execution deadline for the current invocation.
-    pub fn deadline(&self) -> SystemTime {
-        SystemTime::UNIX_EPOCH + Duration::from_millis(self.deadline)
+        Context::try_from((config, headers));
     }
 }