From 17d81565bedbf5a2403f059ed829eddd9263e086 Mon Sep 17 00:00:00 2001
From: Daria Terekhova <daria.terekhova@actionengine.com>
Date: Tue, 11 Jul 2023 12:57:03 +0300
Subject: [PATCH 1/6] Warning fix

---
 modules/i3s/src/index.ts | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/modules/i3s/src/index.ts b/modules/i3s/src/index.ts
index c50f71ed3f..78ea82b813 100644
--- a/modules/i3s/src/index.ts
+++ b/modules/i3s/src/index.ts
@@ -33,6 +33,7 @@ export type {
   OperationalLayer,
   TextureSetDefinitionFormats
 } from './types';
+export type {FileProvider} from './lib/parsers/parse-zip/file-provider';
 
 export {COORDINATE_SYSTEM} from './lib/parsers/constants';
 
@@ -44,4 +45,4 @@ export {I3SBuildingSceneLayerLoader} from './i3s-building-scene-layer-loader';
 export {I3SNodePageLoader} from './i3s-node-page-loader';
 export {ArcGisWebSceneLoader} from './arcgis-webscene-loader';
 export {parseZipLocalFileHeader} from './lib/parsers/parse-zip/local-file-header';
-export {FileProvider} from './lib/parsers/parse-zip/file-provider';
+export {parseSLPK} from './lib/parsers/parse-slpk/parse-slpk';

From 8ba55eb8034e69650050207bafdf0c487ade4218 Mon Sep 17 00:00:00 2001
From: Daria Terekhova <daria.terekhova@actionengine.com>
Date: Tue, 11 Jul 2023 12:57:03 +0300
Subject: [PATCH 2/6] Logic via FileHandler added

Bigint logic implementation
---
 modules/i3s/src/i3s-slpk-loader.ts            | 10 ++-
 .../src/lib/parsers/parse-slpk/parse-slpk.ts  | 49 ++-----------
 .../parsers/parse-slpk/search-from-the-end.ts | 26 +++++++
 .../lib/parsers/parse-slpk/slpk-archieve.ts   | 21 +++---
 .../parsers/parse-zip/buffer-file-provider.ts | 55 ---------------
 .../lib/parsers/parse-zip/cd-file-header.ts   | 34 ++++-----
 .../parse-zip/data-view-file-provider.ts      | 70 +++++++++++++++++++
 .../lib/parsers/parse-zip/file-provider.ts    | 16 +++--
 .../parsers/parse-zip/local-file-header.ts    | 24 ++++---
 modules/i3s/test/cd-file-header.spec.js       |  4 +-
 modules/i3s/test/local-file-header.spec.js    |  4 +-
 .../i3s-server/controllers/slpk-controller.js | 15 ++--
 modules/tile-converter/src/index.ts           |  1 +
 .../helpers/file-handle-provider.ts           | 48 +++++++++----
 .../src/slpk-extractor/helpers/fs-promises.ts | 44 ++++++++++++
 .../src/slpk-extractor/slpk-extractor.ts      | 20 +++---
 16 files changed, 259 insertions(+), 182 deletions(-)
 create mode 100644 modules/i3s/src/lib/parsers/parse-slpk/search-from-the-end.ts
 delete mode 100644 modules/i3s/src/lib/parsers/parse-zip/buffer-file-provider.ts
 create mode 100644 modules/i3s/src/lib/parsers/parse-zip/data-view-file-provider.ts
 create mode 100644 modules/tile-converter/src/slpk-extractor/helpers/fs-promises.ts

diff --git a/modules/i3s/src/i3s-slpk-loader.ts b/modules/i3s/src/i3s-slpk-loader.ts
index 63216c431f..fe5fbfd62a 100644
--- a/modules/i3s/src/i3s-slpk-loader.ts
+++ b/modules/i3s/src/i3s-slpk-loader.ts
@@ -1,5 +1,6 @@
 import {LoaderOptions, LoaderWithParser} from '@loaders.gl/loader-utils';
-import {parseSLPK} from './lib/parsers/parse-slpk/parse-slpk';
+import {parseSLPK as parseSLPKFromProvider} from './lib/parsers/parse-slpk/parse-slpk';
+import {DataViewFileProvider} from './lib/parsers/parse-zip/data-view-file-provider';
 
 // __VERSION__ is injected by babel-plugin-version-inline
 // @ts-ignore TS2304: Cannot find name '__VERSION__'.
@@ -12,6 +13,13 @@ export type SLPKLoaderOptions = LoaderOptions & {
   };
 };
 
+async function parseSLPK(data: ArrayBuffer, options: SLPKLoaderOptions = {}) {
+  return (await parseSLPKFromProvider(new DataViewFileProvider(new DataView(data)))).getFile(
+    options.slpk?.path ?? '',
+    options.slpk?.pathMode
+  );
+}
+
 /**
  * Loader for SLPK - Scene Layer Package
  */
diff --git a/modules/i3s/src/lib/parsers/parse-slpk/parse-slpk.ts b/modules/i3s/src/lib/parsers/parse-slpk/parse-slpk.ts
index 4ef1aa7cf6..4a9ac8d8c6 100644
--- a/modules/i3s/src/lib/parsers/parse-slpk/parse-slpk.ts
+++ b/modules/i3s/src/lib/parsers/parse-slpk/parse-slpk.ts
@@ -1,45 +1,13 @@
-import type {SLPKLoaderOptions} from '../../../i3s-slpk-loader';
-import {DataViewFileProvider} from '../parse-zip/buffer-file-provider';
 import {parseZipCDFileHeader} from '../parse-zip/cd-file-header';
+import {FileProvider} from '../parse-zip/file-provider';
 import {parseZipLocalFileHeader} from '../parse-zip/local-file-header';
+import {searchFromTheEnd} from './search-from-the-end';
 import {SLPKArchive} from './slpk-archieve';
 
-/**
- * Returns one byte from the provided buffer at the provided position
- * @param offset - position where to read
- * @param buffer - buffer to read
- * @returns one byte from the provided buffer at the provided position
- */
-const getByteAt = (offset: number, buffer: DataView): number => {
-  return buffer.getUint8(buffer.byteOffset + offset);
-};
-
-export async function parseSLPK(data: ArrayBuffer, options: SLPKLoaderOptions = {}) {
-  const archive = new DataView(data);
+export const parseSLPK = async (fileProvider: FileProvider): Promise<SLPKArchive> => {
   const cdFileHeaderSignature = [80, 75, 1, 2];
 
-  const searchWindow = [
-    getByteAt(archive.byteLength - 1, archive),
-    getByteAt(archive.byteLength - 2, archive),
-    getByteAt(archive.byteLength - 3, archive),
-    undefined
-  ];
-
-  let hashCDOffset = 0;
-
-  // looking for the last record in the central directory
-  for (let i = archive.byteLength - 4; i > -1; i--) {
-    searchWindow[3] = searchWindow[2];
-    searchWindow[2] = searchWindow[1];
-    searchWindow[1] = searchWindow[0];
-    searchWindow[0] = getByteAt(i, archive);
-    if (searchWindow.every((val, index) => val === cdFileHeaderSignature[index])) {
-      hashCDOffset = i;
-      break;
-    }
-  }
-
-  const fileProvider = new DataViewFileProvider(archive);
+  const hashCDOffset = await searchFromTheEnd(fileProvider, cdFileHeaderSignature);
 
   const cdFileHeader = await parseZipCDFileHeader(hashCDOffset, fileProvider);
 
@@ -56,7 +24,7 @@ export async function parseSLPK(data: ArrayBuffer, options: SLPKLoaderOptions =
   }
 
   const fileDataOffset = localFileHeader.fileDataOffset;
-  const hashFile = archive.buffer.slice(
+  const hashFile = await fileProvider.slice(
     fileDataOffset,
     fileDataOffset + localFileHeader.compressedSize
   );
@@ -65,8 +33,5 @@ export async function parseSLPK(data: ArrayBuffer, options: SLPKLoaderOptions =
     throw new Error('No hash file in slpk');
   }
 
-  return await new SLPKArchive(data, hashFile).getFile(
-    options.slpk?.path ?? '',
-    options.slpk?.pathMode
-  );
-}
+  return new SLPKArchive(fileProvider, hashFile);
+};
diff --git a/modules/i3s/src/lib/parsers/parse-slpk/search-from-the-end.ts b/modules/i3s/src/lib/parsers/parse-slpk/search-from-the-end.ts
new file mode 100644
index 0000000000..7996a4a16d
--- /dev/null
+++ b/modules/i3s/src/lib/parsers/parse-slpk/search-from-the-end.ts
@@ -0,0 +1,26 @@
+import {FileProvider} from 'modules/i3s/src/lib/parsers/parse-zip/file-provider';
+
+export const searchFromTheEnd = async (file: FileProvider, target: number[]): Promise<bigint> => {
+  const searchWindow = [
+    await file.getUint8(file.length - 1n),
+    await file.getUint8(file.length - 2n),
+    await file.getUint8(file.length - 3n),
+    undefined
+  ];
+
+  let targetOffset = 0n;
+
+  // looking for the last record in the central directory
+  for (let i = file.length - 4n; i > -1; i--) {
+    searchWindow[3] = searchWindow[2];
+    searchWindow[2] = searchWindow[1];
+    searchWindow[1] = searchWindow[0];
+    searchWindow[0] = await file.getUint8(i);
+    if (searchWindow.every((val, index) => val === target[index])) {
+      targetOffset = i;
+      break;
+    }
+  }
+
+  return targetOffset;
+};
diff --git a/modules/i3s/src/lib/parsers/parse-slpk/slpk-archieve.ts b/modules/i3s/src/lib/parsers/parse-slpk/slpk-archieve.ts
index f689dccda2..e588e8dd09 100644
--- a/modules/i3s/src/lib/parsers/parse-slpk/slpk-archieve.ts
+++ b/modules/i3s/src/lib/parsers/parse-slpk/slpk-archieve.ts
@@ -1,7 +1,7 @@
 import md5 from 'md5';
 import {parseZipLocalFileHeader} from '../parse-zip/local-file-header';
-import {DataViewFileProvider} from '../parse-zip/buffer-file-provider';
 import {GZipCompression} from '@loaders.gl/compression';
+import {FileProvider} from '../parse-zip/file-provider';
 
 /** Element of hash array */
 type HashElement = {
@@ -12,7 +12,7 @@ type HashElement = {
   /**
    * File offset in the archive
    */
-  offset: number;
+  offset: bigint;
 };
 
