File size: 3,606 Bytes
1477a90 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 | // Code generated by @openmeter/typespec-typescript. DO NOT EDIT.
import { unwrap, type RequestOptions, type Result } from './types.js'
// A misbehaving server — inconsistent `meta.page.total`/`size`, or a
// `meta.page.next` cursor that never resolves to an empty page — would
// otherwise make these generators loop forever. 10,000 pages is far beyond
// any real OpenMeter list, so hitting it means the server's pagination
// contract broke, not that the caller has a legitimately large list.
const MAX_PAGINATION_PAGES = 10_000
export class PaginationLimitExceededError extends Error {
constructor(limit: number) {
super(
`pagination exceeded the maximum of ${limit} pages; the server may be returning inconsistent pagination metadata`,
)
this.name = 'PaginationLimitExceededError'
}
}
interface PageNumberEnvelope<TItem> {
data: TItem[]
meta: { page: { number: number; size: number; total: number } }
}
interface PageNumberRequest {
page?: { number?: number; size?: number }
}
/**
* Iterates every item of a page-number-paginated list operation, advancing
* `page.number` from wherever the caller's own request starts. Every other
* field on `request` — filters, sort, page.size — is sent unchanged on every
* page fetch; only the page number advances. Stops on a page shorter than
* the server's own reported `size` (including an empty page) or once the
* running item count reaches the server's reported `total`, whichever comes
* first — so a final page that exactly fills `total` does not trigger one
* more, empty request.
*/
export async function* paginatePages<TItem, TReq extends PageNumberRequest>(
fetchPage: (
req: TReq,
options?: RequestOptions,
) => Promise<Result<PageNumberEnvelope<TItem>>>,
request: TReq,
options?: RequestOptions,
): AsyncGenerator<TItem, void, undefined> {
let req = request
let seen = 0
for (let page = 0; page < MAX_PAGINATION_PAGES; page++) {
const res = unwrap(await fetchPage(req, options))
yield* res.data
seen += res.data.length
const { number, size, total } = res.meta.page
if (res.data.length === 0 || res.data.length < size || seen >= total) {
return
}
req = { ...req, page: { ...req.page, number: number + 1 } } as TReq
}
throw new PaginationLimitExceededError(MAX_PAGINATION_PAGES)
}
interface CursorEnvelope<TItem> {
data: TItem[]
meta: { page: { next: string | null } }
}
interface CursorRequest {
page?: { after?: string; before?: string; size?: number }
}
/**
* Iterates every item of a cursor-paginated list operation, following
* `meta.page.next` until the server stops returning one. Despite carrying a
* `format: uri` annotation in the spec, `next` is the opaque cursor token the
* API expects back verbatim in `page.after` on the following request — not a
* URI to fetch directly. Every other field on `request` is sent unchanged on
* every page fetch; only `page.after` advances.
*/
export async function* paginateCursor<TItem, TReq extends CursorRequest>(
fetchPage: (
req: TReq,
options?: RequestOptions,
) => Promise<Result<CursorEnvelope<TItem>>>,
request: TReq,
options?: RequestOptions,
): AsyncGenerator<TItem, void, undefined> {
let req = request
for (let page = 0; page < MAX_PAGINATION_PAGES; page++) {
const res = unwrap(await fetchPage(req, options))
yield* res.data
const next = res.meta.page.next
if (!next) {
return
}
req = { ...req, page: { ...req.page, after: next } } as TReq
}
throw new PaginationLimitExceededError(MAX_PAGINATION_PAGES)
}
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