Switch LatencyTracker to the DeviceConfig API

Test: manual
Bug: 162927074

Change-Id: I4eaae9db74ac1b23bdd0e90a6981a852375f788b

3 files changed, 20 insertions, 58 deletions

diff --git a/core/java/android/provider/DeviceConfig.java b/core/java/android/provider/DeviceConfig.java
index 97c9f4bbb4ba..0c4f8de449e6 100644
--- a/core/java/android/provider/DeviceConfig.java
+++ b/core/java/android/provider/DeviceConfig.java
@@ -457,6 +457,13 @@ public final class DeviceConfig {
      */
     public static final String NAMESPACE_CONFIGURATION = "configuration";
 
+    /**
+     * LatencyTracker properties definitions.
+     *
+     * @hide
+     */
+    public static final String NAMESPACE_LATENCY_TRACKER = "latency_tracker";
+
     private static final Object sLock = new Object();
     @GuardedBy("sLock")
     private static ArrayMap<OnPropertiesChangedListener, Pair<String, Executor>> sListeners =
diff --git a/core/java/android/provider/Settings.java b/core/java/android/provider/Settings.java
index 3e48168eabe0..fcc0222015c0 100644
--- a/core/java/android/provider/Settings.java
+++ b/core/java/android/provider/Settings.java
@@ -14576,19 +14576,6 @@ public final class Settings {
          */
         public static final String MAXIMUM_OBSCURING_OPACITY_FOR_TOUCH =
                 "maximum_obscuring_opacity_for_touch";
-
-        /**
-         * LatencyTracker settings.
-         *
-         * The following strings are supported as keys:
-         * <pre>
-         *     enabled              (boolean)
-         *     sampling_interval    (int)
-         * </pre>
-         *
-         * @hide
-         */
-        public static final String LATENCY_TRACKER = "latency_tracker";
     }
 
     /**
diff --git a/core/java/com/android/internal/util/LatencyTracker.java b/core/java/com/android/internal/util/LatencyTracker.java
index a87e8aaa0e64..8012540ed314 100644
--- a/core/java/com/android/internal/util/LatencyTracker.java
+++ b/core/java/com/android/internal/util/LatencyTracker.java
@@ -15,15 +15,11 @@
 package com.android.internal.util;
 
 import android.content.Context;
-import android.database.ContentObserver;
-import android.net.Uri;
 import android.os.Build;
 import android.os.SystemClock;
 import android.os.Trace;
-import android.os.UserHandle;
-import android.provider.Settings;
+import android.provider.DeviceConfig;
 import android.util.EventLog;
-import android.util.KeyValueListParser;
 import android.util.Log;
 import android.util.SparseLongArray;
 
@@ -135,8 +131,16 @@ public class LatencyTracker {
         mSamplingInterval = DEFAULT_SAMPLING_INTERVAL;
 
         // Post initialization to the background in case we're running on the main thread.
-        BackgroundThread.getHandler().post(this::registerSettingsObserver);
-        BackgroundThread.getHandler().post(this::readSettings);
+        BackgroundThread.getHandler().post(() -> this.updateProperties(
+                DeviceConfig.getProperties(DeviceConfig.NAMESPACE_LATENCY_TRACKER)));
+        DeviceConfig.addOnPropertiesChangedListener(DeviceConfig.NAMESPACE_LATENCY_TRACKER,
+                BackgroundThread.getExecutor(), this::updateProperties);
+    }
+
+    private void updateProperties(DeviceConfig.Properties properties) {
+        mSamplingInterval = properties.getInt(SETTINGS_SAMPLING_INTERVAL_KEY,
+                DEFAULT_SAMPLING_INTERVAL);
+        mEnabled = properties.getBoolean(SETTINGS_ENABLED_KEY, DEFAULT_ENABLED);
     }
 
     /**
@@ -171,28 +175,6 @@ public class LatencyTracker {
         }
     }
 
-    private void registerSettingsObserver() {
-        Uri settingsUri = Settings.Global.getUriFor(Settings.Global.LATENCY_TRACKER);
-        mContext.getContentResolver().registerContentObserver(
-                settingsUri, false, new SettingsObserver(this), UserHandle.myUserId());
-    }
-
-    private void readSettings() {
-        KeyValueListParser parser = new KeyValueListParser(',');
-        String settingsValue = Settings.Global.getString(mContext.getContentResolver(),
-                Settings.Global.LATENCY_TRACKER);
-
-        try {
-            parser.setString(settingsValue);
-            mSamplingInterval = parser.getInt(SETTINGS_SAMPLING_INTERVAL_KEY,
-                    DEFAULT_SAMPLING_INTERVAL);
-            mEnabled = parser.getBoolean(SETTINGS_ENABLED_KEY, DEFAULT_ENABLED);
-        } catch (IllegalArgumentException e) {
-            Log.e(TAG, "Incorrect settings format", e);
-            mEnabled = false;
-        }
-    }
-
     public static boolean isEnabled(Context ctx) {
         return getInstance(ctx).isEnabled();
     }
@@ -236,8 +218,8 @@ public class LatencyTracker {
     /**
      * Logs an action that has started and ended. This needs to be called from the main thread.
      *
-     * @param action          The action to end. One of the ACTION_* values.
-     * @param duration        The duration of the action in ms.
+     * @param action   The action to end. One of the ACTION_* values.
+     * @param duration The duration of the action in ms.
      */
     public void logAction(int action, int duration) {
         boolean shouldSample = ThreadLocalRandom.current().nextInt() % mSamplingInterval == 0;
@@ -260,18 +242,4 @@ public class LatencyTracker {
                     FrameworkStatsLog.UI_ACTION_LATENCY_REPORTED, STATSD_ACTION[action], duration);
         }
     }
-
-    private static class SettingsObserver extends ContentObserver {
-        private final LatencyTracker mThisTracker;
-
-        SettingsObserver(LatencyTracker thisTracker) {
-            super(BackgroundThread.getHandler());
-            mThisTracker = thisTracker;
-        }
-
-        @Override
-        public void onChange(boolean selfChange, Uri uri, int userId) {
-            mThisTracker.readSettings();
-        }
-    }
 }