stats: introduce stats client

envoy-mobile.tulsiproj/Configs/all.tulsigen

@@ -23,8 +23,8 @@
     "//library/swift/test:retry_policy_mapper_tests_lib",
     "//library/swift/test:retry_policy_tests",
     "//library/swift/test:retry_policy_tests_lib",
-    "//library/swift/test:stream_client_builder_tests",
-    "//library/swift/test:stream_client_builder_tests_lib"
+    "//library/swift/test:engine_builder_tests",
+    "//library/swift/test:engine_builder_tests_lib"
   ],
   "optionSet" : {
     "BazelBuildOptionsDebug" : {

examples/java/hello_world/MainActivity.java

@@ -5,15 +5,15 @@
 import android.os.Handler;
 import android.os.HandlerThread;
 import android.util.Log;
-import io.envoyproxy.envoymobile.AndroidStreamClientBuilder;
+import io.envoyproxy.envoymobile.AndroidEngineBuilder;
+import io.envoyproxy.envoymobile.Engine;
 import io.envoyproxy.envoymobile.RequestHeaders;
 import io.envoyproxy.envoymobile.RequestHeadersBuilder;
 import io.envoyproxy.envoymobile.RequestMethod;
 import io.envoyproxy.envoymobile.ResponseHeaders;
 import androidx.recyclerview.widget.DividerItemDecoration;
 import androidx.recyclerview.widget.LinearLayoutManager;
 import androidx.recyclerview.widget.RecyclerView;
-import io.envoyproxy.envoymobile.StreamClient;
 import io.envoyproxy.envoymobile.shared.Failure;
 import io.envoyproxy.envoymobile.shared.ResponseRecyclerViewAdapter;
 import io.envoyproxy.envoymobile.shared.Success;
@@ -29,7 +29,7 @@ public class MainActivity extends Activity {
   private static final String REQUEST_PATH = "/ping";
   private static final String REQUEST_SCHEME = "https";
 
-  private StreamClient streamClient;
+  private Engine engine;
   private RecyclerView recyclerView;
 
   private HandlerThread thread = new HandlerThread(REQUEST_HANDLER_THREAD_NAME);
@@ -40,7 +40,7 @@ protected void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
     setContentView(R.layout.activity_main);
 
-    streamClient = new AndroidStreamClientBuilder(getApplication()).build();
+    engine = new AndroidEngineBuilder(getApplication()).build();
 
     recyclerView = (RecyclerView)findViewById(R.id.recycler_view);
     recyclerView.setLayoutManager(new LinearLayoutManager(this));
@@ -76,7 +76,8 @@ private void makeRequest() {
     RequestHeaders requestHeaders = new RequestHeadersBuilder(RequestMethod.GET, REQUEST_SCHEME,
                                                               REQUEST_AUTHORITY, REQUEST_PATH)
                                         .build();
-    streamClient.newStreamPrototype()
+    engine.streamClient()
+        .newStreamPrototype()
         .setOnResponseHeaders((responseHeaders, endStream) -> {
           Integer status = responseHeaders.getHttpStatus();
           String message = "received headers with status " + status;

examples/kotlin/hello_world/MainActivity.kt

@@ -8,10 +8,10 @@ import android.util.Log
 import androidx.recyclerview.widget.DividerItemDecoration
 import androidx.recyclerview.widget.LinearLayoutManager
 import androidx.recyclerview.widget.RecyclerView
-import io.envoyproxy.envoymobile.AndroidStreamClientBuilder
+import io.envoyproxy.envoymobile.AndroidEngineBuilder
+import io.envoyproxy.envoymobile.Engine
 import io.envoyproxy.envoymobile.RequestHeadersBuilder
 import io.envoyproxy.envoymobile.RequestMethod
-import io.envoyproxy.envoymobile.StreamClient
 import io.envoyproxy.envoymobile.UpstreamHttpProtocol
 import io.envoyproxy.envoymobile.shared.Failure
 import io.envoyproxy.envoymobile.shared.ResponseRecyclerViewAdapter
@@ -30,13 +30,13 @@ class MainActivity : Activity() {
   private val thread = HandlerThread(REQUEST_HANDLER_THREAD_NAME)
   private lateinit var recyclerView: RecyclerView
   private lateinit var viewAdapter: ResponseRecyclerViewAdapter
-  private lateinit var streamClient: StreamClient
+  private lateinit var engine: Engine
 
   override fun onCreate(savedInstanceState: Bundle?) {
     super.onCreate(savedInstanceState)
     setContentView(R.layout.activity_main)
 