 /** Description of real paths for different file types */
@@ -55,10 +55,10 @@ const PATH_DESCRIPTIONS: {test: RegExp; extensions: string[]}[] = [
  * Class for handling information about slpk file
  */
 export class SLPKArchive {
-  slpkArchive: DataView;
-  hashArray: {hash: Buffer; offset: number}[];
-  constructor(slpkArchiveBuffer: ArrayBuffer, hashFile: ArrayBuffer) {
-    this.slpkArchive = new DataView(slpkArchiveBuffer);
+  slpkArchive: FileProvider;
+  hashArray: {hash: Buffer; offset: bigint}[];
+  constructor(slpkArchive: FileProvider, hashFile: ArrayBuffer) {
+    this.slpkArchive = slpkArchive;
     this.hashArray = this.parseHashFile(hashFile);
   }
 
@@ -77,7 +77,7 @@ export class SLPKArchive {
           hashFileBuffer.byteOffset + i + 24
         )
       );
-      const offset = offsetBuffer.getUint32(offsetBuffer.byteOffset, true);
+      const offset = offsetBuffer.getBigUint64(offsetBuffer.byteOffset, true);
       hashArray.push({
         hash: Buffer.from(
           hashFileBuffer.subarray(hashFileBuffer.byteOffset + i, hashFileBuffer.byteOffset + i + 16)
@@ -155,15 +155,12 @@ export class SLPKArchive {
       return undefined;
     }
 
-    const localFileHeader = await parseZipLocalFileHeader(
-      this.slpkArchive.byteOffset + fileInfo?.offset,
-      new DataViewFileProvider(this.slpkArchive)
-    );
+    const localFileHeader = await parseZipLocalFileHeader(fileInfo?.offset, this.slpkArchive);
     if (!localFileHeader) {
       return undefined;
     }
 
-    const compressedFile = this.slpkArchive.buffer.slice(
+    const compressedFile = this.slpkArchive.slice(
       localFileHeader.fileDataOffset,
       localFileHeader.fileDataOffset + localFileHeader.compressedSize
     );
diff --git a/modules/i3s/src/lib/parsers/parse-zip/buffer-file-provider.ts b/modules/i3s/src/lib/parsers/parse-zip/buffer-file-provider.ts
deleted file mode 100644
index 4f1d048c85..0000000000
--- a/modules/i3s/src/lib/parsers/parse-zip/buffer-file-provider.ts
+++ /dev/null
@@ -1,55 +0,0 @@
-import {FileProvider} from './file-provider';
-
-/**
- * Provides file data using DataView
- */
-export class DataViewFileProvider implements FileProvider {
-  /**
-   * The DataView from which data is provided
-   */
-  private file: DataView;
-
-  constructor(file: DataView) {
-    this.file = file;
-  }
-
-  /**
-   * Gets an unsigned 8-bit integer at the specified byte offset from the start of the file.
-   * @param offset The offset, in bytes, from the start of the file where to read the data.
-   */
-  getUint8(offset: number): Promise<number> {
-    return Promise.resolve(this.file.getUint8(offset));
-  }
-
-  /**
-   * Gets an unsigned 16-bit integer at the specified byte offset from the start of the file.
-   * @param offset The offset, in bytes, from the start of the file where to read the data.
-   */
-  getUint16(offset: number): Promise<number> {
-    return Promise.resolve(this.file.getUint16(offset, true));
-  }
-
-  /**
-   * Gets an unsigned 32-bit integer at the specified byte offset from the start of the file.
-   * @param offset The offset, in bytes, from the start of the file where to read the data.
-   */
-  getUint32(offset: number): Promise<number> {
-    return Promise.resolve(this.file.getUint32(offset, true));
-  }
-
-  /**
-   * returns an ArrayBuffer whose contents are a copy of this file bytes from startOffset, inclusive, up to endOffset, exclusive.
-   * @param startOffset The offset, in bytes, from the start of the file where to start reading the data.
-   * @param endOffset The offset, in bytes, from the start of the file where to end reading the data.
-   */
-  slice(startOffset: number, endOffset: number): Promise<ArrayBuffer> {
-    return Promise.resolve(this.file.buffer.slice(startOffset, endOffset));
-  }
-
-  /**
-   * the length (in bytes) of the data.
-   */
-  get length() {
-    return this.file.byteLength;
-  }
-}
diff --git a/modules/i3s/src/lib/parsers/parse-zip/cd-file-header.ts b/modules/i3s/src/lib/parsers/parse-zip/cd-file-header.ts
index ba9f4083a1..8e7e1a0fc2 100644
--- a/modules/i3s/src/lib/parsers/parse-zip/cd-file-header.ts
+++ b/modules/i3s/src/lib/parsers/parse-zip/cd-file-header.ts
@@ -14,9 +14,9 @@ export type ZipCDFileHeader = {
   /** File name */
   fileName: string;
   /** Extra field offset */
-  extraOffset: number;
+  extraOffset: bigint;
   /** Relative offset of local file header */
-  localHeaderOffset: number;
+  localHeaderOffset: bigint;
 };
 
 /**
@@ -26,16 +26,16 @@ export type ZipCDFileHeader = {
  * @returns Info from the header
  */
 export const parseZipCDFileHeader = async (
-  headerOffset: number,
+  headerOffset: bigint,
   buffer: FileProvider
 ): Promise<ZipCDFileHeader> => {
   const offsets = {
-    CD_COMPRESSED_SIZE_OFFSET: 20,
-    CD_UNCOMPRESSED_SIZE_OFFSET: 24,
-    CD_FILE_NAME_LENGTH_OFFSET: 28,
-    CD_EXTRA_FIELD_LENGTH_OFFSET: 30,
-    CD_LOCAL_HEADER_OFFSET_OFFSET: 42,
-    CD_FILE_NAME_OFFSET: 46
+    CD_COMPRESSED_SIZE_OFFSET: 20n,
+    CD_UNCOMPRESSED_SIZE_OFFSET: 24n,
+    CD_FILE_NAME_LENGTH_OFFSET: 28n,
+    CD_EXTRA_FIELD_LENGTH_OFFSET: 30n,
+    CD_LOCAL_HEADER_OFFSET_OFFSET: 42n,
+    CD_FILE_NAME_OFFSET: 46n
   };
 
   const compressedSize = await buffer.getUint32(headerOffset + offsets.CD_COMPRESSED_SIZE_OFFSET);
@@ -49,29 +49,29 @@ export const parseZipCDFileHeader = async (
   const fileName = new TextDecoder().decode(
     await buffer.slice(
       headerOffset + offsets.CD_FILE_NAME_OFFSET,
-      headerOffset + offsets.CD_FILE_NAME_OFFSET + fileNameLength
+      headerOffset + offsets.CD_FILE_NAME_OFFSET + BigInt(fileNameLength)
     )
   );
 
-  const extraOffset = headerOffset + offsets.CD_FILE_NAME_OFFSET + fileNameLength;
+  const extraOffset = headerOffset + offsets.CD_FILE_NAME_OFFSET + BigInt(fileNameLength);
 
   const oldFormatOffset = await buffer.getUint32(
     headerOffset + offsets.CD_LOCAL_HEADER_OFFSET_OFFSET
   );
 
-  let fileDataOffset = oldFormatOffset;
-  if (fileDataOffset === 0xffffffff) {
-    let offsetInZip64Data = 4;
+  let fileDataOffset = BigInt(oldFormatOffset);
+  if (fileDataOffset === BigInt(0xffffffff)) {
+    let offsetInZip64Data = 4n;
     // looking for info that might be also be in zip64 extra field
     if (compressedSize === 0xffffffff) {
-      offsetInZip64Data += 8;
+      offsetInZip64Data += 8n;
     }
     if (uncompressedSize === 0xffffffff) {
-      offsetInZip64Data += 8;
+      offsetInZip64Data += 8n;
     }
 
     // getUint32 needs to be replaced with getBigUint64 for archieves bigger than 2gb
-    fileDataOffset = await buffer.getUint32(extraOffset + offsetInZip64Data); // setting it to the one from zip64
+    fileDataOffset = await buffer.getBigUint64(extraOffset + offsetInZip64Data); // setting it to the one from zip64
   }
   const localHeaderOffset = fileDataOffset;
 
diff --git a/modules/i3s/src/lib/parsers/parse-zip/data-view-file-provider.ts b/modules/i3s/src/lib/parsers/parse-zip/data-view-file-provider.ts
new file mode 100644
index 0000000000..66bc6bda7c
--- /dev/null
+++ b/modules/i3s/src/lib/parsers/parse-zip/data-view-file-provider.ts
@@ -0,0 +1,70 @@
+import {FileProvider} from './file-provider';
+
+const toNumber = (bigint: bigint) => {
+  if (bigint > Number.MAX_SAFE_INTEGER) {
+    throw new Error('Offset is out of bounds');
+  }
+  return Number(bigint);
+};
+
+/**
+ * Provides file data using DataView
+ */
+export class DataViewFileProvider implements FileProvider {
+  /**
+   * The DataView from which data is provided
+   */
+  private file: DataView;
+
+  constructor(file: DataView) {
+    this.file = file;
+  }
+
+  /**
+   * Gets an unsigned 8-bit integer (unsigned byte) at the specified byte offset from the start of the file.
+   * @param offset The offset, in bytes, from the start of the file where to read the data.
+   */
+  getUint8(offset: bigint): Promise<number> {
+    return Promise.resolve(this.file.getUint8(toNumber(offset)));
+  }
+
+  /**
+   * Gets an unsigned 16-bit integer (unsigned byte) at the specified byte offset from the start of the file.
+   * @param offset The offset, in bytes, from the start of the file where to read the data.
+   */
+  getUint16(offset: bigint): Promise<number> {
+    return Promise.resolve(this.file.getUint16(toNumber(offset), true));
+  }
+
+  /**
+   * Gets an unsigned 32-bit integer (unsigned byte) at the specified byte offset from the start of the file.
+   * @param offset The offset, in bytes, from the start of the file where to read the data.
+   */
+  getUint32(offset: bigint): Promise<number> {
+    return Promise.resolve(this.file.getUint32(toNumber(offset), true));
+  }
+
+  /**
+   * Gets an unsigned 64-bit integer at the specified byte offset from the start of the file.
+   * @param offset The offset, in bytes, from the start of the file where to read the data.
+   */
+  getBigUint64(offset: bigint): Promise<bigint> {
+    return Promise.resolve(this.file.getBigUint64(toNumber(offset), true));
+  }
+
+  /**
+   * returns an ArrayBuffer whose contents are a copy of this file bytes from startOffset, inclusive, up to endOffset, exclusive.
+   * @param startOffset The offset, in bytes, from the start of the file where to start reading the data.
+   * @param endOffset The offset, in bytes, from the start of the file where to end reading the data.
+   */
+  slice(startOffset: bigint, endOffset: bigint): Promise<ArrayBuffer> {
+    return Promise.resolve(this.file.buffer.slice(toNumber(startOffset), toNumber(endOffset)));
+  }
+
+  /**
+   * the length (in bytes) of the data.
+   */
+  get length() {
+    return BigInt(this.file.byteLength);
+  }
+}
diff --git a/modules/i3s/src/lib/parsers/parse-zip/file-provider.ts b/modules/i3s/src/lib/parsers/parse-zip/file-provider.ts
index 4d0cebf9c7..656c75ad00 100644
--- a/modules/i3s/src/lib/parsers/parse-zip/file-provider.ts
+++ b/modules/i3s/src/lib/parsers/parse-zip/file-provider.ts
@@ -6,29 +6,35 @@ export interface FileProvider {
    * Gets an unsigned 8-bit integer at the specified byte offset from the start of the file.
    * @param offset The offset, in bytes, from the start of the file where to read the data.
    */
-  getUint8(offset: number): Promise<number>;
+  getUint8(offset: bigint): Promise<number>;
 
