1 // Copyright 2019 The Abseil 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 // https://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 #ifndef ABSL_STATUS_INTERNAL_STATUS_INTERNAL_H_ 15 #define ABSL_STATUS_INTERNAL_STATUS_INTERNAL_H_ 16 17 #include <atomic> 18 #include <cstdint> 19 #include <memory> 20 #include <string> 21 #include <utility> 22 23 #include "absl/base/attributes.h" 24 #include "absl/base/config.h" 25 #include "absl/container/inlined_vector.h" 26 #include "absl/strings/cord.h" 27 #include "absl/strings/string_view.h" 28 #include "absl/types/optional.h" 29 30 #ifndef SWIG 31 // Disabled for SWIG as it doesn't parse attributes correctly. 32 namespace absl { 33 ABSL_NAMESPACE_BEGIN 34 // Returned Status objects may not be ignored. Codesearch doesn't handle ifdefs 35 // as part of a class definitions (b/6995610), so we use a forward declaration. 36 // 37 // TODO(b/176172494): ABSL_MUST_USE_RESULT should expand to the more strict 38 // [[nodiscard]]. For now, just use [[nodiscard]] directly when it is available. 39 #if ABSL_HAVE_CPP_ATTRIBUTE(nodiscard) 40 class [[nodiscard]] ABSL_ATTRIBUTE_TRIVIAL_ABI Status; 41 #else 42 class ABSL_MUST_USE_RESULT ABSL_ATTRIBUTE_TRIVIAL_ABI Status; 43 #endif 44 ABSL_NAMESPACE_END 45 } // namespace absl 46 #endif // !SWIG 47 48 namespace absl { 49 ABSL_NAMESPACE_BEGIN 50 51 enum class StatusCode : int; 52 enum class StatusToStringMode : int; 53 54 namespace status_internal { 55 56 // Container for status payloads. 57 struct Payload { 58 std::string type_url; 59 absl::Cord payload; 60 }; 61 62 using Payloads = absl::InlinedVector<Payload, 1>; 63 64 // Reference-counted representation of Status data. 65 class StatusRep { 66 public: StatusRep(absl::StatusCode code_arg,absl::string_view message_arg,std::unique_ptr<status_internal::Payloads> payloads_arg)67 StatusRep(absl::StatusCode code_arg, absl::string_view message_arg, 68 std::unique_ptr<status_internal::Payloads> payloads_arg) 69 : ref_(int32_t{1}), 70 code_(code_arg), 71 message_(message_arg), 72 payloads_(std::move(payloads_arg)) {} 73 code()74 absl::StatusCode code() const { return code_; } message()75 const std::string& message() const { return message_; } 76 77 // Ref and unref are const to allow access through a const pointer, and are 78 // used during copying operations. Ref()79 void Ref() const { ref_.fetch_add(1, std::memory_order_relaxed); } 80 void Unref() const; 81 82 // Payload methods correspond to the same methods in absl::Status. 83 absl::optional<absl::Cord> GetPayload(absl::string_view type_url) const; 84 void SetPayload(absl::string_view type_url, absl::Cord payload); 85 struct EraseResult { 86 bool erased; 87 uintptr_t new_rep; 88 }; 89 EraseResult ErasePayload(absl::string_view type_url); 90 void ForEachPayload( 91 absl::FunctionRef<void(absl::string_view, const absl::Cord&)> visitor) 92 const; 93 94 std::string ToString(StatusToStringMode mode) const; 95 96 bool operator==(const StatusRep& other) const; 97 bool operator!=(const StatusRep& other) const { return !(*this == other); } 98 99 // Returns an equivalent heap allocated StatusRep with refcount 1. 100 // 101 // `this` is not safe to be used after calling as it may have been deleted. 102 StatusRep* CloneAndUnref() const; 103 104 private: 105 mutable std::atomic<int32_t> ref_; 106 absl::StatusCode code_; 107 108 // As an internal implementation detail, we guarantee that if status.message() 109 // is non-empty, then the resulting string_view is null terminated. 110 // This is required to implement 'StatusMessageAsCStr(...)' 111 std::string message_; 112 std::unique_ptr<status_internal::Payloads> payloads_; 113 }; 114 115 absl::StatusCode MapToLocalCode(int value); 116 117 // Returns a pointer to a newly-allocated string with the given `prefix`, 118 // suitable for output as an error message in assertion/`CHECK()` failures. 119 // 120 // This is an internal implementation detail for Abseil logging. 121 std::string* MakeCheckFailString(const absl::Status* status, 122 const char* prefix); 123 124 } // namespace status_internal 125 126 ABSL_NAMESPACE_END 127 } // namespace absl 128 129 #endif // ABSL_STATUS_INTERNAL_STATUS_INTERNAL_H_ 130