mirror of
https://github.com/morluto/rea.git
synced 2026-11-06 23:06:18 +00:00
morluto
a7004c7df1
Reuse the positional range owner for target metadata, Hopper Mach-O selection and Kuna spans. Preserve physical failures, completed span evidence and cleanup ownership across cancellation and short reads. Validated 147 focused file and lifecycle tests; ten new cases reproduced failures against the prior implementation.
41 lines
1.3 KiB
TypeScript
41 lines
1.3 KiB
TypeScript
import type { FileHandle } from "node:fs/promises";
|
|
|
|
/**
|
|
* Fill a positional window until its end or explicit EOF, without owning the descriptor.
|
|
* Checkpoints receive cumulative acquired bytes so an owner can defer cancellation
|
|
* of a completed range to its finalization without losing the completed observation.
|
|
*/
|
|
export const readFileHandleRange = async (
|
|
handle: Pick<FileHandle, "read">,
|
|
position: number,
|
|
length: number,
|
|
assertActive: (bytesRead: number) => void = () => {},
|
|
): Promise<Buffer> => {
|
|
if (
|
|
!Number.isSafeInteger(position) ||
|
|
position < 0 ||
|
|
!Number.isSafeInteger(length) ||
|
|
length < 0 ||
|
|
!Number.isSafeInteger(position + length)
|
|
)
|
|
throw new RangeError("Invalid file read range");
|
|
assertActive(0);
|
|
const bytes = Buffer.alloc(length);
|
|
let filled = 0;
|
|
while (filled < length) {
|
|
assertActive(filled);
|
|
const { bytesRead } = await handle.read(
|
|
bytes,
|
|
filled,
|
|
length - filled,
|
|
position + filled,
|
|
);
|
|
// Let the caller interpret physical EOF before checking cancellation.
|
|
// A native I/O rejection also remains primary if cancellation arrived in flight.
|
|
if (bytesRead === 0) break;
|
|
filled += bytesRead;
|
|
assertActive(filled);
|
|
}
|
|
return bytes.subarray(0, filled);
|
|
};
|