From e4f5c7933dbceab9082f8f1730344fca2e6663ca Mon Sep 17 00:00:00 2001
From: Dmitri Bourlatchkov <dmitri.bourlatchkov@gmail.com>
Date: Mon, 15 Sep 2025 18:50:53 -0400
Subject: [PATCH] Avoid exceptions on ETag matches

Exceptions have runtime overhead, which is avoidable in this case.
---
 .../iceberg/IcebergCatalogAdapter.java        | 21 +++++++++----------
 1 file changed, 10 insertions(+), 11 deletions(-)

diff --git a/runtime/service/src/main/java/org/apache/polaris/service/catalog/iceberg/IcebergCatalogAdapter.java b/runtime/service/src/main/java/org/apache/polaris/service/catalog/iceberg/IcebergCatalogAdapter.java
index 7ed3e2d298..0560c6497a 100644
--- a/runtime/service/src/main/java/org/apache/polaris/service/catalog/iceberg/IcebergCatalogAdapter.java
+++ b/runtime/service/src/main/java/org/apache/polaris/service/catalog/iceberg/IcebergCatalogAdapter.java
@@ -30,7 +30,6 @@
 import jakarta.enterprise.inject.Any;
 import jakarta.enterprise.inject.Instance;
 import jakarta.inject.Inject;
-import jakarta.ws.rs.WebApplicationException;
 import jakarta.ws.rs.core.HttpHeaders;
 import jakarta.ws.rs.core.Response;
 import jakarta.ws.rs.core.SecurityContext;
@@ -440,24 +439,24 @@ public Response loadTable(
         securityContext,
         prefix,
         catalog -> {
-          LoadTableResponse response;
+          Optional<LoadTableResponse> response;
 
           if (delegationModes.isEmpty()) {
-            response =
-                catalog
-                    .loadTableIfStale(tableIdentifier, ifNoneMatch, snapshots)
-                    .orElseThrow(() -> new WebApplicationException(Response.Status.NOT_MODIFIED));
+            response = catalog.loadTableIfStale(tableIdentifier, ifNoneMatch, snapshots);
           } else {
             Optional<String> refreshCredentialsEndpoint =
                 getRefreshCredentialsEndpoint(delegationModes, prefix, tableIdentifier);
             response =
-                catalog
-                    .loadTableWithAccessDelegationIfStale(
-                        tableIdentifier, ifNoneMatch, snapshots, refreshCredentialsEndpoint)
-                    .orElseThrow(() -> new WebApplicationException(Response.Status.NOT_MODIFIED));
+                catalog.loadTableWithAccessDelegationIfStale(
+                    tableIdentifier, ifNoneMatch, snapshots, refreshCredentialsEndpoint);
+          }
+
+          if (response.isEmpty()) {
+            return Response.notModified().build();
           }
 
-          return tryInsertETagHeader(Response.ok(response), response, namespace, table).build();
+          return tryInsertETagHeader(Response.ok(response.get()), response.get(), namespace, table)
+              .build();
         });
   }