1 files changed, 58 insertions, 0 deletions
diff --git a/Firestore/Source/Util/FSTDispatchQueue.h b/Firestore/Source/Util/FSTDispatchQueue.h
new file mode 100644
index 0000000..da6b3fe
--- /dev/null
+++ b/Firestore/Source/Util/FSTDispatchQueue.h
@@ -0,0 +1,58 @@
+/*
+ * 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>
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface FSTDispatchQueue : NSObject
+
+/** Creates and returns an FSTDispatchQueue wrapping the specified dispatch_queue_t. */
++ (instancetype)queueWith:(dispatch_queue_t)dispatchQueue;
+
+- (instancetype)init __attribute__((unavailable("Use static constructor method.")));
+
+/**
+ * Asserts that we are already running on this queue (actually, we can only verify that the
+ * queue's label is the same, but hopefully that's good enough.)
+ */
+- (void)verifyIsCurrentQueue;
+
+/**
+ * Same as dispatch_async() except it asserts that we're not already on the queue, since this
+ * generally indicates a bug (and can lead to re-ordering of operations, etc).
+ *
+ * @param block The block to run.
+ */
+- (void)dispatchAsync:(void (^)())block;
+
+/**
+ * Unlike dispatchAsync: this method does not require you to dispatch to a different queue than
+ * the current one (thus it is equivalent to a raw dispatch_async()).
+ *
+ * This is useful, e.g. for dispatching to the user's queue directly from user API call (in which
+ * case we don't know if we're already on the user's queue or not).
+ *
+ * @param block The block to run.
+ */
+- (void)dispatchAsyncAllowingSameQueue:(void (^)())block;
+
+/** The underlying wrapped dispatch_queue_t */
+@property(nonatomic, strong, readonly) dispatch_queue_t queue;
+
+@end
+
+NS_ASSUME_NONNULL_END