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 GRPC_SRC_CORE_LIB_TRANSPORT_TRANSPORT_IMPL_H
20 #define GRPC_SRC_CORE_LIB_TRANSPORT_TRANSPORT_IMPL_H
21 
22 #include <grpc/support/port_platform.h>
23 
24 #include <stddef.h>
25 
26 #include "absl/strings/string_view.h"
27 
28 #include "src/core/lib/iomgr/closure.h"
29 #include "src/core/lib/iomgr/endpoint.h"
30 #include "src/core/lib/iomgr/iomgr_fwd.h"
31 #include "src/core/lib/promise/arena_promise.h"
32 #include "src/core/lib/resource_quota/arena.h"
33 #include "src/core/lib/transport/transport.h"
34 #include "src/core/lib/transport/transport_fwd.h"
35 
36 typedef struct grpc_transport_vtable {
37   // Memory required for a single stream element - this is allocated by upper
38   // layers and initialized by the transport
39   size_t sizeof_stream;  // = sizeof(transport stream)
40 
41   // HACK: inproc does not handle stream op batch callbacks correctly (receive
42   // ops are required to complete prior to on_complete triggering).
43   // This flag is used to disable coalescing of batches in connected_channel for
44   // that specific transport.
45   // TODO(ctiller): This ought not be necessary once we have promises complete.
46   bool hacky_disable_stream_op_batch_coalescing_in_connected_channel;
47 
48   // name of this transport implementation
49   const char* name;
50 
51   // implementation of grpc_transport_init_stream
52   int (*init_stream)(grpc_transport* self, grpc_stream* stream,
53                      grpc_stream_refcount* refcount, const void* server_data,
54                      grpc_core::Arena* arena);
55 
56   // Create a promise to execute one client call.
57   // If this is non-null, it may be used in preference to
58   // perform_stream_op.
59   // If this is used in preference to perform_stream_op, the
60   // following can be omitted also:
61   //   - calling init_stream, destroy_stream, set_pollset, set_pollset_set
62   //   - allocation of memory for call data (sizeof_stream may be ignored)
63   // There is an on-going migration to move all filters to providing this, and
64   // then to drop perform_stream_op.
65   grpc_core::ArenaPromise<grpc_core::ServerMetadataHandle> (*make_call_promise)(
66       grpc_transport* self, grpc_core::CallArgs call_args);
67 
68   // implementation of grpc_transport_set_pollset
69   void (*set_pollset)(grpc_transport* self, grpc_stream* stream,
70                       grpc_pollset* pollset);
71 
72   // implementation of grpc_transport_set_pollset
73   void (*set_pollset_set)(grpc_transport* self, grpc_stream* stream,
74                           grpc_pollset_set* pollset_set);
75 
76   // implementation of grpc_transport_perform_stream_op
77   void (*perform_stream_op)(grpc_transport* self, grpc_stream* stream,
78                             grpc_transport_stream_op_batch* op);
79 
80   // implementation of grpc_transport_perform_op
81   void (*perform_op)(grpc_transport* self, grpc_transport_op* op);
82 
83   // implementation of grpc_transport_destroy_stream
84   void (*destroy_stream)(grpc_transport* self, grpc_stream* stream,
85                          grpc_closure* then_schedule_closure);
86 
87   // implementation of grpc_transport_destroy
88   void (*destroy)(grpc_transport* self);
89 
90   // implementation of grpc_transport_get_endpoint
91   grpc_endpoint* (*get_endpoint)(grpc_transport* self);
92 } grpc_transport_vtable;
93 
94 // an instance of a grpc transport
95 struct grpc_transport {
96   struct RawPointerChannelArgTag {};
ChannelArgNamegrpc_transport97   static absl::string_view ChannelArgName() { return GRPC_ARG_TRANSPORT; }
98   // pointer to a vtable defining operations on this transport
99   const grpc_transport_vtable* vtable;
100 };
101 
102 #endif  // GRPC_SRC_CORE_LIB_TRANSPORT_TRANSPORT_IMPL_H
103