[Android] Expose IDataViewer as public Java API

lib/CMakeLists.txt

@@ -60,6 +60,7 @@ endif()
 
 if(MATSDK_BUILD_JNI_WRAPPER)
   list(APPEND SRCS
+    jni/JavaDataViewerProxy.cpp
     jni/JniConvertors.cpp
     jni/LogManager_jni.cpp
     jni/Logger_jni.cpp

lib/android_build/app/src/androidTest/java/com/microsoft/applications/events/maesdktest/LogManagerDDVUnitTest.java

@@ -25,6 +25,7 @@
 import com.microsoft.applications.events.DebugEventType;
 import com.microsoft.applications.events.DiagLevel;
 import com.microsoft.applications.events.HttpClient;
+import com.microsoft.applications.events.IDataViewer;
 import com.microsoft.applications.events.ILogConfiguration;
 import com.microsoft.applications.events.ILogManager;
 import com.microsoft.applications.events.ILogger;
@@ -42,7 +43,10 @@
 import java.util.SortedMap;
 import java.util.TreeMap;
 import java.util.TreeSet;
+import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.FutureTask;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
 
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -247,6 +251,119 @@ public void startDDVonLogManager() {
     LogManager.flushAndTeardown();
   }
 
+  @Test
+  public void registerDataViewer_whenCallbackThrows_continuesDispatchAndStopsAfterUnregister()
+      throws Exception {
+    System.loadLibrary("maesdk");
+    Context appContext = InstrumentationRegistry.getInstrumentation().getTargetContext();
+    if (s_client == null) {
+      s_client = new MockHttpClient(appContext);
+    }
+    OfflineRoom.connectContext(appContext);
+
+    final String token =
+        "0123456789abcdef9123456789abcdef-01234567-0123-0123-0123-0123456789ab-0124";
+    final String factoryName = "JavaDataViewer" + System.nanoTime();
+    ILogConfiguration custom = LogManager.logConfigurationFactory();
+    custom.set(LogConfigurationKey.CFG_STR_PRIMARY_TOKEN, token);
+    custom.set(LogConfigurationKey.CFG_STR_COLLECTOR_URL, "https://viewer.contoso.com/");
+    custom.set(LogConfigurationKey.CFG_STR_FACTORY_NAME, factoryName);
+    custom.set(LogConfigurationKey.CFG_STR_CACHE_FILE_PATH, factoryName);
+
+    ILogManager manager = LogManagerProvider.createLogManager(custom);
+    CountDownLatch receivedPacket = new CountDownLatch(1);
+    AtomicInteger receivedByteCount = new AtomicInteger();
+    AtomicInteger receivingViewerCalls = new AtomicInteger();
+    AtomicInteger throwingViewerCalls = new AtomicInteger();
+    IDataViewer throwingViewer =
+        new IDataViewer() {
+          @Override
+          public void receiveData(byte[] packetData) {
+            throwingViewerCalls.incrementAndGet();
+            throw new IllegalStateException("Expected callback failure");
+          }
+
+          @Override
+          public String getName() {
+            return "throwing-viewer";
+          }
+
+          @Override
+          public boolean isTransmissionEnabled() {
+            return true;
+          }
+
+          @Override
+          public String getCurrentEndpoint() {
+            return "";
+          }
+        };
+    IDataViewer receivingViewer =
+        new IDataViewer() {
+          @Override
+          public void receiveData(byte[] packetData) {
+            receivingViewerCalls.incrementAndGet();
+            receivedByteCount.set(packetData.length);
+            receivedPacket.countDown();
+          }
+
+          @Override
+          public String getName() {
+            return "receiving-viewer";
+          }
+
+          @Override
+          public boolean isTransmissionEnabled() {
+            return true;
+          }
+
+          @Override
+          public String getCurrentEndpoint() {
+            return "http://127.0.0.1";
+          }
+        };
+
+    try {
+      assertThat(manager.registerDataViewer(throwingViewer), is(true));
+      assertThat(manager.registerDataViewer(receivingViewer), is(true));
+      assertThat(manager.registerDataViewer(receivingViewer), is(false));
+
+      ILogger logger = manager.getLogger(token, "java-data-viewer-test", "");
+      logger.logEvent("javaDataViewerCallback");
+      manager.uploadNow();
+
+      assertThat(receivedPacket.await(5, TimeUnit.SECONDS), is(true));
+      assertThat(receivedByteCount.get(), greaterThan(0));
+
+      assertThat(manager.unregisterDataViewer("receiving-viewer"), is(true));
+      assertThat(manager.unregisterDataViewer("receiving-viewer"), is(false));
+
+      // Unregistering must actually stop callbacks, not merely drop the bookkeeping entry: a
+      // bridge that left the proxy in the native DataViewerCollection would still pass the
+      // assertions above. Drive a second dispatch and use the still-registered throwing viewer
+      // as the witness that one really occurred, then assert the unregistered viewer was not
+      // called again.
+      final int receivingCallsAtUnregister = receivingViewerCalls.get();
+      final int throwingCallsAtUnregister = throwingViewerCalls.get();
+
+      logger.logEvent("javaDataViewerCallbackAfterUnregister");
+      manager.uploadNow();
+
+      final long deadline = System.currentTimeMillis() + 10000;
+      while (throwingViewerCalls.get() <= throwingCallsAtUnregister
+          && System.currentTimeMillis() < deadline) {
+        Thread.sleep(50);
+      }
+
+      assertThat(throwingViewerCalls.get(), greaterThan(throwingCallsAtUnregister));
+      assertThat(receivingViewerCalls.get(), is(receivingCallsAtUnregister));
+
+      assertThat(manager.unregisterDataViewer("throwing-viewer"), is(true));
+    } finally {
+      manager.close();
+    }
+  }
+
   /*
   Disabling this test since it requires private modules.
 

