Add support for metrics in stream response handler

src/main/java/software/amazon/awssdk/crt/http/HttpStreamBaseResponseHandler.java

@@ -87,4 +87,12 @@ default int onResponseBody(HttpStreamBase stream, byte[] bodyBytesIn) {
      */
     void onResponseComplete(HttpStreamBase stream, int errorCode);
 
+    /**
+     * Called right before stream is complete, whether successful or unsuccessful.
+     * @param stream The HTTP stream to which the metrics apply
+     * @param metrics The [HttpStreamMetrics] containing metrics for the given stream
+     */
+    default void onMetrics(HttpStreamBase stream, HttpStreamMetrics metrics) {
+        /* Optional callback, nothing to do by default */
+    }
 }

src/main/java/software/amazon/awssdk/crt/http/HttpStreamMetrics.java

@@ -0,0 +1,66 @@
+/*
+ * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package software.amazon.awssdk.crt.http;
+
+/**
+ * Holds tracing metrics for an HTTP stream. Maps to `struct aws_http_stream_metrics` in **aws-c-http**'s
+ * **request_response.h**.
+ */
+public class HttpStreamMetrics {
+    private final long sendStartTimestampNs;
+    private final long sendEndTimestampNs;
+    private final long sendingDurationNs;
+    private final long receiveStartTimestampNs;
+    private final long receiveEndTimestampNs;
+    private final long receivingDurationNs;
+    private final int streamId;
+
+    HttpStreamMetrics(
+            long sendStartTimestampNs,
+            long sendEndTimestampNs,
+            long sendingDurationNs,
+            long receiveStartTimestampNs,
+            long receiveEndTimestampNs,
+            long receivingDurationNs,
+            int streamId
+    ) {
+        this.sendStartTimestampNs = sendStartTimestampNs;
+        this.sendEndTimestampNs = sendEndTimestampNs;
+        this.sendingDurationNs = sendingDurationNs;
+        this.receiveStartTimestampNs = receiveStartTimestampNs;
+        this.receiveEndTimestampNs = receiveEndTimestampNs;
+        this.receivingDurationNs = receivingDurationNs;
+        this.streamId = streamId;
+    }
+
+    public long getSendStartTimestampNs() {
+        return sendStartTimestampNs;
+    }
+
+    public long getSendEndTimestampNs() {
+        return sendEndTimestampNs;
+    }
+
+    public long getSendingDurationNs() {
+        return sendingDurationNs;
+    }
+
+    public long getReceiveStartTimestampNs() {
+        return receiveStartTimestampNs;
+    }
+
+    public long getReceiveEndTimestampNs() {
+        return receiveEndTimestampNs;
+    }
+
+    public long getReceivingDurationNs() {
+        return receivingDurationNs;
+    }
+
+    public int getStreamId() {
+        return streamId;
+    }
+}

src/main/java/software/amazon/awssdk/crt/http/HttpStreamResponseHandler.java

@@ -65,4 +65,12 @@ default int onResponseBody(HttpStream stream, byte[] bodyBytesIn) {
      */
     void onResponseComplete(HttpStream stream, int errorCode);
 
+    /**
+     * Called right before stream is complete, whether successful or unsuccessful.
+     * @param stream The HTTP stream to which the metrics apply
+     * @param metrics The [HttpStreamMetrics] containing metrics for the given stream
+     */
+    default void onMetrics(HttpStream stream, HttpStreamMetrics metrics) {
+        /* Optional callback, nothing to do by default */
+    }
 }

src/main/java/software/amazon/awssdk/crt/http/HttpStreamResponseHandlerNativeAdapter.java

@@ -58,4 +58,12 @@ void onResponseComplete(HttpStreamBase stream, int errorCode) {
             responseHandler.onResponseComplete((HttpStream) stream, errorCode);
         }
     }
+
+    void onMetrics(HttpStreamBase stream, HttpStreamMetrics metrics) {
+        if (this.responseBaseHandler != null) {
+            responseBaseHandler.onMetrics(stream, metrics);
+        } else {
+            responseHandler.onMetrics((HttpStream) stream, metrics);
+        }
+    }
 }

src/native/http_request_response.c

@@ -311,6 +311,57 @@ void aws_java_http_stream_on_stream_destroy_fn(void *user_data) {
     /********** JNI ENV RELEASE **********/
 }
 
