From 40d5446c4be5c5901e28de199cdd739d7739ac4a Mon Sep 17 00:00:00 2001
From: t-p-white <towhite@mozilla.com>
Date: Wed, 21 Jun 2023 15:54:09 +0100
Subject: [PATCH] Bug 1840341 - Add memory telemetry for experiment

---
 app/metrics.yaml                              | 18 ++++++++++++
 .../org/mozilla/fenix/FenixApplication.kt     | 28 +++++++++++++++++++
 .../org/mozilla/fenix/FenixApplicationTest.kt |  9 +++++-
 3 files changed, 54 insertions(+), 1 deletion(-)

diff --git a/app/metrics.yaml b/app/metrics.yaml
index 3e95597ca..ac008fceb 100644
--- a/app/metrics.yaml
+++ b/app/metrics.yaml
@@ -2434,6 +2434,24 @@ metrics:
     metadata:
       tags:
         - Notifications
+  ram_more_than_threshold:
+    type: boolean
+    lifetime: application
+    description: True if the device's asserted 'advertised' RAM is more than the given threshold.
+    send_in_pings:
+      - metrics
+    bugs:
+      - https://bugzilla.mozilla.org/show_bug.cgi?id=1840341
+    data_reviews:
+      - https://github.com/mozilla-mobile/firefox-android/pull/2620
+    data_sensitivity:
+      - technical
+    notification_emails:
+      - android-probes@mozilla.com
+    expires: 128
+    metadata:
+      tags:
+        - Experiments
 
 customize_home:
   most_visited_sites:
diff --git a/app/src/main/java/org/mozilla/fenix/FenixApplication.kt b/app/src/main/java/org/mozilla/fenix/FenixApplication.kt
index d87bf8307..ed9424100 100644
--- a/app/src/main/java/org/mozilla/fenix/FenixApplication.kt
+++ b/app/src/main/java/org/mozilla/fenix/FenixApplication.kt
@@ -5,6 +5,8 @@
 package org.mozilla.fenix
 
 import android.annotation.SuppressLint
+import android.app.ActivityManager
+import android.content.Context
 import android.net.Uri
 import android.os.Build
 import android.os.Build.VERSION.SDK_INT
@@ -109,6 +111,19 @@ import org.mozilla.fenix.wallpapers.Wallpaper
 import java.util.UUID
 import java.util.concurrent.TimeUnit
 
+/**
+ * The actual RAM threshold is 2GB.
+ *
+ * To enable simpler reporting, we want to use the device's 'advertised' RAM.
+ * As [ActivityManager.MemoryInfo.totalMem] is not the device's 'advertised' RAM spec & we cannot
+ * access [ActivityManager.MemoryInfo.advertisedMem] across all Android versions, we will use a
+ * proxy value of 1.6GB. This is based on 1.5GB with a small 'excess' buffer. We assert that all
+ * values above this proxy value are 2GB or more.
+ */
+private const val RAM_THRESHOLD_PROXY_GB = 1.6F
+
+private const val RAM_THRESHOLD_BYTES = RAM_THRESHOLD_PROXY_GB * (1e+9).toLong()
+
 /**
  *The main application class for Fenix. Records data to measure initialization performance.
  *  Installs [CrashReporter], initializes [Glean]  in fenix builds and setup Megazord in the main process.
@@ -689,6 +704,7 @@ open class FenixApplication : LocaleAwareApplication(), Provider {
         settings: Settings,
         browsersCache: BrowsersCache = BrowsersCache,
         mozillaProductDetector: MozillaProductDetector = MozillaProductDetector,
+        isDeviceRamAboveThreshold: Boolean = isDeviceRamAboveThreshold(),
     ) {
         setPreferenceMetrics(settings)
         with(Metrics) {
@@ -786,6 +802,8 @@ open class FenixApplication : LocaleAwareApplication(), Provider {
             marketingNotificationAllowed.set(
                 notificationManagerCompat.isNotificationChannelEnabled(MARKETING_CHANNEL_ID),
             )
+
+            ramMoreThanThreshold.set(isDeviceRamAboveThreshold)
         }
 
         with(AndroidAutofill) {
@@ -826,6 +844,16 @@ open class FenixApplication : LocaleAwareApplication(), Provider {
         }
     }
 
+    private fun deviceRamBytes(): Long {
+        val memoryInfo = ActivityManager.MemoryInfo()
+        val activityManager = getSystemService(Context.ACTIVITY_SERVICE) as ActivityManager
+        activityManager.getMemoryInfo(memoryInfo)
+
+        return memoryInfo.totalMem
+    }
+
+    private fun isDeviceRamAboveThreshold() = deviceRamBytes() > RAM_THRESHOLD_BYTES
+
     @Suppress("ComplexMethod")
     private fun setPreferenceMetrics(
         settings: Settings,
diff --git a/app/src/test/java/org/mozilla/fenix/FenixApplicationTest.kt b/app/src/test/java/org/mozilla/fenix/FenixApplicationTest.kt
index a9c8fd65e..984546cc3 100644
--- a/app/src/test/java/org/mozilla/fenix/FenixApplicationTest.kt
+++ b/app/src/test/java/org/mozilla/fenix/FenixApplicationTest.kt
@@ -148,7 +148,13 @@ class FenixApplicationTest {
         assertTrue(settings.contileContextId.isEmpty())
         assertNull(TopSites.contextId.testGetValue())
 
-        application.setStartupMetrics(browserStore, settings, browsersCache, mozillaProductDetector)
+        application.setStartupMetrics(
+            browserStore = browserStore,
+            settings = settings,
+            browsersCache = browsersCache,
+            mozillaProductDetector = mozillaProductDetector,
+            isDeviceRamAboveThreshold = true,
+        )
 
         // Verify that browser defaults metrics are set.
         assertEquals("Mozilla", Metrics.distributionId.testGetValue())
@@ -186,6 +192,7 @@ class FenixApplicationTest {
         assertEquals(true, Preferences.inactiveTabsEnabled.testGetValue())
         assertEquals(expectedAppInstallSource, Metrics.installSource.testGetValue())
         assertEquals(true, Metrics.defaultWallpaper.testGetValue())
+        assertEquals(true, Metrics.ramMoreThanThreshold.testGetValue())
 
         val contextId = TopSites.contextId.testGetValue()!!.toString()