stats: Capture all the strings used to accumulate http stats in an object, plumbed through the system.

include/envoy/http/BUILD

@@ -32,6 +32,7 @@ envoy_cc_library(
 envoy_cc_library(
     name = "codes_interface",
     hdrs = ["codes.h"],
+    deps = ["//include/envoy/stats:stats_interface"],
 )
 
 envoy_cc_library(
@@ -44,6 +45,15 @@ envoy_cc_library(
     ],
 )
 
+envoy_cc_library(
+    name = "context_interface",
+    hdrs = ["context.h"],
+    deps = [
+        ":codes_interface",
+        "//include/envoy/tracing:http_tracer_interface",
+    ],
+)
+
 envoy_cc_library(
     name = "filter_interface",
     hdrs = ["filter.h"],

include/envoy/http/codes.h

@@ -1,5 +1,9 @@
 #pragma once
 
+#include <chrono>
+
+#include "envoy/stats/scope.h"
+
 namespace Envoy {
 namespace Http {
 
@@ -73,5 +77,59 @@ enum class Code {
   // clang-format on
 };
 
+/**
+ * Manages updating of statistics for HTTP Status Codes. Sets up string-tokens
+ * for fast combining of tokens based on scope, status-code buckets (2xx,
+ * 4xx...), and exact status code.
+ */
+class CodeStats {
+public:
+  virtual ~CodeStats() = default;
+
+  struct ResponseStatInfo {
+    Stats::Scope& global_scope_;
+    Stats::Scope& cluster_scope_;
+    const std::string& prefix_;
+    uint64_t response_status_code_;
+    bool internal_request_;
+    const std::string& request_vhost_name_;
+    const std::string& request_vcluster_name_;
+    const std::string& from_zone_;
+    const std::string& to_zone_;
+    bool upstream_canary_;
+  };
+
+  struct ResponseTimingInfo {
+    Stats::Scope& global_scope_;
+    Stats::Scope& cluster_scope_;
+    const std::string& prefix_;
+    std::chrono::milliseconds response_time_;
+    bool upstream_canary_;
+    bool internal_request_;
+    const std::string& request_vhost_name_;
+    const std::string& request_vcluster_name_;
+    const std::string& from_zone_;
+    const std::string& to_zone_;
+  };
+
+  /**
+   * Charge a simple response stat to an upstream.
+   */
+  virtual void chargeBasicResponseStat(Stats::Scope& scope, const std::string& prefix,
+                                       Code response_code) const PURE;
+
+  /**
+   * Charge a response stat to both agg counters (*xx) as well as code specific counters. This
+   * routine also looks for the x-envoy-upstream-canary header and if it is set, also charges
+   * canary stats.
+   */
+  virtual void chargeResponseStat(const ResponseStatInfo& info) const PURE;
+
+  /**
+   * Charge a response timing to the various dynamic stat postfixes.
+   */
+  virtual void chargeResponseTiming(const ResponseTimingInfo& info) const PURE;
+};
+
 } // namespace Http
 } // namespace Envoy

include/envoy/http/context.h

@@ -0,0 +1,24 @@
+#pragma once
+
+#include <memory>
+
+#include "envoy/http/codes.h"
+#include "envoy/tracing/http_tracer.h"
+
+namespace Envoy {
+namespace Http {
+
+/**
+ * Captures http-related structures with cardinality of one per server.
+ */
+class Context {
+public:
+  virtual ~Context() = default;
+  virtual Tracing::HttpTracer& tracer() PURE;
+  virtual CodeStats& codeStats() PURE;
+};
+
+using ContextPtr = std::unique_ptr<Context>;
+
+} // namespace Http
+} // namespace Envoy

include/envoy/server/BUILD

@@ -24,7 +24,6 @@ envoy_cc_library(
     deps = [
         ":config_tracker_interface",
         "//include/envoy/buffer:buffer_interface",
-        "//include/envoy/http:codes_interface",
         "//include/envoy/http:filter_interface",
         "//include/envoy/http:header_map_interface",
         "//include/envoy/http:query_params_interface",
@@ -37,6 +36,7 @@ envoy_cc_library(
     hdrs = ["configuration.h"],
     external_deps = ["abseil_optional"],
     deps = [
+        "//include/envoy/http:context_interface",
         "//include/envoy/ratelimit:ratelimit_interface",
         "//include/envoy/tracing:http_tracer_interface",
         "//include/envoy/upstream:cluster_manager_interface",
@@ -95,6 +95,7 @@ envoy_cc_library(
         "//include/envoy/api:api_interface",
         "//include/envoy/common:mutex_tracer",
         "//include/envoy/event:timer_interface",
+        "//include/envoy/http:context_interface",
         "//include/envoy/http:query_params_interface",
         "//include/envoy/init:init_interface",
         "//include/envoy/local_info:local_info_interface",
@@ -143,6 +144,8 @@ envoy_cc_library(
     deps = [
         ":admin_interface",
         "//include/envoy/access_log:access_log_interface",
+        "//include/envoy/http:codes_interface",
+        "//include/envoy/http:context_interface",
         "//include/envoy/http:filter_interface",
         "//include/envoy/init:init_interface",
         "//include/envoy/json:json_object_interface",

