GRPC C++  1.32.0
message_allocator.h
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1 /*
2  *
3  * Copyright 2019 gRPC authors.
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5  * Licensed under the Apache License, Version 2.0 (the "License");
6  * you may not use this file except in compliance with the License.
7  * You may obtain a copy of the License at
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14  * See the License for the specific language governing permissions and
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17  */
18 
19 #ifndef GRPCPP_IMPL_CODEGEN_MESSAGE_ALLOCATOR_H
20 #define GRPCPP_IMPL_CODEGEN_MESSAGE_ALLOCATOR_H
21 
22 namespace grpc {
23 #ifndef GRPC_CALLBACK_API_NONEXPERIMENTAL
24 namespace experimental {
25 #endif
26 
27 // NOTE: This is an API for advanced users who need custom allocators.
28 // Per rpc struct for the allocator. This is the interface to return to user.
30  public:
31  virtual ~RpcAllocatorState() = default;
32  // Optionally deallocate request early to reduce the size of working set.
33  // A custom MessageAllocator needs to be registered to make use of this.
34  // This is not abstract because implementing it is optional.
35  virtual void FreeRequest() {}
36 };
37 
38 // This is the interface returned by the allocator.
39 // grpc library will call the methods to get request/response pointers and to
40 // release the object when it is done.
41 template <typename RequestT, typename ResponseT>
43  public:
44  // Release this object. For example, if the custom allocator's
45  // AllocateMessasge creates an instance of a subclass with new, the Release()
46  // should do a "delete this;".
47  virtual void Release() = 0;
48  RequestT* request() { return request_; }
49  ResponseT* response() { return response_; }
50 
51  protected:
52  void set_request(RequestT* request) { request_ = request; }
53  void set_response(ResponseT* response) { response_ = response; }
54 
55  private:
56  // NOTE: subclasses should set these pointers.
57  RequestT* request_;
58  ResponseT* response_;
59 };
60 
61 // A custom allocator can be set via the generated code to a callback unary
62 // method, such as SetMessageAllocatorFor_Echo(custom_allocator). The allocator
63 // needs to be alive for the lifetime of the server.
64 // Implementations need to be thread-safe.
65 template <typename RequestT, typename ResponseT>
67  public:
68  virtual ~MessageAllocator() = default;
70 };
71 
72 #ifndef GRPC_CALLBACK_API_NONEXPERIMENTAL
73 } // namespace experimental
74 #endif
75 
76 // TODO(vjpai): Remove namespace experimental when de-experimentalized fully.
77 #ifdef GRPC_CALLBACK_API_NONEXPERIMENTAL
78 namespace experimental {
79 
80 using ::grpc::RpcAllocatorState;
81 
82 template <typename RequestT, typename ResponseT>
83 using MessageHolder = ::grpc::MessageHolder<RequestT, ResponseT>;
84 
85 template <typename RequestT, typename ResponseT>
86 using MessageAllocator = ::grpc::MessageAllocator<RequestT, ResponseT>;
87 
88 } // namespace experimental
89 #endif
90 
91 } // namespace grpc
92 
93 #endif // GRPCPP_IMPL_CODEGEN_MESSAGE_ALLOCATOR_H
grpc::experimental::RpcAllocatorState::~RpcAllocatorState
virtual ~RpcAllocatorState()=default
grpc::experimental::MessageHolder::set_request
void set_request(RequestT *request)
Definition: message_allocator.h:52
grpc
This header provides an object that reads bytes directly from a grpc::ByteBuffer, via the ZeroCopyInp...
Definition: alarm.h:24
grpc::experimental::MessageAllocator
Definition: message_allocator.h:66
grpc::experimental::MessageAllocator::~MessageAllocator
virtual ~MessageAllocator()=default
grpc::experimental::RpcAllocatorState::FreeRequest
virtual void FreeRequest()
Definition: message_allocator.h:35
grpc::experimental::RpcAllocatorState
Definition: message_allocator.h:29
grpc::experimental::MessageHolder::set_response
void set_response(ResponseT *response)
Definition: message_allocator.h:53
grpc::experimental::MessageHolder::response
ResponseT * response()
Definition: message_allocator.h:49
grpc::experimental::MessageAllocator::AllocateMessages
virtual MessageHolder< RequestT, ResponseT > * AllocateMessages()=0
grpc::experimental::MessageHolder::Release
virtual void Release()=0
grpc::experimental::MessageHolder
Definition: message_allocator.h:42
grpc::experimental::MessageHolder::request
RequestT * request()
Definition: message_allocator.h:48