downthemall/lib/mime.ts
Nils Maier dabf7f8a28 Prerolling and mime detection for some downloads
Only attempt this for a limited subset of downloads for now.
Related #45
2019-09-04 14:15:05 +02:00

56 lines
1.3 KiB
TypeScript

"use strict";
// License: MIT
import mime from "../data/mime.json";
export class MimeInfo {
public readonly type: string;
public readonly extensions: Set<string>;
public readonly major: string;
public readonly minor: string;
public readonly primary: string;
constructor(type: string, extensions: string[]) {
this.type = type;
const [major, minor] = type.split("/", 2);
this.major = major;
this.minor = minor;
[this.primary] = extensions;
this.extensions = new Set(extensions);
Object.freeze(this);
}
}
export const MimeDB = new class {
private readonly mimeToExts: Map<string, MimeInfo>;
constructor() {
const exts = new Map<string, string[]>();
for (const [prim, more] of Object.entries(mime.e)) {
let toadd = more;
if (!Array.isArray(toadd)) {
toadd = [toadd];
}
toadd.unshift(prim);
exts.set(prim, toadd);
}
this.mimeToExts = new Map(Array.from(
Object.entries(mime.m),
([mime, prim]) => [mime, new MimeInfo(mime, exts.get(prim) || [prim])]
));
}
getPrimary(mime: string) {
const info = this.mimeToExts.get(mime.trim().toLocaleLowerCase());
return info ? info.primary : "";
}
getMime(mime: string) {
return this.mimeToExts.get(mime.trim().toLocaleLowerCase());
}
}();