   /**
    * Gets an unsigned 16-bit integer at the specified byte offset from the start of the file.
    * @param offset The offset, in bytes, from the start of the file where to read the data.
    */
-  getUint16(offset: number): Promise<number>;
+  getUint16(offset: bigint): Promise<number>;
 
   /**
    * Gets an unsigned 32-bit integer at the specified byte offset from the start of the file.
    * @param offset The offset, in bytes, from the file of the view where to read the data.
    */
-  getUint32(offset: number): Promise<number>;
+  getUint32(offset: bigint): Promise<number>;
+
+  /**
+   * Gets an unsigned 32-bit integer (unsigned byte) at the specified byte offset from the start of the file.
+   * @param offset The offset, in byte, from the file of the view where to read the data.
+   */
+  getBigUint64(offset: bigint): Promise<bigint>;
 
   /**
    * returns an ArrayBuffer whose contents are a copy of this file bytes from startOffset, inclusive, up to endOffset, exclusive.
    * @param startOffset The offset, in bytes, from the start of the file where to start reading the data.
    * @param endOffset The offset, in bytes, from the start of the file where to end reading the data.
    */
-  slice(startOffset: number, endOffset: number): Promise<ArrayBuffer>;
+  slice(startOffset: bigint, endOffset: bigint): Promise<ArrayBuffer>;
 
   /**
    * the length (in bytes) of the data.
    */
-  length: number;
+  length: bigint;
 }
diff --git a/modules/i3s/src/lib/parsers/parse-zip/local-file-header.ts b/modules/i3s/src/lib/parsers/parse-zip/local-file-header.ts
index 8e47b0f8c9..1528a8623f 100644
--- a/modules/i3s/src/lib/parsers/parse-zip/local-file-header.ts
+++ b/modules/i3s/src/lib/parsers/parse-zip/local-file-header.ts
@@ -12,16 +12,16 @@ export type ZipLocalFileHeader = {
   /** Extra field length */
   extraFieldLength: number;
   /** Offset of the file data */
-  fileDataOffset: number;
+  fileDataOffset: bigint;
   /** Compressed size */
-  compressedSize: number;
+  compressedSize: bigint;
 };
 
 const offsets = {
-  COMPRESSED_SIZE_OFFSET: 18,
-  FILE_NAME_LENGTH_OFFSET: 26,
-  EXTRA_FIELD_LENGTH_OFFSET: 28,
-  FILE_NAME_OFFSET: 30
+  COMPRESSED_SIZE_OFFSET: 18n,
+  FILE_NAME_LENGTH_OFFSET: 26n,
+  EXTRA_FIELD_LENGTH_OFFSET: 28n,
+  FILE_NAME_OFFSET: 30n
 };
 
 const signature = Buffer.from([0x50, 0x4b, 0x03, 0x04]);
@@ -33,10 +33,10 @@ const signature = Buffer.from([0x50, 0x4b, 0x03, 0x04]);
  * @returns Info from the header
  */
 export const parseZipLocalFileHeader = async (
-  headerOffset: number,
+  headerOffset: bigint,
   buffer: FileProvider
 ): Promise<ZipLocalFileHeader | undefined> => {
-  if (Buffer.from(await buffer.slice(headerOffset, headerOffset + 4)).compare(signature) !== 0) {
+  if (Buffer.from(await buffer.slice(headerOffset, headerOffset + 4n)).compare(signature) !== 0) {
     return Promise.resolve(undefined);
   }
 
@@ -45,15 +45,17 @@ export const parseZipLocalFileHeader = async (
   const fileName = new TextDecoder().decode(
     await buffer.slice(
       headerOffset + offsets.FILE_NAME_OFFSET,
-      headerOffset + offsets.FILE_NAME_OFFSET + fileNameLength
+      headerOffset + offsets.FILE_NAME_OFFSET + BigInt(fileNameLength)
     )
   );
   const extraFieldLength = await buffer.getUint16(headerOffset + offsets.EXTRA_FIELD_LENGTH_OFFSET);
 
   const fileDataOffset =
-    headerOffset + offsets.FILE_NAME_OFFSET + fileNameLength + extraFieldLength;
+    headerOffset + offsets.FILE_NAME_OFFSET + BigInt(fileNameLength + extraFieldLength);
 
-  const compressedSize = await buffer.getUint32(headerOffset + offsets.COMPRESSED_SIZE_OFFSET);
+  const compressedSize = BigInt(
+    await buffer.getUint32(headerOffset + offsets.COMPRESSED_SIZE_OFFSET)
+  ); // add zip 64 logic
 
   return {
     fileNameLength,
diff --git a/modules/i3s/test/cd-file-header.spec.js b/modules/i3s/test/cd-file-header.spec.js
index dc5921333d..314e4e3f62 100644
--- a/modules/i3s/test/cd-file-header.spec.js
+++ b/modules/i3s/test/cd-file-header.spec.js
@@ -1,11 +1,11 @@
 import test from 'tape-promise/tape';
 import {DATA_ARRAY} from './data/test.zip.js';
 import {parseZipCDFileHeader} from '../src/lib/parsers/parse-zip/cd-file-header.js';
-import {DataViewFileProvider} from '../src/lib/parsers/parse-zip/buffer-file-provider.js';
+import {DataViewFileProvider} from '../src/lib/parsers/parse-zip/data-view-file-provider.js';
 
 test('SLPKLoader#central directory file header parse', async (t) => {
   const cdFileHeader = await parseZipCDFileHeader(
-    78,
+    78n,
     new DataViewFileProvider(new DataView(DATA_ARRAY.buffer))
   );
   t.deepEqual(cdFileHeader.compressedSize, 39);
diff --git a/modules/i3s/test/local-file-header.spec.js b/modules/i3s/test/local-file-header.spec.js
index 1a4c5bba79..2df38d1815 100644
--- a/modules/i3s/test/local-file-header.spec.js
+++ b/modules/i3s/test/local-file-header.spec.js
@@ -1,11 +1,11 @@
 import test from 'tape-promise/tape';
 import {DATA_ARRAY} from './data/test.zip.js';
 import {parseZipLocalFileHeader} from '../src/lib/parsers/parse-zip/local-file-header.js';
-import {DataViewFileProvider} from '../src/lib/parsers/parse-zip/buffer-file-provider.js';
+import {DataViewFileProvider} from '../src/lib/parsers/parse-zip/data-view-file-provider.js';
 
 test('SLPKLoader#local file header parse', async (t) => {
   const localFileHeader = await parseZipLocalFileHeader(
-    0,
+    0n,
     new DataViewFileProvider(new DataView(DATA_ARRAY.buffer))
   );
   t.deepEqual(localFileHeader?.compressedSize, 39);
diff --git a/modules/tile-converter/src/i3s-server/controllers/slpk-controller.js b/modules/tile-converter/src/i3s-server/controllers/slpk-controller.js
index 590574dd29..6b2e9317da 100644
--- a/modules/tile-converter/src/i3s-server/controllers/slpk-controller.js
+++ b/modules/tile-converter/src/i3s-server/controllers/slpk-controller.js
@@ -1,12 +1,12 @@
 require('@loaders.gl/polyfills');
-const {fetchFile, parse} = require('@loaders.gl/core');
-const {SLPKLoader} = require('@loaders.gl/i3s');
+const {parseSLPK} = require('@loaders.gl/i3s');
 const path = require('path');
+const {FileHandleProvider} = require('@loaders.gl/tile-converter');
 
 let slpkArchive;
 
 const loadArchive = async (fullLayerPath) => {
-  slpkArchive = await (await fetchFile(fullLayerPath)).arrayBuffer();
+  slpkArchive = await parseSLPK(await FileHandleProvider.from(fullLayerPath));
 };
 
 const I3S_LAYER_PATH = process.env.I3sLayerPath || ''; // eslint-disable-line no-process-env, no-undef
@@ -19,14 +19,7 @@ async function getFileByUrl(url) {
   let uncompressedFile;
   if (trimmedPath) {
     try {
-      uncompressedFile = Buffer.from(
-        await parse(slpkArchive, SLPKLoader, {
-          slpk: {
-            path: trimmedPath[1],
-            pathMode: 'http'
-          }
-        })
-      );
+      uncompressedFile = Buffer.from(await slpkArchive.getFile(trimmedPath[1], 'http'));
     } catch (e) {}
   }
   return uncompressedFile;
diff --git a/modules/tile-converter/src/index.ts b/modules/tile-converter/src/index.ts
index c2b412ee13..3deecad0e4 100644
--- a/modules/tile-converter/src/index.ts
+++ b/modules/tile-converter/src/index.ts
@@ -1,2 +1,3 @@
 export {default as I3SConverter} from './i3s-converter/i3s-converter';
 export {default as Tiles3DConverter} from './3d-tiles-converter/3d-tiles-converter';
+export {FileHandleProvider} from './slpk-extractor/helpers/file-handle-provider';
diff --git a/modules/tile-converter/src/slpk-extractor/helpers/file-handle-provider.ts b/modules/tile-converter/src/slpk-extractor/helpers/file-handle-provider.ts
index 777a7ef942..201384d8a3 100644
--- a/modules/tile-converter/src/slpk-extractor/helpers/file-handle-provider.ts
+++ b/modules/tile-converter/src/slpk-extractor/helpers/file-handle-provider.ts
@@ -1,5 +1,5 @@
 import {FileProvider} from '@loaders.gl/i3s';
-import {promises as fsPromises, PathLike} from 'fs';
+import {FileHandle} from './fs-promises';
 