+void aws_java_http_stream_on_stream_metrics_fn(
+    struct aws_http_stream *stream,
+    const struct aws_http_stream_metrics *metrics,
+    void *user_data) {
+    struct http_stream_binding *binding = (struct http_stream_binding *)user_data;
+
+    /********** JNI ENV ACQUIRE **********/
+    JNIEnv *env = aws_jni_acquire_thread_env(binding->jvm);
+    if (env == NULL) {
+        /* If we can't get an environment, then the JVM is probably shutting down.  Don't crash. */
+        return;
+    }
+
+    /* Convert metrics to Java HttpStreamMetrics obj */
+    jobject jni_metrics = (*env)->NewObject(
+        env,
+        http_stream_metrics_properties.http_stream_metrics_class,
+        http_stream_metrics_properties.constructor_id,
+        (jlong)metrics->send_start_timestamp_ns,
+        (jlong)metrics->send_end_timestamp_ns,
+        (jlong)metrics->sending_duration_ns,
+        (jlong)metrics->receive_start_timestamp_ns,
+        (jlong)metrics->receive_end_timestamp_ns,
+        (jlong)metrics->receiving_duration_ns,
+
+        /* Stream IDs are 31-bit unsigned integers, which fits into Java's regular (signed) 32-bit int */
+        (jint)metrics->stream_id
+    );
+
+    (*env)->CallVoidMethod(
+        env,
+        binding->java_http_response_stream_handler,
+        http_stream_response_handler_properties.onMetrics,
+        binding->java_http_stream_base,
+        jni_metrics);
+
+    /* Delete local reference to metrics object */
+    (*env)->DeleteLocalRef(env, jni_metrics);
+
+    if (aws_jni_check_and_clear_exception(env)) {
+        /* Close the Connection if the Java Callback throws an Exception */
+        aws_http_connection_close(aws_http_stream_get_connection(stream));
+
+        AWS_LOGF_ERROR(AWS_LS_HTTP_STREAM, "id=%p: Received Exception from onMetrics", (void *)stream);
+        aws_raise_error(AWS_ERROR_HTTP_CALLBACK_FAILURE);
+    }
+
+    aws_jni_release_thread_env(binding->jvm, env);
+    /********** JNI ENV RELEASE **********/
+}
+
 jobjectArray aws_java_http_headers_from_native(JNIEnv *env, struct aws_http_headers *headers) {
     (void)headers;
     jobjectArray ret;
@@ -383,6 +434,7 @@ static jobject s_make_request_general(
         .on_response_body = aws_java_http_stream_on_incoming_body_fn,
         .on_complete = aws_java_http_stream_on_stream_complete_fn,
         .on_destroy = aws_java_http_stream_on_stream_destroy_fn,
+        .on_metrics = aws_java_http_stream_on_stream_metrics_fn,
         .user_data = stream_binding,
     };
 

src/native/java_class_ids.c

@@ -522,6 +522,10 @@ static void s_cache_http_stream_response_handler_native_adapter(JNIEnv *env) {
     http_stream_response_handler_properties.onResponseComplete =
         (*env)->GetMethodID(env, cls, "onResponseComplete", "(Lsoftware/amazon/awssdk/crt/http/HttpStreamBase;I)V");
     AWS_FATAL_ASSERT(http_stream_response_handler_properties.onResponseComplete);
+
+    http_stream_response_handler_properties.onMetrics =
+        (*env)->GetMethodID(env, cls, "onMetrics", "(Lsoftware/amazon/awssdk/crt/http/HttpStreamBase;Lsoftware/amazon/awssdk/crt/http/HttpStreamMetrics;)V");
+    AWS_FATAL_ASSERT(http_stream_response_handler_properties.onMetrics);
 }
 
 struct java_http_stream_write_chunk_completion_properties http_stream_write_chunk_completion_properties;
@@ -535,6 +539,17 @@ static void s_cache_http_stream_write_chunk_completion_properties(JNIEnv *env) {
     AWS_FATAL_ASSERT(http_stream_write_chunk_completion_properties.callback);
 }
 
+struct java_http_stream_metrics_properties http_stream_metrics_properties;
+
+static void s_cache_http_stream_metrics_properties(JNIEnv *env) {
+    jclass cls = (*env)->FindClass(env, "software/amazon/awssdk/crt/http/HttpStreamMetrics");
+    AWS_FATAL_ASSERT(cls);
+    http_stream_metrics_properties.http_stream_metrics_class = (*env)->NewGlobalRef(env, cls);
+
+    http_stream_metrics_properties.constructor_id = (*env)->GetMethodID(env, cls, "<init>", "(JJJJJJI)V");
+    AWS_FATAL_ASSERT(http_stream_metrics_properties.constructor_id);
+}
+
 struct java_event_stream_server_listener_properties event_stream_server_listener_properties;
 
 static void s_cache_event_stream_server_listener_properties(JNIEnv *env) {
@@ -2316,6 +2331,7 @@ static void s_cache_java_class_ids(void *user_data) {
     s_cache_http2_stream(env);
     s_cache_http_stream_response_handler_native_adapter(env);
     s_cache_http_stream_write_chunk_completion_properties(env);
+    s_cache_http_stream_metrics_properties(env);
     s_cache_event_stream_server_listener_properties(env);
     s_cache_event_stream_server_listener_handler_properties(env);
     s_cache_event_stream_server_connection_handler_properties(env);

src/native/java_class_ids.h

@@ -236,6 +236,7 @@ struct java_http_stream_response_handler_native_adapter_properties {
     jmethodID onResponseHeadersDone;
     jmethodID onResponseBody;
     jmethodID onResponseComplete;
+    jmethodID onMetrics;
 };
 extern struct java_http_stream_response_handler_native_adapter_properties http_stream_response_handler_properties;
 
@@ -245,6 +246,13 @@ struct java_http_stream_write_chunk_completion_properties {
 };
 extern struct java_http_stream_write_chunk_completion_properties http_stream_write_chunk_completion_properties;
 
+/* HtppStreamMetrics */
+struct java_http_stream_metrics_properties {
+    jclass http_stream_metrics_class;
+    jmethodID constructor_id;
+};
+extern struct java_http_stream_metrics_properties http_stream_metrics_properties;
+
 /* EventStreamServerListener */
 struct java_event_stream_server_listener_properties {
     jmethodID onShutdownComplete;