Data cycle ends on last second of month.

When data cycle resets on a day invalid in given month, snap the
cycle to last second of month.  Previous behavior was to bump fully
into next month, but that causes cycle loops.

Includes tests to verify.

Bug: 4623124
Change-Id: I2f233091f6f1df33a2814284519cbc04532874e9

1 files changed, 66 insertions, 5 deletions

diff --git a/services/tests/servicestests/src/com/android/server/NetworkPolicyManagerServiceTest.java b/services/tests/servicestests/src/com/android/server/NetworkPolicyManagerServiceTest.java
index 91fef22..09f8ff3 100644
--- a/services/tests/servicestests/src/com/android/server/NetworkPolicyManagerServiceTest.java
+++ b/services/tests/servicestests/src/com/android/server/NetworkPolicyManagerServiceTest.java
@@ -20,14 +20,18 @@ import static android.content.Intent.ACTION_UID_REMOVED;
 import static android.content.Intent.EXTRA_UID;
 import static android.net.ConnectivityManager.CONNECTIVITY_ACTION;
 import static android.net.ConnectivityManager.TYPE_WIFI;
+import static android.net.NetworkPolicy.LIMIT_DISABLED;
 import static android.net.NetworkPolicy.SNOOZE_NEVER;
+import static android.net.NetworkPolicy.WARNING_DISABLED;
 import static android.net.NetworkPolicyManager.POLICY_NONE;
 import static android.net.NetworkPolicyManager.POLICY_REJECT_METERED_BACKGROUND;
 import static android.net.NetworkPolicyManager.RULE_ALLOW_ALL;
 import static android.net.NetworkPolicyManager.RULE_REJECT_METERED;
 import static android.net.NetworkPolicyManager.computeLastCycleBoundary;
+import static android.net.NetworkPolicyManager.computeNextCycleBoundary;
 import static android.net.NetworkStats.TAG_NONE;
 import static android.net.NetworkStats.UID_ALL;
+import static android.text.format.DateUtils.DAY_IN_MILLIS;
 import static android.text.format.DateUtils.MINUTE_IN_MILLIS;
 import static com.android.server.net.NetworkPolicyManagerService.TYPE_LIMIT;
 import static com.android.server.net.NetworkPolicyManagerService.TYPE_LIMIT_SNOOZED;
@@ -79,6 +83,7 @@ import org.easymock.EasyMock;
 import org.easymock.IAnswer;
 
 import java.io.File;
+import java.util.LinkedHashSet;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Future;
 import java.util.concurrent.TimeUnit;
@@ -402,7 +407,7 @@ public class NetworkPolicyManagerServiceTest extends AndroidTestCase {
         final NetworkPolicy policy = new NetworkPolicy(
                 sTemplateWifi, 5, 1024L, 1024L, SNOOZE_NEVER);
         final long actualCycle = computeLastCycleBoundary(currentTime, policy);
-        assertEquals(expectedCycle, actualCycle);
+        assertTimeEquals(expectedCycle, actualCycle);
     }
 
     public void testLastCycleBoundaryLastMonth() throws Exception {
@@ -413,7 +418,7 @@ public class NetworkPolicyManagerServiceTest extends AndroidTestCase {
         final NetworkPolicy policy = new NetworkPolicy(
                 sTemplateWifi, 20, 1024L, 1024L, SNOOZE_NEVER);
         final long actualCycle = computeLastCycleBoundary(currentTime, policy);
-        assertEquals(expectedCycle, actualCycle);
+        assertTimeEquals(expectedCycle, actualCycle);
     }
 
     public void testLastCycleBoundaryThisMonthFebruary() throws Exception {
@@ -424,18 +429,48 @@ public class NetworkPolicyManagerServiceTest extends AndroidTestCase {
         final NetworkPolicy policy = new NetworkPolicy(
                 sTemplateWifi, 30, 1024L, 1024L, SNOOZE_NEVER);
         final long actualCycle = computeLastCycleBoundary(currentTime, policy);
-        assertEquals(expectedCycle, actualCycle);
+        assertTimeEquals(expectedCycle, actualCycle);
     }
 