include/envoy/server/filter_config.h

@@ -4,6 +4,8 @@
 
 #include "envoy/access_log/access_log.h"
 #include "envoy/api/v2/core/base.pb.h"
+#include "envoy/http/codes.h"
+#include "envoy/http/context.h"
 #include "envoy/http/filter.h"
 #include "envoy/init/init.h"
 #include "envoy/json/json_object.h"
@@ -140,6 +142,11 @@ class FactoryContext {
    * @return OverloadManager& the overload manager for the server.
    */
   virtual OverloadManager& overloadManager() PURE;
+
+  /**
+   * @return Http::Context& a reference to the http context.
+   */
+  virtual Http::Context& httpContext() PURE;
 };
 
 class ListenerFactoryContext : public FactoryContext {

include/envoy/server/instance.h

@@ -8,6 +8,7 @@
 #include "envoy/api/api.h"
 #include "envoy/common/mutex_tracer.h"
 #include "envoy/event/timer.h"
+#include "envoy/http/context.h"
 #include "envoy/init/init.h"
 #include "envoy/local_info/local_info.h"
 #include "envoy/network/listen_socket.h"
@@ -189,9 +190,9 @@ class Instance {
   virtual Stats::Store& stats() PURE;
 
   /**
-   * @return the server-wide http tracer.
+   * @return the server-wide http context.
    */
-  virtual Tracing::HttpTracer& httpTracer() PURE;
+  virtual Http::Context& httpContext() PURE;
 
   /**
    * @return ThreadLocal::Instance& the thread local storage engine for the server. This is used to

source/common/http/BUILD

@@ -17,6 +17,7 @@ envoy_cc_library(
         "//include/envoy/event:dispatcher_interface",
         "//include/envoy/http:async_client_interface",
         "//include/envoy/http:codec_interface",
+        "//include/envoy/http:context_interface",
         "//include/envoy/http:header_map_interface",
         "//include/envoy/http:message_interface",
         "//include/envoy/router:router_interface",
@@ -92,6 +93,17 @@ envoy_cc_library(
     ],
 )
 
+envoy_cc_library(
+    name = "context_lib",
+    srcs = ["context_impl.cc"],
+    hdrs = ["context_impl.h"],
+    deps = [
+        ":codes_lib",
+        "//include/envoy/http:context_interface",
+        "//source/common/tracing:http_tracer_lib",
+    ],
+)
+
 envoy_cc_library(
     name = "conn_pool_base_lib",
     srcs = ["conn_pool_base.cc"],
@@ -137,6 +149,7 @@ envoy_cc_library(
         "//include/envoy/event:deferred_deletable",
         "//include/envoy/event:dispatcher_interface",
         "//include/envoy/http:codec_interface",
+        "//include/envoy/http:context_interface",
         "//include/envoy/http:filter_interface",
         "//include/envoy/http:header_map_interface",
         "//include/envoy/local_info:local_info_interface",
@@ -150,7 +163,6 @@ envoy_cc_library(
         "//include/envoy/stats:stats_interface",
         "//include/envoy/stats:stats_macros",
         "//include/envoy/stats:timespan",
-        "//include/envoy/tracing:http_tracer_interface",
         "//include/envoy/upstream:upstream_interface",
         "//source/common/access_log:access_log_formatter_lib",
         "//source/common/buffer:buffer_lib",

source/common/http/async_client_impl.cc

@@ -36,10 +36,11 @@ AsyncClientImpl::AsyncClientImpl(Upstream::ClusterInfoConstSharedPtr cluster,
                                  const LocalInfo::LocalInfo& local_info,
                                  Upstream::ClusterManager& cm, Runtime::Loader& runtime,
                                  Runtime::RandomGenerator& random,
-                                 Router::ShadowWriterPtr&& shadow_writer)
+                                 Router::ShadowWriterPtr&& shadow_writer,
+                                 Http::Context& http_context)
     : cluster_(cluster),
       config_("http.async-client.", local_info, stats_store, cm, runtime, random,
-              std::move(shadow_writer), true, false, false, dispatcher.timeSystem()),
+              std::move(shadow_writer), true, false, false, dispatcher.timeSystem(), http_context),
       dispatcher_(dispatcher) {}
 
 AsyncClientImpl::~AsyncClientImpl() {

source/common/http/async_client_impl.h

@@ -13,6 +13,7 @@
 #include "envoy/event/dispatcher.h"
 #include "envoy/http/async_client.h"
 #include "envoy/http/codec.h"
+#include "envoy/http/context.h"
 #include "envoy/http/header_map.h"
 #include "envoy/http/message.h"
 #include "envoy/router/router.h"
@@ -42,7 +43,8 @@ class AsyncClientImpl final : public AsyncClient {
   AsyncClientImpl(Upstream::ClusterInfoConstSharedPtr cluster, Stats::Store& stats_store,
                   Event::Dispatcher& dispatcher, const LocalInfo::LocalInfo& local_info,
                   Upstream::ClusterManager& cm, Runtime::Loader& runtime,
-                  Runtime::RandomGenerator& random, Router::ShadowWriterPtr&& shadow_writer);
+                  Runtime::RandomGenerator& random, Router::ShadowWriterPtr&& shadow_writer,
+                  Http::Context& http_context);
   ~AsyncClientImpl();
 
   // Http::AsyncClient