Make server timestamp methods static, rename ServerTimestamps

firebase-firestore/src/main/java/com/google/firebase/firestore/Query.java

@@ -40,7 +40,7 @@
 import com.google.firebase.firestore.model.DocumentKey;
 import com.google.firebase.firestore.model.ResourcePath;
 import com.google.firebase.firestore.model.value.ProtoValues;
-import com.google.firebase.firestore.model.value.ServerTimestampValue;
+import com.google.firebase.firestore.model.value.ServerTimestamps;
 import com.google.firebase.firestore.util.Executors;
 import com.google.firebase.firestore.util.Util;
 import com.google.firestore.v1.ArrayValue;
@@ -751,7 +751,7 @@ private Bound boundFromDocumentSnapshot(
         components.add(ProtoValues.refValue(firestore.getDatabaseId(), document.getKey()));
       } else {
         Value value = document.getField(orderBy.getField());
-        if (ServerTimestampValue.isServerTimestamp(value)) {
+        if (ServerTimestamps.isServerTimestamp(value)) {
           throw new IllegalArgumentException(
               "Invalid query. You are trying to start or end a query using a document for which "
                   + "the field '"

firebase-firestore/src/main/java/com/google/firebase/firestore/UserDataWriter.java

@@ -14,13 +14,15 @@
 
 package com.google.firebase.firestore;
 
+import static com.google.firebase.firestore.model.value.ServerTimestamps.getLocalWriteTime;
+import static com.google.firebase.firestore.model.value.ServerTimestamps.getPreviousValue;
+import static com.google.firebase.firestore.model.value.ServerTimestamps.isServerTimestamp;
 import static com.google.firebase.firestore.util.Assert.fail;
 
 import androidx.annotation.RestrictTo;
 import com.google.firebase.Timestamp;
 import com.google.firebase.firestore.model.DatabaseId;
 import com.google.firebase.firestore.model.DocumentKey;
-import com.google.firebase.firestore.model.value.ServerTimestampValue;
 import com.google.firebase.firestore.util.Logger;
 import com.google.firestore.v1.ArrayValue;
 import com.google.firestore.v1.Value;
@@ -52,8 +54,8 @@ public class UserDataWriter {
   Object convertValue(Value value) {
     switch (value.getValueTypeCase()) {
       case MAP_VALUE:
-        if (ServerTimestampValue.isServerTimestamp(value)) {
-          return convertServerTimestamp(new ServerTimestampValue(value));
+        if (isServerTimestamp(value)) {
+          return convertServerTimestamp(value);
         }
         return convertObject(value.getMapValue().getFieldsMap());
       case ARRAY_VALUE:
@@ -90,14 +92,16 @@ Map<String, Object> convertObject(Map<String, Value> mapValue) {
     return result;
   }
 
-  private Object convertServerTimestamp(ServerTimestampValue value) {
+  private Object convertServerTimestamp(Value serverTimestampValue) {
     switch (serverTimestampBehavior) {
       case PREVIOUS:
-        return value.getPreviousValue() == null ? null : convertValue(value.getPreviousValue());
+        Value previousValue = getPreviousValue(serverTimestampValue);
+        if (previousValue == null) {
+          return null;
+        }
+        return convertValue(previousValue);
       case ESTIMATE:
-        return !timestampsInSnapshots
-            ? value.getLocalWriteTime().toDate()
-            : value.getLocalWriteTime();
+        return convertTimestamp(getLocalWriteTime(serverTimestampValue));
       default:
         return null;
     }

firebase-firestore/src/main/java/com/google/firebase/firestore/model/mutation/ServerTimestampOperation.java

@@ -16,7 +16,7 @@
 
 import androidx.annotation.Nullable;
 import com.google.firebase.Timestamp;
-import com.google.firebase.firestore.model.value.ServerTimestampValue;
+import com.google.firebase.firestore.model.value.ServerTimestamps;
 import com.google.firestore.v1.Value;
 
 /** Transforms a value into a server-generated timestamp. */
@@ -31,7 +31,7 @@ public static ServerTimestampOperation getInstance() {
 
   @Override
   public Value applyToLocalView(@Nullable Value previousValue, Timestamp localWriteTime) {
-    return ServerTimestampValue.valueOf(localWriteTime, previousValue);
+    return ServerTimestamps.valueOf(localWriteTime, previousValue);
   }
 
   @Override

firebase-firestore/src/main/java/com/google/firebase/firestore/model/value/ObjectValue.java

