SkirdaElectronLauncher/app/assets/js/assetguard.js

436 lines
16 KiB
JavaScript

/**
* AssetGuard
*
* This module aims to provide a comprehensive and stable method for processing
* and downloading game assets for the WesterosCraft server. A central object
* stores download meta for several identifiers (categories). This meta data
* is initially empty until one of the module's processing functions are called.
* That function will process the corresponding asset index and validate any exisitng
* local files. If a file is missing or fails validation, it will be placed into an
* array which acts as a queue. This queue is wrapped in a download tracker object
* so that essential information can be cached. The download tracker object is then
* assigned as the value of the identifier in the central object. These download
* trackers will remain idle until an async process is started to process them.
*
* Once the async process is started, any enqueued assets will be downloaded. The central
* object will emit events throughout the download whose name correspond to the identifier
* being processed. For example, if the 'assets' identifier was being processed, whenever
* the download stream recieves data, the event 'assetsdlprogress' will be emitted off of
* the central object instance. This can be listened to by external modules allowing for
* categorical tracking of the downloading process.
*
* @module assetguard
*/
//Requirements
const fs = require('fs')
const request = require('request')
const path = require('path')
const mkpath = require('mkdirp');
const async = require('async')
const crypto = require('crypto')
const EventEmitter = require('events');
const {remote} = require('electron')
/* Classes */
/** Class representing a base asset. */
class Asset{
/**
* Create an asset.
*
* @param {any} id - id of the asset.
* @param {String} hash - hash value of the asset.
* @param {Number} size - size in bytes of the asset.
* @param {String} from - url where the asset can be found.
* @param {String} to - absolute local file path of the asset.
*/
constructor(id, hash, size, from, to){
this.id = id
this.hash = hash
this.size = size
this.from = from
this.to = to
}
}
/** Class representing a mojang library. */
class Library extends Asset{
/**
* Converts the process.platform OS names to match mojang's OS names.
*/
static mojangFriendlyOS(){
const opSys = process.platform
if (opSys === 'darwin') {
return 'osx';
} else if (opSys === 'win32'){
return 'windows';
} else if (opSys === 'linux'){
return 'linux';
} else {
return 'unknown_os';
}
}
/**
* Checks whether or not a library is valid for download on a particular OS, following
* the rule format specified in the mojang version data index. If the allow property has
* an OS specified, then the library can ONLY be downloaded on that OS. If the disallow
* property has instead specified an OS, the library can be downloaded on any OS EXCLUDING
* the one specified.
*
* @param {Object} rules - the Library's download rules.
* @returns {Boolean} - true if the Library follows the specified rules, otherwise false.
*/
static validateRules(rules){
if(rules == null) return true
let result = true
rules.forEach(function(rule){
const action = rule['action']
const osProp = rule['os']
if(action != null){
if(osProp != null){
const osName = osProp['name']
const osMoj = Library.mojangFriendlyOS()
if(action === 'allow'){
result = osName === osMoj
return
} else if(action === 'disallow'){
result = osName !== osMoj
return
}
}
}
})
return result
}
}
/**
* Class representing a download tracker. This is used to store meta data
* about a download queue, including the queue itself.
*/
class DLTracker {
/**
* Create a DLTracker
*
* @param {Array.<Asset>} dlqueue - an array containing assets queued for download.
* @param {Number} dlsize - the combined size of each asset in the download queue array.
*/
constructor(dlqueue, dlsize){
this.dlqueue = dlqueue
this.dlsize = dlsize
}
}
/**
* Central object class used for control flow. This object stores data about
* categories of downloads. Each category is assigned an identifier with a
* DLTracker object as its value. Combined information is also stored, such as
* the total size of all the queued files in each category. This event is used
* to emit events so that external modules can listen into processing done in
* this module.
*/
class AssetGuard extends EventEmitter{
/**
* AssetGuard class should only ever have one instance which is defined in
* this module. On creation the object's properties are never-null default
* values. Each identifier is resolved to an empty DLTracker.
*/
constructor(){
super()
this.totaldlsize = 0;
this.progress = 0;
this.assets = new DLTracker([], 0)
this.libraries = new DLTracker([], 0)
this.files = new DLTracker([], 0)
}
}
//Instance of AssetGuard
const instance = new AssetGuard()
// Utility Functions
/**
* Validate that a file exists and matches a given hash value.
*
* @param {String} filePath - the path of the file to validate.
* @param {String} algo - the hash algorithm to check against.
* @param {String} hash - the existing hash to check against.
* @returns {Boolean} - true if the file exists and calculated hash matches the given hash, otherwise false.
*/
validateLocal = function(filePath, algo, hash){
if(fs.existsSync(filePath)){
let fileName = path.basename(filePath)
let shasum = crypto.createHash(algo)
let content = fs.readFileSync(filePath)
shasum.update(content)
let calcdhash = shasum.digest('hex')
return calcdhash === hash
}
return false;
}
/**
* Initiate an async download process for an AssetGuard DLTracker.
*
* @param {String} identifier - the identifier of the AssetGuard DLTracker.
* @param {Number} limit - optional. The number of async processes to run in parallel.
* @returns {Boolean} - true if the process began, otherwise false.