-    streamClient = AndroidStreamClientBuilder(application).build()
+    engine = AndroidEngineBuilder(application).build()
 
     recyclerView = findViewById(R.id.recycler_view) as RecyclerView
     recyclerView.layoutManager = LinearLayoutManager(this)
@@ -82,7 +82,8 @@ class MainActivity : Activity() {
     )
       .addUpstreamHttpProtocol(UpstreamHttpProtocol.HTTP2)
       .build()
-    streamClient
+    engine
+      .streamClient()
       .newStreamPrototype()
       .setOnResponseHeaders { responseHeaders, _ ->
         val status = responseHeaders.httpStatus ?: 0L

examples/objective-c/hello_world/ViewController.m

@@ -35,12 +35,13 @@ - (instancetype)init {
 - (void)startEnvoy {
   NSLog(@"starting Envoy...");
   NSError *error;
-  StreamClientBuilder *builder = [[StreamClientBuilder alloc] init];
-  self.client = [builder buildAndReturnError:&error];
+  EngineBuilder *builder = [[EngineBuilder alloc] init];
+  id<Engine> engine = [builder buildAndReturnError:&error];
   if (error) {
     NSLog(@"starting Envoy failed: %@", error);
   } else {
     NSLog(@"started Envoy, beginning requests...");
+    self.client = [engine streamClient];
     [self startRequests];
   }
 }

examples/swift/hello_world/ViewController.swift

@@ -15,9 +15,10 @@ final class ViewController: UITableViewController {
     super.viewDidLoad()
     do {
       NSLog("starting Envoy...")
-      self.client = try StreamClientBuilder()
+      self.client = try EngineBuilder()
         .addFilter(factory: DemoFilter.init)
         .build()
+        .streamClient
     } catch let error {
       NSLog("starting Envoy failed: \(error)")
     }

library/common/config_template.cc

@@ -212,6 +212,9 @@ stats_flush_interval: {{ stats_flush_interval_seconds }}s
         - safe_regex:
             google_re2: {}
             regex: '^http.dispatcher.*'
+        - safe_regex:
+            google_re2: {}
+            regex: '^client.*'
         - safe_regex:
             google_re2: {}
             regex: '^http.hcm.decompressor.*'

library/common/engine.cc

@@ -93,6 +93,19 @@ Engine::~Engine() {
   main_thread_.join();
 }
 
+void Engine::recordCounter(std::string elements, uint64_t count) {
+  if (server_) {
+    server_->dispatcher().post([this, elements, count]() -> void {
+      static const std::string client = "client";
+      absl::string_view prefix{client};
+      absl::string_view dynamic_elements{elements};
+      Stats::Utility::counterFromElements(server_->serverFactoryContext().scope(),
+                                          {prefix, dynamic_elements})
+          .add(count);
+    });
+  }
+}
+
 void Engine::flushStats() {
   // The server will be null if the post-init callback has not been completed within run().
   // In this case, we can simply ignore the flush.

library/common/engine.h

@@ -35,6 +35,11 @@ class Engine {
    */
   Http::Dispatcher& httpDispatcher();
 
+  /**
+   * Increment a counter with a given string of elements and by the given count.
+   */
+  void recordCounter(std::string elements, uint64_t count);
+
   /**
    * Flush the stats sinks outside of a flushing interval.
    * Note: stats flushing may not be synchronous.

library/common/jni/jni_interface.cc

@@ -77,6 +77,13 @@ Java_io_envoyproxy_envoymobile_engine_AndroidJniLibrary_setPreferredNetwork(JNIE
   return set_preferred_network(static_cast<envoy_network_t>(network));
 }
 
+extern "C" JNIEXPORT void JNICALL
+Java_io_envoyproxy_envoymobile_engine_JniLibrary_recordCounter(JNIEnv* env,
+                                                               jclass, // class
+                                                               jstring elements, jint count) {
+  record_counter(env->GetStringUTFChars(elements, nullptr), count);
+}
+
 extern "C" JNIEXPORT void JNICALL
 Java_io_envoyproxy_envoymobile_engine_AndroidJniLibrary_flushStats(JNIEnv* env,
                                                                    jclass // class

library/common/main_interface.cc

@@ -69,6 +69,12 @@ envoy_status_t set_preferred_network(envoy_network_t network) {
   return ENVOY_SUCCESS;
 }
 
+void record_counter(const char* elements, uint64_t count) {
+  if (auto e = engine_.lock()) {
+    e->recordCounter(std::string(elements), count);
+  }
+}
+
 void flush_stats() {
   if (auto e = engine_.lock()) {
     e->flushStats();

library/common/main_interface.h

@@ -96,6 +96,11 @@ envoy_engine_t init_engine();
  */
 envoy_status_t set_preferred_network(envoy_network_t network);
 
+/**
+ * Increment a counter with the given elements and by the given count.
+ */
+void record_counter(const char* elements, uint64_t count);
+
 /**
  * Flush the stats sinks outside of a flushing interval.
  * Note: flushing before the engine has started will result in a no-op.