 /**
  * Provides file data using node fs library
@@ -9,22 +9,22 @@ export class FileHandleProvider implements FileProvider {
    * Returns a new copy of FileHandleProvider
    * @param path The path to the file in file system
    */
-  static async from(path: PathLike): Promise<FileHandleProvider> {
-    const fileDescriptor = await fsPromises.open(path);
-    return new FileHandleProvider(fileDescriptor, (await fileDescriptor.stat()).size);
+  static async from(path: string): Promise<FileHandleProvider> {
+    const fileDescriptor = await FileHandle.open(path);
+    return new FileHandleProvider(fileDescriptor, fileDescriptor.stat.size);
   }
 
   /**
    * The FileHandle from which data is provided
    */
-  private fileDescriptor: fsPromises.FileHandle;
+  private fileDescriptor: FileHandle;
 
   /**
    * The file length in bytes
    */
-  private size: number;
+  private size: bigint;
 
-  private constructor(fileDescriptor: fsPromises.FileHandle, size: number) {
+  private constructor(fileDescriptor: FileHandle, size: bigint) {
     this.fileDescriptor = fileDescriptor;
     this.size = size;
   }
@@ -33,7 +33,7 @@ export class FileHandleProvider implements FileProvider {
    * Gets an unsigned 8-bit integer (unsigned byte) at the specified byte offset from the start of the file.
    * @param offset The offset, in bytes, from the start of the file where to read the data.
    */
-  async getUint8(offset: number): Promise<number> {
+  async getUint8(offset: bigint): Promise<number> {
     const val = new Uint8Array(
       (await this.fileDescriptor.read(Buffer.alloc(1), 0, 1, offset)).buffer.buffer
     ).at(0);
@@ -47,7 +47,7 @@ export class FileHandleProvider implements FileProvider {
    * Gets an unsigned 16-bit integer (unsigned byte) at the specified byte offset from the start of the file.
    * @param offset The offset, in bytes, from the start of the file where to read the data.
    */
-  async getUint16(offset: number): Promise<number> {
+  async getUint16(offset: bigint): Promise<number> {
     const val = new Uint16Array(
       (await this.fileDescriptor.read(Buffer.alloc(2), 0, 2, offset)).buffer.buffer
     ).at(0);
@@ -61,7 +61,7 @@ export class FileHandleProvider implements FileProvider {
    * Gets an unsigned 32-bit integer (unsigned byte) at the specified byte offset from the start of the file.
    * @param offset The offset, in bytes, from the start of the file where to read the data.
    */
-  async getUint32(offset: number): Promise<number> {
+  async getUint32(offset: bigint): Promise<number> {
     const val = new Uint32Array(
       (await this.fileDescriptor.read(Buffer.alloc(4), 0, 4, offset)).buffer.buffer
     ).at(0);
@@ -71,21 +71,39 @@ export class FileHandleProvider implements FileProvider {
     return val;
   }
 
+  /**
+   * Gets an unsigned 32-bit integer (unsigned byte) at the specified byte offset from the start of the file.
+   * @param offset The offset, in bytes, from the start of the file where to read the data.
+   */
+  async getBigUint64(offset: bigint): Promise<bigint> {
+    const val = new BigInt64Array(
+      (await this.fileDescriptor.read(Buffer.alloc(8), 0, 4, offset)).buffer.buffer
+    ).at(0);
+    if (val === undefined) {
+      throw new Error('something went wrong');
+    }
+    return val;
+  }
+
   /**
    * returns an ArrayBuffer whose contents are a copy of this file bytes from startOffset, inclusive, up to endOffset, exclusive.
-   * @param startOffset The offset, in bytes, from the start of the file where to start reading the data.
+   * @param startOffsset The offset, in byte, from the start of the file where to start reading the data.
    * @param endOffset The offset, in bytes, from the start of the file where to end reading the data.
    */
-  async slice(startOffset: number, endOffset: number): Promise<ArrayBuffer> {
-    const length = endOffset - startOffset;
-    return (await this.fileDescriptor.read(Buffer.alloc(length), 0, length, startOffset)).buffer
+  async slice(startOffsset: bigint, endOffset: bigint): Promise<ArrayBuffer> {
+    const bigLength = endOffset - startOffsset;
+    if (bigLength > Number.MAX_SAFE_INTEGER) {
+      throw new Error('too big slice');
+    }
+    const length = Number(bigLength);
+    return (await this.fileDescriptor.read(Buffer.alloc(length), 0, length, startOffsset)).buffer
       .buffer;
   }
 
   /**
    * the length (in bytes) of the data.
    */
-  get length(): number {
+  get length(): bigint {
     return this.size;
   }
 }
diff --git a/modules/tile-converter/src/slpk-extractor/helpers/fs-promises.ts b/modules/tile-converter/src/slpk-extractor/helpers/fs-promises.ts
new file mode 100644
index 0000000000..d2e53fd865
--- /dev/null
+++ b/modules/tile-converter/src/slpk-extractor/helpers/fs-promises.ts
@@ -0,0 +1,44 @@
+import {read, open, stat, BigIntStats} from 'fs';
+
+export type FileReadResult = {
+  bytesRead: number;
+  buffer: Buffer;
+};
+
+export class FileHandle {
+  private fileDescriptor: number;
+  private stats: BigIntStats;
+  private constructor(fileDescriptor: number, stats: BigIntStats) {
+    this.fileDescriptor = fileDescriptor;
+    this.stats = stats;
+  }
+
+  static open = async (path: string): Promise<FileHandle> => {
+    const [fd, stats] = await Promise.all([
+      new Promise<number>((s) => {
+        open(path, undefined, undefined, (_err, fd) => s(fd));
+      }),
+      new Promise<BigIntStats>((s) => {
+        stat(path, {bigint: true}, (_err, stats) => s(stats));
+      })
+    ]);
+    return new FileHandle(fd, stats);
+  };
+
+  read = (
+    buffer: Buffer,
+    offset: number,
+    length: number,
+    position: number | bigint
+  ): Promise<FileReadResult> => {
+    return new Promise((s) => {
+      read(this.fileDescriptor, buffer, offset, length, position, (_err, bytesRead, buffer) =>
+        s({bytesRead, buffer})
+      );
+    });
+  };
+
+  get stat(): BigIntStats {
+    return this.stats;
+  }
+}
diff --git a/modules/tile-converter/src/slpk-extractor/slpk-extractor.ts b/modules/tile-converter/src/slpk-extractor/slpk-extractor.ts
index 897a3a48bb..6266585862 100644
--- a/modules/tile-converter/src/slpk-extractor/slpk-extractor.ts
+++ b/modules/tile-converter/src/slpk-extractor/slpk-extractor.ts
@@ -3,13 +3,11 @@ import {isBrowser} from '@loaders.gl/core';
 import {BROWSER_ERROR_MESSAGE} from '../constants';
 import {FileHandleProvider} from './helpers/file-handle-provider';
 import {parseZipLocalFileHeader} from '@loaders.gl/i3s';
+import {promises as fsPromises, existsSync} from 'fs';
 import {path} from '@loaders.gl/loader-utils';
 import {GZipCompression} from '@loaders.gl/compression';
-import {writeFile} from '../lib/utils/file-utils';
+// import { writeFile } from '../lib/utils/file-utils';
 
-/**
- * names of files that should be changed to index
- */
 const indexNames = [
   '3dSceneLayer.json.gz',
   '3dNodeIndexDocument.json.gz',
@@ -27,9 +25,9 @@ type File = {
 /**
  * Converter from slpk to i3s
  */
-export default class SLPKExtractor {
+export default class SLPKConverter {
   /**
-   * extract slpk to i3s
+   * Convert slpk to i3s
    * @param options
    * @param options.inputUrl the url to read SLPK file
    * @param options.outputPath the output filename
@@ -43,7 +41,7 @@ export default class SLPKExtractor {
 
     const provider = await FileHandleProvider.from(inputUrl);
 
-    let localHeader = await parseZipLocalFileHeader(0, provider);
+    let localHeader = await parseZipLocalFileHeader(0n, provider);
     while (localHeader) {
       await this.writeFile(
         await this.unGzip({
@@ -68,6 +66,7 @@ export default class SLPKExtractor {
    * Defines file name and path for i3s format
    * @param fileName initial file name and path
    */
+
   private correctIndexNames(fileName: string): string | null {
     if (indexNames.includes(path.filename(path.join('/', fileName)))) {
       return path.join(path.dirname(fileName), 'index.json.gz');
@@ -85,6 +84,7 @@ export default class SLPKExtractor {
       const compression = new GZipCompression();
 
       const decompressedData = await compression.decompress(file.data);
+
       return {data: decompressedData, name: (file.name ?? '').slice(0, -3)};
     }
     return Promise.resolve(file);
@@ -96,7 +96,9 @@ export default class SLPKExtractor {
     }
     const finalPath = path.join(outputPath, options.name);
     const dirName = path.dirname(finalPath);
-    const fileName = path.filename(finalPath);
-    await writeFile(dirName, options.data, fileName);
+    if (!existsSync(dirName)) {
+      await fsPromises.mkdir(dirName, {recursive: true});
+    }
+    await fsPromises.writeFile(finalPath, Buffer.from(options.data));
   }
 }

From 3337ae2a69b864785b7bce27292a1bf65e917c1b Mon Sep 17 00:00:00 2001
From: Daria Terekhova <daria.terekhova@actionengine.com>
Date: Wed, 12 Jul 2023 14:23:42 +0300
Subject: [PATCH 3/6] ZIP64 support added

---
 .../lib/parsers/parse-zip/cd-file-header.ts   | 32 ++++++++--------
 .../parsers/parse-zip/local-file-header.ts    | 38 +++++++++++++++----
 modules/tile-converter/src/i3s-server/app.js  |  2 +-
 .../src/slpk-extractor/slpk-extractor.ts      |  9 ++---
 4 files changed, 52 insertions(+), 29 deletions(-)

diff --git a/modules/i3s/src/lib/parsers/parse-zip/cd-file-header.ts b/modules/i3s/src/lib/parsers/parse-zip/cd-file-header.ts
index 8e7e1a0fc2..b5febad67a 100644
--- a/modules/i3s/src/lib/parsers/parse-zip/cd-file-header.ts
+++ b/modules/i3s/src/lib/parsers/parse-zip/cd-file-header.ts
@@ -6,9 +6,9 @@ import {FileProvider} from './file-provider';
  */
 export type ZipCDFileHeader = {
   /** Compressed size */
-  compressedSize: number;
+  compressedSize: bigint;
   /** Uncompressed size */
-  uncompressedSize: number;
+  uncompressedSize: bigint;
   /** File name length */
   fileNameLength: number;
   /** File name */
@@ -38,10 +38,12 @@ export const parseZipCDFileHeader = async (
     CD_FILE_NAME_OFFSET: 46n
   };
 