@@ -44,7 +44,7 @@ public ObjectValue(Value value) {
         value.getValueTypeCase() == Value.ValueTypeCase.MAP_VALUE,
         "ObjectValues should be backed by a MapValue");
     hardAssert(
-        !ServerTimestampValue.isServerTimestamp(value),
+        !ServerTimestamps.isServerTimestamp(value),
         "ServerTimestamps should not be used as an ObjectValue");
     this.internalValue = value;
   }

firebase-firestore/src/main/java/com/google/firebase/firestore/model/value/ProtoValues.java

@@ -14,6 +14,8 @@
 
 package com.google.firebase.firestore.model.value;
 
+import static com.google.firebase.firestore.model.value.ServerTimestamps.getLocalWriteTime;
+import static com.google.firebase.firestore.model.value.ServerTimestamps.isServerTimestamp;
 import static com.google.firebase.firestore.util.Assert.fail;
 import static com.google.firebase.firestore.util.Assert.hardAssert;
 
@@ -78,7 +80,7 @@ public static int typeOrder(Value value) {
       case ARRAY_VALUE:
         return TYPE_ORDER_ARRAY;
       case MAP_VALUE:
-        if (ServerTimestampValue.isServerTimestamp(value)) {
+        if (isServerTimestamp(value)) {
           return TYPE_ORDER_TIMESTAMP;
         }
         return TYPE_ORDER_MAP;
@@ -115,13 +117,9 @@ public static boolean equals(Value left, Value right) {
   }
 
   private static boolean timestampEquals(Value left, Value right) {
-    if (ServerTimestampValue.isServerTimestamp(left)
-        && ServerTimestampValue.isServerTimestamp(right)) {
-      return new ServerTimestampValue(left)
-          .getLocalWriteTime()
-          .equals(new ServerTimestampValue(right).getLocalWriteTime());
-    } else if (ServerTimestampValue.isServerTimestamp(left)
-        || ServerTimestampValue.isServerTimestamp(right)) {
+    if (isServerTimestamp(left) && isServerTimestamp(right)) {
+      return getLocalWriteTime(left).equals(getLocalWriteTime(right));
+    } else if (isServerTimestamp(left) || isServerTimestamp(right)) {
       return false;
     }
 
@@ -241,27 +239,30 @@ private static int compareNumbers(Value left, Value right) {
   }
 
   private static int compareTimestamps(Value left, Value right) {
-    if (ServerTimestampValue.isServerTimestamp(left)
-        && ServerTimestampValue.isServerTimestamp(right)) {
-      return new ServerTimestampValue(left)
-          .getLocalWriteTime()
-          .compareTo(new ServerTimestampValue(right).getLocalWriteTime());
-    } else if (ServerTimestampValue.isServerTimestamp(left)) {
-      // Server timestamps come after all concrete timestamps.
-      return 1;
-    } else if (ServerTimestampValue.isServerTimestamp(right)) {
-      // Server timestamps come after all concrete timestamps.
-      return -1;
+    if (isServerTimestamp(left)) {
+      if (isServerTimestamp(right)) {
+        return compareTimestamps(getLocalWriteTime(left), getLocalWriteTime(right));
+      } else {
+        // Server timestamps come after all concrete timestamps.
+        return 1;
+      }
+    } else {
+      if (isServerTimestamp(right)) {
+        // Server timestamps come after all concrete timestamps.
+        return -1;
+      } else {
+        return compareTimestamps(left.getTimestampValue(), right.getTimestampValue());
+      }
     }
+  }
 
-    int comparison =
-        Util.compareLongs(
-            left.getTimestampValue().getSeconds(), right.getTimestampValue().getSeconds());
-    if (comparison != 0) {
-      return comparison;
+  private static int compareTimestamps(Timestamp left, Timestamp right) {
+    int cmp = Util.compareLongs(left.getSeconds(), right.getSeconds());
+    if (cmp != 0) {
+      return cmp;
     }
-    return Util.compareIntegers(
-        left.getTimestampValue().getNanos(), right.getTimestampValue().getNanos());
+
+    return Util.compareIntegers(left.getNanos(), right.getNanos());
   }
 
   private static int compareReferences(String leftPath, String rightPath) {

firebase-firestore/src/main/java/com/google/firebase/firestore/model/value/ServerTimestampValue.java → firebase-firestore/src/main/java/com/google/firebase/firestore/model/value/ServerTimestamps.java

@@ -14,49 +14,40 @@
 
 package com.google.firebase.firestore.model.value;
 
