Ensure client ID is included in chunk cache lookup key

Author: sd109

Cargo.lock

@@ -70,6 +70,7 @@ zerocopy = { version = "0.6.1", features = ["alloc", "simd"] }
 zune-inflate = "0.2.54"
 cached = { version = "0.54.0", features = ["disk_store", "async"] }
 bytes = { version = "1.9.0", features = ["serde"] }
+uuid = { version = "1.12.1", features = ["v4"] }
 
 [dev-dependencies]
 criterion = { version = "0.4", features = ["async_tokio", "html_reports"] }

Cargo.toml

@@ -178,7 +178,7 @@ async fn schema() -> &'static str {
     disk = true,
     create = r##"{ DiskCacheBuilder::new("test-cache").set_disk_directory("./").build().expect("valid disk cache builder") }"##,
     key = "String",
-    convert = r##"{ format!("{:?}", request_data) }"##
+    convert = r##"{ format!("{},{:?}", client, request_data) }"##
 )]
 async fn download_object<'a>(
     client: &s3_client::S3Client,

src/app.rs

@@ -1,6 +1,8 @@
 //! A simplified S3 client that supports downloading objects.
 //! It attempts to hide the complexities of working with the AWS SDK for S3.
 
+use std::fmt::Display;
+
 use crate::error::ActiveStorageError;
 use crate::resource_manager::ResourceManager;
 
@@ -88,10 +90,24 @@ impl S3ClientMap {
 }
 
 /// S3 client object.
-#[derive(Clone, Debug)]
+#[derive(Clone)]
 pub struct S3Client {
     /// Underlying AWS SDK S3 client object.
     client: Client,
+    /// A unique identifier for the client
+    // TODO: Make this a hash of url + access key + secret key
+    // using https://github.com/RustCrypto/hashes?tab=readme-ov-file
+    // This will be more urgently required once an ageing mechanism
+    // is implemented for [crate::S3ClientMap].
+    id: String,
+}
+
+// Required so that client can be used as part of the lookup
+// key for a local chunk cache.
+impl Display for S3Client {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.id)
+    }
 }
 
 impl S3Client {
@@ -120,7 +136,10 @@ impl S3Client {
             .force_path_style(true)
             .build();
         let client = Client::from_conf(s3_config);
-        Self { client }
+        Self {
+            client,
+            id: uuid::Uuid::new_v4().to_string(),
+        }
     }
 
     /// Downloads an object from object storage and returns the data as Bytes