     public void testLastCycleBoundaryLastMonthFebruary() throws Exception {
         // assume cycle day of "30th" in february, which should clamp
         final long currentTime = parseTime("2007-03-14T00:00:00.000Z");
-        final long expectedCycle = parseTime("2007-03-01T00:00:00.000Z");
+        final long expectedCycle = parseTime("2007-02-28T23:59:59.000Z");
 
         final NetworkPolicy policy = new NetworkPolicy(
                 sTemplateWifi, 30, 1024L, 1024L, SNOOZE_NEVER);
         final long actualCycle = computeLastCycleBoundary(currentTime, policy);
-        assertEquals(expectedCycle, actualCycle);
+        assertTimeEquals(expectedCycle, actualCycle);
+    }
+
+    public void testNextCycleSane() throws Exception {
+        final NetworkPolicy policy = new NetworkPolicy(
+                sTemplateWifi, 31, WARNING_DISABLED, LIMIT_DISABLED, SNOOZE_NEVER);
+        final LinkedHashSet<Long> seen = new LinkedHashSet<Long>();
+
+        // walk forwards, ensuring that cycle boundaries don't get stuck
+        long currentCycle = computeNextCycleBoundary(parseTime("2011-08-01T00:00:00.000Z"), policy);
+        for (int i = 0; i < 128; i++) {
+            long nextCycle = computeNextCycleBoundary(currentCycle, policy);
+            assertEqualsFuzzy(DAY_IN_MILLIS * 30, nextCycle - currentCycle, DAY_IN_MILLIS * 3);
+            assertUnique(seen, nextCycle);
+            currentCycle = nextCycle;
+        }
+    }
+
+    public void testLastCycleSane() throws Exception {
+        final NetworkPolicy policy = new NetworkPolicy(
+                sTemplateWifi, 31, WARNING_DISABLED, LIMIT_DISABLED, SNOOZE_NEVER);
+        final LinkedHashSet<Long> seen = new LinkedHashSet<Long>();
+
+        // walk backwards, ensuring that cycle boundaries look sane
+        long currentCycle = computeLastCycleBoundary(parseTime("2011-08-04T00:00:00.000Z"), policy);
+        for (int i = 0; i < 128; i++) {
+            long lastCycle = computeLastCycleBoundary(currentCycle, policy);
+            assertEqualsFuzzy(DAY_IN_MILLIS * 30, currentCycle - lastCycle, DAY_IN_MILLIS * 3);
+            assertUnique(seen, lastCycle);
+            currentCycle = lastCycle;
+        }
     }
 
     public void testNetworkPolicyAppliedCycleLastMonth() throws Exception {
@@ -734,6 +769,32 @@ public class NetworkPolicyManagerServiceTest extends AndroidTestCase {
         }
     }
 
+    private static void assertTimeEquals(long expected, long actual) {
+        if (expected != actual) {
+            fail("expected " + formatTime(expected) + " but was actually " + formatTime(actual));
+        }
+    }
+
+    private static String formatTime(long millis) {
+        final Time time = new Time(Time.TIMEZONE_UTC);
+        time.set(millis);
+        return time.format3339(false);
+    }
+
+    private static void assertEqualsFuzzy(long expected, long actual, long fuzzy) {
+        final long low = expected - fuzzy;
+        final long high = expected + fuzzy;
+        if (actual < low || actual > high) {
+            fail("value " + actual + " is outside [" + low + "," + high + "]");
+        }
+    }
+
+    private static void assertUnique(LinkedHashSet<Long> seen, Long value) {
+        if (!seen.add(value)) {
+            fail("found duplicate time " + value + " in series " + seen.toString());
+        }
+    }
+
     private static void assertNotificationType(int expected, String actualTag) {
         assertEquals(
                 Integer.toString(expected), actualTag.substring(actualTag.lastIndexOf(':') + 1));