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Move some common type definitions into archive/common.js and some comments.

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This commit is contained in:
Jeff Schiller 2024-01-20 16:12:55 -08:00
parent 4fc0c3da2b
commit 45fdedd663
11 changed files with 75 additions and 83 deletions
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28
archive/zip.js
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@ -12,6 +12,10 @@
*/
import { ByteBuffer } from '../io/bytebuffer.js';
import { CENTRAL_FILE_HEADER_SIG, CRC32_MAGIC_NUMBER, END_OF_CENTRAL_DIR_SIG,
LOCAL_FILE_HEADER_SIG } from './common.js';
/** @typedef {import('./common.js').FileInfo} FileInfo */
/** @type {MessagePort} */
let hostPort;
@ -28,14 +32,6 @@ let hostPort;
* The client should append the bytes to a single buffer in the order they were received.
*/
// TODO(bitjs): De-dupe this typedef and the one in compress.js.
/**
* @typedef FileInfo An object that is sent by the client to represent a file.
* @property {string} fileName The name of this file. TODO: Includes the path?
* @property {number} lastModTime The number of ms since the Unix epoch (1970-01-01 at midnight).
* @property {Uint8Array} fileData The raw bytes of the file.
*/
// TODO(bitjs): Figure out where this typedef should live.
/**
* @typedef CompressFilesMessage A message the client sends to the implementation.
@ -46,12 +42,6 @@ let hostPort;
// TODO: Support DEFLATE.
// TODO: Support options that can let client choose levels of compression/performance.
// TODO(bitjs): These constants should be defined in a common isomorphic ES module.
const zLocalFileHeaderSignature = 0x04034b50;
const zCentralFileHeaderSignature = 0x02014b50;
const zEndOfCentralDirSignature = 0x06054b50;
const zCRC32MagicNumber = 0xedb88320; // 0xdebb20e3;
/**
* @typedef CentralDirectoryFileHeaderInfo An object to be used to construct the central directory.
* @property {string} fileName
@ -93,7 +83,7 @@ function createCRC32Table() {
for (let n = 0; n < 256; n++) {
let c = n;
for (let k = 0; k < 8; k++) {
c = ((c & 1) ? (zCRC32MagicNumber ^ (c >>> 1)) : (c >>> 1));
c = ((c & 1) ? (CRC32_MAGIC_NUMBER ^ (c >>> 1)) : (c >>> 1));
}
table[n] = c;
}
@ -157,7 +147,7 @@ function zipOneFile(file) {
/** @type {ByteBuffer} */
const buffer = new ByteBuffer(fileHeaderSize + file.fileData.byteLength);
buffer.writeNumber(zLocalFileHeaderSignature, 4); // Magic number.
buffer.writeNumber(LOCAL_FILE_HEADER_SIG, 4); // Magic number.
buffer.writeNumber(0x0A, 2); // Version.
buffer.writeNumber(0, 2); // General Purpose Flags.
buffer.writeNumber(0, 2); // Compression Method. 0 = Store only.
@ -201,7 +191,7 @@ function writeCentralFileDirectory() {
const buffer = new ByteBuffer(cdsLength + 22);
for (const cdInfo of centralDirectoryInfos) {
buffer.writeNumber(zCentralFileHeaderSignature, 4); // Magic number.
buffer.writeNumber(CENTRAL_FILE_HEADER_SIG, 4); // Magic number.
buffer.writeNumber(0, 2); // Version made by. // 0x31e
buffer.writeNumber(0, 2); // Version needed to extract (minimum). // 0x14
buffer.writeNumber(0, 2); // General purpose bit flag
@ -222,7 +212,7 @@ function writeCentralFileDirectory() {
}
// 22 more bytes.
buffer.writeNumber(zEndOfCentralDirSignature, 4); // Magic number.
buffer.writeNumber(END_OF_CENTRAL_DIR_SIG, 4); // Magic number.
buffer.writeNumber(0, 2); // Number of this disk.
buffer.writeNumber(0, 2); // Disk where central directory starts.
buffer.writeNumber(filesCompressed.length, 2); // Number of central directory records on this disk.
@ -287,7 +277,7 @@ export function connect(port) {
export function disconnect() {
if (!hostPort) {
throw `hostPort was not connected in unzip.js`;
throw `hostPort was not connected in zip.js`;
}
hostPort = null;