Merge "Introduce trimMemory to AppIconCacheManager" am: 10ae330a97

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/2308424

Change-Id: I9e4049722b4c341aa57d656ae572d6522de49f65
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

packages/SettingsLib/src/com/android/settingslib/applications/AppIconCacheManager.java

@@ -22,13 +22,16 @@ import android.os.UserHandle;
 import android.util.Log;
 import android.util.LruCache;
 
+import androidx.annotation.VisibleForTesting;
+
 /**
  * Cache app icon for management.
  */
 public class AppIconCacheManager {
     private static final String TAG = "AppIconCacheManager";
     private static final float CACHE_RATIO = 0.1f;
-    private static final int MAX_CACHE_SIZE_IN_KB = getMaxCacheInKb();
+    @VisibleForTesting
+    static final int MAX_CACHE_SIZE_IN_KB = getMaxCacheInKb();
     private static final String DELIMITER = ":";
     private static AppIconCacheManager sAppIconCacheManager;
     private final LruCache<String, Drawable> mDrawableCache;
@@ -109,4 +112,25 @@ public class AppIconCacheManager {
     private static int getMaxCacheInKb() {
         return Math.round(CACHE_RATIO * Runtime.getRuntime().maxMemory() / 1024);
     }
+
+    /**
+     * Clears as much memory as possible.
+     *
+     * @see android.content.ComponentCallbacks2#onTrimMemory(int)
+     */
+    public void trimMemory(int level) {
+        if (level >= android.content.ComponentCallbacks2.TRIM_MEMORY_BACKGROUND) {
+            // Time to clear everything
+            if (sAppIconCacheManager != null) {
+                sAppIconCacheManager.mDrawableCache.trimToSize(0);
+            }
+        } else if (level >= android.content.ComponentCallbacks2.TRIM_MEMORY_UI_HIDDEN
+                || level == android.content.ComponentCallbacks2.TRIM_MEMORY_RUNNING_CRITICAL) {
+            // Tough time but still affordable, clear half of the cache
+            if (sAppIconCacheManager != null) {
+                final int maxSize = sAppIconCacheManager.mDrawableCache.maxSize();
+                sAppIconCacheManager.mDrawableCache.trimToSize(maxSize / 2);
+            }
+        }
+    }
 }

packages/SettingsLib/tests/robotests/src/com/android/settingslib/applications/AppIconCacheManagerTest.java

@@ -34,11 +34,21 @@ import org.robolectric.RobolectricTestRunner;
 public class AppIconCacheManagerTest {
 
     private static final String APP_PACKAGE_NAME = "com.test.app";
+    private static final String APP_PACKAGE_NAME1 = "com.test.app1";
+    private static final String APP_PACKAGE_NAME2 = "com.test.app2";
+    private static final String APP_PACKAGE_NAME3 = "com.test.app3";
     private static final int APP_UID = 9999;
 
     @Mock
     private Drawable mIcon;
 
+    @Mock
+    private Drawable mIcon1;
+    @Mock
+    private Drawable mIcon2;
+    @Mock
+    private Drawable mIcon3;
+
     private AppIconCacheManager mAppIconCacheManager;
 
     @Before
@@ -48,6 +58,29 @@ public class AppIconCacheManagerTest {
         doReturn(10).when(mIcon).getIntrinsicHeight();
         doReturn(10).when(mIcon).getIntrinsicWidth();
         doReturn(mIcon).when(mIcon).mutate();
+
+        // Algorithm for trim memory test:
+        // The real maxsize is defined by AppIconCacheManager.MAX_CACHE_SIZE_IN_KB, and the size
+        // of each element is calculated as following:
+        // n * n * 4 / 1024
+        // In the testcase, we want to mock the maxsize of LruCache is 3, so the formula calculating
+        // the size of each element will be like:
+        // n * n * 4 / 1024 = maxsize / 3
+        // Thus, n = square_root(maxsize / 3 * 1024 / 4), which can be used as an icon size.
+        final int iconSize =
+                (int) Math.sqrt(AppIconCacheManager.MAX_CACHE_SIZE_IN_KB / 3f * 1024f / 4f);
+
+        doReturn(iconSize).when(mIcon1).getIntrinsicHeight();
+        doReturn(iconSize).when(mIcon1).getIntrinsicWidth();
+        doReturn(mIcon1).when(mIcon1).mutate();
+
+        doReturn(iconSize).when(mIcon2).getIntrinsicHeight();
+        doReturn(iconSize).when(mIcon2).getIntrinsicWidth();
+        doReturn(mIcon2).when(mIcon2).mutate();
+
+        doReturn(iconSize).when(mIcon3).getIntrinsicHeight();
+        doReturn(iconSize).when(mIcon3).getIntrinsicWidth();
+        doReturn(mIcon3).when(mIcon3).mutate();
     }
 
     @After
@@ -106,4 +139,41 @@ public class AppIconCacheManagerTest {
 
         assertThat(mAppIconCacheManager.get(APP_PACKAGE_NAME, APP_UID)).isNull();
     }
+
+    @Test
+    public void trimMemory_levelSatisfied_shouldNotCacheIcon() {
+
+        mAppIconCacheManager.put(APP_PACKAGE_NAME1, APP_UID, mIcon1);
+        mAppIconCacheManager.put(APP_PACKAGE_NAME2, APP_UID, mIcon2);
+        mAppIconCacheManager.put(APP_PACKAGE_NAME3, APP_UID, mIcon3);
+
+        // Expected to trim size to 0
+        final int level = android.content.ComponentCallbacks2.TRIM_MEMORY_BACKGROUND;
+        mAppIconCacheManager.trimMemory(level);
+
+        // None of the elements should be cached
+        assertThat(mAppIconCacheManager.get(APP_PACKAGE_NAME1, APP_UID)).isNull();
+        assertThat(mAppIconCacheManager.get(APP_PACKAGE_NAME2, APP_UID)).isNull();
+        assertThat(mAppIconCacheManager.get(APP_PACKAGE_NAME3, APP_UID)).isNull();
+    }
+
+    @Test
+    public void trimMemory_levelSatisfied_shouldCacheAtLeastHalf() {
+
+        mAppIconCacheManager.put(APP_PACKAGE_NAME1, APP_UID, mIcon1);
+        mAppIconCacheManager.put(APP_PACKAGE_NAME2, APP_UID, mIcon2);
+        mAppIconCacheManager.put(APP_PACKAGE_NAME3, APP_UID, mIcon3);
+
+        // Get the last element
+        mAppIconCacheManager.get(APP_PACKAGE_NAME1, APP_UID);
+
+        // Expected to trim size to half of it, which is int( 3 / 2 ) = 1
+        final int level = android.content.ComponentCallbacks2.TRIM_MEMORY_RUNNING_CRITICAL;
+        mAppIconCacheManager.trimMemory(level);
+
+        // There should be only one cached element, which is the last recently used one
+        assertThat(mAppIconCacheManager.get(APP_PACKAGE_NAME1, APP_UID)).isNotNull();
+        assertThat(mAppIconCacheManager.get(APP_PACKAGE_NAME2, APP_UID)).isNull();
+        assertThat(mAppIconCacheManager.get(APP_PACKAGE_NAME3, APP_UID)).isNull();
+    }
 }