1 // Copyright 2022 gRPC authors.
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 // http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14
15 #include <grpc/support/port_platform.h>
16
17 #include "src/core/lib/surface/call_trace.h"
18
19 #include <functional>
20 #include <memory>
21 #include <string>
22 #include <utility>
23
24 #include "absl/base/thread_annotations.h"
25 #include "absl/container/flat_hash_map.h"
26 #include "absl/meta/type_traits.h"
27 #include "absl/status/status.h"
28 #include "absl/strings/str_cat.h"
29
30 #include <grpc/support/log.h>
31
32 #include "src/core/lib/channel/channel_stack.h"
33 #include "src/core/lib/gprpp/no_destruct.h"
34 #include "src/core/lib/gprpp/sync.h"
35 #include "src/core/lib/iomgr/closure.h"
36 #include "src/core/lib/promise/activity.h"
37 #include "src/core/lib/promise/arena_promise.h"
38 #include "src/core/lib/promise/poll.h"
39 #include "src/core/lib/transport/metadata_batch.h"
40 #include "src/core/lib/transport/transport.h"
41
42 namespace grpc_core {
43
PromiseTracingFilterFor(const grpc_channel_filter * filter)44 const grpc_channel_filter* PromiseTracingFilterFor(
45 const grpc_channel_filter* filter) {
46 struct DerivedFilter : public grpc_channel_filter {
47 explicit DerivedFilter(const grpc_channel_filter* filter)
48 : grpc_channel_filter{
49 // start_transport_stream_op_batch:
50 grpc_call_next_op,
51 // make_call_promise:
52 [](grpc_channel_element* elem, CallArgs call_args,
53 NextPromiseFactory next_promise_factory)
54 -> ArenaPromise<ServerMetadataHandle> {
55 auto* source_filter =
56 static_cast<const DerivedFilter*>(elem->filter)->filter;
57 gpr_log(
58 GPR_DEBUG,
59 "%s[%s] CreateCallPromise: client_initial_metadata=%s",
60 Activity::current()->DebugTag().c_str(),
61 source_filter->name,
62 call_args.client_initial_metadata->DebugString().c_str());
63 return [source_filter, child = next_promise_factory(
64 std::move(call_args))]() mutable {
65 gpr_log(GPR_DEBUG, "%s[%s] PollCallPromise: begin",
66 Activity::current()->DebugTag().c_str(),
67 source_filter->name);
68 auto r = child();
69 if (auto* p = r.value_if_ready()) {
70 gpr_log(GPR_DEBUG, "%s[%s] PollCallPromise: done: %s",
71 Activity::current()->DebugTag().c_str(),
72 source_filter->name, (*p)->DebugString().c_str());
73 } else {
74 gpr_log(GPR_DEBUG, "%s[%s] PollCallPromise: <<pending>>",
75 Activity::current()->DebugTag().c_str(),
76 source_filter->name);
77 }
78 return r;
79 };
80 },
81 grpc_channel_next_op, /* sizeof_call_data: */ 0,
82 // init_call_elem:
83 [](grpc_call_element*, const grpc_call_element_args*) {
84 return absl::OkStatus();
85 },
86 grpc_call_stack_ignore_set_pollset_or_pollset_set,
87 // destroy_call_elem:
88 [](grpc_call_element*, const grpc_call_final_info*,
89 grpc_closure*) {},
90 // sizeof_channel_data:
91 0,
92 // init_channel_elem:
93 [](grpc_channel_element*, grpc_channel_element_args*) {
94 return absl::OkStatus();
95 },
96 // post_init_channel_elem:
97 [](grpc_channel_stack*, grpc_channel_element*) {},
98 // destroy_channel_elem:
99 [](grpc_channel_element*) {}, grpc_channel_next_get_info,
100 // name:
101 nullptr},
102 filter(filter),
103 name_str(absl::StrCat(filter->name, ".trace")) {
104 this->name = name_str.c_str();
105 }
106 const grpc_channel_filter* const filter;
107 const std::string name_str;
108 };
109 struct Globals {
110 Mutex mu;
111 absl::flat_hash_map<const grpc_channel_filter*,
112 std::unique_ptr<DerivedFilter>>
113 map ABSL_GUARDED_BY(mu);
114 };
115 auto* globals = NoDestructSingleton<Globals>::Get();
116 MutexLock lock(&globals->mu);
117 auto it = globals->map.find(filter);
118 if (it != globals->map.end()) return it->second.get();
119 return globals->map.emplace(filter, std::make_unique<DerivedFilter>(filter))
120 .first->second.get();
121 }
122
123 } // namespace grpc_core
124