// Copyright (c) 2012 The Chromium Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #ifndef BASE_GUID_H_ #define BASE_GUID_H_ #include #include #include #include "base/base_export.h" #include "base/hash/hash.h" #include "base/strings/string_piece.h" #include "build/build_config.h" namespace base { // DEPRECATED, use GUID::GenerateRandomV4() instead. BASE_EXPORT std::string GenerateGUID(); // DEPRECATED, use GUID::ParseCaseInsensitive() and GUID::is_valid() instead. BASE_EXPORT bool IsValidGUID(StringPiece input); BASE_EXPORT bool IsValidGUID(StringPiece16 input); // DEPRECATED, use GUID::ParseLowercase() and GUID::is_valid() instead. BASE_EXPORT bool IsValidGUIDOutputString(StringPiece input); // For unit testing purposes only. Do not use outside of tests. BASE_EXPORT std::string RandomDataToGUIDString(const uint64_t bytes[2]); class BASE_EXPORT GUID { public: // Generate a 128-bit random GUID in the form of version 4. see RFC 4122, // section 4.4. The format of GUID version 4 must be // xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx, where y is one of [8, 9, a, b]. The // hexadecimal values "a" through "f" are output as lower case characters. // A cryptographically secure random source will be used, but consider using // UnguessableToken for greater type-safety if GUID format is unnecessary. static GUID GenerateRandomV4(); // Returns a valid GUID if the input string conforms to the GUID format, and // an invalid GUID otherwise. Note that this does NOT check if the hexadecimal // values "a" through "f" are in lower case characters. static GUID ParseCaseInsensitive(StringPiece input); static GUID ParseCaseInsensitive(StringPiece16 input); // Similar to ParseCaseInsensitive(), but all hexadecimal values "a" through // "f" must be lower case characters. static GUID ParseLowercase(StringPiece input); static GUID ParseLowercase(StringPiece16 input); // Constructs an invalid GUID. GUID(); GUID(const GUID& other); GUID& operator=(const GUID& other); GUID(GUID&& other); GUID& operator=(GUID&& other); bool is_valid() const { return !lowercase_.empty(); } // Returns the GUID in a lowercase string format if it is valid, and an empty // string otherwise. The returned value is guaranteed to be parsed by // ParseLowercase(). // // NOTE: While AsLowercaseString() is currently a trivial getter, callers // should not treat it as such. When the internal type of base::GUID changes, // this will be a non-trivial converter. See the TODO above `lowercase_` for // more context. const std::string& AsLowercaseString() const; // Invalid GUIDs are equal. bool operator==(const GUID& other) const; bool operator!=(const GUID& other) const; bool operator<(const GUID& other) const; bool operator<=(const GUID& other) const; bool operator>(const GUID& other) const; bool operator>=(const GUID& other) const; private: // TODO(crbug.com/1026195): Consider using a different internal type. // Most existing representations of GUIDs in the codebase use std::string, // so matching the internal type will avoid inefficient string conversions // during the migration to base::GUID. // // The lowercase form of the GUID. Empty for invalid GUIDs. std::string lowercase_; }; // For runtime usage only. Do not store the result of this hash, as it may // change in future Chromium revisions. struct BASE_EXPORT GUIDHash { size_t operator()(const GUID& guid) const { // TODO(crbug.com/1026195): Avoid converting to string to take the hash when // the internal type is migrated to a non-string type. return FastHash(guid.AsLowercaseString()); } }; // Stream operator so GUID objects can be used in logging statements. BASE_EXPORT std::ostream& operator<<(std::ostream& out, const GUID& guid); } // namespace base #endif // BASE_GUID_H_