-import static com.google.firebase.firestore.util.Assert.hardAssert;
-
 import androidx.annotation.Nullable;
 import com.google.firebase.Timestamp;
 import com.google.firebase.firestore.DocumentSnapshot;
 import com.google.firestore.v1.MapValue;
 import com.google.firestore.v1.Value;
 
 /**
- * Represents a locally-applied Server Timestamp.
+ * Methods for manipulating locally-applied Server Timestamps.
  *
  * <p>Server Timestamps are backed by MapValues that contain an internal field `__type__` with a
  * value of `server_timestamp`. The previous value and local write time are stored in its
  * `__previous_value__` and `__local_write_time__` fields respectively.
  *
  * <p>Notes:
- * <li>ServerTimestampValue instances are created as the result of applying a TransformMutation (see
+ * <li>ServerTimestamp Values are created as the result of applying a TransformMutation (see
  *     TransformMutation.applyTo()). They can only exist in the local view of a document. Therefore
  *     they do not need to be parsed or serialized.
  * <li>When evaluated locally (e.g. via DocumentSnapshot data), they evaluate to null.
- * <li>They sort after all TimestampValues. With respect to other ServerTimestampValues, they sort
+ * <li>They sort after all Timestamp Values. With respect to other ServerTimestamp Values, they sort
  *     by their localWriteTime.
  */
-public final class ServerTimestampValue {
+public final class ServerTimestamps {
   private static final String SERVER_TIMESTAMP_SENTINEL = "server_timestamp";
   private static final String TYPE_KEY = "__type__";
   private static final String PREVIOUS_VALUE_KEY = "__previous_value__";
   private static final String LOCAL_WRITE_TIME_KEY = "__local_write_time__";
 
+  private ServerTimestamps() {}
+
   public static boolean isServerTimestamp(@Nullable Value value) {
     Value type = value == null ? null : value.getMapValue().getFieldsOrDefault(TYPE_KEY, null);
     return type != null && SERVER_TIMESTAMP_SENTINEL.equals(type.getStringValue());
   }
 
-  private final Value internalValue;
-
-  public ServerTimestampValue(Value value) {
-    hardAssert(
-        ServerTimestampValue.isServerTimestamp(value),
-        "Backing value is not a ServerTimestampValue");
-    this.internalValue = value;
-  }
-
   public static Value valueOf(Timestamp localWriteTime, @Nullable Value previousValue) {
     Value encodedType = Value.newBuilder().setStringValue(SERVER_TIMESTAMP_SENTINEL).build();
     Value encodeWriteTime =
@@ -86,17 +77,19 @@ public static Value valueOf(Timestamp localWriteTime, @Nullable Value previousVa
    * backend responds with the timestamp {@link DocumentSnapshot.ServerTimestampBehavior}.
    */
   @Nullable
-  public Value getPreviousValue() {
-    Value previousValue = internalValue.getMapValue().getFieldsOrDefault(PREVIOUS_VALUE_KEY, null);
-    if (ServerTimestampValue.isServerTimestamp(previousValue)) {
-      return new ServerTimestampValue(previousValue).getPreviousValue();
+  public static Value getPreviousValue(Value serverTimestampValue) {
+    Value previousValue =
+        serverTimestampValue.getMapValue().getFieldsOrDefault(PREVIOUS_VALUE_KEY, null);
+    if (isServerTimestamp(previousValue)) {
+      return getPreviousValue(previousValue);
     }
     return previousValue;
   }
 
-  public Timestamp getLocalWriteTime() {
-    com.google.protobuf.Timestamp localWriteTime =
-        internalValue.getMapValue().getFieldsOrThrow(LOCAL_WRITE_TIME_KEY).getTimestampValue();
-    return new Timestamp(localWriteTime.getSeconds(), localWriteTime.getNanos());
+  public static com.google.protobuf.Timestamp getLocalWriteTime(Value serverTimestampValue) {
+    return serverTimestampValue
+        .getMapValue()
+        .getFieldsOrThrow(LOCAL_WRITE_TIME_KEY)
+        .getTimestampValue();
   }
 }

firebase-firestore/src/test/java/com/google/firebase/firestore/QuerySnapshotTest.java

@@ -33,7 +33,7 @@
 import com.google.firebase.firestore.model.Document;
 import com.google.firebase.firestore.model.DocumentSet;
 import com.google.firebase.firestore.model.value.ObjectValue;
-import com.google.firebase.firestore.model.value.ServerTimestampValue;
+import com.google.firebase.firestore.model.value.ServerTimestamps;
 import java.util.Arrays;
 import java.util.Date;
 import java.util.List;
@@ -86,7 +86,7 @@ public void testToObjects() {
         .thenReturn(new FirebaseFirestoreSettings.Builder().build());
 