-  const compressedSize = await buffer.getUint32(headerOffset + offsets.CD_COMPRESSED_SIZE_OFFSET);
+  let compressedSize = BigInt(
+    await buffer.getUint32(headerOffset + offsets.CD_COMPRESSED_SIZE_OFFSET)
+  );
 
-  const uncompressedSize = await buffer.getUint32(
-    headerOffset + offsets.CD_UNCOMPRESSED_SIZE_OFFSET
+  let uncompressedSize = BigInt(
+    await buffer.getUint32(headerOffset + offsets.CD_UNCOMPRESSED_SIZE_OFFSET)
   );
 
   const fileNameLength = await buffer.getUint16(headerOffset + offsets.CD_FILE_NAME_LENGTH_OFFSET);
@@ -60,17 +62,17 @@ export const parseZipCDFileHeader = async (
   );
 
   let fileDataOffset = BigInt(oldFormatOffset);
+  let offsetInZip64Data = 4n;
+  // looking for info that might be also be in zip64 extra field
+  if (uncompressedSize === BigInt(0xffffffff)) {
+    uncompressedSize = await buffer.getBigUint64(extraOffset + offsetInZip64Data);
+    offsetInZip64Data += 8n;
+  }
+  if (compressedSize === BigInt(0xffffffff)) {
+    compressedSize = await buffer.getBigUint64(extraOffset + offsetInZip64Data);
+    offsetInZip64Data += 8n;
+  }
   if (fileDataOffset === BigInt(0xffffffff)) {
-    let offsetInZip64Data = 4n;
-    // looking for info that might be also be in zip64 extra field
-    if (compressedSize === 0xffffffff) {
-      offsetInZip64Data += 8n;
-    }
-    if (uncompressedSize === 0xffffffff) {
-      offsetInZip64Data += 8n;
-    }
-
-    // getUint32 needs to be replaced with getBigUint64 for archieves bigger than 2gb
     fileDataOffset = await buffer.getBigUint64(extraOffset + offsetInZip64Data); // setting it to the one from zip64
   }
   const localHeaderOffset = fileDataOffset;
diff --git a/modules/i3s/src/lib/parsers/parse-zip/local-file-header.ts b/modules/i3s/src/lib/parsers/parse-zip/local-file-header.ts
index 1528a8623f..c25bede77e 100644
--- a/modules/i3s/src/lib/parsers/parse-zip/local-file-header.ts
+++ b/modules/i3s/src/lib/parsers/parse-zip/local-file-header.ts
@@ -19,6 +19,7 @@ export type ZipLocalFileHeader = {
 
 const offsets = {
   COMPRESSED_SIZE_OFFSET: 18n,
+  UNCOMPRESSED_SIZE_OFFSET: 22n,
   FILE_NAME_LENGTH_OFFSET: 26n,
   EXTRA_FIELD_LENGTH_OFFSET: 28n,
   FILE_NAME_OFFSET: 30n
@@ -42,21 +43,44 @@ export const parseZipLocalFileHeader = async (
 
   const fileNameLength = await buffer.getUint16(headerOffset + offsets.FILE_NAME_LENGTH_OFFSET);
 
-  const fileName = new TextDecoder().decode(
-    await buffer.slice(
-      headerOffset + offsets.FILE_NAME_OFFSET,
-      headerOffset + offsets.FILE_NAME_OFFSET + BigInt(fileNameLength)
+  const fileName = new TextDecoder()
+    .decode(
+      await buffer.slice(
+        headerOffset + offsets.FILE_NAME_OFFSET,
+        headerOffset + offsets.FILE_NAME_OFFSET + BigInt(fileNameLength)
+      )
     )
-  );
+    .split('\\')
+    .join('/');
   const extraFieldLength = await buffer.getUint16(headerOffset + offsets.EXTRA_FIELD_LENGTH_OFFSET);
 
-  const fileDataOffset =
+  let fileDataOffset =
     headerOffset + offsets.FILE_NAME_OFFSET + BigInt(fileNameLength + extraFieldLength);
 
-  const compressedSize = BigInt(
+  let compressedSize = BigInt(
     await buffer.getUint32(headerOffset + offsets.COMPRESSED_SIZE_OFFSET)
   ); // add zip 64 logic
 
+  let uncompressedSize = BigInt(
+    await buffer.getUint32(headerOffset + offsets.UNCOMPRESSED_SIZE_OFFSET)
+  ); // add zip 64 logic
+
+  const extraOffset = headerOffset + offsets.FILE_NAME_OFFSET + BigInt(fileNameLength);
+
+  let offsetInZip64Data = 4n;
+  // looking for info that might be also be in zip64 extra field
+  if (uncompressedSize === BigInt(0xffffffff)) {
+    uncompressedSize = await buffer.getBigUint64(extraOffset + offsetInZip64Data);
+    offsetInZip64Data += 8n;
+  }
+  if (compressedSize === BigInt(0xffffffff)) {
+    compressedSize = await buffer.getBigUint64(extraOffset + offsetInZip64Data);
+    offsetInZip64Data += 8n;
+  }
+  if (fileDataOffset === BigInt(0xffffffff)) {
+    fileDataOffset = await buffer.getBigUint64(extraOffset + offsetInZip64Data); // setting it to the one from zip64
+  }
+
   return {
     fileNameLength,
     fileName,
diff --git a/modules/tile-converter/src/i3s-server/app.js b/modules/tile-converter/src/i3s-server/app.js
index aa65065d01..8ae6c97691 100644
--- a/modules/tile-converter/src/i3s-server/app.js
+++ b/modules/tile-converter/src/i3s-server/app.js
@@ -4,7 +4,6 @@ const logger = require('morgan');
 const cors = require('cors');
 
 const indexRouter = require('./routes/index');
-const {sceneServerRouter, router} = require('./routes/slpk-router');
 
 const I3S_LAYER_PATH = process.env.I3sLayerPath || ''; // eslint-disable-line no-process-env, no-undef
 const app = express();
@@ -16,6 +15,7 @@ app.use(express.static(path.join(__dirname, 'public')));
 app.use(cors());
 
 if (/\.slpk$/.test(I3S_LAYER_PATH)) {
+  const {sceneServerRouter, router} = require('./routes/slpk-router');
   app.use('/SceneServer/layers/0', router);
   app.use('/SceneServer', sceneServerRouter);
 } else {
diff --git a/modules/tile-converter/src/slpk-extractor/slpk-extractor.ts b/modules/tile-converter/src/slpk-extractor/slpk-extractor.ts
index 6266585862..46dcca5ffb 100644
--- a/modules/tile-converter/src/slpk-extractor/slpk-extractor.ts
+++ b/modules/tile-converter/src/slpk-extractor/slpk-extractor.ts
@@ -3,10 +3,9 @@ import {isBrowser} from '@loaders.gl/core';
 import {BROWSER_ERROR_MESSAGE} from '../constants';
 import {FileHandleProvider} from './helpers/file-handle-provider';
 import {parseZipLocalFileHeader} from '@loaders.gl/i3s';
-import {promises as fsPromises, existsSync} from 'fs';
 import {path} from '@loaders.gl/loader-utils';
 import {GZipCompression} from '@loaders.gl/compression';
-// import { writeFile } from '../lib/utils/file-utils';
+import {writeFile} from '../lib/utils/file-utils';
 
 const indexNames = [
   '3dSceneLayer.json.gz',
@@ -96,9 +95,7 @@ export default class SLPKConverter {
     }
     const finalPath = path.join(outputPath, options.name);
     const dirName = path.dirname(finalPath);
-    if (!existsSync(dirName)) {
-      await fsPromises.mkdir(dirName, {recursive: true});
-    }
-    await fsPromises.writeFile(finalPath, Buffer.from(options.data));
+    const fileName = path.filename(finalPath);
+    await writeFile(dirName, options.data, fileName);
   }
 }

From 2ca05a49cd8205385cef3b30321d31c6ea57b92e Mon Sep 17 00:00:00 2001
From: Daria Terekhova <daria.terekhova@actionengine.com>
Date: Tue, 18 Jul 2023 22:19:13 +0300
Subject: [PATCH 4/6] Docs and tests added

---
 modules/i3s/src/i3s-slpk-loader.ts            | 24 +++++++---
 .../src/lib/parsers/parse-slpk/parse-slpk.ts  |  9 +++-
 .../parsers/parse-slpk/search-from-the-end.ts | 12 ++++-
 .../parse-zip/data-view-file-provider.ts      | 43 +++++++++--------
 .../lib/parsers/parse-zip/file-provider.ts    |  2 +-
 .../parsers/parse-zip/local-file-header.ts    |  2 +-
 .../src/lib/parsers/parse-zip/signature.ts    |  2 +
 modules/i3s/test/index.js                     |  4 ++
 modules/i3s/test/search-from-the-end.spec.js  | 15 ++++++
 .../{ => zip-utils}/cd-file-header.spec.js    | 10 ++--
 .../test/zip-utils/data-view-provider.spec.js | 34 ++++++++++++++
 .../{ => zip-utils}/local-file-header.spec.js |  8 ++--
 .../helpers/file-handle-provider.ts           |  8 ++--
 .../src/slpk-extractor/helpers/fs-promises.ts | 22 +++++++++
 .../src/slpk-extractor/slpk-extractor.ts      |  2 +-
 modules/tile-converter/test/index.js          |  2 +
 .../file-handle-provider.spec.js              | 47 +++++++++++++++++++
 .../test/slpk-extractor/file-handle.spec.js   | 20 ++++++++
 18 files changed, 219 insertions(+), 47 deletions(-)
 create mode 100644 modules/i3s/src/lib/parsers/parse-zip/signature.ts
 create mode 100644 modules/i3s/test/search-from-the-end.spec.js
 rename modules/i3s/test/{ => zip-utils}/cd-file-header.spec.js (51%)
 create mode 100644 modules/i3s/test/zip-utils/data-view-provider.spec.js
 rename modules/i3s/test/{ => zip-utils}/local-file-header.spec.js (50%)
 create mode 100644 modules/tile-converter/test/slpk-extractor/file-handle-provider.spec.js
 create mode 100644 modules/tile-converter/test/slpk-extractor/file-handle.spec.js

diff --git a/modules/i3s/src/i3s-slpk-loader.ts b/modules/i3s/src/i3s-slpk-loader.ts
index fe5fbfd62a..e2bdf39865 100644
--- a/modules/i3s/src/i3s-slpk-loader.ts
+++ b/modules/i3s/src/i3s-slpk-loader.ts
@@ -6,20 +6,16 @@ import {DataViewFileProvider} from './lib/parsers/parse-zip/data-view-file-provi
 // @ts-ignore TS2304: Cannot find name '__VERSION__'.
 const VERSION = typeof __VERSION__ !== 'undefined' ? __VERSION__ : 'latest';
 
