1 files changed, 101 insertions, 0 deletions
diff --git a/src/objective-c/GRPCClient/private/GRPCChannelPool.h b/src/objective-c/GRPCClient/private/GRPCChannelPool.h
new file mode 100644
index 0000000000..e00ee69e63
--- /dev/null
+++ b/src/objective-c/GRPCClient/private/GRPCChannelPool.h
@@ -0,0 +1,101 @@
+/*
+ *
+ * Copyright 2018 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 <GRPCClient/GRPCCallOptions.h>
+
+#import "GRPCChannelFactory.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+@protocol GRPCChannel;
+@class GRPCChannel;
+@class GRPCChannelPool;
+@class GRPCCompletionQueue;
+@class GRPCChannelConfiguration;
+@class GRPCWrappedCall;
+
+/**
+ * A proxied channel object that can be retained and used to create GRPCWrappedCall object
+ * regardless of the current connection status. If a connection is not established when a
+ * GRPCWrappedCall object is requested, it issues a connection/reconnection. This behavior is to
+ * follow that of gRPC core's channel object.
+ */
+@interface GRPCPooledChannel : NSObject
+
+- (nullable instancetype)init NS_UNAVAILABLE;
+
++ (nullable instancetype) new NS_UNAVAILABLE;
+
+/**
+ * Initialize with an actual channel object \a channel and a reference to the channel pool.
+ */
+- (nullable instancetype)initWithChannelConfiguration:
+    (GRPCChannelConfiguration *)channelConfiguration;
+
+/**
+ * Create a GRPCWrappedCall object (grpc_call) from this channel. If channel is disconnected, get a
+ * new channel object from the channel pool.
+ */
+- (nullable GRPCWrappedCall *)wrappedCallWithPath:(NSString *)path
+                                  completionQueue:(GRPCCompletionQueue *)queue
+                                      callOptions:(GRPCCallOptions *)callOptions;
+
+/**
+ * Notify the pooled channel that a wrapped call object is no longer referenced and will be
+ * dealloc'ed.
+ */
+- (void)notifyWrappedCallDealloc:(GRPCWrappedCall *)wrappedCall;
+
+/**
+ * Force the channel to disconnect immediately. GRPCWrappedCall objects previously created with
+ * \a wrappedCallWithPath are failed if not already finished. Subsequent calls to
+ * unmanagedCallWithPath: will attempt to reconnect to the remote channel.
+ */
+- (void)disconnect;
+
+@end
+
+/**
+ * Manage the pool of connected channels. When a channel is no longer referenced by any call,
+ * destroy the channel after a certain period of time elapsed.
+ */
+@interface GRPCChannelPool : NSObject
+
+- (nullable instancetype)init NS_UNAVAILABLE;
+
++ (nullable instancetype) new NS_UNAVAILABLE;
+
+/**
+ * Get the global channel pool.
+ */
++ (nullable instancetype)sharedInstance;
+
+/**
+ * Return a channel with a particular configuration. The channel may be a cached channel.
+ */
+- (nullable GRPCPooledChannel *)channelWithHost:(NSString *)host
+                                    callOptions:(GRPCCallOptions *)callOptions;
+
+/**
+ * Disconnect all channels in this pool.
+ */
+- (void)disconnectAllChannels;
+
+@end
+
+NS_ASSUME_NONNULL_END