MISC: Support importing Steam Cloud save file manually (#2583)

electron/saveDataBinaryFormat.d.ts

@@ -1 +1,4 @@
+export declare const encodeBytesToBase64String: (bytes: Uint8Array<ArrayBuffer>) => string;
+export declare const decodeBase64BytesToBytes: (bytes: Uint8Array<ArrayBuffer>) => Uint8Array<ArrayBuffer>;
 export declare const isBinaryFormat: (saveData: string | Uint8Array<ArrayBuffer>) => boolean;
+export declare const isSteamCloudFormat: (saveData: string | Uint8Array<ArrayBuffer>) => boolean;

electron/saveDataBinaryFormat.js

@@ -1,13 +1,68 @@
 // The 2 magic bytes of the gzip header plus the mandatory compression type of DEFLATE
-const magicBytes = [0x1f, 0x8b, 0x08];
+const magicBytesOfDeflateGzip = new Uint8Array([0x1f, 0x8b, 0x08]);
+// Base64-encoded string of magicBytesOfDeflateGzip
+const base64EncodingOfMagicBytes = encodeBytesToBase64String(magicBytesOfDeflateGzip);
+// Convert the base64-encoded string to a byte array
+const byteArrayOfBase64EncodingOfMagicBytes = Uint8Array.from(base64EncodingOfMagicBytes, (c) => c.charCodeAt(0));
 
+/**
+ * @param {Uint8Array} bytes
+ * @returns {string}
+ */
+function encodeBytesToBase64String(bytes) {
+  let binaryString = "";
+  for (let i = 0; i < bytes.length; i++) {
+    binaryString += String.fromCharCode(bytes[i]);
+  }
+  return btoa(binaryString);
+}
+
+/**
+ * @param {Uint8Array} bytes
+ * @returns {Uint8Array}
+ */
+function decodeBase64BytesToBytes(bytes) {
+  let base64String = "";
+  for (let i = 0; i < bytes.length; i++) {
+    base64String += String.fromCharCode(bytes[i]);
+  }
+  const decodedBinaryString = atob(base64String);
+  const result = new Uint8Array(decodedBinaryString.length);
+  for (let i = 0; i < decodedBinaryString.length; i++) {
+    result[i] = decodedBinaryString.charCodeAt(i);
+  }
+  return result;
+}
+
+/**
+ * @param {string | Uint8Array} rawData
+ * @returns {boolean}
+ */
 function isBinaryFormat(rawData) {
-  for (let i = 0; i < magicBytes.length; ++i) {
-    if (magicBytes[i] !== rawData[i]) {
+  for (let i = 0; i < magicBytesOfDeflateGzip.length; ++i) {
+    if (magicBytesOfDeflateGzip[i] !== rawData[i]) {
       return false;
     }
   }
   return true;
 }
 
-module.exports = { isBinaryFormat };
+/**
+ * The Steam Cloud save file is a base64-encoded gz file.
+ *
+ * @param {string | Uint8Array} rawData
+ * @returns {boolean}
+ */
+function isSteamCloudFormat(rawData) {
+  if (typeof rawData === "string") {
+    return rawData.startsWith(base64EncodingOfMagicBytes);
+  }
+  for (let i = 0; i < byteArrayOfBase64EncodingOfMagicBytes.length; ++i) {
+    if (byteArrayOfBase64EncodingOfMagicBytes[i] !== rawData[i]) {
+      return false;
+    }
+  }
+  return true;
+}
+
+module.exports = { encodeBytesToBase64String, decodeBase64BytesToBytes, isBinaryFormat, isSteamCloudFormat };

electron/storage.js

@@ -6,7 +6,7 @@ const fs = require("fs/promises");
 const log = require("electron-log");
 const flatten = require("lodash/flatten");
 const Store = require("electron-store");
-const { isBinaryFormat } = require("./saveDataBinaryFormat");
+const { decodeBase64BytesToBytes, isBinaryFormat, isSteamCloudFormat } = require("./saveDataBinaryFormat");
 const store = new Store();
 const { steamworksClient } = require("./steamworksUtils");
 
@@ -224,7 +224,7 @@ async function getSteamCloudSaveData() {
 async function saveGameToDisk(window, electronGameData) {
   const currentFolder = getSaveFolder(window);
   let saveFolderSizeBytes = await getFolderSizeInBytes(currentFolder);
-  const maxFolderSizeBytes = store.get("autosave-quota", 1e8); // 100Mb per playerIndentifier
+  const maxFolderSizeBytes = store.get("autosave-quota", 1e8); // 100Mb
   const remainingSpaceBytes = maxFolderSizeBytes - saveFolderSizeBytes;
   log.debug(`Folder Usage: ${saveFolderSizeBytes} bytes`);
   log.debug(`Folder Capacity: ${maxFolderSizeBytes} bytes`);
@@ -282,6 +282,9 @@ async function loadFileFromDisk(path) {
   if (isBinaryFormat(buffer)) {
     // Save file is in the binary format.
     content = buffer;
+  } else if (isSteamCloudFormat(buffer)) {
+    // Save file is in the Steam Cloud format.
+    content = decodeBase64BytesToBytes(buffer);
   } else {
     // Save file is in the base64 format.
     content = buffer.toString("utf8");

src/SaveObject.ts

@@ -23,7 +23,7 @@ import { pushGameSaved, pushImportResult } from "./Electron";
 import { getGoSave, loadGo } from "./Go/SaveLoad";
 import { SaveData } from "./types";
 import { SaveDataError, canUseBinaryFormat, decodeSaveData, encodeJsonSaveString } from "./utils/SaveDataUtils";
-import { isBinaryFormat } from "../electron/saveDataBinaryFormat";
+import { decodeBase64BytesToBytes, isBinaryFormat, isSteamCloudFormat } from "../electron/saveDataBinaryFormat";
 import { downloadContentAsFile } from "./utils/FileUtils";
 import { handleGetSaveDataInfoError } from "./utils/ErrorHandler";
 import { isObject, assertObject } from "./utils/TypeAssertion";
@@ -346,6 +346,9 @@ class BitburnerSaveObject implements BitburnerSaveObjectType {
     if (isBinaryFormat(rawData)) {
       return rawData;
     }
+    if (isSteamCloudFormat(rawData)) {
+      return decodeBase64BytesToBytes(rawData);
+    }
     return new TextDecoder().decode(rawData);
   }
 

tools/pretty-save.js

@@ -1,15 +1,21 @@
 /* eslint-disable @typescript-eslint/no-var-requires */
 const fs = require("fs").promises;
 const path = require("path");
-const { isBinaryFormat } = require("../electron/saveDataBinaryFormat");
+const { decodeBase64BytesToBytes, isBinaryFormat, isSteamCloudFormat } = require("../electron/saveDataBinaryFormat");
+
+async function decompress(data) {
+  const decompressedReadableStream = new Blob([data]).stream().pipeThrough(new DecompressionStream("gzip"));
+  return await new Response(decompressedReadableStream).text();
+}
 
 async function getSave(file) {
   const data = await fs.readFile(file);
 
   let jsonSaveString;
   if (isBinaryFormat(data)) {
-    const decompressedReadableStream = new Blob([data]).stream().pipeThrough(new DecompressionStream("gzip"));
-    jsonSaveString = await new Response(decompressedReadableStream).text();
+    jsonSaveString = await decompress(data);
+  } else if (isSteamCloudFormat(data)) {
+    jsonSaveString = await decompress(decodeBase64BytesToBytes(data));
   } else {
     jsonSaveString = decodeURIComponent(escape(atob(data)));
   }