[SP26.2] add a method in NetworkStats that removes empty entries am: fb16574069 am: 7bb7d94d39

Change-Id: I388b1d3677d362da2595739913880efa9a643a03

core/java/android/net/NetworkStats.java

@@ -1195,18 +1195,24 @@ public final class NetworkStats implements Parcelable {
 
     /**
      * Remove all rows that match one of specified UIDs.
+     * This mutates the original structure in place.
      * @hide
      */
     public void removeUids(int[] uids) {
-        int nextOutputEntry = 0;
+        filter(e -> !ArrayUtils.contains(uids, e.uid));
-        for (int i = 0; i < size; i++) {
+    }
-            if (!ArrayUtils.contains(uids, uid[i])) {
-                maybeCopyEntry(nextOutputEntry, i);
-                nextOutputEntry++;
-            }
-        }
 
-        size = nextOutputEntry;
+    /**
+     * Remove all rows that match one of specified UIDs.
+     * @return the result object.
+     * @hide
+     */
+    @NonNull
+    public NetworkStats removeEmptyEntries() {
+        final NetworkStats ret = this.clone();
+        ret.filter(e -> e.rxBytes != 0 || e.rxPackets != 0 || e.txBytes != 0 || e.txPackets != 0
+                || e.operations != 0);
+        return ret;
     }
 
     /**

tests/net/java/android/net/NetworkStatsTest.java

@@ -502,6 +502,53 @@ public class NetworkStatsTest {
                 DEFAULT_NETWORK_NO, 64L, 2L, 0L, 0L, 0L);
     }
 
+    @Test
+    public void testRemoveEmptyEntries() throws Exception {
+        // Test empty stats.
+        final NetworkStats statsEmpty = new NetworkStats(TEST_START, 3);
+        assertEquals(0, statsEmpty.removeEmptyEntries().size());
+
+        // Test stats with non-zero entry.
+        final NetworkStats statsNonZero = new NetworkStats(TEST_START, 1)
+                .insertEntry(TEST_IFACE, 99, SET_DEFAULT, TAG_NONE, METERED_NO,
+                        ROAMING_NO, DEFAULT_NETWORK_NO, 1L, 128L, 0L, 2L, 20L);
+        assertEquals(1, statsNonZero.size());
+        final NetworkStats expectedNonZero = statsNonZero.removeEmptyEntries();
+        assertEquals(1, expectedNonZero.size());
+        assertValues(expectedNonZero, 0, TEST_IFACE, 99, SET_DEFAULT, TAG_NONE, METERED_NO,
+                ROAMING_NO, DEFAULT_NETWORK_NO, 1L, 128L, 0L, 2L, 20L);
+
+        // Test stats with empty entry.
+        final NetworkStats statsZero = new NetworkStats(TEST_START, 1)
+                .insertEntry(TEST_IFACE, 99, SET_DEFAULT, TAG_NONE, METERED_NO,
+                        ROAMING_NO, DEFAULT_NETWORK_NO, 0L, 0L, 0L, 0L, 0L);
+        assertEquals(1, statsZero.size());
+        final NetworkStats expectedZero = statsZero.removeEmptyEntries();
+        assertEquals(1, statsZero.size()); // Assert immutable.
+        assertEquals(0, expectedZero.size());
+
+        // Test stats with multiple entries.
+        final NetworkStats statsMultiple = new NetworkStats(TEST_START, 0)
+                .insertEntry(TEST_IFACE, 100, SET_DEFAULT, TAG_NONE, 2L, 64L, 0L, 2L, 20L)
+                .insertEntry(TEST_IFACE2, 100, SET_DEFAULT, TAG_NONE, 4L, 32L, 0L, 0L, 0L)
+                .insertEntry(TEST_IFACE, 101, SET_DEFAULT, 0xF00D, 0L, 0L, 0L, 0L, 0L)
+                .insertEntry(TEST_IFACE, 101, SET_DEFAULT, 0xF00D, 0L, 0L, 0L, 0L, 0L)
+                .insertEntry(TEST_IFACE2, 100, SET_DEFAULT, 0xF00D, 8L, 0L, 0L, 0L, 0L)
+                .insertEntry(TEST_IFACE2, 100, SET_FOREGROUND, TAG_NONE, 0L, 8L, 0L, 0L, 0L)
+                .insertEntry(TEST_IFACE, 101, SET_DEFAULT, TAG_NONE, 0L, 0L, 4L, 0L, 0L)
+                .insertEntry(TEST_IFACE, 101, SET_DEFAULT, 0xF00D, 0L, 0L, 0L, 2L, 0L)
+                .insertEntry(TEST_IFACE, 101, SET_DEFAULT, 0xF00D, 0L, 0L, 0L, 0L, 1L);
+        assertEquals(9, statsMultiple.size());
+        final NetworkStats expectedMultiple = statsMultiple.removeEmptyEntries();
+        assertEquals(9, statsMultiple.size()); // Assert immutable.
+        assertEquals(7, expectedMultiple.size());
+        assertValues(expectedMultiple.getTotalIncludingTags(null), 14L, 104L, 4L, 4L, 21L);
+
+        // Test stats with multiple empty entries.
+        assertEquals(statsMultiple.size(), statsMultiple.subtract(statsMultiple).size());
+        assertEquals(0, statsMultiple.subtract(statsMultiple).removeEmptyEntries().size());
+    }
+
     @Test
     public void testClone() throws Exception {
         final NetworkStats original = new NetworkStats(TEST_START, 5)