b/158262661: Move snake to json segment mapping to per-operation instead of global

api/envoy/v6/http/path_matcher/config.proto

@@ -26,17 +26,14 @@ message PathMatcherRule {
   // Operation name (selector) used as a unique ID for the operation.
   string operation = 2 [(validate.rules).string.min_bytes = 1];
 
-  // If set, the path parameters in the `pattern` must be extracted.
-  // Ref:
+  // If set, the path parameters in the `pattern` must be extracted. Ref:
   // https://cloud.google.com/endpoints/docs/openapi/openapi-extensions#understanding_path_translation
   PathParameterExtractionRule path_parameter_extraction = 3;
 }
 
 message PathParameterExtractionRule {
   // Each rule has a mapping of snake_case segments to jsonCase segments.
-  // For example, for a URI template: /{foo_bar}
-  //  * snake_name = "foo_bar"
-  //  * json_name = "fooBar"
+  // If the map is empty, the path params still need to be extracted.
   map<string, string> snake_to_json_segments = 2;
 }
 

src/api_proxy/path_matcher/BUILD

@@ -58,6 +58,7 @@ envoy_basic_cc_library(
         ":path_matcher_lib",
         "//external:abseil_flat_hash_map",
         "//external:abseil_strings",
+        "//external:protobuf",
     ],
 )
 

src/envoy/http/backend_auth/filter_config.h

@@ -26,7 +26,7 @@ namespace backend_auth {
 /**
  * All stats for the backend auth filter. @see stats_macros.h
  */
-#define ALL_PATH_MATCHER_FILTER_STATS(COUNTER) \
+#define ALL_BACKEND_AUTH_FILTER_STATS(COUNTER) \
   COUNTER(denied_by_no_operation)              \
   COUNTER(denied_by_no_token)                  \
   COUNTER(allowed_by_no_configured_rules)      \
@@ -36,7 +36,7 @@ namespace backend_auth {
  * Wrapper struct for backend auth filter stats. @see stats_macros.h
  */
 struct FilterStats {
-  ALL_PATH_MATCHER_FILTER_STATS(GENERATE_COUNTER_STRUCT)
+  ALL_BACKEND_AUTH_FILTER_STATS(GENERATE_COUNTER_STRUCT)
 };
 
 class FilterConfig {

src/envoy/http/backend_auth/filter_config_impl.h

@@ -56,7 +56,7 @@ class FilterConfigImpl
   FilterStats generateStats(const std::string& prefix,
                             Envoy::Stats::Scope& scope) {
     const std::string final_prefix = prefix + "backend_auth.";
-    return {ALL_PATH_MATCHER_FILTER_STATS(
+    return {ALL_BACKEND_AUTH_FILTER_STATS(
         POOL_COUNTER_PREFIX(scope, final_prefix))};
   }
 

src/envoy/http/backend_auth/filter_test.cc

@@ -53,7 +53,7 @@ class BackendAuthFilterTest : public ::testing::Test {
   }
 
   testing::NiceMock<Envoy::Stats::MockIsolatedStatsStore> scope_;
-  FilterStats stats_{ALL_PATH_MATCHER_FILTER_STATS(
+  FilterStats stats_{ALL_BACKEND_AUTH_FILTER_STATS(
       POOL_COUNTER_PREFIX(scope_, "backend_auth."))};
 
   std::shared_ptr<MockFilterConfigParser> mock_filter_config_parser_;

src/envoy/http/path_matcher/filter_config.cc

@@ -39,7 +39,7 @@ FilterConfig::FilterConfig(
     // Only stores the operations that need path param extraction.
     if (rule.has_path_parameter_extraction()) {
       path_param_extractions_[rule.operation()] =
-          rule.path_parameter_extraction();
+          &rule.path_parameter_extraction();
     }
   }
   path_matcher_ = pmb.Build();

src/envoy/http/path_matcher/filter_config.h

@@ -78,10 +78,7 @@ class FilterConfig : public Envoy::Logger::Loggable<Envoy::Logger::Id::filter> {
       return nullptr;
     }
 
-    // Relies on pointer safety in absl::flat_hash_map.
-    // The map will never change after filter config is generated, so it should
-    // be safe.
-    return &(operation_it->second);
+    return operation_it->second;
   }
 
   FilterStats& stats() { return stats_; }
@@ -100,9 +97,9 @@ class FilterConfig : public Envoy::Logger::Loggable<Envoy::Logger::Id::filter> {
 
   // Map from operation id to a PathParameterExtractionRule.
   // Only stores the operations that need path param extraction.
-  absl::flat_hash_map<
-      std::string,
-      ::espv2::api::envoy::v6::http::path_matcher::PathParameterExtractionRule>
+  absl::flat_hash_map<std::string,
+                      const ::espv2::api::envoy::v6::http::path_matcher::
+                          PathParameterExtractionRule*>
       path_param_extractions_;
 
   FilterStats stats_;