Thread: fill in ticks in active timestamp

This commit fills in the ticks of active timestamp of randomly generated
dataset as defined in Thread spec.

Bug: 347838683
Change-Id: I5d8ba3ca7728e1890996fdd64198f7bc90bfb1fa

thread/framework/java/android/net/thread/OperationalDatasetTimestamp.java

@@ -65,11 +65,32 @@ public final class OperationalDatasetTimestamp {
      */
     @NonNull
     public static OperationalDatasetTimestamp fromInstant(@NonNull Instant instant) {
+        return OperationalDatasetTimestamp.fromInstant(instant, true /* isAuthoritativeSource */);
+    }
+
+    /**
+     * Creates a new {@link OperationalDatasetTimestamp} object from an {@link Instant}.
+     *
+     * <p>The {@code seconds} is set to {@code instant.getEpochSecond()}, {@code ticks} is set to
+     * {@link instant#getNano()} based on frequency of 32768 Hz, and {@code isAuthoritativeSource}
+     * is set to {@code isAuthoritativeSource}.
+     *
+     * <p>Note that this conversion can lose precision and a value returned by {@link #toInstant}
+     * may not equal exactly the {@code instant}.
+     *
+     * @throws IllegalArgumentException if {@code instant.getEpochSecond()} is larger than {@code
+     *     0xffffffffffffL}
+     * @see toInstant
+     * @hide
+     */
+    @NonNull
+    public static OperationalDatasetTimestamp fromInstant(
+            @NonNull Instant instant, boolean isAuthoritativeSource) {
         int ticks = getRoundedTicks(instant.getNano());
         long seconds = instant.getEpochSecond() + ticks / TICKS_UPPER_BOUND;
         // the rounded ticks can be 0x8000 if instant.getNano() >= 999984742
         ticks = ticks % TICKS_UPPER_BOUND;
-        return new OperationalDatasetTimestamp(seconds, ticks, true /* isAuthoritativeSource */);
+        return new OperationalDatasetTimestamp(seconds, ticks, isAuthoritativeSource);
     }
 
     /**

thread/service/java/com/android/server/thread/ThreadNetworkControllerService.java

@@ -884,9 +884,7 @@ final class ThreadNetworkControllerService extends IThreadNetworkController.Stub
         final byte[] securityFlags = new byte[] {(byte) 0xff, (byte) 0xf8};
 
         return new ActiveOperationalDataset.Builder()
-                .setActiveTimestamp(
-                        new OperationalDatasetTimestamp(
-                                now.getEpochSecond() & 0xffffffffffffL, 0, authoritative))
+                .setActiveTimestamp(OperationalDatasetTimestamp.fromInstant(now, authoritative))
                 .setExtendedPanId(newRandomBytes(random, LENGTH_EXTENDED_PAN_ID))
                 .setPanId(panId)
                 .setNetworkName(networkName)

thread/tests/unit/src/android/net/thread/OperationalDatasetTimestampTest.java

@@ -40,6 +40,19 @@ public final class OperationalDatasetTimestampTest {
                 () -> OperationalDatasetTimestamp.fromTlvValue(new byte[7]));
     }
 
+    @Test
+    public void fromInstant_authoritativeIsSetAsSpecified() {
+        Instant instant = Instant.now();
+
+        OperationalDatasetTimestamp timestampAuthoritativeFalse =
+                OperationalDatasetTimestamp.fromInstant(instant, false);
+        OperationalDatasetTimestamp timestampAuthoritativeTrue =
+                OperationalDatasetTimestamp.fromInstant(instant, true);
+
+        assertThat(timestampAuthoritativeFalse.isAuthoritativeSource()).isEqualTo(false);
+        assertThat(timestampAuthoritativeTrue.isAuthoritativeSource()).isEqualTo(true);
+    }
+
     @Test
     public void fromTlvValue_goodValue_success() {
         OperationalDatasetTimestamp timestamp =

thread/tests/unit/src/com/android/server/thread/ThreadNetworkControllerServiceTest.java

@@ -98,6 +98,8 @@ import org.mockito.MockitoSession;
 import java.nio.charset.StandardCharsets;
 import java.time.Clock;
 import java.time.DateTimeException;
+import java.time.Instant;
+import java.time.ZoneId;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.atomic.AtomicReference;
@@ -584,6 +586,55 @@ public final class ThreadNetworkControllerServiceTest {
         assertThat(activeDataset.getActiveTimestamp().isAuthoritativeSource()).isFalse();
     }
 
+    @Test
+    public void createRandomizedDataset_zeroNanoseconds_returnsZeroTicks() throws Exception {
+        Instant now = Instant.ofEpochSecond(0, 0);
+        Clock clock = Clock.fixed(now, ZoneId.systemDefault());
+        MockitoSession session =
+                ExtendedMockito.mockitoSession().mockStatic(SystemClock.class).startMocking();
+        final IActiveOperationalDatasetReceiver mockReceiver =
+                ExtendedMockito.mock(IActiveOperationalDatasetReceiver.class);
+
+        try {
+            ExtendedMockito.when(SystemClock.currentNetworkTimeClock()).thenReturn(clock);
+            mService.createRandomizedDataset(DEFAULT_NETWORK_NAME, mockReceiver);
+            mTestLooper.dispatchAll();
+        } finally {
+            session.finishMocking();
+        }
+
+        verify(mockReceiver, never()).onError(anyInt(), anyString());
+        verify(mockReceiver, times(1)).onSuccess(mActiveDatasetCaptor.capture());
+        ActiveOperationalDataset activeDataset = mActiveDatasetCaptor.getValue();
+        assertThat(activeDataset.getActiveTimestamp().getTicks()).isEqualTo(0);
+    }
+
+    @Test
+    public void createRandomizedDataset_maxNanoseconds_returnsMaxTicks() throws Exception {
+        // The nanoseconds to ticks conversion is rounded in the current implementation.
+        // 32767.5 / 32768 * 1000000000 = 999984741.2109375, using 999984741 to
+        // produce the maximum ticks.
+        Instant now = Instant.ofEpochSecond(0, 999984741);
+        Clock clock = Clock.fixed(now, ZoneId.systemDefault());
+        MockitoSession session =
+                ExtendedMockito.mockitoSession().mockStatic(SystemClock.class).startMocking();
+        final IActiveOperationalDatasetReceiver mockReceiver =
+                ExtendedMockito.mock(IActiveOperationalDatasetReceiver.class);
+
+        try {
+            ExtendedMockito.when(SystemClock.currentNetworkTimeClock()).thenReturn(clock);
+            mService.createRandomizedDataset(DEFAULT_NETWORK_NAME, mockReceiver);
+            mTestLooper.dispatchAll();
+        } finally {
+            session.finishMocking();
+        }
+
+        verify(mockReceiver, never()).onError(anyInt(), anyString());
+        verify(mockReceiver, times(1)).onSuccess(mActiveDatasetCaptor.capture());
+        ActiveOperationalDataset activeDataset = mActiveDatasetCaptor.getValue();
+        assertThat(activeDataset.getActiveTimestamp().getTicks()).isEqualTo(32767);
+    }
+
     @Test
     public void createRandomizedDataset_hasNetworkTimeClock_datasetActiveTimestampIsAuthoritative()
             throws Exception {