Initial

1 files changed, 118 insertions, 0 deletions

diff --git a/Firebase/Messaging/FIRMessagingPendingTopicsList.h b/Firebase/Messaging/FIRMessagingPendingTopicsList.h
new file mode 100644
index 0000000..c5a306a
--- /dev/null
+++ b/Firebase/Messaging/FIRMessagingPendingTopicsList.h
@@ -0,0 +1,118 @@
+/*
+ * 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 <Foundation/Foundation.h>
+
+#import "FIRMessagingTopicsCommon.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+/**
+ *  Represents a single batch of topics, with the same action.
+ *
+ *  Topic operations which have the same action (subscribe or unsubscribe) can be executed
+ *  simultaneously, as the order of operations do not matter with the same action. The set of
+ *  topics is unique, as it doesn't make sense to apply the same action to the same topic
+ *  repeatedly; the result would be the same as the first time.
+ */
+@interface FIRMessagingTopicBatch : NSObject <NSCoding>
+
+@property(nonatomic, readonly, assign) FIRMessagingTopicAction action;
+@property(nonatomic, readonly, copy) NSMutableSet <NSString *> *topics;
+
+- (instancetype)init NS_UNAVAILABLE;
+- (instancetype)initWithAction:(FIRMessagingTopicAction)action NS_DESIGNATED_INITIALIZER;
+
+@end
+
+@class FIRMessagingPendingTopicsList;
+/**
+ *  This delegate must be supplied to the instance of FIRMessagingPendingTopicsList, via the
+ *  @cdelegate property. It lets the
+ *  pending topics list know whether or not it can begin making requests via
+ *  @c-pendingTopicsListCanRequestTopicUpdates:, and handles the request to actually
+ *  perform the topic operation. The delegate also handles when the pending topics list is updated,
+ *  so that it can be archived or persisted.
+ *
+ *  @see FIRMessagingPendingTopicsList
+ */
+@protocol FIRMessagingPendingTopicsListDelegate <NSObject>
+
+- (void)pendingTopicsList:(FIRMessagingPendingTopicsList *)list
+  requestedUpdateForTopic:(NSString *)topic
+                   action:(FIRMessagingTopicAction)action
+               completion:(FIRMessagingTopicOperationCompletion)completion;
+- (void)pendingTopicsListDidUpdate:(FIRMessagingPendingTopicsList *)list;
+- (BOOL)pendingTopicsListCanRequestTopicUpdates:(FIRMessagingPendingTopicsList *)list;
+
+@end
+
+/**
+ *  FIRMessagingPendingTopicsList manages a list of topic subscription updates, batched by the same
+ *  action (subscribe or unsubscribe). The list roughly maintains the order of the topic operations,
+ *  batched together whenever the topic action (subscribe or unsubscribe) changes.
+ *
+ *  Topics operations are batched by action because it is safe to perform the same topic action
+ *  (subscribe or unsubscribe) on many topics simultaneously. After each batch is successfully
+ *  completed, the next batch operations can begin.
+ *
+ *  When asked to resume its operations, FIRMessagingPendingTopicsList will begin performing updates
+ *  of its current batch of topics. For example, it may begin subscription operations for topics
+ *  [A, B, C] simultaneously.
+ *
+ *  When the current batch is completed, the next batch of operations will be started. For example
+ *  the list may begin unsubscribe operations for [D, A, E]. Note that because A is in both batches,
+ *  A will be correctly subscribed in the first batch, then unsubscribed as part of the second batch
+ *  of operations. Without batching, it would be ambiguous whether A's subscription operation or the
+ *  unsubscription operation would be completed first.
+ *
+ *  An app can subscribe and unsubscribe from many topics, and this class helps persist the pending
+ *  topics and perform the operation safely and correctly.
+ *
+ *  When a topic fails to subscribe or unsubscribe due to a network error, it is considered a
+ *  recoverable error, and so it remains in the current batch until it is succesfully completed.
+ *  Topic updates are completed when they either (a) succeed, (b) are cancelled, or (c) result in an
+ *  unrecoverable error. Any error outside of `NSURLErrorDomain` is considered an unrecoverable
+ *  error.
+ *
+ *  In addition to maintaining the list of pending topic updates, FIRMessagingPendingTopicsList also
+ *  can track completion handlers for topic operations.
+ *
+ *  @discussion Completion handlers for topic updates are not maintained if it was restored from a
+ *  keyed archive. They are only called if the topic operation finished within the same app session.
+ *
+ *  You must supply an object conforming to FIRMessagingPendingTopicsListDelegate in order for the
+ *  topic operations to execute.
+ *
+ *  @see FIRMessagingPendingTopicsListDelegate
+ */
+@interface FIRMessagingPendingTopicsList : NSObject <NSCoding>
+
+@property(nonatomic, weak) NSObject <FIRMessagingPendingTopicsListDelegate> *delegate;
+
+@property(nonatomic, readonly, strong, nullable) NSDate *archiveDate;
+@property(nonatomic, readonly) NSUInteger numberOfBatches;
+
+
+- (instancetype)init NS_DESIGNATED_INITIALIZER;
+- (void)addOperationForTopic:(NSString *)topic
+                  withAction:(FIRMessagingTopicAction)action
+                  completion:(nullable FIRMessagingTopicOperationCompletion)completion;
+- (void)resumeOperationsIfNeeded;
+
+@end
+
+NS_ASSUME_NONNULL_END