+/** options to load data from SLPK */
 export type SLPKLoaderOptions = LoaderOptions & {
   slpk?: {
+    /** path inside the slpk archive */
     path?: string;
+    /** mode of the path */
     pathMode?: 'http' | 'raw';
   };
 };
 
-async function parseSLPK(data: ArrayBuffer, options: SLPKLoaderOptions = {}) {
-  return (await parseSLPKFromProvider(new DataViewFileProvider(new DataView(data)))).getFile(
-    options.slpk?.path ?? '',
-    options.slpk?.pathMode
-  );
-}
-
 /**
  * Loader for SLPK - Scene Layer Package
  */
@@ -33,3 +29,17 @@ export const SLPKLoader: LoaderWithParser<Buffer, never, SLPKLoaderOptions> = {
   extensions: ['slpk'],
   options: {}
 };
+
+/**
+ * returns a single file from the slpk archive
+ * @param data slpk archive data
+ * @param options options
+ * @returns requested file
+ */
+
+async function parseSLPK(data: ArrayBuffer, options: SLPKLoaderOptions = {}) {
+  return (await parseSLPKFromProvider(new DataViewFileProvider(new DataView(data)))).getFile(
+    options.slpk?.path ?? '',
+    options.slpk?.pathMode
+  );
+}
diff --git a/modules/i3s/src/lib/parsers/parse-slpk/parse-slpk.ts b/modules/i3s/src/lib/parsers/parse-slpk/parse-slpk.ts
index 4a9ac8d8c6..c36ddcb507 100644
--- a/modules/i3s/src/lib/parsers/parse-slpk/parse-slpk.ts
+++ b/modules/i3s/src/lib/parsers/parse-slpk/parse-slpk.ts
@@ -1,11 +1,18 @@
 import {parseZipCDFileHeader} from '../parse-zip/cd-file-header';
 import {FileProvider} from '../parse-zip/file-provider';
 import {parseZipLocalFileHeader} from '../parse-zip/local-file-header';
+import {ZipSignature} from '../parse-zip/signature';
 import {searchFromTheEnd} from './search-from-the-end';
 import {SLPKArchive} from './slpk-archieve';
 
+/**
+ * Creates slpk file handler from raw file
+ * @param fileProvider raw file data
+ * @returns slpk file handler
+ */
+
 export const parseSLPK = async (fileProvider: FileProvider): Promise<SLPKArchive> => {
-  const cdFileHeaderSignature = [80, 75, 1, 2];
+  const cdFileHeaderSignature: ZipSignature = [0x50, 0x4b, 0x01, 0x02];
 
   const hashCDOffset = await searchFromTheEnd(fileProvider, cdFileHeaderSignature);
 
diff --git a/modules/i3s/src/lib/parsers/parse-slpk/search-from-the-end.ts b/modules/i3s/src/lib/parsers/parse-slpk/search-from-the-end.ts
index 7996a4a16d..b370cdb51b 100644
--- a/modules/i3s/src/lib/parsers/parse-slpk/search-from-the-end.ts
+++ b/modules/i3s/src/lib/parsers/parse-slpk/search-from-the-end.ts
@@ -1,6 +1,16 @@
 import {FileProvider} from 'modules/i3s/src/lib/parsers/parse-zip/file-provider';
+import {ZipSignature} from '../parse-zip/signature';
 
-export const searchFromTheEnd = async (file: FileProvider, target: number[]): Promise<bigint> => {
+/**
+ * looking for the last occurrence of the provided
+ * @param file
+ * @param target
+ * @returns
+ */
+export const searchFromTheEnd = async (
+  file: FileProvider,
+  target: ZipSignature
+): Promise<bigint> => {
   const searchWindow = [
     await file.getUint8(file.length - 1n),
     await file.getUint8(file.length - 2n),
diff --git a/modules/i3s/src/lib/parsers/parse-zip/data-view-file-provider.ts b/modules/i3s/src/lib/parsers/parse-zip/data-view-file-provider.ts
index 66bc6bda7c..c0a18508f1 100644
--- a/modules/i3s/src/lib/parsers/parse-zip/data-view-file-provider.ts
+++ b/modules/i3s/src/lib/parsers/parse-zip/data-view-file-provider.ts
@@ -1,5 +1,10 @@
 import {FileProvider} from './file-provider';
 
+/**
+ * Checks if bigint can be converted to number and convert it if possible
+ * @param bigint bigint to be converted
+ * @returns number
+ */
 const toNumber = (bigint: bigint) => {
   if (bigint > Number.MAX_SAFE_INTEGER) {
     throw new Error('Offset is out of bounds');
@@ -7,13 +12,9 @@ const toNumber = (bigint: bigint) => {
   return Number(bigint);
 };
 
-/**
- * Provides file data using DataView
- */
+/** Provides file data using DataView */
 export class DataViewFileProvider implements FileProvider {
-  /**
-   * The DataView from which data is provided
-   */
+  /** The DataView from which data is provided */
   private file: DataView;
 
   constructor(file: DataView) {
@@ -21,35 +22,35 @@ export class DataViewFileProvider implements FileProvider {
   }
 
   /**
-   * Gets an unsigned 8-bit integer (unsigned byte) at the specified byte offset from the start of the file.
+   * Gets an unsigned 8-bit integer at the specified byte offset from the start of the file.
    * @param offset The offset, in bytes, from the start of the file where to read the data.
    */
-  getUint8(offset: bigint): Promise<number> {
-    return Promise.resolve(this.file.getUint8(toNumber(offset)));
+  async getUint8(offset: bigint): Promise<number> {
+    return this.file.getUint8(toNumber(offset));
   }
 
   /**
-   * Gets an unsigned 16-bit integer (unsigned byte) at the specified byte offset from the start of the file.
+   * Gets an unsigned 16-bit intege at the specified byte offset from the start of the file.
    * @param offset The offset, in bytes, from the start of the file where to read the data.
    */
-  getUint16(offset: bigint): Promise<number> {
-    return Promise.resolve(this.file.getUint16(toNumber(offset), true));
+  async getUint16(offset: bigint): Promise<number> {
+    return this.file.getUint16(toNumber(offset), true);
   }
 
   /**
-   * Gets an unsigned 32-bit integer (unsigned byte) at the specified byte offset from the start of the file.
+   * Gets an unsigned 32-bit integer at the specified byte offset from the start of the file.
    * @param offset The offset, in bytes, from the start of the file where to read the data.
    */
-  getUint32(offset: bigint): Promise<number> {
-    return Promise.resolve(this.file.getUint32(toNumber(offset), true));
+  async getUint32(offset: bigint): Promise<number> {
+    return this.file.getUint32(toNumber(offset), true);
   }
 
   /**
    * Gets an unsigned 64-bit integer at the specified byte offset from the start of the file.
    * @param offset The offset, in bytes, from the start of the file where to read the data.
    */
-  getBigUint64(offset: bigint): Promise<bigint> {
-    return Promise.resolve(this.file.getBigUint64(toNumber(offset), true));
+  async getBigUint64(offset: bigint): Promise<bigint> {
+    return this.file.getBigUint64(toNumber(offset), true);
   }
 
   /**
@@ -57,13 +58,11 @@ export class DataViewFileProvider implements FileProvider {
    * @param startOffset The offset, in bytes, from the start of the file where to start reading the data.
    * @param endOffset The offset, in bytes, from the start of the file where to end reading the data.
    */
-  slice(startOffset: bigint, endOffset: bigint): Promise<ArrayBuffer> {
-    return Promise.resolve(this.file.buffer.slice(toNumber(startOffset), toNumber(endOffset)));
+  async slice(startOffset: bigint, endOffset: bigint): Promise<ArrayBuffer> {
+    return this.file.buffer.slice(toNumber(startOffset), toNumber(endOffset));
   }
 
-  /**
-   * the length (in bytes) of the data.
-   */
+  /** the length (in bytes) of the data. */
   get length() {
     return BigInt(this.file.byteLength);
   }
diff --git a/modules/i3s/src/lib/parsers/parse-zip/file-provider.ts b/modules/i3s/src/lib/parsers/parse-zip/file-provider.ts
index 656c75ad00..5f5d2e0455 100644
--- a/modules/i3s/src/lib/parsers/parse-zip/file-provider.ts
+++ b/modules/i3s/src/lib/parsers/parse-zip/file-provider.ts
@@ -21,7 +21,7 @@ export interface FileProvider {
   getUint32(offset: bigint): Promise<number>;
 
   /**
-   * Gets an unsigned 32-bit integer (unsigned byte) at the specified byte offset from the start of the file.
+   * Gets an unsigned 32-bit integer at the specified byte offset from the start of the file.
    * @param offset The offset, in byte, from the file of the view where to read the data.
    */
   getBigUint64(offset: bigint): Promise<bigint>;
diff --git a/modules/i3s/src/lib/parsers/parse-zip/local-file-header.ts b/modules/i3s/src/lib/parsers/parse-zip/local-file-header.ts
index c25bede77e..9b3833d1e6 100644
--- a/modules/i3s/src/lib/parsers/parse-zip/local-file-header.ts
+++ b/modules/i3s/src/lib/parsers/parse-zip/local-file-header.ts
@@ -25,7 +25,7 @@ const offsets = {
   FILE_NAME_OFFSET: 30n
 };
 
-const signature = Buffer.from([0x50, 0x4b, 0x03, 0x04]);
+export const signature = Buffer.from([0x50, 0x4b, 0x03, 0x04]);
 
