Bug 1708669 - Register FOG custom pings on Android builds to enable Glean functionality. r=chutten,geckoview-reviewers,agi

This instantiates the FOG service, which in turn registers an idle
observer, which is required for FOG IPC to be triggered occasionally.

Glean itself will be controlled by the surrounding Android application.
Glean symbols are shipped in this GeckoView build.
Any metrics recorded in Gecko will be passed through to the Android
application, e.g. Fenix.

This also re-exports `rlb_flush_dispatcher` to be called by Glean Core from the Kotlin side.

Currently this does not support sending custom pings inside Gecko.
Testing Glean metrics in an Android build will be enabled in subsequent commits.

Differential Revision: https://phabricator.services.mozilla.com/D126799

mobile/android/chrome/geckoview/geckoview.js

@@ -774,6 +774,13 @@ function startup() {
       SafeBrowsing.init();
     });
 
+    InitLater(() => {
+      // It's enough to run this once to set up FOG.
+      // (See also bug 1730026.)
+      const FOG = Cc["@mozilla.org/toolkit/glean;1"].createInstance(Ci.nsIFOG);
+      FOG.registerCustomPings();
+    });
+
     // This should always go last, since the idle tasks (except for the ones with
     // timeouts) should execute in order. Note that this observer notification is
     // not guaranteed to fire, since the window could close before we get here.

toolkit/components/glean/ipc/FOGIPC.cpp

@@ -27,7 +27,6 @@ namespace glean {
  *                    serialized payload that the Rust impl hands you.
  */
 void FlushFOGData(std::function<void(ipc::ByteBuf&&)>&& aResolver) {
-#ifndef MOZ_GLEAN_ANDROID
   ByteBuf buf;
   uint32_t ipcBufferSize = impl::fog_serialize_ipc_buf();
   bool ok = buf.Allocate(ipcBufferSize);
@@ -39,7 +38,6 @@ void FlushFOGData(std::function<void(ipc::ByteBuf&&)>&& aResolver) {
     return;
   }
   aResolver(std::move(buf));
-#endif
 }
 
 /**
@@ -49,7 +47,6 @@ void FlushFOGData(std::function<void(ipc::ByteBuf&&)>&& aResolver) {
  */
 void FlushAllChildData(
     std::function<void(nsTArray<ipc::ByteBuf>&&)>&& aResolver) {
-#ifndef MOZ_GLEAN_ANDROID
   nsTArray<ContentParent*> parents;
   ContentParent::GetAll(parents);
   if (parents.Length() == 0) {
@@ -79,7 +76,6 @@ void FlushAllChildData(
                  aResolver(std::move(results));
                }
              });
-#endif
 }
 
 /**
@@ -87,10 +83,8 @@ void FlushAllChildData(
  * @param buf - a bincoded serialized payload that the Rust impl understands.
  */
 void FOGData(ipc::ByteBuf&& buf) {
-#ifndef MOZ_GLEAN_ANDROID
   fog_ipc::buffer_sizes.Accumulate(buf.mLen);
   impl::fog_use_ipc_buf(buf.mData, buf.mLen);
-#endif
 }
 
 /**
@@ -98,7 +92,6 @@ void FOGData(ipc::ByteBuf&& buf) {
  * @param buf - a bincoded serialized payload that the Rust impl understands.
  */
 void SendFOGData(ipc::ByteBuf&& buf) {
-#ifndef MOZ_GLEAN_ANDROID
   switch (XRE_GetProcessType()) {
     case GeckoProcessType_Content:
       mozilla::dom::ContentChild::GetSingleton()->SendFOGData(std::move(buf));
@@ -106,7 +99,6 @@ void SendFOGData(ipc::ByteBuf&& buf) {
     default:
       MOZ_ASSERT_UNREACHABLE("Unsuppored process type");
   }
-#endif
 }
 
 /**

toolkit/components/glean/src/lib.rs

@@ -46,6 +46,11 @@ pub extern "C" fn fog_shutdown() {
     glean::shutdown();
 }
 
+#[no_mangle]
+pub extern "C" fn fog_register_pings() {
+    fog::pings::register_pings();
+}
+
 static mut PENDING_BUF: Vec<u8> = Vec::new();
 
 // IPC serialization/deserialization methods

toolkit/components/glean/xpcom/FOG.cpp

@@ -28,6 +28,9 @@ using glean::LogToBrowserConsole;
 // Defined by `glean_ffi`. We reexport it here for later use.
 extern "C" NS_EXPORT void glean_enable_logging(void);
 
+// Defined by `glean`. We reexport it here for use by the Glean Core SDK.
+extern "C" NS_EXPORT void rlb_flush_dispatcher(void);
+
 // Workaround to force a re-export of the `no_mangle` symbols from `glean_ffi`
 //
 // Due to how linking works and hides symbols the symbols from `glean_ffi` might
@@ -80,20 +83,18 @@ already_AddRefed<FOG> FOG::GetSingleton() {
   return do_AddRef(gFOG);
 }
 
-void FOG::Shutdown() {
-#ifndef MOZ_GLEAN_ANDROID
-  glean::impl::fog_shutdown();
-#endif
-}
+void FOG::Shutdown() { glean::impl::fog_shutdown(); }
 
 NS_IMETHODIMP
 FOG::InitializeFOG(const nsACString& aDataPathOverride,
                    const nsACString& aAppIdOverride) {
-#ifdef MOZ_GLEAN_ANDROID
-  return NS_OK;
-#else
   return glean::impl::fog_init(&aDataPathOverride, &aAppIdOverride);
-#endif
+}
+
+NS_IMETHODIMP
+FOG::RegisterCustomPings() {
+  glean::impl::fog_register_pings();
+  return NS_OK;
 }
 
 NS_IMETHODIMP

toolkit/components/glean/xpcom/nsIFOG.idl

@@ -22,6 +22,13 @@ interface nsIFOG : nsISupports
    */
   void initializeFOG([optional] in AUTF8String aDataPathOverride, [optional] in AUTF8String aAppIdOverride);
 
+  /**
+   * Register custom pings.
+   *
+   * Ensure all custom pings are registered with Glean.
+   */
+  void registerCustomPings();
+
   /**
    * Enable or Disable the logging of pings in the Glean SDK.
    * See https://firefox-source-docs.mozilla.org/toolkit/components/glean/testing.html