Files
NetMesh/application/state/sftp/transferControlEpoch.ts

44 lines
1.3 KiB
TypeScript
Raw Normal View History

/**
* Monotonic control epoch per transfer id.
*
* Pause soft-drain / watchdogs capture an epoch when they start. Resume (or a
* newer pause) bumps the epoch so every in-flight soft-drain becomes a no-op
* instead of racing the live stream. Process-global so it survives panel unmount.
*/
const epochs = new Map<string, number>();
// A scalar generation prevents ABA when a settled task id is reused. It does
// not retain task ids, while making every new control round process-unique.
let nextEpoch = 0;
export function getTransferControlEpoch(taskId: string): number {
return epochs.get(taskId) ?? 0;
}
/** Bump and return the new epoch. Call on intentional Pause and Resume. */
export function bumpTransferControlEpoch(taskId: string): number {
const next = nextEpoch + 1;
nextEpoch = next;
epochs.set(taskId, next);
return next;
}
export function isTransferControlEpochCurrent(taskId: string, epoch: number): boolean {
return epochs.get(taskId) === epoch;
}
/** Release control epochs after the transfer tree has fully settled. */
export function settleTransferControlEpochTree(
rootTaskId: string,
childIds: readonly string[] = [],
): void {
epochs.delete(rootTaskId);
for (const childId of childIds) epochs.delete(childId);
}
/** Test helper. */
export function resetTransferControlEpochsForTests(): void {
epochs.clear();
nextEpoch = 0;
}