router: pre-reserve header_parser vectors by their sizes (#37130)

Modifying HeaderParser creation to pre-reserve vectors sizes. Small perf nit in the router ingestion. Risk Level: low Testing: N/A Docs Changes: N/A Release Notes: N/A Platform Specific Features: N/A Signed-off-by: Adi Suissa-Peleg <[email protected]>
envoyproxy · Nov 16, 2024 · 80eae33 · 80eae33
1 parent 448e4e1
commit 80eae33
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/source/common/router/header_parser.cc b/source/common/router/header_parser.cc
@@ -87,6 +87,7 @@ HeadersToAddEntry::HeadersToAddEntry(const HeaderValue& header_value,
 absl::StatusOr<HeaderParserPtr>
 HeaderParser::configure(const Protobuf::RepeatedPtrField<HeaderValueOption>& headers_to_add) {
   HeaderParserPtr header_parser(new HeaderParser());
+  header_parser->headers_to_add_.reserve(headers_to_add.size());
   for (const auto& header_value_option : headers_to_add) {
     auto entry_or_error = HeadersToAddEntry::create(header_value_option);
     RETURN_IF_NOT_OK_REF(entry_or_error.status());
@@ -103,6 +104,7 @@ absl::StatusOr<HeaderParserPtr> HeaderParser::configure(
     HeaderAppendAction append_action) {
   HeaderParserPtr header_parser(new HeaderParser());
 
+  header_parser->headers_to_add_.reserve(headers_to_add.size());
   for (const auto& header_value : headers_to_add) {
     auto entry_or_error = HeadersToAddEntry::create(header_value, append_action);
     RETURN_IF_NOT_OK_REF(entry_or_error.status());
@@ -120,6 +122,7 @@ HeaderParser::configure(const Protobuf::RepeatedPtrField<HeaderValueOption>& hea
   RETURN_IF_NOT_OK_REF(parser_or_error.status());
   HeaderParserPtr header_parser = std::move(parser_or_error.value());
 
+  header_parser->headers_to_remove_.reserve(headers_to_remove.size());
   for (const auto& header : headers_to_remove) {
     // We reject :-prefix (e.g. :path) removal here. This is dangerous, since other aspects of
     // request finalization assume their existence and they are needed for well-formedness in most