 /**
  * Parses local file header of zip file
diff --git a/modules/i3s/src/lib/parsers/parse-zip/signature.ts b/modules/i3s/src/lib/parsers/parse-zip/signature.ts
new file mode 100644
index 0000000000..60b6c486b8
--- /dev/null
+++ b/modules/i3s/src/lib/parsers/parse-zip/signature.ts
@@ -0,0 +1,2 @@
+/** Description of zip signature type */
+export type ZipSignature = [number, number, number, number];
diff --git a/modules/i3s/test/index.js b/modules/i3s/test/index.js
index 04a0e240b1..eec73ed793 100644
--- a/modules/i3s/test/index.js
+++ b/modules/i3s/test/index.js
@@ -8,3 +8,7 @@ import './i3s-attribute-loader.spec';
 import './i3s-content-loader.spec';
 import './i3s-building-scene-layer-loader.spec';
 import './arcgis-webscene-loader.spec';
+import './zip-utils/data-view-provider.spec';
+import './zip-utils/cd-file-header.spec';
+import './zip-utils/local-file-header.spec';
+import './search-from-the-end.spec';
diff --git a/modules/i3s/test/search-from-the-end.spec.js b/modules/i3s/test/search-from-the-end.spec.js
new file mode 100644
index 0000000000..20e886d95d
--- /dev/null
+++ b/modules/i3s/test/search-from-the-end.spec.js
@@ -0,0 +1,15 @@
+import test from 'tape-promise/tape';
+import {DATA_ARRAY} from './data/test.zip.js';
+import {searchFromTheEnd} from '../src/lib/parsers/parse-slpk/search-from-the-end';
+import {DataViewFileProvider} from '../src/lib/parsers/parse-zip/data-view-file-provider';
+
+test('SLPKLoader#searchFromTheEnd', async (t) => {
+  t.equals(
+    await searchFromTheEnd(
+      new DataViewFileProvider(new DataView(DATA_ARRAY.buffer)),
+      [0x50, 0x4b, 0x03, 0x04]
+    ),
+    0n
+  );
+  t.end();
+});
diff --git a/modules/i3s/test/cd-file-header.spec.js b/modules/i3s/test/zip-utils/cd-file-header.spec.js
similarity index 51%
rename from modules/i3s/test/cd-file-header.spec.js
rename to modules/i3s/test/zip-utils/cd-file-header.spec.js
index 314e4e3f62..c06945164a 100644
--- a/modules/i3s/test/cd-file-header.spec.js
+++ b/modules/i3s/test/zip-utils/cd-file-header.spec.js
@@ -1,16 +1,16 @@
 import test from 'tape-promise/tape';
-import {DATA_ARRAY} from './data/test.zip.js';
-import {parseZipCDFileHeader} from '../src/lib/parsers/parse-zip/cd-file-header.js';
-import {DataViewFileProvider} from '../src/lib/parsers/parse-zip/data-view-file-provider.js';
+import {DATA_ARRAY} from '../data/test.zip.js';
+import {parseZipCDFileHeader} from '../../src/lib/parsers/parse-zip/cd-file-header';
+import {DataViewFileProvider} from '../../src/lib/parsers/parse-zip/data-view-file-provider';
 
 test('SLPKLoader#central directory file header parse', async (t) => {
   const cdFileHeader = await parseZipCDFileHeader(
     78n,
     new DataViewFileProvider(new DataView(DATA_ARRAY.buffer))
   );
-  t.deepEqual(cdFileHeader.compressedSize, 39);
+  t.deepEqual(cdFileHeader.compressedSize, 39n);
   t.deepEqual(cdFileHeader.fileNameLength, 9);
   t.deepEqual(cdFileHeader.fileName, 'test.json');
-  t.deepEqual(cdFileHeader.localHeaderOffset, 0);
+  t.deepEqual(cdFileHeader.localHeaderOffset, 0n);
   t.end();
 });
diff --git a/modules/i3s/test/zip-utils/data-view-provider.spec.js b/modules/i3s/test/zip-utils/data-view-provider.spec.js
new file mode 100644
index 0000000000..8739a5b094
--- /dev/null
+++ b/modules/i3s/test/zip-utils/data-view-provider.spec.js
@@ -0,0 +1,34 @@
+import test from 'tape-promise/tape';
+import {DATA_ARRAY} from '../data/test.zip.js';
+import {DataViewFileProvider} from '../../src/lib/parsers/parse-zip/data-view-file-provider';
+import {signature} from '../../src/lib/parsers/parse-zip/local-file-header';
+
+test('DataViewFileProvider#slice', async (t) => {
+  const provider = new DataViewFileProvider(new DataView(DATA_ARRAY.buffer));
+  t.equals(Buffer.from(await provider.slice(0n, 4n)).compare(signature), 0);
+  t.end();
+});
+
+test('DataViewFileProvider#getUint8', async (t) => {
+  const provider = new DataViewFileProvider(new DataView(DATA_ARRAY.buffer));
+  t.equals(await provider.getUint8(0n), 80);
+  t.end();
+});
+
+test('DataViewFileProvider#local file header parse', async (t) => {
+  const provider = new DataViewFileProvider(new DataView(DATA_ARRAY.buffer));
+  t.equals(await provider.getUint16(0n), 19280);
+  t.end();
+});
+
+test('DataViewFileProvider#local file header parse', async (t) => {
+  const provider = new DataViewFileProvider(new DataView(DATA_ARRAY.buffer));
+  t.equals(await provider.getUint32(0n), 67324752);
+  t.end();
+});
+
+test('DataViewFileProvider#local file header parse', async (t) => {
+  const provider = new DataViewFileProvider(new DataView(DATA_ARRAY.buffer));
+  t.equals(await provider.getBigUint64(0n), 563035920091984n);
+  t.end();
+});
diff --git a/modules/i3s/test/local-file-header.spec.js b/modules/i3s/test/zip-utils/local-file-header.spec.js
similarity index 50%
rename from modules/i3s/test/local-file-header.spec.js
rename to modules/i3s/test/zip-utils/local-file-header.spec.js
index 2df38d1815..d3ba69ff38 100644
--- a/modules/i3s/test/local-file-header.spec.js
+++ b/modules/i3s/test/zip-utils/local-file-header.spec.js
@@ -1,14 +1,14 @@
 import test from 'tape-promise/tape';
-import {DATA_ARRAY} from './data/test.zip.js';
-import {parseZipLocalFileHeader} from '../src/lib/parsers/parse-zip/local-file-header.js';
-import {DataViewFileProvider} from '../src/lib/parsers/parse-zip/data-view-file-provider.js';
+import {DATA_ARRAY} from '../data/test.zip.js';
+import {parseZipLocalFileHeader} from '../../src/lib/parsers/parse-zip/local-file-header';
+import {DataViewFileProvider} from '../../src/lib/parsers/parse-zip/data-view-file-provider';
 
 test('SLPKLoader#local file header parse', async (t) => {
   const localFileHeader = await parseZipLocalFileHeader(
     0n,
     new DataViewFileProvider(new DataView(DATA_ARRAY.buffer))
   );
-  t.deepEqual(localFileHeader?.compressedSize, 39);
+  t.deepEqual(localFileHeader?.compressedSize, 39n);
   t.deepEqual(localFileHeader?.fileNameLength, 9);
   t.end();
 });
diff --git a/modules/tile-converter/src/slpk-extractor/helpers/file-handle-provider.ts b/modules/tile-converter/src/slpk-extractor/helpers/file-handle-provider.ts
index 201384d8a3..95c9de64a9 100644
--- a/modules/tile-converter/src/slpk-extractor/helpers/file-handle-provider.ts
+++ b/modules/tile-converter/src/slpk-extractor/helpers/file-handle-provider.ts
@@ -30,7 +30,7 @@ export class FileHandleProvider implements FileProvider {
   }
 
   /**
-   * Gets an unsigned 8-bit integer (unsigned byte) at the specified byte offset from the start of the file.
+   * Gets an unsigned 8-bit integer at the specified byte offset from the start of the file.
    * @param offset The offset, in bytes, from the start of the file where to read the data.
    */
   async getUint8(offset: bigint): Promise<number> {
@@ -44,7 +44,7 @@ export class FileHandleProvider implements FileProvider {
   }
 
   /**
-   * Gets an unsigned 16-bit integer (unsigned byte) at the specified byte offset from the start of the file.
+   * Gets an unsigned 16-bit integer at the specified byte offset from the start of the file.
    * @param offset The offset, in bytes, from the start of the file where to read the data.
    */
   async getUint16(offset: bigint): Promise<number> {
@@ -58,7 +58,7 @@ export class FileHandleProvider implements FileProvider {
   }
 
   /**
-   * Gets an unsigned 32-bit integer (unsigned byte) at the specified byte offset from the start of the file.
+   * Gets an unsigned 32-bit integer at the specified byte offset from the start of the file.
    * @param offset The offset, in bytes, from the start of the file where to read the data.
    */
   async getUint32(offset: bigint): Promise<number> {
@@ -72,7 +72,7 @@ export class FileHandleProvider implements FileProvider {
   }
 
   /**
-   * Gets an unsigned 32-bit integer (unsigned byte) at the specified byte offset from the start of the file.
+   * Gets an unsigned 32-bit integer at the specified byte offset from the start of the file.
    * @param offset The offset, in bytes, from the start of the file where to read the data.
    */
   async getBigUint64(offset: bigint): Promise<bigint> {
diff --git a/modules/tile-converter/src/slpk-extractor/helpers/fs-promises.ts b/modules/tile-converter/src/slpk-extractor/helpers/fs-promises.ts
index d2e53fd865..785f583a11 100644
--- a/modules/tile-converter/src/slpk-extractor/helpers/fs-promises.ts
+++ b/modules/tile-converter/src/slpk-extractor/helpers/fs-promises.ts
@@ -1,10 +1,14 @@
 import {read, open, stat, BigIntStats} from 'fs';
 
+/** file reading result */
 export type FileReadResult = {
+  /** amount of the bytes read */
   bytesRead: number;
+  /** the buffer filled with data from file*/
   buffer: Buffer;
 };
 
+/** Object handling file info */
 export class FileHandle {
   private fileDescriptor: number;
   private stats: BigIntStats;
@@ -12,6 +16,12 @@ export class FileHandle {
     this.fileDescriptor = fileDescriptor;
     this.stats = stats;
   }
+  /**
+   * Opens a `FileHandle`.
+   *
+   * @param path path to the file
+   * @return Fulfills with a {FileHandle} object.
+   */
 
   static open = async (path: string): Promise<FileHandle> => {
     const [fd, stats] = await Promise.all([
@@ -25,6 +35,18 @@ export class FileHandle {
     return new FileHandle(fd, stats);
   };
 