library/java/src/io/envoyproxy/envoymobile/engine/AndroidEngineImpl.java

@@ -35,4 +35,9 @@ public int runWithConfig(EnvoyConfiguration envoyConfiguration, String logLevel)
     // application.registerActivityLifecycleCallbacks(monitor);
     return envoyEngine.runWithConfig(envoyConfiguration, logLevel);
   }
+
+  @Override
+  public void recordCounter(String elements, int count) {
+    envoyEngine.recordCounter(elements, count);
+  }
 }

library/java/src/io/envoyproxy/envoymobile/engine/EnvoyEngine.java

@@ -28,4 +28,12 @@ public interface EnvoyEngine {
    * @return A status indicating if the action was successful.
    */
   int runWithConfig(EnvoyConfiguration envoyConfiguration, String logLevel);
+
+  /**
+   * Increments a counter with the given count.
+   *
+   * @param elements Elements of the counter stat.
+   * @param count Amount to add to the counter.
+   */
+  void recordCounter(String elements, int count);
 }

library/java/src/io/envoyproxy/envoymobile/engine/EnvoyEngineImpl.java

@@ -56,4 +56,15 @@ public int runWithConfig(String configurationYAML, String logLevel) {
   public int runWithConfig(EnvoyConfiguration envoyConfiguration, String logLevel) {
     return runWithConfig(envoyConfiguration.resolveTemplate(JniLibrary.templateString()), logLevel);
   }
+
+  /**
+   * Increment a counter with the given count.
+   *
+   * @param elements Elements of the counter stat.
+   * @param count Amount to add to the counter.
+   */
+  @Override
+  public void recordCounter(String elements, int count) {
+    JniLibrary.recordCounter(elements, count);
+  }
 }

library/java/src/io/envoyproxy/envoymobile/engine/JniLibrary.java

@@ -139,4 +139,9 @@ private static class JavaLoader {
    *         configurations.
    */
   public static native String templateString();
+
+  /**
+   * Increment a counter.
+   */
+  protected static native void recordCounter(String elements, int count);
 }

library/kotlin/src/io/envoyproxy/envoymobile/AndroidStreamClientBuilder.kt → library/kotlin/src/io/envoyproxy/envoymobile/AndroidEngineBuilder.kt

@@ -3,10 +3,10 @@ package io.envoyproxy.envoymobile
 import android.app.Application
 import io.envoyproxy.envoymobile.engine.AndroidEngineImpl
 
-class AndroidStreamClientBuilder @JvmOverloads constructor (
+class AndroidEngineBuilder @JvmOverloads constructor(
   application: Application,
   baseConfiguration: BaseConfiguration = Standard()
-) : StreamClientBuilder(baseConfiguration) {
+) : EngineBuilder(baseConfiguration) {
   init {
     addEngineType { AndroidEngineImpl(application) }
   }

library/kotlin/src/io/envoyproxy/envoymobile/BUILD

@@ -20,7 +20,7 @@ android_artifacts(
 kt_android_library(
     name = "envoy_lib",
     srcs = [
-        "AndroidStreamClientBuilder.kt",
+        "AndroidEngineBuilder.kt",
     ],
     custom_package = "io.envoyproxy.envoymobile",
     manifest = "EnvoyManifest.xml",
@@ -36,7 +36,9 @@ kt_android_library(
 envoy_mobile_kt_library(
     name = "envoy_interfaces_lib",
     srcs = glob([
-        "EnvoyClient.kt",
+        "Engine.kt",
+        "EngineBuilder.kt",
+        "EngineImpl.kt",
         "EnvoyError.kt",
         "Headers.kt",
         "HeadersBuilder.kt",
@@ -52,15 +54,18 @@ envoy_mobile_kt_library(
         "ResponseTrailersBuilder.kt",
         "RetryPolicy.kt",
         "RetryPolicyMapper.kt",
+        "StatsClient.kt",
+        "StatsClientImpl.kt",
         "Stream.kt",
-        "StreamClient.kt",
-        "StreamClientBuilder.kt",
         "StreamCallbacks.kt",
+        "StreamClient.kt",
+        "StreamClientImpl.kt",
         "StreamPrototype.kt",
         "UpstreamHttpProtocol.kt",
         "filters/*.kt",
         "grpc/*.kt",
         "mocks/*.kt",
+        "stats/*.kt",
     ]),
     visibility = ["//visibility:public"],
     deps = [

library/kotlin/src/io/envoyproxy/envoymobile/Engine.kt

@@ -0,0 +1,18 @@
+package io.envoyproxy.envoymobile
+
+/**
+ * Engine represents a running instance of Envoy Mobile, and provides client interfaces that run on
+ * that instance.
+ */
+interface Engine {
+
+  /**
+   *  @return a {@link StreamClient} for opening and managing HTTP streams.
+   */
+  fun streamClient(): StreamClient
+
+  /**
+   *  @return a {@link StatsClient} for recording time series metrics.
+   */
+  fun statsClient(): StatsClient
+}