| import { CACHE_ONE_YEAR } from '../../lib/constants' | |
| /** | |
| * The revalidate option used internally for pages. A value of `false` means | |
| * that the page should not be revalidated. A number means that the page | |
| * should be revalidated after the given number of seconds (this also includes | |
| * `1` which means to revalidate after 1 second). A value of `0` is not a valid | |
| * value for this option. | |
| */ | |
| export type Revalidate = number | false | |
| export interface CacheControl { | |
| revalidate: Revalidate | |
| expire: number | undefined | |
| } | |
| export function getCacheControlHeader({ | |
| revalidate, | |
| expire, | |
| }: CacheControl): string { | |
| const swrHeader = | |
| typeof revalidate === 'number' && | |
| expire !== undefined && | |
| revalidate < expire | |
| ? `, stale-while-revalidate=${expire - revalidate}` | |
| : '' | |
| if (revalidate === 0) { | |
| return 'private, no-cache, no-store, max-age=0, must-revalidate' | |
| } else if (typeof revalidate === 'number') { | |
| return `s-maxage=${revalidate}${swrHeader}` | |
| } | |
| return `s-maxage=${CACHE_ONE_YEAR}${swrHeader}` | |
| } | |