1 files changed, 90 insertions, 0 deletions
diff --git a/Firestore/Source/Model/FSTDatabaseID.mm b/Firestore/Source/Model/FSTDatabaseID.mm
new file mode 100644
index 0000000..bff5855
--- /dev/null
+++ b/Firestore/Source/Model/FSTDatabaseID.mm
@@ -0,0 +1,90 @@
+/*
+ * Copyright 2017 Google
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#import "Firestore/Source/Model/FSTDatabaseID.h"
+
+#import "Firestore/Source/Util/FSTAssert.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+/** The default name for "unset" database ID in resource names. */
+NSString *const kDefaultDatabaseID = @"(default)";
+
+#pragma mark - FSTDatabaseID
+
+@implementation FSTDatabaseID
+
++ (instancetype)databaseIDWithProject:(NSString *)projectID database:(NSString *)databaseID {
+  return [[FSTDatabaseID alloc] initWithProject:projectID database:databaseID];
+}
+
+/**
+ * Designated initializer.
+ *
+ * @param projectID The project for the database.
+ * @param databaseID The database in the datastore.
+ */
+- (instancetype)initWithProject:(NSString *)projectID database:(NSString *)databaseID {
+  if (self = [super init]) {
+    FSTAssert(databaseID, @"databaseID cannot be nil");
+    _projectID = [projectID copy];
+    _databaseID = [databaseID copy];
+  }
+  return self;
+}
+
+- (BOOL)isEqual:(id)other {
+  if (other == self) return YES;
+  if (![[other class] isEqual:[self class]]) return NO;
+
+  return [self isEqualToDatabaseId:other];
+}
+
+- (NSUInteger)hash {
+  NSUInteger hash = [self.projectID hash];
+  hash = hash * 31u + [self.databaseID hash];
+  return hash;
+}
+
+- (NSString *)description {
+  return [NSString
+      stringWithFormat:@"<FSTDatabaseID: project:%@ database:%@>", self.projectID, self.databaseID];
+}
+
+- (NSComparisonResult)compare:(FSTDatabaseID *)other {
+  NSComparisonResult cmp = [self.projectID compare:other.projectID];
+  return cmp == NSOrderedSame ? [self.databaseID compare:other.databaseID] : cmp;
+}
+
+- (BOOL)isDefaultDatabase {
+  return [self.databaseID isEqualToString:kDefaultDatabaseID];
+}
+
+- (BOOL)isEqualToDatabaseId:(FSTDatabaseID *)databaseID {
+  if (self == databaseID) return YES;
+  if (databaseID == nil) return NO;
+  if (self.projectID != databaseID.projectID &&
+      ![self.projectID isEqualToString:databaseID.projectID])
+    return NO;
+  if (self.databaseID != databaseID.databaseID &&
+      ![self.databaseID isEqualToString:databaseID.databaseID])
+    return NO;
+  return YES;
+}
+
+@end
+
+NS_ASSUME_NONNULL_END