Let default checksum provider return DefaultRequestChecksumOverride

This commit addresses #3465 (comment)

aws/rust-runtime/aws-inlineable/src/http_request_checksum.rs

@@ -60,7 +60,7 @@ impl Storable for RequestChecksumInterceptorState {
     type Storer = StoreReplace<Self>;
 }
 
-pub(crate) type CustomDefaultFn = Box<
+type CustomDefaultFn = Box<
     dyn Fn(Option<ChecksumAlgorithm>, &ConfigBag) -> Option<ChecksumAlgorithm>
         + Send
         + Sync

aws/rust-runtime/aws-inlineable/src/s3_express.rs

@@ -767,25 +767,30 @@ pub(crate) mod runtime_plugin {
 }
 
 pub(crate) mod checksum {
+    use crate::http_request_checksum::DefaultRequestChecksumOverride;
     use aws_smithy_checksums::ChecksumAlgorithm;
     use aws_smithy_types::config_bag::ConfigBag;
 
     pub(crate) fn provide_default_checksum_algorithm(
-        original_checksum: Option<ChecksumAlgorithm>,
-        cfg: &ConfigBag,
-    ) -> Option<ChecksumAlgorithm> {
-        // S3 does not have the `ChecksumAlgorithm::Md5`, therefore customers cannot set it
-        // from outside.
-        if original_checksum != Some(ChecksumAlgorithm::Md5) {
-            return original_checksum;
-        }
-
-        if crate::s3_express::utils::for_s3_express(cfg) {
-            // S3 Express requires setting the default checksum algorithm to CRC-32
-            Some(ChecksumAlgorithm::Crc32)
-        } else {
-            original_checksum
+    ) -> crate::http_request_checksum::DefaultRequestChecksumOverride {
+        fn _provide_default_checksum_algorithm(
+            original_checksum: Option<ChecksumAlgorithm>,
+            cfg: &ConfigBag,
+        ) -> Option<ChecksumAlgorithm> {
+            // S3 does not have the `ChecksumAlgorithm::Md5`, therefore customers cannot set it
+            // from outside.
+            if original_checksum != Some(ChecksumAlgorithm::Md5) {
+                return original_checksum;
+            }
+
+            if crate::s3_express::utils::for_s3_express(cfg) {
+                // S3 Express requires setting the default checksum algorithm to CRC-32
+                Some(ChecksumAlgorithm::Crc32)
+            } else {
+                original_checksum
+            }
         }
+        DefaultRequestChecksumOverride::new(_provide_default_checksum_algorithm)
     }
 }
 

aws/sdk-codegen/src/main/kotlin/software/amazon/smithy/rustsdk/customize/s3/S3ExpressDecorator.kt

@@ -32,7 +32,6 @@ import software.amazon.smithy.rust.codegen.core.util.getTrait
 import software.amazon.smithy.rustsdk.AwsCargoDependency
 import software.amazon.smithy.rustsdk.AwsRuntimeType
 import software.amazon.smithy.rustsdk.InlineAwsDependency
-import software.amazon.smithy.rustsdk.awsInlineableHttpRequestChecksum
 
 class S3ExpressDecorator : ClientCodegenDecorator {
     override val name: String = "S3ExpressDecorator"
@@ -245,9 +244,6 @@ class S3ExpressRequestChecksumCustomization(
             *preludeScope,
             "ChecksumAlgorithm" to RuntimeType.smithyChecksums(runtimeConfig).resolve("ChecksumAlgorithm"),
             "ConfigBag" to RuntimeType.configBag(runtimeConfig),
-            "DefaultRequestChecksumOverride" to
-                runtimeConfig.awsInlineableHttpRequestChecksum()
-                    .resolve("DefaultRequestChecksumOverride"),
             "Document" to RuntimeType.smithyTypes(runtimeConfig).resolve("Document"),
             "for_s3_express" to s3ExpressModule(runtimeConfig).resolve("utils::for_s3_express"),
             "provide_default_checksum_algorithm" to s3ExpressModule(runtimeConfig).resolve("checksum::provide_default_checksum_algorithm"),
@@ -262,9 +258,7 @@ class S3ExpressRequestChecksumCustomization(
                     if (checksumTrait.isRequestChecksumRequired) {
                         rustTemplate(
                             """
-                            ${section.newLayerName}.store_put(#{DefaultRequestChecksumOverride}::new(
-                                #{provide_default_checksum_algorithm}
-                            ));
+                            ${section.newLayerName}.store_put(#{provide_default_checksum_algorithm}());
                             """,
                             *codegenScope,
                             "customDefault" to