igir/dist/src/types/patches/patch.js

🕹 A zero-setup ROM collection manager that sorts, filters, extracts or archives, patches, and reports on collections of any size on any OS.

import path from 'node:path';
import IgirException from '../exceptions/igirException.js';
export default class Patch {
    file;
    crcBefore;
    crcAfter;
    sizeAfter;
    constructor(file, crcBefore, crcAfter, sizeAfter) {
        this.file = file;
        this.crcBefore = crcBefore;
        this.crcAfter = crcAfter;
        this.sizeAfter = sizeAfter;
    }
    static getCrcFromPath(fileBasename) {
        const matches = /(^|[^a-z0-9])([a-f0-9]{8})([^a-z0-9]|$)/i.exec(fileBasename);
        if (matches && matches.length >= 3) {
            return matches[2].toLowerCase();
        }
        throw new IgirException(`couldn't parse base file CRC for patch: ${fileBasename}`);
    }
    getFile() {
        return this.file;
    }
    getCrcBefore() {
        return this.crcBefore;
    }
    getCrcAfter() {
        return this.crcAfter;
    }
    getSizeAfter() {
        return this.sizeAfter;
    }
    getRomName() {
        return path
            .parse(this.getFile().getExtractedFilePath())
            .name.replaceAll(new RegExp(this.getCrcBefore(), 'gi'), '')
            .replaceAll(/  +/g, ' ')
            .trim();
    }
    static async readUpsUint(fp) {
        let data = 0;
        let shift = 1;
        while (!fp.isEOF()) {
            const x = (await fp.readNext(1)).readUInt8();
            data += (x & 0x7f) * shift; // drop the left-most bit
            if (x & 0x80) {
                // left-most bit is telling us this is the end
                break;
            }
            shift <<= 7;
            data += shift;
        }
        return data;
    }
    static async readVcdiffUintFromFile(fp) {
        let num = 0;
        while (!fp.isEOF()) {
            const bits = (await fp.readNext(1)).readUInt8();
            num = (num << 7) + (bits & 0x7f);
            if (!(bits & 0x80)) {
                // left-most bit is telling us to keep going
                break;
            }
        }
        return num;
    }
    static readVcdiffUintFromBuffer(buffer, offset = 0) {
        let num = 0;
        let lastOffset = offset;
        while (lastOffset < buffer.length) {
            const bits = buffer.readUInt8(lastOffset);
            lastOffset += 1;
            num = (num << 7) + (bits & 0x7f);
            if (!(bits & 0x80)) {
                // left-most bit is telling us to keep going
                break;
            }
        }
        return [num, lastOffset];
    }
}