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

Author: codedread

archive/common.js

@@ -1,14 +1,19 @@
 /**
  * common.js
  *
- * Provides common functionality for compressing and decompressing.
+ * Provides common definitions or functionality needed by multiple modules.
  *
  * Licensed under the MIT License
  *
  * Copyright(c) 2023 Google Inc.
  */
 
-// Requires the following JavaScript features: MessageChannel, MessagePort, and dynamic imports.
+/**
+ * @typedef FileInfo An object that is sent to the implementation representing a file to compress.
+ * @property {string} fileName The name of the 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 bytes of the file.
+ */
 
 /**
  * @typedef Implementation
@@ -51,3 +56,23 @@ export async function getConnectedPort(implFilename) {
     });
   });
 }
+
+// Zip-specific things.
+
+export const LOCAL_FILE_HEADER_SIG = 0x04034b50;
+export const CENTRAL_FILE_HEADER_SIG = 0x02014b50;
+export const END_OF_CENTRAL_DIR_SIG = 0x06054b50;
+export const CRC32_MAGIC_NUMBER = 0xedb88320;
+export const ARCHIVE_EXTRA_DATA_SIG = 0x08064b50;
+export const DIGITAL_SIGNATURE_SIG = 0x05054b50;
+export const END_OF_CENTRAL_DIR_LOCATOR_SIG = 0x07064b50;
+export const DATA_DESCRIPTOR_SIG = 0x08074b50;
+
+/**
+ * @readonly
+ * @enum {number}
+ */
+export const ZipCompressionMethod = {
+  STORE: 0,   // Default.
+  DEFLATE: 8, // As per http://tools.ietf.org/html/rfc1951.
+};

archive/compress.js

@@ -8,7 +8,7 @@
  * Copyright(c) 2023 Google Inc.
  */
 
-import { getConnectedPort } from './common.js';
+import { ZipCompressionMethod, getConnectedPort } from './common.js';
 
 // NOTE: THIS IS A VERY HACKY WORK-IN-PROGRESS! THE API IS NOT FROZEN! USE AT YOUR OWN RISK!
 
@@ -19,15 +19,6 @@ import { getConnectedPort } from './common.js';
  * @property {Uint8Array} fileData The bytes of the file.
  */
 
-/**
- * @readonly
- * @enum {number}
- */
-export const ZipCompressionMethod = {
-  STORE: 0, // Default.
-  // DEFLATE: 8,
-};
-
 // export const DeflateCompressionMethod = {
 //   NO_COMPRESSION: 0,
 //   COMPRESSION_FIXED_HUFFMAN: 1,
@@ -36,17 +27,15 @@ export const ZipCompressionMethod = {
 
 /**
  * Data elements are packed into bytes in order of increasing bit number within the byte,
-   i.e., starting with the least-significant bit of the byte.
+ * i.e., starting with the least-significant bit of the byte.
  * Data elements other than Huffman codes are packed starting with the least-significant bit of the
-   data element.
+ * data element.
  * Huffman codes are packed starting with the most-significant bit of the code.
  */
 
 /**
  * @typedef CompressorOptions
  * @property {ZipCompressionMethod} zipCompressionMethod
- * @property {DeflateCompressionMethod=} deflateCompressionMethod Only present if
- *     zipCompressionMethod is set to DEFLATE.
  */
 
 /**
@@ -91,6 +80,7 @@ export class Zipper {
      * @private
      */
     this.zipCompressionMethod = options.zipCompressionMethod || ZipCompressionMethod.STORE;
+    if (this.zipCompressionMethod === ZipCompressionMethod.DEFLATE) throw `DEFLATE not supported.`;
 
     /**
      * @type {CompressStatus}

archive/events.js

@@ -19,9 +19,9 @@ export const UnarchiveEventType = {
   ERROR: 'error'
 };
 
-/**
- * An unarchive event.
- */
+// TODO: Use CustomEvent and a @template and remove these boilerplate events.
+
+/** An unarchive event. */
 export class UnarchiveEvent extends Event {
   /**
    * @param {string} type The event type.
@@ -31,9 +31,7 @@ export class UnarchiveEvent extends Event {
   }
 }
 