lib/android_build/maesdk/consumer-rules.pro

@@ -0,0 +1,4 @@
+-keep interface com.microsoft.applications.events.IDataViewer { *; }
+-keep class * implements com.microsoft.applications.events.IDataViewer {
+    public *;
+}

lib/android_build/maesdk/src/main/java/com/microsoft/applications/events/IDataViewer.java

@@ -0,0 +1,32 @@
+//
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// SPDX-License-Identifier: Apache-2.0
+//
+package com.microsoft.applications.events;
+
+import androidx.annotation.Keep;
+
+/**
+ * Receives copies of packets uploaded by the SDK.
+ *
+ * <p>Implementations must return a stable, unique name for the lifetime of the registration.
+ * Callbacks can occur on an SDK worker thread and should return promptly. Implementations must not
+ * reenter the SDK from within a callback: do not register or unregister viewers, and do not close
+ * the owning {@link ILogManager}, because closing unregisters every viewer while the callback is
+ * still in progress.
+ */
+@Keep
+public interface IDataViewer {
+
+  /** Receives an encoded telemetry packet after it has been prepared for upload. */
+  void receiveData(byte[] packetData);
+
+  /** Returns the stable, unique name used to register this viewer. */
+  String getName();
+
+  /** Returns whether this viewer is currently accepting packet callbacks. */
+  boolean isTransmissionEnabled();
+
+  /** Returns the endpoint currently used by this viewer, or an empty string when disabled. */
+  String getCurrentEndpoint();
+}

lib/android_build/maesdk/src/main/java/com/microsoft/applications/events/ILogManager.java

@@ -59,6 +59,34 @@ public interface ILogManager extends AutoCloseable {
 
   public String getCurrentEndpoint();
 
+  /**
+   * Registers a caller-provided data viewer with this LogManager.
+   *
+   * <p>This is an optional capability. The default implementation returns {@code false} so that
+   * existing implementations of this interface remain source compatible; implementations that
+   * support data viewers override it.
+   *
+   * @return {@code true} when the viewer was registered, {@code false} for invalid input, a
+   *     duplicate viewer name, or when the implementation does not support data viewers
+   */
+  default boolean registerDataViewer(IDataViewer dataViewer) {
+    return false;
+  }
+
+  /**
+   * Unregisters a caller-provided data viewer by its unique name.
+   *
+   * <p>This is an optional capability. The default implementation returns {@code false} so that
+   * existing implementations of this interface remain source compatible; implementations that
+   * support data viewers override it.
+   *
+   * @return {@code true} when the viewer was unregistered, {@code false} when it was not
+   *     registered, or when the implementation does not support data viewers
+   */
+  default boolean unregisterDataViewer(String viewerName) {
+    return false;
+  }
+
   public LogSessionData getLogSessionData();
 
   public void setLevelFilter(int defaultLevel, int[] allowedLevels);

lib/android_build/maesdk/src/main/java/com/microsoft/applications/events/LogManagerProvider.java

@@ -226,6 +226,28 @@ public String getCurrentEndpoint() {
       return nativeGetCurrentEndpoint(nativeLogManager);
     }
 
+    protected native boolean nativeRegisterDataViewer(
+        long nativeLogManager, IDataViewer dataViewer);
+
+    @Override
+    public boolean registerDataViewer(IDataViewer dataViewer) {
+      if (dataViewer == null) {
+        return false;
+      }
+      return nativeRegisterDataViewer(nativeLogManager, dataViewer);
+    }
+
+    protected native boolean nativeUnregisterDataViewer(
+        long nativeLogManager, String viewerName);
+
+    @Override
+    public boolean unregisterDataViewer(String viewerName) {
+      if (viewerName == null || viewerName.isEmpty()) {
+        return false;
+      }
+      return nativeUnregisterDataViewer(nativeLogManager, viewerName);
+    }
+
     protected static class LogSessionDataImpl implements LogSessionData {
       @Keep
       private long m_first_time;

lib/api/DataViewerCollection.cpp

@@ -16,7 +16,14 @@ namespace MAT_NS_BEGIN {
             return;
 
         LOCKGUARD(m_dataViewerMapLock);
-        for(const auto& viewer : m_dataViewerCollection)
+        // Dispatch over a snapshot rather than the member directly. m_dataViewerMapLock is
+        // recursive, so a viewer that reenters the SDK from ReceiveData - for example by
+        // closing the owning LogManager, which unregisters every viewer - would otherwise
+        // erase from the very vector being iterated here and invalidate the iterator.
+        // Holding shared_ptr copies additionally keeps each viewer alive for the duration of
+        // its own callback, even if that callback drops the last other reference to it.
+        const auto viewers = m_dataViewerCollection;
+        for(const auto& viewer : viewers)
         {
             // Task 3568800: Integrate ThreadPool to IDataViewerCollection
             viewer->ReceiveData(packetData);