Merge pull request #19 from zlern2k/master

New definitions

.gitignore

@@ -4,3 +4,4 @@
 *.iml
 .DS_Store
 /build
+.watchmanconfig

yearclass/src/main/java/com/facebook/device/yearclass/YearClass.java

@@ -7,11 +7,11 @@
  */
 package com.facebook.device.yearclass;
 
+import android.content.Context;
+
 import java.util.ArrayList;
 import java.util.Collections;
 
-import android.content.Context;
-
 public class YearClass {
   // Year definitions
   public static final int CLASS_UNKNOWN = -1;
@@ -22,6 +22,7 @@ public class YearClass {
   public static final int CLASS_2012 = 2012;
   public static final int CLASS_2013 = 2013;
   public static final int CLASS_2014 = 2014;
+  public static final int CLASS_2015 = 2015;
 
   private static final long MB = 1024 * 1024;
   private static final int MHZ_IN_KHZ = 1000;
@@ -40,7 +41,7 @@ public static int get(Context c) {
     if (mYearCategory == null) {
       synchronized(YearClass.class) {
         if (mYearCategory == null) {
-          mYearCategory = categorizeByYear(c);
+          mYearCategory = categorizeByYear2016Method(c);
         }
       }
     }
@@ -53,6 +54,33 @@ private static void conditionallyAdd(ArrayList<Integer> list, int value) {
     }
   }
 
+  /**
+   * This formulation of year class smooths out the distribution of devices in the field
+   * in early 2016 so that the buckets are a bit more even in size and performance metrics
+   * (specifically app startup time, scrolling perf, animations) are more uniform within
+   * the buckets than with the 2014 calculations.
+   */
+  private static int categorizeByYear2016Method(Context c) {
+    long totalRam = DeviceInfo.getTotalMemory(c);
+    if (totalRam == DeviceInfo.DEVICEINFO_UNKNOWN) {
+      return categorizeByYear2014Method(c);
+    }
+
+    if (totalRam <= 768 * MB) {
+      return DeviceInfo.getNumberOfCPUCores() <= 1 ? CLASS_2009 : CLASS_2010;
+    }
+    if (totalRam <= 1024 * MB) {
+      return DeviceInfo.getCPUMaxFreqKHz() < 1300 * MHZ_IN_KHZ ? CLASS_2011 : CLASS_2012;
+    }
+    if (totalRam <= 1536 * MB) {
+      return DeviceInfo.getCPUMaxFreqKHz() < 1800 * MHZ_IN_KHZ ? CLASS_2012 : CLASS_2013;
+    }
+    if (totalRam <= 2048 * MB) {
+      return CLASS_2013;
+    }
+    return totalRam <= 3 * 1024 * MB ? CLASS_2014 : CLASS_2015;
+  }
+
   /**
    * Calculates the "best-in-class year" of the device. This represents the top-end or flagship
    * devices of that year, not the actual release year of the phone. For example, the Galaxy Duos
@@ -61,7 +89,7 @@ private static void conditionallyAdd(ArrayList<Integer> list, int value) {
    *
    * @return The year when this device would have been considered top-of-the-line.
    */
-  private static int categorizeByYear(Context c) {
+  private static int categorizeByYear2014Method(Context c) {
     ArrayList<Integer> componentYears = new ArrayList<Integer>();
     conditionallyAdd(componentYears, getNumCoresYear());
     conditionallyAdd(componentYears, getClockSpeedYear());

yearclass/src/test/java/com/facebook/device/yearclass/YearClassTest.java

@@ -24,12 +24,44 @@ public class YearClassTest {
 
   @PrepareForTest(DeviceInfo.class)
   @Test
-  public void testGetYearCategory() {
+  public void testGetYearCategoryS7() {
+    // CPU, frequency, RAM, and YearClass values from Samsung Galaxy S7 (global edition).
+    int yearClass = getYearClass(8, 2600000, 3663L * 1024 * 1024);
+    assertEquals(YearClass.CLASS_2015, yearClass);
+  }
+
+  @PrepareForTest(DeviceInfo.class)
+  @Test
+  public void testGetYearCategoryG4() {
+    // CPU, frequency, RAM, and YearClass values from LG G4.
+    int yearClass = getYearClass(6, 1824000, 2778L * 1024 * 1024);
+    assertEquals(YearClass.CLASS_2014, yearClass);
+  }
+
+  @PrepareForTest(DeviceInfo.class)
+  @Test
+  public void testGetYearCategoryS5() {
     // CPU, frequency, RAM, and YearClass values from Samsung Galaxy S5.
     int yearClass = getYearClass(4, 2457600, 1946939392L);
     assertEquals(YearClass.CLASS_2013, yearClass);
   }
 
+  @PrepareForTest(DeviceInfo.class)
+  @Test
+  public void testGetYearCategoryGalaxyJ1() {
+    // CPU, frequency, RAM, and YearClass values from Samsung Galaxy J1.
+    int yearClass = getYearClass(2, 1248000, 716L * 1024 * 1024);
+    assertEquals(YearClass.CLASS_2010, yearClass);
+  }
+
+  @PrepareForTest(DeviceInfo.class)
+  @Test
+  public void testGetYearCategoryP8lite() {
+    // CPU, frequency, RAM, and YearClass values from Huawei P8lite.
+    int yearClass = getYearClass(8, 1200000, 1858L * 1024 * 1024);
+    assertEquals(YearClass.CLASS_2013, yearClass);
+  }
+
   @PrepareForTest(DeviceInfo.class)
   @Test
   public void testEmptyCase() {