sc4/lib/utils/mapped-tgi-index.js

A command line utility for automating SimCity 4 modding tasks & modifying savegames

// # MappedIndex()
export default class MappedIndex {
    tgi = new Map();
    ti = new Map();
    t = new Map();
    // ## constructor()
    constructor(entries = []) {
        for (let j = 0; j < entries.length; j++) {
            let entry = entries[j];
            let { type: t, group: g, instance: i } = entry;
            set(this.tgi, hhh(t, g, i), j);
            set(this.ti, hh(t, i), j);
            set(this.t, h(t), j);
        }
    }
    // ## load(cache)
    // Loads an index from cache.
    load(cache) {
        this.tgi = new Map(cache.tgi);
        this.ti = new Map(cache.ti);
        this.t = new Map(cache.t);
        return this;
    }
    // ## findTGI()
    findTGI(t, g, i) {
        return get(this.tgi, hhh(t, g, i));
    }
    // ## findType()
    findType(t) {
        return get(this.t, h(t));
    }
    // ## findTI()
    findTI(t, i) {
        return get(this.ti, hh(t, i));
    }
    // ## toJSON()
    toJSON() {
        return {
            tgi: [...this.tgi.entries()],
            ti: [...this.ti.entries()],
            t: [...this.t.entries()],
        };
    }
}
// The hash functions we use for one, two or three values.
const h = (t) => BigInt(t);
const hh = (t, g) => BigInt(t) << 32n | BigInt(g);
const hhh = (t, g, i) => BigInt(t) << 64n |
    BigInt(g) << 32n |
    BigInt(i);
// # get(arr, dict, key)
// Accessor function for easily reading values from our maps.
function get(dict, key) {
    return dict.get(key) ?? [];
}
// # set(dict, key, value)
function set(dict, key, value) {
    let arr = dict.get(key);
    if (arr) {
        arr.push(value);
    }
    else {
        dict.set(key, [value]);
    }
}