caching: Refactored registration of inline headers in the CacheFilter…

… tree to a separate header file (#12576)

Refactored registration of inline headers in the CacheFilter tree to a separate header file.

Signed-off-by: Yosry Ahmed <yosryahmed@google.com>

source/extensions/filters/http/cache/BUILD

@@ -20,10 +20,10 @@ envoy_cc_library(
         ":cache_headers_utils_lib",
         ":cacheability_utils_lib",
         ":http_cache_lib",
+        ":inline_headers_handles",
         "//source/common/common:enum_to_int",
         "//source/common/common:logger_lib",
         "//source/common/common:macros",
-        "//source/common/http:header_map_lib",
         "//source/common/http:headers_lib",
         "//source/common/http:utility_lib",
         "//source/extensions/filters/http/common:pass_through_filter_lib",
@@ -37,6 +37,7 @@ envoy_cc_library(
     hdrs = ["cacheability_utils.h"],
     deps = [
         ":cache_headers_utils_lib",
+        ":inline_headers_handles",
         "//source/common/common:utility_lib",
         "//source/common/http:headers_lib",
     ],
@@ -53,6 +54,7 @@ envoy_cc_library(
     hdrs = ["http_cache.h"],
     deps = [
         ":cache_headers_utils_lib",
+        ":inline_headers_handles",
         ":key_cc_proto",
         "//include/envoy/buffer:buffer_interface",
         "//include/envoy/common:time_interface",
@@ -78,6 +80,14 @@ envoy_cc_library(
     ],
 )
 
+envoy_cc_library(
+    name = "inline_headers_handles",
+    hdrs = ["inline_headers_handles.h"],
+    deps = [
+        "//source/common/http:headers_lib",
+    ],
+)
+
 envoy_cc_extension(
     name = "config",
     srcs = ["config.cc"],

source/extensions/filters/http/cache/cache_filter.cc

@@ -5,6 +5,7 @@
 #include "common/http/utility.h"
 
 #include "extensions/filters/http/cache/cacheability_utils.h"
+#include "extensions/filters/http/cache/inline_headers_handles.h"
 
 #include "absl/strings/string_view.h"
 
@@ -274,9 +275,8 @@ bool CacheFilter::shouldUpdateCachedEntry(const Http::ResponseHeaderMap& respons
   // and assuming a single cached response per key:
   // If the 304 response contains a strong validator (etag) that does not match the cached response,
   // the cached response should not be updated.
-  const Http::HeaderEntry* response_etag = response_headers.get(Http::CustomHeaders::get().Etag);
-  const Http::HeaderEntry* cached_etag =
-      lookup_result_->headers_->get(Http::CustomHeaders::get().Etag);
+  const Http::HeaderEntry* response_etag = response_headers.getInline(etag_handle.handle());
+  const Http::HeaderEntry* cached_etag = lookup_result_->headers_->getInline(etag_handle.handle());
   return !response_etag || (cached_etag && cached_etag->value().getStringView() ==
                                                response_etag->value().getStringView());
 }
@@ -288,25 +288,24 @@ void CacheFilter::injectValidationHeaders(Http::RequestHeaderMap& request_header
          "injectValidationHeaders precondition unsatisfied: the "
          "CacheFilter is not validating a cache lookup result");
 
-  const Http::HeaderEntry* etag_header =
-      lookup_result_->headers_->get(Http::CustomHeaders::get().Etag);
+  const Http::HeaderEntry* etag_header = lookup_result_->headers_->getInline(etag_handle.handle());
   const Http::HeaderEntry* last_modified_header =
-      lookup_result_->headers_->get(Http::CustomHeaders::get().LastModified);
+      lookup_result_->headers_->getInline(last_modified_handle.handle());
 
   if (etag_header) {
     absl::string_view etag = etag_header->value().getStringView();
-    request_headers.setReferenceKey(Http::CustomHeaders::get().IfNoneMatch, etag);
+    request_headers.setInline(if_none_match_handle.handle(), etag);
   }
   if (CacheHeadersUtils::httpTime(last_modified_header) != SystemTime()) {
     // Valid Last-Modified header exists.
     absl::string_view last_modified = last_modified_header->value().getStringView();
-    request_headers.setReferenceKey(Http::CustomHeaders::get().IfModifiedSince, last_modified);
+    request_headers.setInline(if_modified_since_handle.handle(), last_modified);
   } else {
     // Either Last-Modified is missing or invalid, fallback to Date.
     // A correct behaviour according to:
     // https://httpwg.org/specs/rfc7232.html#header.if-modified-since
     absl::string_view date = lookup_result_->headers_->getDateValue();
-    request_headers.setReferenceKey(Http::CustomHeaders::get().IfModifiedSince, date);
+    request_headers.setInline(if_modified_since_handle.handle(), date);
   }
 }
 

source/extensions/filters/http/cache/cache_filter.h

@@ -6,7 +6,6 @@
 #include <vector>
 
 #include "envoy/extensions/filters/http/cache/v3alpha/cache.pb.h"
-#include "envoy/http/header_map.h"
 
 #include "common/common/logger.h"
 

source/extensions/filters/http/cache/cacheability_utils.cc

@@ -5,6 +5,8 @@
 #include "common/common/macros.h"
 #include "common/common/utility.h"
 
+#include "extensions/filters/http/cache/inline_headers_handles.h"
+
 namespace Envoy {
 namespace Extensions {
 namespace HttpFilters {
@@ -30,11 +32,6 @@ const std::vector<const Http::LowerCaseString*>& conditionalHeaders() {
 }
 } // namespace
 
