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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_IMPL_METADATA_MAP_H
20 #define GRPCPP_IMPL_METADATA_MAP_H
21 
22 #include <grpc/grpc.h>
23 #include <grpcpp/support/slice.h>
24 
25 #include <map>
26 
27 namespace grpc {
28 
29 namespace internal {
30 
31 const char kBinaryErrorDetailsKey[] = "grpc-status-details-bin";
32 
33 class MetadataMap {
34  public:
MetadataMap()35   MetadataMap() { Setup(); }
36 
~MetadataMap()37   ~MetadataMap() { Destroy(); }
38 
GetBinaryErrorDetails()39   std::string GetBinaryErrorDetails() {
40     // if filled_, extract from the multimap for O(log(n))
41     if (filled_) {
42       auto iter = map_.find(kBinaryErrorDetailsKey);
43       if (iter != map_.end()) {
44         return std::string(iter->second.begin(), iter->second.length());
45       }
46     }
47     // if not yet filled, take the O(n) lookup to avoid allocating the
48     // multimap until it is requested.
49     // TODO(ncteisen): plumb this through core as a first class object, just
50     // like code and message.
51     else {
52       for (size_t i = 0; i < arr_.count; i++) {
53         if (strncmp(reinterpret_cast<const char*>(
54                         GRPC_SLICE_START_PTR(arr_.metadata[i].key)),
55                     kBinaryErrorDetailsKey,
56                     GRPC_SLICE_LENGTH(arr_.metadata[i].key)) == 0) {
57           return std::string(reinterpret_cast<const char*>(
58                                  GRPC_SLICE_START_PTR(arr_.metadata[i].value)),
59                              GRPC_SLICE_LENGTH(arr_.metadata[i].value));
60         }
61       }
62     }
63     return std::string();
64   }
65 
map()66   std::multimap<grpc::string_ref, grpc::string_ref>* map() {
67     FillMap();
68     return &map_;
69   }
arr()70   grpc_metadata_array* arr() { return &arr_; }
71 
Reset()72   void Reset() {
73     filled_ = false;
74     map_.clear();
75     Destroy();
76     Setup();
77   }
78 
79  private:
80   bool filled_ = false;
81   grpc_metadata_array arr_;
82   std::multimap<grpc::string_ref, grpc::string_ref> map_;
83 
Destroy()84   void Destroy() { grpc_metadata_array_destroy(&arr_); }
85 
Setup()86   void Setup() { memset(&arr_, 0, sizeof(arr_)); }
87 
FillMap()88   void FillMap() {
89     if (filled_) return;
90     filled_ = true;
91     for (size_t i = 0; i < arr_.count; i++) {
92       // TODO(yangg) handle duplicates?
93       map_.insert(std::pair<grpc::string_ref, grpc::string_ref>(
94           StringRefFromSlice(&arr_.metadata[i].key),
95           StringRefFromSlice(&arr_.metadata[i].value)));
96     }
97   }
98 };
99 }  // namespace internal
100 
101 }  // namespace grpc
102 
103 #endif  // GRPCPP_IMPL_METADATA_MAP_H
104