     ObjectValue objectData =
-        ObjectValue.fromMap(map("timestamp", ServerTimestampValue.valueOf(Timestamp.now(), null)));
+        ObjectValue.fromMap(map("timestamp", ServerTimestamps.valueOf(Timestamp.now(), null)));
     QuerySnapshot foo = TestUtil.querySnapshot("foo", map(), map("a", objectData), true, false);
 
     List<POJO> docs = foo.toObjects(POJO.class);

firebase-firestore/src/test/java/com/google/firebase/firestore/model/MutationTest.java

@@ -45,7 +45,7 @@
 import com.google.firebase.firestore.model.mutation.TransformMutation;
 import com.google.firebase.firestore.model.value.ObjectValue;
 import com.google.firebase.firestore.model.value.ProtoValues;
-import com.google.firebase.firestore.model.value.ServerTimestampValue;
+import com.google.firebase.firestore.model.value.ServerTimestamps;
 import com.google.firestore.v1.Value;
 import java.util.Arrays;
 import java.util.Collections;
@@ -157,7 +157,7 @@ public void testAppliesLocalServerTimestampTransformsToDocuments() {
     // Server timestamps aren't parsed, so we manually insert it.
     ObjectValue expectedData =
         wrapObject(map("foo", map("bar", "<server-timestamp>"), "baz", "baz-value"));
-    Value fieldValue = ServerTimestampValue.valueOf(timestamp, wrap("bar-value"));
+    Value fieldValue = ServerTimestamps.valueOf(timestamp, wrap("bar-value"));
     expectedData = expectedData.toBuilder().set(field("foo.bar"), fieldValue).build();
 
     Document expectedDoc =

firebase-firestore/src/test/java/com/google/firebase/firestore/model/ProtoValuesTest.java

@@ -26,7 +26,7 @@
 import com.google.firebase.Timestamp;
 import com.google.firebase.firestore.GeoPoint;
 import com.google.firebase.firestore.model.value.ProtoValues;
-import com.google.firebase.firestore.model.value.ServerTimestampValue;
+import com.google.firebase.firestore.model.value.ServerTimestamps;
 import com.google.firebase.firestore.testutil.ComparatorTester;
 import com.google.firebase.firestore.testutil.TestUtil;
 import com.google.firestore.v1.Value;
@@ -81,12 +81,11 @@ public void testValueEquality() {
         .addEqualityGroup(wrap("\u00e9a"))
         .addEqualityGroup(wrap(date1), wrap(timestamp1))
         .addEqualityGroup(wrap(timestamp2))
-        // NOTE: ServerTimestampValues can't be parsed via wrap().
+        // NOTE: ServerTimestamps can't be parsed via wrap().
         .addEqualityGroup(
-            new EqualsWrapper(ServerTimestampValue.valueOf(new Timestamp(date1), null)),
-            new EqualsWrapper(ServerTimestampValue.valueOf(new Timestamp(date1), null)))
-        .addEqualityGroup(
-            new EqualsWrapper(ServerTimestampValue.valueOf(new Timestamp(date2), null)))
+            new EqualsWrapper(ServerTimestamps.valueOf(new Timestamp(date1), null)),
+            new EqualsWrapper(ServerTimestamps.valueOf(new Timestamp(date1), null)))
+        .addEqualityGroup(new EqualsWrapper(ServerTimestamps.valueOf(new Timestamp(date2), null)))
         .addEqualityGroup(wrap(geoPoint1), wrap(new GeoPoint(1, 0)))
         .addEqualityGroup(wrap(geoPoint2))
         .addEqualityGroup(
@@ -143,10 +142,8 @@ public void testValueOrdering() {
 
         // server timestamps come after all concrete timestamps.
         // NOTE: server timestamps can't be parsed with wrap().
-        .addEqualityGroup(
-            new EqualsWrapper(ServerTimestampValue.valueOf(new Timestamp(date1), null)))
-        .addEqualityGroup(
-            new EqualsWrapper(ServerTimestampValue.valueOf(new Timestamp(date2), null)))
+        .addEqualityGroup(new EqualsWrapper(ServerTimestamps.valueOf(new Timestamp(date1), null)))
+        .addEqualityGroup(new EqualsWrapper(ServerTimestamps.valueOf(new Timestamp(date2), null)))
 
         // strings
         .addEqualityGroup(wrap(""))