1 line
8.0 KiB
Plaintext
1 line
8.0 KiB
Plaintext
|
{"version":3,"file":"time.js","sources":["../../src/time.ts"],"sourcesContent":["import { GLOBAL_OBJ } from './worldwide';\n\nconst ONE_SECOND_IN_MS = 1000;\n\n/**\n * A partial definition of the [Performance Web API]{@link https://developer.mozilla.org/en-US/docs/Web/API/Performance}\n * for accessing a high-resolution monotonic clock.\n */\ninterface Performance {\n /**\n * The millisecond timestamp at which measurement began, measured in Unix time.\n */\n timeOrigin: number;\n /**\n * Returns the current millisecond timestamp, where 0 represents the start of measurement.\n */\n now(): number;\n}\n\n/**\n * Returns a timestamp in seconds since the UNIX epoch using the Date API.\n *\n * TODO(v8): Return type should be rounded.\n */\nexport function dateTimestampInSeconds(): number {\n return Date.now() / ONE_SECOND_IN_MS;\n}\n\n/**\n * Returns a wrapper around the native Performance API browser implementation, or undefined for browsers that do not\n * support the API.\n *\n * Wrapping the native API works around differences in behavior from different browsers.\n */\nfunction createUnixTimestampInSecondsFunc(): () => number {\n const { performance } = GLOBAL_OBJ as typeof GLOBAL_OBJ & { performance?: Performance };\n if (!performance || !performance.now) {\n return dateTimestampInSeconds;\n }\n\n // Some browser and environments don't have a timeOrigin, so we fallback to\n // using Date.now() to compute the starting time.\n const approxStartingTimeOrigin = Date.now() - performance.now();\n const timeOrigin = performance.timeOrigin == undefined ? approxStartingTimeOrigin : performance.timeOrigin;\n\n // performance.now() is a monotonic clock, which means it starts at 0 when the process begins. To get the current\n // wall clock time (actual UNIX timestamp), we need to add the starting time origin and the current time elapsed.\n //\n // TODO: This does not account for the case where the monotonic clock that powers performance.now() drifts from the\n // wall clock time, which causes the returned timestamp to be inaccurate. We should investigate how to detect and\n // correct for this.\n // See: https://github.com/getsentry/sentry-javascript/issues/2590\n // See: https://github.com/mdn/content/issues/4713\n // See: https://dev.to/noamr/when-a-millisecond-is-not-a-millisecond-3h6\n return () => {\n return (timeOrigin + performance.now()) / ONE_SECOND_IN_MS;\n };\n}\n\n/**\n * Returns a timestamp in seconds since the UNIX epoch using either the Performance or Date APIs, depending on the\n * availability of the Performance API.\n *\n * BUG: Note that because of how browsers implement the Performance API, the clock might stop when the computer is\n * asleep. This creates a skew between `dateTimestampInSeconds` and `timestampInSeconds`. The\n * skew can grow to arbitrary amounts like days, weeks or months.\n * See https://github.com/getsentry/sentry-javascript/issues/2590.\n */\nexport const timestampInSeconds = createUnixTimestampInSecondsFunc();\n\n/**\n * Re-exported with an old name for backwards-compatibility.\n * TODO (v8): Remove this\n *\n * @deprecated Use `timestampInSeconds` instead.\n */\nexport const timestampWithMs = timestampInSeconds;\n\n/**\n * Internal helper to store what is the source of browserPerformanceTimeOrigin below. For debugging only.\n */\nexport let _browserPerformanceTimeOriginMode: string;\n\n/**\n * The number of milliseconds since the UNIX epoch. This value is only usable in a browser, and only when the\n * performance API is available.\n */\nexport const browserPerformanceTimeOrigin = ((): number | undefined => {\n // Unfortunately browsers may report an inaccurate time origin data, through either performance.timeOrigin or\n // performance.timing.navigationStart, which results in poor results in performance data. We only treat time origin\n // data as reliable if they are within a reasonable threshold of the current time.\n\n const { performance } = GLOBAL_OBJ as typeof GLOBAL_OBJ & Window;\n if (!performance || !performance.now) {\n _browserPerforma
|