+  /**
+   * Reads data from the file and stores that in the given buffer.
+   *
+   * If the file is not modified concurrently, the end-of-file is reached when the
+   * number of bytes read is zero.
+   * @param buffer A buffer that will be filled with the file data read.
+   * @param offset The location in the buffer at which to start filling.
+   * @param length The number of bytes to read.
+   * @param position The location where to begin reading data from the file. If `null`, data will be read from the current file position, and the position will be updated. If `position` is an
+   * integer, the current file position will remain unchanged.
+   * @return Fulfills upon success with a FileReadResult object
+   */
   read = (
     buffer: Buffer,
     offset: number,
diff --git a/modules/tile-converter/src/slpk-extractor/slpk-extractor.ts b/modules/tile-converter/src/slpk-extractor/slpk-extractor.ts
index 46dcca5ffb..f19bd12174 100644
--- a/modules/tile-converter/src/slpk-extractor/slpk-extractor.ts
+++ b/modules/tile-converter/src/slpk-extractor/slpk-extractor.ts
@@ -26,7 +26,7 @@ type File = {
  */
 export default class SLPKConverter {
   /**
-   * Convert slpk to i3s
+   * Extract slpk to i3s
    * @param options
    * @param options.inputUrl the url to read SLPK file
    * @param options.outputPath the output filename
diff --git a/modules/tile-converter/test/index.js b/modules/tile-converter/test/index.js
index aa5222a129..d70c66b0ac 100644
--- a/modules/tile-converter/test/index.js
+++ b/modules/tile-converter/test/index.js
@@ -13,6 +13,8 @@ import './i3s-converter/helpers/preprocess-3d-tiles.spec';
 
 import './i3s-converter/i3s-converter.spec';
 import './slpk-extractor/slpk-extractor.spec';
+import './slpk-extractor/file-handle-provider.spec';
+import './slpk-extractor/file-handle.spec';
 import './utils/cli-utils.spec';
 
 import './3d-tiles-converter/helpers/b3dm-converter.spec';
diff --git a/modules/tile-converter/test/slpk-extractor/file-handle-provider.spec.js b/modules/tile-converter/test/slpk-extractor/file-handle-provider.spec.js
new file mode 100644
index 0000000000..1ccf3592c6
--- /dev/null
+++ b/modules/tile-converter/test/slpk-extractor/file-handle-provider.spec.js
@@ -0,0 +1,47 @@
+import test from 'tape-promise/tape';
+import {signature} from '../../../i3s/src/lib/parsers/parse-zip/local-file-header';
+import {FileHandleProvider} from '@loaders.gl/tile-converter';
+import {isBrowser} from '@loaders.gl/core';
+
+const SLPKUrl = 'modules/i3s/test/data/DA12_subset.slpk';
+
+test('FileHandleProvider#slice', async (t) => {
+  if (!isBrowser) {
+    const provider = await FileHandleProvider.from(SLPKUrl);
+    t.equals(Buffer.from(await provider.slice(0n, 4n)).compare(signature), 0);
+  }
+  t.end();
+});
+
+test('FileHandleProvider#getUint8', async (t) => {
+  if (!isBrowser) {
+    const provider = await FileHandleProvider.from(SLPKUrl);
+    t.equals(await provider.getUint8(0n), 80);
+    t.end();
+  }
+  t.end();
+});
+
+test('FileHandleProvider#local file header parse', async (t) => {
+  if (!isBrowser) {
+    const provider = await FileHandleProvider.from(SLPKUrl);
+    t.equals(await provider.getUint16(0n), 19280);
+  }
+  t.end();
+});
+
+test('FileHandleProvider#local file header parse', async (t) => {
+  if (!isBrowser) {
+    const provider = await FileHandleProvider.from(SLPKUrl);
+    t.equals(await provider.getUint32(0n), 67324752);
+  }
+  t.end();
+});
+
+test('FileHandleProvider#local file header parse', async (t) => {
+  if (!isBrowser) {
+    const provider = await FileHandleProvider.from(SLPKUrl);
+    t.equals(await provider.getBigUint64(0n), 67324752n);
+  }
+  t.end();
+});
diff --git a/modules/tile-converter/test/slpk-extractor/file-handle.spec.js b/modules/tile-converter/test/slpk-extractor/file-handle.spec.js
new file mode 100644
index 0000000000..15edda5d74
--- /dev/null
+++ b/modules/tile-converter/test/slpk-extractor/file-handle.spec.js
@@ -0,0 +1,20 @@
+import test from 'tape-promise/tape';
+import {isBrowser} from '@loaders.gl/core';
+import {FileHandle} from '../../src/slpk-extractor/helpers/fs-promises';
+import {promises as fsPromises} from 'fs';
+
+const SLPKUrl = 'modules/i3s/test/data/DA12_subset.slpk';
+
+test('FileHandle#open and read', async (t) => {
+  if (!isBrowser) {
+    const provider = await FileHandle.open(SLPKUrl);
+    const fsHandler = await fsPromises.open(SLPKUrl);
+    t.equals(
+      (await provider.read(Buffer.alloc(4), 0, 4, 1)).buffer.compare(
+        (await fsHandler.read(Buffer.alloc(4), 0, 4, 1)).buffer
+      ),
+      0
+    );
+  }
+  t.end();
+});

From 2a4e08e843c4c41597035bfc8df9134163e25300 Mon Sep 17 00:00:00 2001
From: Daria Terekhova <daria.terekhova@actionengine.com>
Date: Thu, 20 Jul 2023 13:02:32 +0300
Subject: [PATCH 5/6] Review fixes

---
 modules/i3s/src/lib/parsers/parse-slpk/parse-slpk.ts          | 3 +--
 modules/i3s/src/lib/parsers/parse-slpk/search-from-the-end.ts | 4 +++-
 modules/i3s/src/lib/parsers/parse-zip/signature.ts            | 2 --
 ...{data-view-provider.spec.js => data-view-provider.spec.ts} | 4 ++--
 4 files changed, 6 insertions(+), 7 deletions(-)
 delete mode 100644 modules/i3s/src/lib/parsers/parse-zip/signature.ts
 rename modules/i3s/test/zip-utils/{data-view-provider.spec.js => data-view-provider.spec.ts} (96%)

diff --git a/modules/i3s/src/lib/parsers/parse-slpk/parse-slpk.ts b/modules/i3s/src/lib/parsers/parse-slpk/parse-slpk.ts
index c36ddcb507..e99ee17705 100644
--- a/modules/i3s/src/lib/parsers/parse-slpk/parse-slpk.ts
+++ b/modules/i3s/src/lib/parsers/parse-slpk/parse-slpk.ts
@@ -1,8 +1,7 @@
 import {parseZipCDFileHeader} from '../parse-zip/cd-file-header';
 import {FileProvider} from '../parse-zip/file-provider';
 import {parseZipLocalFileHeader} from '../parse-zip/local-file-header';
-import {ZipSignature} from '../parse-zip/signature';
-import {searchFromTheEnd} from './search-from-the-end';
+import {ZipSignature, searchFromTheEnd} from './search-from-the-end';
 import {SLPKArchive} from './slpk-archieve';
 
 /**
diff --git a/modules/i3s/src/lib/parsers/parse-slpk/search-from-the-end.ts b/modules/i3s/src/lib/parsers/parse-slpk/search-from-the-end.ts
index b370cdb51b..55ba569159 100644
--- a/modules/i3s/src/lib/parsers/parse-slpk/search-from-the-end.ts
+++ b/modules/i3s/src/lib/parsers/parse-slpk/search-from-the-end.ts
@@ -1,5 +1,7 @@
 import {FileProvider} from 'modules/i3s/src/lib/parsers/parse-zip/file-provider';
-import {ZipSignature} from '../parse-zip/signature';
+
+/** Description of zip signature type */
+export type ZipSignature = [number, number, number, number];
 
 /**
  * looking for the last occurrence of the provided
diff --git a/modules/i3s/src/lib/parsers/parse-zip/signature.ts b/modules/i3s/src/lib/parsers/parse-zip/signature.ts
deleted file mode 100644
index 60b6c486b8..0000000000
--- a/modules/i3s/src/lib/parsers/parse-zip/signature.ts
+++ /dev/null
@@ -1,2 +0,0 @@
-/** Description of zip signature type */
-export type ZipSignature = [number, number, number, number];
diff --git a/modules/i3s/test/zip-utils/data-view-provider.spec.js b/modules/i3s/test/zip-utils/data-view-provider.spec.ts
similarity index 96%
rename from modules/i3s/test/zip-utils/data-view-provider.spec.js
rename to modules/i3s/test/zip-utils/data-view-provider.spec.ts
index 8739a5b094..82bae226c1 100644
--- a/modules/i3s/test/zip-utils/data-view-provider.spec.js
+++ b/modules/i3s/test/zip-utils/data-view-provider.spec.ts
@@ -1,7 +1,7 @@
 import test from 'tape-promise/tape';
 import {DATA_ARRAY} from '../data/test.zip.js';
-import {DataViewFileProvider} from '../../src/lib/parsers/parse-zip/data-view-file-provider';
-import {signature} from '../../src/lib/parsers/parse-zip/local-file-header';
+import {DataViewFileProvider} from '../../src/lib/parsers/parse-zip/data-view-file-provider.js';
+import {signature} from '../../src/lib/parsers/parse-zip/local-file-header.js';
 
 test('DataViewFileProvider#slice', async (t) => {
   const provider = new DataViewFileProvider(new DataView(DATA_ARRAY.buffer));

From 4b9cedadfb8e92813e605babec7e95ab200fa636 Mon Sep 17 00:00:00 2001
From: Daria Terekhova <daria.terekhova@actionengine.com>
Date: Thu, 20 Jul 2023 15:24:42 +0300
Subject: [PATCH 6/6] Test fix

---
 modules/i3s/test/zip-utils/data-view-provider.spec.ts | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/modules/i3s/test/zip-utils/data-view-provider.spec.ts b/modules/i3s/test/zip-utils/data-view-provider.spec.ts
index 82bae226c1..8739a5b094 100644
--- a/modules/i3s/test/zip-utils/data-view-provider.spec.ts
+++ b/modules/i3s/test/zip-utils/data-view-provider.spec.ts
@@ -1,7 +1,7 @@
 import test from 'tape-promise/tape';
 import {DATA_ARRAY} from '../data/test.zip.js';
-import {DataViewFileProvider} from '../../src/lib/parsers/parse-zip/data-view-file-provider.js';
-import {signature} from '../../src/lib/parsers/parse-zip/local-file-header.js';
+import {DataViewFileProvider} from '../../src/lib/parsers/parse-zip/data-view-file-provider';
+import {signature} from '../../src/lib/parsers/parse-zip/local-file-header';
 
 test('DataViewFileProvider#slice', async (t) => {
   const provider = new DataViewFileProvider(new DataView(DATA_ARRAY.buffer));