--- /dev/null
+/*
+ * 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 "FIRMessaging.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
fnp / wl-app.git / blobdiff