| /* |
| * |
| * Copyright 2015 gRPC authors. |
| * |
| * 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 "GRXWriter.h" |
| #import "GRXWriteable.h" |
| |
| /** |
| * This is a thread-safe wrapper over a GRXWriteable instance. It lets one enqueue calls to a |
| * GRXWriteable instance for the main thread, guaranteeing that writesFinishedWithError: is the last |
| * message sent to it (no matter what messages are sent to the wrapper, in what order, nor from |
| * which thread). It also guarantees that, if cancelWithError: is called from the main thread (e.g. |
| * by the app cancelling the writes), no further messages are sent to the writeable except |
| * writesFinishedWithError:. |
| * |
| * TODO(jcanizales): Let the user specify another queue for the writeable callbacks. |
| */ |
| @interface GRXConcurrentWriteable : NSObject |
| |
| /** |
| * The GRXWriteable passed is the wrapped writeable. |
| * The GRXWriteable instance is retained until writesFinishedWithError: is sent to it, and released |
| * after that. |
| */ |
| - (instancetype)initWithWriteable:(id<GRXWriteable>)writeable |
| dispatchQueue:(dispatch_queue_t)queue NS_DESIGNATED_INITIALIZER; |
| - (instancetype)initWithWriteable:(id<GRXWriteable>)writeable; |
| |
| /** |
| * Enqueues writeValue: to be sent to the writeable in the main thread. |
| * The passed handler is invoked from the main thread after writeValue: returns. |
| */ |
| - (void)enqueueValue:(id)value completionHandler:(void (^)())handler; |
| |
| /** |
| * Enqueues writesFinishedWithError:nil to be sent to the writeable in the main thread. After that |
| * message is sent to the writeable, all other methods of this object are effectively noops. |
| */ |
| - (void)enqueueSuccessfulCompletion; |
| |
| /** |
| * If the writeable has not yet received a writesFinishedWithError: message, this will enqueue one |
| * to be sent to it in the main thread, and cancel all other pending messages to the writeable |
| * enqueued by this object (both past and future). |
| * The error argument cannot be nil. |
| */ |
| - (void)cancelWithError:(NSError *)error; |
| |
| /** |
| * Cancels all pending messages to the writeable enqueued by this object (both past and future). |
| * Because the writeable won't receive writesFinishedWithError:, this also releases the writeable. |
| */ |
| - (void)cancelSilently; |
| @end |