1 files changed, 171 insertions, 0 deletions
diff --git a/mobile/android/geckoview/src/main/java/org/mozilla/geckoview/RuntimeTelemetry.java b/mobile/android/geckoview/src/main/java/org/mozilla/geckoview/RuntimeTelemetry.java
new file mode 100644
index 0000000000..1fad0cb17e
--- /dev/null
+++ b/mobile/android/geckoview/src/main/java/org/mozilla/geckoview/RuntimeTelemetry.java
@@ -0,0 +1,171 @@
+/* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
+ * vim: ts=4 sw=4 expandtab:
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.geckoview;
+
+import androidx.annotation.AnyThread;
+import androidx.annotation.NonNull;
+import org.mozilla.gecko.GeckoThread;
+import org.mozilla.gecko.annotation.WrapForJNI;
+import org.mozilla.gecko.mozglue.JNIObject;
+
+/** The telemetry API gives access to telemetry data of the Gecko runtime. */
+public final class RuntimeTelemetry {
+  protected RuntimeTelemetry() {}
+
+  /**
+   * The runtime telemetry metric object.
+   *
+   * @param <T> type of the underlying metric sample
+   */
+  public static class Metric<T> {
+    /** The runtime metric name. */
+    public final @NonNull String name;
+
+    /** The metric values. */
+    public final @NonNull T value;
+
+    /* package */ Metric(final String name, final T value) {
+      this.name = name;
+      this.value = value;
+    }
+
+    @Override
+    public String toString() {
+      return "name: " + name + ", value: " + value;
+    }
+
+    // For testing
+    protected Metric() {
+      name = null;
+      value = null;
+    }
+  }
+
+  /** The Histogram telemetry metric object. */
+  public static class Histogram extends Metric<long[]> {
+    /** Whether or not this is a Categorical Histogram. */
+    public final boolean isCategorical;
+
+    /* package */ Histogram(final boolean isCategorical, final String name, final long[] value) {
+      super(name, value);
+      this.isCategorical = isCategorical;
+    }
+
+    // For testing
+    protected Histogram() {
+      super(null, null);
+      isCategorical = false;
+    }
+  }
+
+  /**
+   * The runtime telemetry delegate. Implement this if you want to receive runtime (Gecko) telemetry
+   * and attach it via {@link GeckoRuntimeSettings.Builder#telemetryDelegate}.
+   */
+  public interface Delegate {
+    /**
+     * A runtime telemetry histogram metric has been received.
+     *
+     * @param metric The runtime metric details.
+     */
+    @AnyThread
+    default void onHistogram(final @NonNull Histogram metric) {}
+
+    /**
+     * A runtime telemetry boolean scalar has been received.
+     *
+     * @param metric The runtime metric details.
+     */
+    @AnyThread
+    default void onBooleanScalar(final @NonNull Metric<Boolean> metric) {}
+
+    /**
+     * A runtime telemetry long scalar has been received.
+     *
+     * @param metric The runtime metric details.
+     */
+    @AnyThread
+    default void onLongScalar(final @NonNull Metric<Long> metric) {}
+
+    /**
+     * A runtime telemetry string scalar has been received.
+     *
+     * @param metric The runtime metric details.
+     */
+    @AnyThread
+    default void onStringScalar(final @NonNull Metric<String> metric) {}
+  }
+
+  // The proxy connects to telemetry core and forwards telemetry events
+  // to the attached delegate.
+  /* package */ static final class Proxy extends JNIObject {
+    private final Delegate mDelegate;
+
+    public Proxy(final @NonNull Delegate delegate) {
+      mDelegate = delegate;
+    }
+
+    // Attach to current runtime.
+    // We might have different mechanics of attaching to specific runtimes
+    // in future, for which case we should split the delegate assignment in
+    // the setup phase from the attaching.
+    public void attach() {
+      if (GeckoThread.isRunning()) {
+        registerDelegateProxy(this);
+      } else {
+        GeckoThread.queueNativeCall(Proxy.class, "registerDelegateProxy", Proxy.class, this);
+      }
+    }
+
+    public @NonNull Delegate getDelegate() {
+      return mDelegate;
+    }
+
+    @WrapForJNI(dispatchTo = "gecko")
+    private static native void registerDelegateProxy(Proxy proxy);
+
+    @WrapForJNI(calledFrom = "gecko")
+    /* package */ void dispatchHistogram(
+        final boolean isCategorical, final String name, final long[] values) {
+      if (mDelegate == null) {
+        // TODO throw?
+        return;
+      }
+      mDelegate.onHistogram(new Histogram(isCategorical, name, values));
+    }
+
+    @WrapForJNI(calledFrom = "gecko")
+    /* package */ void dispatchStringScalar(final String name, final String value) {
+      if (mDelegate == null) {
+        return;
+      }
+      mDelegate.onStringScalar(new Metric<>(name, value));
+    }
+
+    @WrapForJNI(calledFrom = "gecko")
+    /* package */ void dispatchBooleanScalar(final String name, final boolean value) {
+      if (mDelegate == null) {
+        return;
+      }
+      mDelegate.onBooleanScalar(new Metric<>(name, value));
+    }
+
+    @WrapForJNI(calledFrom = "gecko")
+    /* package */ void dispatchLongScalar(final String name, final long value) {
+      if (mDelegate == null) {
+        return;
+      }
+      mDelegate.onLongScalar(new Metric<>(name, value));
+    }
+
+    @Override // JNIObject
+    protected void disposeNative() {
+      // We don't hold native references.
+      throw new UnsupportedOperationException();
+    }
+  }
+}