1 // Copyright (C) 2022 Google LLC 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 ICING_UTIL_FINGERPRINT_UTIL_H_ 16 #define ICING_UTIL_FINGERPRINT_UTIL_H_ 17 18 #include <cstdint> 19 #include <string> 20 #include <string_view> 21 22 namespace icing { 23 namespace lib { 24 25 namespace fingerprint_util { 26 27 // Converts from a fingerprint to a fingerprint string. 28 std::string GetFingerprintString(uint64_t fingerprint); 29 30 // Converts from a fingerprint string to a fingerprint. 31 uint64_t GetFingerprint(std::string_view fingerprint_string); 32 33 // A formatter to properly handle a string that is actually just a hash value. 34 class FingerprintStringFormatter { 35 public: operator()36 std::string operator()(std::string_view fingerprint_string) { 37 uint64_t fingerprint = GetFingerprint(fingerprint_string); 38 return std::to_string(fingerprint); 39 } 40 }; 41 42 } // namespace fingerprint_util 43 44 } // namespace lib 45 } // namespace icing 46 47 #endif // ICING_UTIL_FINGERPRINT_UTIL_H_ 48