implement retry functionality

growthbook · Jul 28, 2023 · 3056df3 · 3056df3
1 parent d65ed40
commit 3056df3
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Showing 2 changed files with 73 additions and 47 deletions.
diff --git a/lib/src/main/java/growthbook/sdk/java/GBEventSourceListener.java b/lib/src/main/java/growthbook/sdk/java/GBEventSourceListener.java
diff --git a/lib/src/main/java/growthbook/sdk/java/GBFeaturesRepository.java b/lib/src/main/java/growthbook/sdk/java/GBFeaturesRepository.java
@@ -5,6 +5,8 @@
 import lombok.Builder;
 import lombok.Getter;
 import okhttp3.*;
+import okhttp3.sse.EventSource;
+import okhttp3.sse.EventSourceListener;
 import okhttp3.sse.EventSources;
 import org.jetbrains.annotations.NotNull;
 
@@ -52,6 +54,8 @@ public class GBFeaturesRepository implements IGBFeaturesRepository {
     private Boolean initialized = false;
 
     private Boolean sseAllowed = false;
+    @Nullable private Request sseRequest = null;
+    @Nullable private EventSource sseEventSource = null;
 
     /**
      * Allows you to get the features JSON from the provided {@link GBFeaturesRepository#getFeaturesEndpoint()}.
@@ -196,28 +200,50 @@ public void initialize() throws FeatureFetchException {
 
     private void initializeSSE() throws FeatureFetchException {
         if (!this.sseAllowed) {
+            // TODO: Fallback to SWR strategy
             System.out.printf("\nNot initializing SSE because header 'X-Sse-Support: enabled' not present on resource returned at %s", this.featuresEndpoint);
             throw new FeatureFetchException(FeatureFetchException.FeatureFetchErrorCode.SSE_CONNECTION_ERROR);
 //            return;
         }
 
-        this.sseHttpClient = new OkHttpClient.Builder()
-            .addInterceptor(new GBFeaturesRepositoryRequestInterceptor())
-            .connectTimeout(0, TimeUnit.SECONDS)
-            .readTimeout(0, TimeUnit.MINUTES)
-            .writeTimeout(0, TimeUnit.MINUTES)
-            .build();
+        createEventSourceListenerAndStartListening();
+    }
+
+    /**
+     * Creates an SSE HTTP client if null.
+     * Creates and enqueues a new asynchronous request to the events endpoint.
+     * Assigns a close listener to recreate the connection.
+     */
+    private void createEventSourceListenerAndStartListening() {
+        this.sseEventSource = null;
+        this.sseRequest = null;
+
+        if (this.sseHttpClient == null) {
+            this.sseHttpClient = new OkHttpClient.Builder()
+                .addInterceptor(new GBFeaturesRepositoryRequestInterceptor())
+                .retryOnConnectionFailure(true)
+                .connectTimeout(0, TimeUnit.SECONDS)
+                .readTimeout(0, TimeUnit.SECONDS)
+                .writeTimeout(0, TimeUnit.SECONDS)
+                .build();
+        }
 
-        Request sseRequest = new Request.Builder()
+        this.sseRequest = new Request.Builder()
             .url(this.eventsEndpoint)
             .header("Accept", "application/json; q=0.5")
             .addHeader("Accept", "text/event-stream")
             .build();
 
-        EventSources
+        this.sseEventSource = EventSources
             .createFactory(this.sseHttpClient)
-            .newEventSource(sseRequest, new GBEventSourceListener());
-
+            .newEventSource(sseRequest, new GBEventSourceListener(new GBEventSourceCloseHandler() {
+                @Override
+                public void onClose(EventSource eventSource) {
+                    eventSource.cancel();
+                    System.out.printf("\n\nGBEventSourceCloseHandler#onClose %s \n\n", eventSource);
+                    createEventSourceListenerAndStartListening();
+                }
+            }));
         this.sseHttpClient.newCall(sseRequest).enqueue(new Callback() {
             @Override
             public void onFailure(@NotNull Call call, @NotNull IOException e) {
@@ -288,6 +314,7 @@ private void fetchFeatures() throws FeatureFetchException {
      * @param response Successful response
      */
     private void onSuccess(Response response) throws FeatureFetchException {
+        // TODO: refactor to not be Response and instead the string
         try {
             ResponseBody responseBody = response.body();
             if (responseBody == null) {
@@ -341,4 +368,40 @@ private void onSuccess(Response response) throws FeatureFetchException {
             );
         }
     }
+
+    private interface GBEventSourceCloseHandler {
+        void onClose(EventSource eventSource);
+    }
+
+    private static class GBEventSourceListener extends EventSourceListener {
+        private final GBEventSourceCloseHandler closeHandler;
+
+        public GBEventSourceListener(GBEventSourceCloseHandler closeHandler) {
+            this.closeHandler = closeHandler;
+        }
+
+        @Override
+        public void onClosed(@NotNull EventSource eventSource) {
+            super.onClosed(eventSource);
+            closeHandler.onClose(eventSource);
+        }
+
+        @Override
+        public void onEvent(@NotNull EventSource eventSource, @Nullable String id, @Nullable String type, @NotNull String data) {
+            System.out.printf("\n\n eventsource = %s - id = %s - type = %s - data = %s \n\n", eventSource, id, type, data);
+            super.onEvent(eventSource, id, type, data);
+        }
+
+        @Override
+        public void onFailure(@NotNull EventSource eventSource, @Nullable Throwable t, @Nullable Response response) {
+            System.out.printf("\n\n eventsource = %s , error = %s , response = %s\n\n", eventSource, t, response);
+            super.onFailure(eventSource, t, response);
+        }
+
+        @Override
+        public void onOpen(@NotNull EventSource eventSource, @NotNull Response response) {
+            System.out.printf("\n\n eventsource = %s , response = %s\n\n", eventSource, response);
+            super.onOpen(eventSource, response);
+        }
+    }
 }