k/protocol/generator: Override fetchable_partition_response

* Introduce `small_fragment_vector` * Switch `fetchable_partition_response` to it Signed-off-by: Ben Pope <[email protected]>
redpanda-data · Oct 10, 2023 · f33973c · f33973c
1 parent 793d7af
commit f33973c
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Showing 5 changed files with 11 additions and 7 deletions.
diff --git a/src/v/kafka/client/fetcher.cc b/src/v/kafka/client/fetcher.cc
@@ -74,7 +74,7 @@ make_fetch_response(const model::topic_partition& tp, std::exception_ptr ex) {
       .aborted{},
       .records{}};
 
-    std::vector<fetch_response::partition_response> responses;
+    small_fragment_vector<fetch_response::partition_response> responses;
     responses.push_back(std::move(pr));
     auto response = fetch_response::partition{.name = tp.topic};
     response.partitions = std::move(responses);

diff --git a/src/v/kafka/protocol/fetch.h b/src/v/kafka/protocol/fetch.h
@@ -213,7 +213,7 @@ struct fetch_response final {
     public:
         using partition_iterator = std::vector<partition>::iterator;
         using partition_response_iterator
-          = std::vector<partition_response>::iterator;
+          = small_fragment_vector<partition_response>::iterator;
 
         struct value_type {
             partition_iterator partition;

diff --git a/src/v/kafka/protocol/schemata/generator.py b/src/v/kafka/protocol/schemata/generator.py
@@ -464,7 +464,8 @@
 # These types, when they appear as the member type of an array, will override
 # the container type from std::vector
 override_member_container = {
-    'metadata_response_partition': 'large_fragment_vector'
+    'metadata_response_partition': 'large_fragment_vector',
+    'fetchable_partition_response': 'small_fragment_vector'
 }
 
 

diff --git a/src/v/kafka/server/handlers/fetch.cc b/src/v/kafka/server/handlers/fetch.cc
@@ -926,9 +926,8 @@ op_context::op_context(request_context&& ctx, ss::smp_service_group ssg)
 
 // insert and reserve space for a new topic in the response
 void op_context::start_response_topic(const fetch_request::topic& topic) {
-    auto& p = response.data.topics.emplace_back(
+    response.data.topics.emplace_back(
       fetchable_topic_response{.name = topic.name});
-    p.partitions.reserve(topic.fetch_partitions.size());
 }
 
 void op_context::start_response_partition(const fetch_request::partition& p) {
@@ -1058,8 +1057,6 @@ ss::future<response_ptr> op_context::send_response() && {
         if (it->is_new_topic) {
             final_response.data.topics.emplace_back(
               fetchable_topic_response{.name = it->partition->name});
-            final_response.data.topics.back().partitions.reserve(
-              it->partition->partitions.size());
         }
 
         fetch_response::partition_response r{

diff --git a/src/v/utils/fragmented_vector.h b/src/v/utils/fragmented_vector.h
@@ -338,3 +338,9 @@ class fragmented_vector {
  */
 template<typename T>
 using large_fragment_vector = fragmented_vector<T, 32 * 1024>;
+
+/**
+ * An alias for a fragmented_vector using a smaller fragment size.
+ */
+template<typename T>
+using small_fragment_vector = fragmented_vector<T, 1024>;