50 lines
1.3 KiB
TypeScript
50 lines
1.3 KiB
TypeScript
|
const thumbnails = new Map<string, string>();
|
||
|
|
const latestFrames = new Map<string, { bytes: Uint8Array; format: string }>();
|
||
|
|
const thumbnailRequests = new Map<string, number>();
|
||
|
|
|
||
|
|
export function setThumbnail(id: string, dataUrl: string) {
|
||
|
|
thumbnails.set(id, dataUrl);
|
||
|
|
}
|
||
|
|
|
||
|
|
export function getThumbnail(id: string) {
|
||
|
|
return thumbnails.get(id) ?? null;
|
||
|
|
}
|
||
|
|
|
||
|
|
export function clearThumbnail(id: string) {
|
||
|
|
thumbnails.delete(id);
|
||
|
|
latestFrames.delete(id);
|
||
|
|
thumbnailRequests.delete(id);
|
||
|
|
}
|
||
|
|
|
||
|
|
export function setLatestFrame(id: string, bytes: Uint8Array, format: string) {
|
||
|
|
latestFrames.set(id, { bytes, format });
|
||
|
|
}
|
||
|
|
|
||
|
|
export function generateThumbnail(id: string): boolean {
|
||
|
|
const frameData = latestFrames.get(id);
|
||
|
|
if (!frameData) {
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
|
||
|
|
const { bytes, format } = frameData;
|
||
|
|
const b64 = Buffer.from(bytes).toString("base64");
|
||
|
|
const mime = format === "webp" ? "image/webp" : "image/jpeg";
|
||
|
|
thumbnails.set(id, `data:${mime};base64,${b64}`);
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
|
||
|
|
export function markThumbnailRequested(id: string) {
|
||
|
|
thumbnailRequests.set(id, Date.now());
|
||
|
|
}
|
||
|
|
|
||
|
|
export function consumeThumbnailRequest(id: string, windowMs = 5000): boolean {
|
||
|
|
const ts = thumbnailRequests.get(id);
|
||
|
|
if (!ts) return false;
|
||
|
|
if (Date.now() - ts > windowMs) {
|
||
|
|
thumbnailRequests.delete(id);
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
thumbnailRequests.delete(id);
|
||
|
|
return true;
|
||
|
|
}
|