qortal-web-builder/zip-store.js

/**
 * Minimal ZIP (STORE / no compression) for browser — one dependency-free helper
 * so PUBLISH_QDN_RESOURCE can ship WEBSITE/APP archives from this Q-App.
 */
(function (global) {
  'use strict';

  const crcTable = (function makeTable() {
    const t = new Uint32Array(256);
    for (let i = 0; i < 256; i++) {
      let c = i;
      for (let k = 0; k < 8; k++) c = (c & 1) ? (0xedb88320 ^ (c >>> 1)) : (c >>> 1);
      t[i] = c >>> 0;
    }
    return t;
  })();

  function crc32(buf) {
    let c = 0xffffffff;
    for (let i = 0; i < buf.length; i++) c = crcTable[(c ^ buf[i]) & 0xff] ^ (c >>> 8);
    return (c ^ 0xffffffff) >>> 0;
  }

  function strToUtf8(s) {
    return new TextEncoder().encode(String(s));
  }

  /** @param {Record<string, Uint8Array|string>} files map path -> bytes or utf8 string */
  function buildZipStore(files) {
    const entries = Object.keys(files).map((name) => {
      const raw = files[name];
      const data = raw instanceof Uint8Array ? raw : strToUtf8(raw);
      return { name, data };
    });

    let offset = 0;
    const parts = [];
    const central = [];

    for (const e of entries) {
      const nameBytes = strToUtf8(e.name);
      const nameLen = nameBytes.length;
      const data = e.data;
      const size = data.length;
      const crc = crc32(data);
      const sig = 0x04034b50;
      const ver = 20;
      const flags = 0;
      const method = 0;
      const time = 0;
      const date = 0;
      const csize = size;
      const hlen = 30 + nameLen;

      const local = new DataView(new ArrayBuffer(hlen + size));
      let p = 0;
      local.setUint32(p, sig, true); p += 4;
      local.setUint16(p, ver, true); p += 2;
      local.setUint16(p, flags, true); p += 2;
      local.setUint16(p, method, true); p += 2;
      local.setUint16(p, time, true); p += 2;
      local.setUint16(p, date, true); p += 2;
      local.setUint32(p, crc, true); p += 4;
      local.setUint32(p, csize, true); p += 4;
      local.setUint32(p, size, true); p += 4;
      local.setUint16(p, nameLen, true); p += 2;
      local.setUint16(p, 0, true); p += 2;
      new Uint8Array(local.buffer).set(nameBytes, p);
      p += nameLen;
      new Uint8Array(local.buffer).set(data, p);

      parts.push(new Uint8Array(local.buffer));
      central.push({
        nameBytes,
        crc,
        size,
        csize,
        localOffset: offset,
      });
      offset += local.buffer.byteLength;
    }

    const cdParts = [];
    let cdSize = 0;
    let cdOffset = offset;
    for (let i = 0; i < central.length; i++) {
      const c = central[i];
      const nameLen = c.nameBytes.length;
      const hlen = 46 + nameLen;
      const buf = new DataView(new ArrayBuffer(46));
      let q = 0;
      buf.setUint32(q, 0x02014b50, true); q += 4;
      buf.setUint16(q, 20, true); q += 2;
      buf.setUint16(q, 20, true); q += 2;
      buf.setUint16(q, 0, true); q += 2;
      buf.setUint16(q, 0, true); q += 2;
      buf.setUint16(q, 0, true); q += 2;
      buf.setUint16(q, 0, true); q += 2;
      buf.setUint32(q, c.crc, true); q += 4;
      buf.setUint32(q, c.csize, true); q += 4;
      buf.setUint32(q, c.size, true); q += 4;
      buf.setUint16(q, nameLen, true); q += 2;
      buf.setUint16(q, 0, true); q += 2;
      buf.setUint16(q, 0, true); q += 2;
      buf.setUint16(q, 0, true); q += 2;
      buf.setUint16(q, 0, true); q += 2;
      buf.setUint32(q, 0, true); q += 4;
      buf.setUint32(q, c.localOffset, true); q += 4;
      const header = new Uint8Array(buf.buffer);
      const merged = new Uint8Array(hlen);
      merged.set(header, 0);
      merged.set(c.nameBytes, 46);
      cdParts.push(merged);
      cdSize += merged.length;
    }

    const eoc = new DataView(new ArrayBuffer(22));
    eoc.setUint32(0, 0x06054b50, true);
    eoc.setUint16(4, 0, true);
    eoc.setUint16(6, 0, true);
    eoc.setUint16(8, entries.length, true);
    eoc.setUint16(10, entries.length, true);
    eoc.setUint32(12, cdSize, true);
    eoc.setUint32(16, cdOffset, true);
    eoc.setUint16(20, 0, true);

    const totalLen = offset + cdSize + 22;
    const out = new Uint8Array(totalLen);
    let o = 0;
    for (const part of parts) {
      out.set(part, o);
      o += part.length;
    }
    for (const part of cdParts) {
      out.set(part, o);
      o += part.length;
    }
    out.set(new Uint8Array(eoc.buffer), o);

    return out;
  }

  global.buildZipStore = buildZipStore;
})(typeof window !== 'undefined' ? window : globalThis);