1/*
2 *
3 * Copyright 2015 gRPC authors.
4 *
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
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 *
17 */
18
19#ifndef GRPCPP_SUPPORT_BYTE_BUFFER_H
20#define GRPCPP_SUPPORT_BYTE_BUFFER_H
21
22#include <vector>
23
24#include <grpc/byte_buffer.h>
25#include <grpc/grpc.h>
26#include <grpc/support/log.h>
27#include <grpcpp/impl/codegen/core_codegen_interface.h>
28#include <grpcpp/impl/serialization_traits.h>
29#include <grpcpp/support/config.h>
30#include <grpcpp/support/slice.h>
31#include <grpcpp/support/status.h>
32
33namespace grpc {
34
35class ServerInterface;
36class ByteBuffer;
37class ServerInterface;
38
39namespace internal {
40template <class RequestType, class ResponseType>
41class CallbackUnaryHandler;
42template <class RequestType, class ResponseType>
43class CallbackServerStreamingHandler;
44template <class RequestType>
45void* UnaryDeserializeHelper(grpc_byte_buffer*, grpc::Status*, RequestType*);
46template <class ServiceType, class RequestType, class ResponseType>
47class ServerStreamingHandler;
48template <grpc::StatusCode code>
49class ErrorMethodHandler;
50class CallOpSendMessage;
51template <class R>
52class CallOpRecvMessage;
53class CallOpGenericRecvMessage;
54class ExternalConnectionAcceptorImpl;
55template <class R>
56class DeserializeFuncType;
57class GrpcByteBufferPeer;
58
59} // namespace internal
60/// A sequence of bytes.
61class ByteBuffer final {
62 public:
63 /// Constuct an empty buffer.
64 ByteBuffer() : buffer_(nullptr) {}
65
66 /// Construct buffer from \a slices, of which there are \a nslices.
67 ByteBuffer(const Slice* slices, size_t nslices) {
68 // The following assertions check that the representation of a grpc::Slice
69 // is identical to that of a grpc_slice: it has a grpc_slice field, and
70 // nothing else.
71 static_assert(std::is_same<decltype(slices[0].slice_), grpc_slice>::value,
72 "Slice must have same representation as grpc_slice");
73 static_assert(sizeof(Slice) == sizeof(grpc_slice),
74 "Slice must have same representation as grpc_slice");
75 // The following assertions check that the representation of a ByteBuffer is
76 // identical to grpc_byte_buffer*: it has a grpc_byte_buffer* field,
77 // and nothing else.
78 static_assert(std::is_same<decltype(buffer_), grpc_byte_buffer*>::value,
79 "ByteBuffer must have same representation as "
80 "grpc_byte_buffer*");
81 static_assert(sizeof(ByteBuffer) == sizeof(grpc_byte_buffer*),
82 "ByteBuffer must have same representation as "
83 "grpc_byte_buffer*");
84 // The const_cast is legal if grpc_raw_byte_buffer_create() does no more
85 // than its advertised side effect of increasing the reference count of the
86 // slices it processes, and such an increase does not affect the semantics
87 // seen by the caller of this constructor.
88 buffer_ = g_core_codegen_interface->grpc_raw_byte_buffer_create(
89 slice: reinterpret_cast<grpc_slice*>(const_cast<Slice*>(slices)), nslices);
90 }
91
92 /// Constuct a byte buffer by referencing elements of existing buffer
93 /// \a buf. Wrapper of core function grpc_byte_buffer_copy . This is not
94 /// a deep copy; it is just a referencing. As a result, its performance is
95 /// size-independent.
96 ByteBuffer(const ByteBuffer& buf) : buffer_(nullptr) { operator=(buf); }
97
98 ~ByteBuffer() {
99 if (buffer_) {
100 g_core_codegen_interface->grpc_byte_buffer_destroy(bb: buffer_);
101 }
102 }
103
104 /// Wrapper of core function grpc_byte_buffer_copy . This is not
105 /// a deep copy; it is just a referencing. As a result, its performance is
106 /// size-independent.
107 ByteBuffer& operator=(const ByteBuffer& buf) {
108 if (this != &buf) {
109 Clear(); // first remove existing data
110 }
111 if (buf.buffer_) {
112 // then copy
113 buffer_ = g_core_codegen_interface->grpc_byte_buffer_copy(bb: buf.buffer_);
114 }
115 return *this;
116 }
117
118 // If this ByteBuffer's representation is a single flat slice, returns a
119 // slice referencing that array.
120 Status TrySingleSlice(Slice* slice) const;
121
122 /// Dump (read) the buffer contents into \a slics.
