1 // Copyright (C) 2019 The Android Open Source Project 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 IORAP_SRC_INODE2FILENAME_INODE_RESULT_H_ 16 #define IORAP_SRC_INODE2FILENAME_INODE_RESULT_H_ 17 18 #include "common/expected.h" 19 #include "inode2filename/inode.h" 20 #include "inode2filename/inode_result.h" 21 #include "inode2filename/system_call.h" 22 23 #include <rxcpp/rx.hpp> 24 25 #include <memory> 26 #include <optional> 27 #include <string> 28 #include <vector> 29 namespace iorap::inode2filename { 30 31 // Tuple of (Inode -> (Filename|Errno)) 32 struct InodeResult { 33 // We set this error when all root directories have been searched and 34 // yet we still could not find a corresponding filename for the inode under search. 35 static constexpr int kCouldNotFindFilename = ENOKEY; 36 37 // An initial inode->filename mapping was found, but subsequent verification for it failed. 38 static constexpr int kVerificationFailed = EKEYEXPIRED; 39 40 // There is always an inode, but sometimes we may fail to resolve the filename. 41 Inode inode; 42 // Value: Contains the filename (with a root directory as a prefix). 43 // Error: Contains the errno, usually one of the above, otherwise some system error. 44 iorap::expected<std::string /*filename*/, int /*errno*/> data; 45 makeSuccessInodeResult46 static InodeResult makeSuccess(Inode inode, std::string filename) { 47 return InodeResult{inode, std::move(filename)}; 48 } 49 makeFailureInodeResult50 static InodeResult makeFailure(Inode inode, int err_no) { 51 return InodeResult{inode, iorap::unexpected{err_no}}; 52 } 53 54 constexpr explicit operator bool() const { 55 return data.has_value(); 56 } 57 58 constexpr bool operator==(const InodeResult& other) const { 59 if (inode == other.inode) { 60 if (data && other.data) { 61 return *data == *other.data; 62 } else if (!data && !other.data) { 63 return data.error() == other.data.error(); 64 } 65 // TODO: operator== for expected 66 } 67 return false; 68 } 69 70 constexpr bool operator!=(const InodeResult& other) const { 71 return !(*this == other); 72 } 73 74 // Returns a human-readable error message, or 'nullopt' if there was no error. 75 std::optional<std::string_view> ErrorMessage() const; 76 }; 77 78 std::ostream& operator<<(std::ostream& os, const InodeResult& result); 79 80 } // namespace iorap::inode2filename 81 82 #endif // IORAP_SRC_INODE2FILENAME_INODE_RESULT_H_