1 // Copyright (C) 2023 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_STORE_NAMESPACE_ID_FINGERPRINT_H_ 16 #define ICING_STORE_NAMESPACE_ID_FINGERPRINT_H_ 17 18 #include <cstddef> 19 #include <cstdint> 20 #include <functional> 21 #include <string> 22 #include <string_view> 23 24 #include "icing/text_classifier/lib3/utils/base/statusor.h" 25 #include "icing/store/namespace-id.h" 26 27 namespace icing { 28 namespace lib { 29 30 // A wrapper class of namespace id and fingerprint. It is usually used as a 31 // unique identifier of a resource, e.g. document (namespace id + 32 // fingerprint(uri)), corpus (namespace id + fingerprint(schema_type_name)). 33 class NamespaceIdFingerprint { 34 public: 35 struct Hasher { operatorHasher36 std::size_t operator()(const NamespaceIdFingerprint& nsid_fp) const { 37 return std::hash<NamespaceId>()(nsid_fp.namespace_id_) ^ 38 std::hash<uint64_t>()(nsid_fp.fingerprint_); 39 } 40 }; 41 42 static constexpr int kEncodedNamespaceIdLength = 3; 43 static constexpr int kMinEncodedLength = kEncodedNamespaceIdLength + 1; 44 45 static libtextclassifier3::StatusOr<NamespaceIdFingerprint> DecodeFromCString( 46 std::string_view encoded_cstr); 47 NamespaceIdFingerprint()48 explicit NamespaceIdFingerprint() 49 : namespace_id_(kInvalidNamespaceId), fingerprint_(0) {} 50 NamespaceIdFingerprint(NamespaceId namespace_id,uint64_t fingerprint)51 explicit NamespaceIdFingerprint(NamespaceId namespace_id, 52 uint64_t fingerprint) 53 : namespace_id_(namespace_id), fingerprint_(fingerprint) {} 54 55 explicit NamespaceIdFingerprint(NamespaceId namespace_id, 56 std::string_view target_str); 57 58 std::string EncodeToCString() const; 59 is_valid()60 bool is_valid() const { return namespace_id_ >= 0; } 61 62 bool operator<(const NamespaceIdFingerprint& other) const { 63 if (namespace_id_ != other.namespace_id_) { 64 return namespace_id_ < other.namespace_id_; 65 } 66 return fingerprint_ < other.fingerprint_; 67 } 68 69 bool operator==(const NamespaceIdFingerprint& other) const { 70 return namespace_id_ == other.namespace_id_ && 71 fingerprint_ == other.fingerprint_; 72 } 73 namespace_id()74 NamespaceId namespace_id() const { return namespace_id_; } fingerprint()75 uint64_t fingerprint() const { return fingerprint_; } 76 77 private: 78 NamespaceId namespace_id_; 79 uint64_t fingerprint_; 80 } __attribute__((packed)); 81 static_assert(sizeof(NamespaceIdFingerprint) == 10, ""); 82 83 } // namespace lib 84 } // namespace icing 85 86 #endif // ICING_STORE_NAMESPACE_ID_FINGERPRINT_H_ 87