1 // Copyright 2017 the V8 project authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef V8_BASE_TIMEZONE_CACHE_H_ 6 #define V8_BASE_TIMEZONE_CACHE_H_ 7 8 namespace v8 { 9 namespace base { 10 11 class TimezoneCache { 12 public: 13 // Short name of the local timezone (e.g., EST) 14 virtual const char* LocalTimezone(double time_ms) = 0; 15 16 // ES #sec-daylight-saving-time-adjustment 17 // Daylight Saving Time Adjustment 18 virtual double DaylightSavingsOffset(double time_ms) = 0; 19 20 // ES #sec-local-time-zone-adjustment 21 // Local Time Zone Adjustment 22 // 23 // https://github.com/tc39/ecma262/pull/778 24 virtual double LocalTimeOffset(double time_ms, bool is_utc) = 0; 25 26 /** 27 * Time zone redetection indicator for Clear function. 28 * 29 * kSkip indicates host time zone doesn't have to be redetected. 30 * kRedetect indicates host time zone should be redetected, and used to set 31 * the default time zone. 32 * 33 * The host time zone detection may require file system access or similar 34 * operations unlikely to be available inside a sandbox. If v8 is run inside a 35 * sandbox, the host time zone has to be detected outside the sandbox 36 * separately. 37 */ 38 enum class TimeZoneDetection { kSkip, kRedetect }; 39 40 // Called when the local timezone changes 41 virtual void Clear(TimeZoneDetection time_zone_detection) = 0; 42 43 // Called when tearing down the isolate 44 virtual ~TimezoneCache() = default; 45 }; 46 47 } // namespace base 48 } // namespace v8 49 50 #endif // V8_BASE_TIMEZONE_CACHE_H_ 51