-Http::RegisterCustomInlineHeader<Http::CustomInlineHeaderRegistry::Type::RequestHeaders>
-    authorization_handle(Http::CustomHeaders::get().Authorization);
-Http::RegisterCustomInlineHeader<Http::CustomInlineHeaderRegistry::Type::ResponseHeaders>
-    cache_control_handle(Http::CustomHeaders::get().CacheControl);
-
 bool CacheabilityUtils::isCacheableRequest(const Http::RequestHeaderMap& headers) {
   const absl::string_view method = headers.getMethodValue();
   const absl::string_view forwarded_proto = headers.getForwardedProtoValue();
@@ -60,7 +57,7 @@ bool CacheabilityUtils::isCacheableRequest(const Http::RequestHeaderMap& headers
 }
 
 bool CacheabilityUtils::isCacheableResponse(const Http::ResponseHeaderMap& headers) {
-  absl::string_view cache_control = headers.getInlineValue(cache_control_handle.handle());
+  absl::string_view cache_control = headers.getInlineValue(response_cache_control_handle.handle());
   ResponseCacheControl response_cache_control(cache_control);
 
   // Only cache responses with explicit validation data, either:

source/extensions/filters/http/cache/http_cache.cc

@@ -11,6 +11,8 @@
 #include "common/http/headers.h"
 #include "common/protobuf/utility.h"
 
+#include "extensions/filters/http/cache/inline_headers_handles.h"
+
 #include "absl/strings/str_split.h"
 #include "absl/strings/string_view.h"
 #include "absl/time/time.h"
@@ -20,13 +22,6 @@ namespace Extensions {
 namespace HttpFilters {
 namespace Cache {
 
-Http::RegisterCustomInlineHeader<Http::CustomInlineHeaderRegistry::Type::RequestHeaders>
-    request_cache_control_handle(Http::CustomHeaders::get().CacheControl);
-Http::RegisterCustomInlineHeader<Http::CustomInlineHeaderRegistry::Type::ResponseHeaders>
-    response_cache_control_handle(Http::CustomHeaders::get().CacheControl);
-Http::RegisterCustomInlineHeader<Http::CustomInlineHeaderRegistry::Type::RequestHeaders>
-    pragma_handler(Http::CustomHeaders::get().Pragma);
-
 std::ostream& operator<<(std::ostream& os, CacheEntryStatus status) {
   switch (status) {
   case CacheEntryStatus::Ok:
@@ -90,7 +85,7 @@ size_t localHashKey(const Key& key) { return stableHashKey(key); }
 void LookupRequest::initializeRequestCacheControl(const Http::RequestHeaderMap& request_headers) {
   const absl::string_view cache_control =
       request_headers.getInlineValue(request_cache_control_handle.handle());
-  const absl::string_view pragma = request_headers.getInlineValue(pragma_handler.handle());
+  const absl::string_view pragma = request_headers.getInlineValue(pragma_handle.handle());
 
   if (!cache_control.empty()) {
     request_cache_control_ = RequestCacheControl(cache_control);

source/extensions/filters/http/cache/inline_headers_handles.h

@@ -0,0 +1,47 @@
+#pragma once
+
+#include "common/http/headers.h"
+
+namespace Envoy {
+namespace Extensions {
+namespace HttpFilters {
+namespace Cache {
+
+inline Http::RegisterCustomInlineHeader<Http::CustomInlineHeaderRegistry::Type::RequestHeaders>
+    authorization_handle(Http::CustomHeaders::get().Authorization);
+
+inline Http::RegisterCustomInlineHeader<Http::CustomInlineHeaderRegistry::Type::RequestHeaders>
+    pragma_handle(Http::CustomHeaders::get().Pragma);
+
+inline Http::RegisterCustomInlineHeader<Http::CustomInlineHeaderRegistry::Type::RequestHeaders>
+    request_cache_control_handle(Http::CustomHeaders::get().CacheControl);
+
+inline Http::RegisterCustomInlineHeader<Http::CustomInlineHeaderRegistry::Type::RequestHeaders>
+    if_match_handle(Http::CustomHeaders::get().IfMatch);
+
+inline Http::RegisterCustomInlineHeader<Http::CustomInlineHeaderRegistry::Type::RequestHeaders>
+    if_none_match_handle(Http::CustomHeaders::get().IfNoneMatch);
+
+inline Http::RegisterCustomInlineHeader<Http::CustomInlineHeaderRegistry::Type::RequestHeaders>
+    if_modified_since_handle(Http::CustomHeaders::get().IfModifiedSince);
+
+inline Http::RegisterCustomInlineHeader<Http::CustomInlineHeaderRegistry::Type::RequestHeaders>
+    if_unmodified_since_handle(Http::CustomHeaders::get().IfUnmodifiedSince);
+
+inline Http::RegisterCustomInlineHeader<Http::CustomInlineHeaderRegistry::Type::RequestHeaders>
+    if_range_handle(Http::CustomHeaders::get().IfRange);
+
+// Response headers inline handles
+inline Http::RegisterCustomInlineHeader<Http::CustomInlineHeaderRegistry::Type::ResponseHeaders>
+    response_cache_control_handle(Http::CustomHeaders::get().CacheControl);
+
+inline Http::RegisterCustomInlineHeader<Http::CustomInlineHeaderRegistry::Type::ResponseHeaders>
+    last_modified_handle(Http::CustomHeaders::get().LastModified);
+
+inline Http::RegisterCustomInlineHeader<Http::CustomInlineHeaderRegistry::Type::ResponseHeaders>
+    etag_handle(Http::CustomHeaders::get().Etag);
+
+} // namespace Cache
+} // namespace HttpFilters
+} // namespace Extensions
+} // namespace Envoy