1 // Copyright 2020 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 #ifndef GRPC_CORE_LIB_SECURITY_AUTHORIZATION_MOCK_CEL_CEL_VALUE_H 16 #define GRPC_CORE_LIB_SECURITY_AUTHORIZATION_MOCK_CEL_CEL_VALUE_H 17 18 // CelValue is a holder, capable of storing all kinds of data 19 // supported by CEL. 20 // CelValue defines explicitly typed/named getters/setters. 21 // When storing pointers to objects, CelValue does not accept ownership 22 // to them and does not control their lifecycle. Instead objects are expected 23 // to be either external to expression evaluation, and controlled beyond the 24 // scope or to be allocated and associated with some allocation/ownership 25 // controller (Arena). 26 // Usage examples: 27 // (a) For primitive types: 28 // CelValue value = CelValue::CreateInt64(1); 29 // (b) For string: 30 // std::string* msg("test"); 31 // CelValue value = CelValue::CreateString(msg); 32 33 #include <grpc/support/port_platform.h> 34 35 #include <memory> 36 37 #include "absl/memory/memory.h" 38 #include "absl/strings/string_view.h" 39 #include "absl/types/span.h" 40 41 namespace grpc_core { 42 namespace mock_cel { 43 44 // Break cyclic depdendencies for container types. 45 class CelMap { 46 public: 47 CelMap() = default; 48 }; 49 50 // This is a temporary stub implementation of CEL APIs. 51 // Once gRPC imports the CEL library, this class will be removed. 52 class CelValue { 53 public: 54 // Default constructor. 55 // Creates CelValue with null data type. CelValue()56 CelValue() : CelValue(nullptr) {} 57 58 // We will use factory methods instead of public constructors 59 // The reason for this is the high risk of implicit type conversions 60 // between bool/int/pointer types. 61 // We rely on copy elision to avoid extra copying. CreateNull()62 static CelValue CreateNull() { return CelValue(nullptr); } 63 CreateInt64(int64_t)64 static CelValue CreateInt64(int64_t /*value*/) { return CreateNull(); } 65 CreateUint64(uint64_t)66 static CelValue CreateUint64(uint64_t /*value*/) { return CreateNull(); } 67 CreateStringView(absl::string_view)68 static CelValue CreateStringView(absl::string_view /*value*/) { 69 return CreateNull(); 70 } 71 CreateString(const std::string *)72 static CelValue CreateString(const std::string* /*str*/) { 73 return CreateNull(); 74 } 75 CreateMap(const CelMap *)76 static CelValue CreateMap(const CelMap* /*value*/) { return CreateNull(); } 77 78 private: 79 // Constructs CelValue wrapping value supplied as argument. 80 // Value type T should be supported by specification of ValueHolder. 81 template <class T> CelValue(T)82 explicit CelValue(T /*value*/) {} 83 }; 84 85 // CelMap implementation that uses STL map container as backing storage. 86 class ContainerBackedMapImpl : public CelMap { 87 public: 88 ContainerBackedMapImpl() = default; 89 Create(absl::Span<std::pair<CelValue,CelValue>>)90 static std::unique_ptr<CelMap> Create( 91 absl::Span<std::pair<CelValue, CelValue>> /*key_values*/) { 92 return absl::make_unique<ContainerBackedMapImpl>(); 93 } 94 }; 95 96 } // namespace mock_cel 97 } // namespace grpc_core 98 99 #endif // GRPC_CORE_LIB_SECURITY_AUTHORIZATION_MOCK_CEL_CEL_VALUE_H 100