-/**
- * Updates all Archiver listeners that an append has occurred.
- */
+/** Updates all Unarchiver listeners that an append has occurred. */
 export class UnarchiveAppendEvent extends UnarchiveEvent {
   /**
    * @param {number} numBytes The number of bytes appended.
@@ -49,9 +47,7 @@ export class UnarchiveAppendEvent extends UnarchiveEvent {
   }
 }
 
-/**
- * Useful for passing info up to the client (for debugging).
- */
+/** Useful for passing info up to the client (for debugging). */
 export class UnarchiveInfoEvent extends UnarchiveEvent {
   /**
    * @param {string} msg The info message.
@@ -67,9 +63,7 @@ export class UnarchiveInfoEvent extends UnarchiveEvent {
   }
 }
 
-/**
- * An unrecoverable error has occured.
- */
+/** An unrecoverable error has occured. */
 export class UnarchiveErrorEvent extends UnarchiveEvent {
   /**
    * @param {string} msg The error message.
@@ -85,18 +79,14 @@ export class UnarchiveErrorEvent extends UnarchiveEvent {
   }
 }
 
-/**
- * Start event.
- */
+/** Start event. */
 export class UnarchiveStartEvent extends UnarchiveEvent {
   constructor() {
     super(UnarchiveEventType.START);
   }
 }
 
-/**
- * Finish event.
- */
+/** Finish event. */
 export class UnarchiveFinishEvent extends UnarchiveEvent {
   /**
    * @param {Object} metadata A collection fo metadata about the archive file.
@@ -108,9 +98,7 @@ export class UnarchiveFinishEvent extends UnarchiveEvent {
 }
 
 // TODO(bitjs): Fully document these. They are confusing.
-/**
- * Progress event.
- */
+/** Progress event. */
 export class UnarchiveProgressEvent extends UnarchiveEvent {
   /**
    * @param {string} currentFilename
@@ -136,9 +124,7 @@ export class UnarchiveProgressEvent extends UnarchiveEvent {
   }
 }
 
-/**
- * Extract event.
- */
+/** Extract event. */
 export class UnarchiveExtractEvent extends UnarchiveEvent {
   /**
    * @param {UnarchivedFile} unarchivedFile

archive/unrar.js

@@ -28,6 +28,7 @@ let hostPort;
 
 // State - consider putting these into a class.
 let unarchiveState = UnarchiveState.NOT_STARTED;
+/** @type {ByteStream} */
 let bytestream = null;
 let allLocalFiles = null;
 let logToConsole = false;

archive/untar.js

@@ -24,6 +24,7 @@ let hostPort;
 
 // State - consider putting these into a class.
 let unarchiveState = UnarchiveState.NOT_STARTED;
+/** @type {ByteStream} */
 let bytestream = null;
 let allLocalFiles = null;
 let logToConsole = false;

archive/unzip.js

@@ -15,6 +15,9 @@
 import { BitStream } from '../io/bitstream.js';
 import { ByteBuffer } from '../io/bytebuffer.js';
 import { ByteStream } from '../io/bytestream.js';
+import { ARCHIVE_EXTRA_DATA_SIG, CENTRAL_FILE_HEADER_SIG, CRC32_MAGIC_NUMBER,
+  DATA_DESCRIPTOR_SIG, DIGITAL_SIGNATURE_SIG, END_OF_CENTRAL_DIR_SIG,
+  LOCAL_FILE_HEADER_SIG } from './common.js';
 
 const UnarchiveState = {
   NOT_STARTED: 0,
@@ -28,6 +31,7 @@ let hostPort;
 
 // State - consider putting these into a class.
 let unarchiveState = UnarchiveState.NOT_STARTED;
+/** @type {ByteStream} */
 let bytestream = null;
 let allLocalFiles = null;
 let logToConsole = false;
@@ -60,24 +64,14 @@ const postProgress = function () {
   });
 };
 