123 Status DumpToSingleSlice(Slice* slice) const;
124
125 /// Dump (read) the buffer contents into \a slices.
126 Status Dump(std::vector<Slice>* slices) const;
127
128 /// Remove all data.
129 void Clear() {
130 if (buffer_) {
131 g_core_codegen_interface->grpc_byte_buffer_destroy(bb: buffer_);
132 buffer_ = nullptr;
133 }
134 }
135
136 /// Make a duplicate copy of the internals of this byte
137 /// buffer so that we have our own owned version of it.
138 /// bbuf.Duplicate(); is equivalent to bbuf=bbuf; but is actually readable.
139 /// This is not a deep copy; it is a referencing and its performance
140 /// is size-independent.
141 void Duplicate() {
142 buffer_ = g_core_codegen_interface->grpc_byte_buffer_copy(bb: buffer_);
143 }
144
145 /// Forget underlying byte buffer without destroying
146 /// Use this only for un-owned byte buffers
147 void Release() { buffer_ = nullptr; }
148
149 /// Buffer size in bytes.
150 size_t Length() const {
151 return buffer_ == nullptr
152 ? 0
153 : g_core_codegen_interface->grpc_byte_buffer_length(bb: buffer_);
154 }
155
156 /// Swap the state of *this and *other.
157 void Swap(ByteBuffer* other) {
158 grpc_byte_buffer* tmp = other->buffer_;
159 other->buffer_ = buffer_;
160 buffer_ = tmp;
161 }
162
163 /// Is this ByteBuffer valid?
164 bool Valid() const { return (buffer_ != nullptr); }
165
166 private:
167 friend class SerializationTraits<ByteBuffer, void>;
168 friend class ServerInterface;
169 friend class internal::CallOpSendMessage;
170 template <class R>
171 friend class internal::CallOpRecvMessage;
172 friend class internal::CallOpGenericRecvMessage;
173 template <class RequestType>
174 friend void* internal::UnaryDeserializeHelper(grpc_byte_buffer*,
175 grpc::Status*, RequestType*);
176 template <class ServiceType, class RequestType, class ResponseType>
177 friend class internal::ServerStreamingHandler;
178 template <class RequestType, class ResponseType>
179 friend class internal::CallbackUnaryHandler;
180 template <class RequestType, class ResponseType>
181 friend class internal::CallbackServerStreamingHandler;
182 template <StatusCode code>
183 friend class internal::ErrorMethodHandler;
184 template <class R>
185 friend class internal::DeserializeFuncType;
186 friend class ProtoBufferReader;
187 friend class ProtoBufferWriter;
188 friend class internal::GrpcByteBufferPeer;
189 friend class internal::ExternalConnectionAcceptorImpl;
190
191 grpc_byte_buffer* buffer_;
192
193 // takes ownership
194 void set_buffer(grpc_byte_buffer* buf) {
195 if (buffer_) {
196 Clear();
197 }
198 buffer_ = buf;
199 }
200
201 grpc_byte_buffer* c_buffer() { return buffer_; }
202 grpc_byte_buffer** c_buffer_ptr() { return &buffer_; }
203
204 class ByteBufferPointer {
205 public:
206 /* NOLINTNEXTLINE(google-explicit-constructor) */
207 ByteBufferPointer(const ByteBuffer* b)
208 : bbuf_(const_cast<ByteBuffer*>(b)) {}
209 /* NOLINTNEXTLINE(google-explicit-constructor) */
210 operator ByteBuffer*() { return bbuf_; }
211 /* NOLINTNEXTLINE(google-explicit-constructor) */
212 operator grpc_byte_buffer*() { return bbuf_->buffer_; }
213 /* NOLINTNEXTLINE(google-explicit-constructor) */
214 operator grpc_byte_buffer**() { return &bbuf_->buffer_; }
215
216 private:
217 ByteBuffer* bbuf_;
218 };
219 ByteBufferPointer bbuf_ptr() const { return ByteBufferPointer(this); }
220};
221
222template <>
223class SerializationTraits<ByteBuffer, void> {
224 public:
225 static Status Deserialize(ByteBuffer* byte_buffer, ByteBuffer* dest) {
226 dest->set_buffer(byte_buffer->buffer_);
227 return Status::OK;
228 }
229 static Status Serialize(const ByteBuffer& source, ByteBuffer* buffer,
230 bool* own_buffer) {
231 *buffer = source;
232 *own_buffer = true;
233 return g_core_codegen_interface->ok();
234 }
235};
236
237} // namespace grpc
238
239#endif // GRPCPP_SUPPORT_BYTE_BUFFER_H
240

source code of include/grpcpp/support/byte_buffer.h