-const zLocalFileHeaderSignature = 0x04034b50;
-const zArchiveExtraDataSignature = 0x08064b50;
-const zCentralFileHeaderSignature = 0x02014b50;
-const zDigitalSignatureSignature = 0x05054b50;
-const zEndOfCentralDirSignature = 0x06054b50;
-const zEndOfCentralDirLocatorSignature = 0x07064b50;
-const zDataDescriptorSignature = 0x08074b50;
-
 // mask for getting the Nth bit (zero-based)
 const BIT = [0x01, 0x02, 0x04, 0x08,
   0x10, 0x20, 0x40, 0x80,
   0x100, 0x200, 0x400, 0x800,
   0x1000, 0x2000, 0x4000, 0x8000];
 
 class ZipLocalFile {
-  /**
-   * @param {ByteStream} bstream 
-   */
+  /** @param {ByteStream} bstream */
   constructor(bstream) {
     if (typeof bstream != typeof {} || !bstream.readNumber || typeof bstream.readNumber != typeof function () { }) {
       return null;
@@ -125,9 +119,9 @@ class ZipLocalFile {
       let foundDataDescriptor = false;
       let numBytesSeeked = 0;
       while (!foundDataDescriptor) {
-        while (bstream.peekNumber(4) !== zLocalFileHeaderSignature &&
-          bstream.peekNumber(4) !== zArchiveExtraDataSignature &&
-          bstream.peekNumber(4) !== zCentralFileHeaderSignature) {
+        while (bstream.peekNumber(4) !== LOCAL_FILE_HEADER_SIG &&
+          bstream.peekNumber(4) !== ARCHIVE_EXTRA_DATA_SIG &&
+          bstream.peekNumber(4) !== CENTRAL_FILE_HEADER_SIG) {
           numBytesSeeked++;
           bstream.readBytes(1);
         }
@@ -143,7 +137,7 @@ class ZipLocalFile {
 
         // From the PKZIP App Note: "The signature value 0x08074b50 is also used by some ZIP
         // implementations as a marker for the Data Descriptor record".
-        if (maybeDescriptorSig === zDataDescriptorSignature) {
+        if (maybeDescriptorSig === DATA_DESCRIPTOR_SIG) {
           if (maybeCompressedSize === (numBytesSeeked - 16)) {
             foundDataDescriptor = true;
             descriptorSize = 16;
@@ -606,7 +600,7 @@ function archiveUnzip() {
   let bstream = bytestream.tee();
 
   // loop until we don't see any more local files or we find a data descriptor.
-  while (bstream.peekNumber(4) == zLocalFileHeaderSignature) {
+  while (bstream.peekNumber(4) == LOCAL_FILE_HEADER_SIG) {
     // Note that this could throw an error if the bstream overflows, which is caught in the
     // message handler.
     const oneLocalFile = new ZipLocalFile(bstream);
@@ -636,7 +630,7 @@ function archiveUnzip() {
   totalFilesInArchive = allLocalFiles.length;
 
   // archive extra data record
-  if (bstream.peekNumber(4) == zArchiveExtraDataSignature) {
+  if (bstream.peekNumber(4) == ARCHIVE_EXTRA_DATA_SIG) {
     if (logToConsole) {
       info(' Found an Archive Extra Data Signature');
     }
@@ -649,13 +643,13 @@ function archiveUnzip() {
 
   // central directory structure
   // TODO: handle the rest of the structures (Zip64 stuff)
-  if (bstream.peekNumber(4) == zCentralFileHeaderSignature) {
+  if (bstream.peekNumber(4) == CENTRAL_FILE_HEADER_SIG) {
     if (logToConsole) {
       info(' Found a Central File Header');
     }
 
     // read all file headers
-    while (bstream.peekNumber(4) == zCentralFileHeaderSignature) {
+    while (bstream.peekNumber(4) == CENTRAL_FILE_HEADER_SIG) {
       bstream.readNumber(4); // signature
       const cdfh = {
         versionMadeBy: bstream.readNumber(2),
@@ -688,7 +682,7 @@ function archiveUnzip() {
   }
 
   // digital signature
-  if (bstream.peekNumber(4) == zDigitalSignatureSignature) {
+  if (bstream.peekNumber(4) == DIGITAL_SIGNATURE_SIG) {
     if (logToConsole) {
       info(' Found a Digital Signature');
     }
@@ -699,7 +693,7 @@ function archiveUnzip() {
   }
 
   let metadata = {};
-  if (bstream.peekNumber(4) == zEndOfCentralDirSignature) {
+  if (bstream.peekNumber(4) == END_OF_CENTRAL_DIR_SIG) {
     bstream.readNumber(4); // signature
     const eocds = {
       numberOfThisDisk: bstream.readNumber(2),