*/
function startAsyncProcess(identifier, limit = 5){
let win = remote.getCurrentWindow()
let acc = 0
const concurrentDlQueue = instance[identifier].dlqueue.slice(0)
if(concurrentDlQueue.length === 0){
return false
} else {
async.eachLimit(concurrentDlQueue, limit, function(asset, cb){
mkpath.sync(path.join(asset.to, ".."))
let req = request(asset.from)
let writeStream = fs.createWriteStream(asset.to)
req.pipe(writeStream)
req.on('data', function(chunk){
instance.progress += chunk.length
acc += chunk.length
instance.emit(identifier + 'dlprogress', acc)
//console.log(identifier + ' Progress', acc/instance[identifier].dlsize)
win.setProgressBar(instance.progress/instance.totaldlsize)
})
writeStream.on('close', cb)
}, function(err){
if(err){
instance.emit(identifier + 'dlerror')
console.log('An item in ' + identifier + ' failed to process');
} else {
instance.emit(identifier + 'dlcomplete')
console.log('All ' + identifier + ' have been processed successfully')
}
instance.totaldlsize -= instance[identifier].dlsize
instance[identifier] = new DLTracker([], 0)
if(instance.totaldlsize === 0) {
win.setProgressBar(-1)
instance.emit('dlcomplete')
}
})
return true
}
}
/* Validation Functions */
/**
* Loads the version data for a given minecraft version.
*
* @param {String} version - the game version for which to load the index data.
* @param {String} basePath - the absolute file path which will be prepended to the given relative paths.
* @param {Boolean} force - optional. If true, the version index will be downloaded even if it exists locally. Defaults to false.
* @returns {Promise.<Object>} - Promise which resolves to the version data object.
*/
function loadVersionData(version, basePath, force = false){
return new Promise(function(fulfill, reject){
const name = version + '.json'
const url = 'https://s3.amazonaws.com/Minecraft.Download/versions/' + version + '/' + name
const versionPath = path.join(basePath, 'versions', version)
const versionFile = path.join(versionPath, name)
if(!fs.existsSync(versionFile) || force){
//This download will never be tracked as it's essential and trivial.
request.head(url, function(err, res, body){
console.log('Preparing download of ' + version + ' assets.')
mkpath.sync(versionPath)
const stream = request(url).pipe(fs.createWriteStream(versionFile))
stream.on('finish', function(){
fulfill(JSON.parse(fs.readFileSync(versionFile)))
})
})
} else {
fulfill(JSON.parse(fs.readFileSync(versionFile)))
}
})
}
/**
* Public asset validation function. This function will handle the validation of assets.
* It will parse the asset index specified in the version data, analyzing each
* asset entry. In this analysis it will check {todo finish later i'm tired ZZzzzz}
*
*/
function validateAssets(versionData, basePath, force = false){
return new Promise(function(fulfill, reject){
_assetChainIndexData(versionData, basePath, force).then(() => {
fulfill()
})
})
}
//Chain the asset tasks to provide full async. The below functions are private.
function _assetChainIndexData(versionData, basePath, force = false){
return new Promise(function(fulfill, reject){
//Asset index constants.
const assetIndex = versionData.assetIndex
const name = assetIndex.id + '.json'
const indexPath = path.join(basePath, 'assets', 'indexes')
const assetIndexLoc = path.join(indexPath, name)
let data = null
if(!fs.existsSync(assetIndexLoc) || force){
console.log('Downloading ' + versionData.id + ' asset index.')
mkpath.sync(indexPath)
const stream = request(assetIndex.url).pipe(fs.createWriteStream(assetIndexLoc))
stream.on('finish', function() {
data = JSON.parse(fs.readFileSync(assetIndexLoc, 'utf-8'))
_assetChainValidateAssets(versionData, basePath, data).then(() => {
fulfill()
})
})
} else {
data = JSON.parse(fs.readFileSync(assetIndexLoc, 'utf-8'))
_assetChainValidateAssets(versionData, basePath, data).then(() => {
fulfill()
})
}
})
}
_assetChainValidateAssets = function(versionData, basePath, indexData){
return new Promise(function(fulfill, reject){
//Asset constants
const resourceURL = 'http://resources.download.minecraft.net/'
const localPath = path.join(basePath, 'assets')
const indexPath = path.join(localPath, 'indexes')
const objectPath = path.join(localPath, 'objects')
const assetDlQueue = []
let dlSize = 0;
//const objKeys = Object.keys(data.objects)
async.forEachOfLimit(indexData.objects, 10, function(value, key, cb){
const hash = value.hash
const assetName = path.join(hash.substring(0, 2), hash)
const urlName = hash.substring(0, 2) + "/" + hash
const ast = new Asset(key, hash, String(value.size), resourceURL + urlName, path.join(objectPath, assetName))
if(!validateLocal(ast.to, 'sha1', ast.hash)){
dlSize += (ast.size*1)
assetDlQueue.push(ast)
}
cb()
}, function(err){
instance.assets = new DLTracker(assetDlQueue, dlSize)
instance.totaldlsize += dlSize
fulfill()
})
})
}
/**
* Public library validation method.
*/
validateLibraries = function(versionData, basePath){
return new Promise(function(fulfill, reject){
const libArr = versionData.libraries
const libPath = path.join(basePath, 'libraries')
const libDlQueue = []
let dlSize = 0
//Check validity of each library. If the hashs don't match, download the library.
async.eachLimit(libArr, 5, function(lib, cb){
if(Library.validateRules(lib.rules)){
let artifact = (lib.natives == null) ? lib.downloads.artifact : lib.downloads.classifiers[lib.natives[Library.mojangFriendlyOS()]]
const libItm = new Library(lib.name, artifact.sha1, artifact.size, artifact.url, path.join(libPath, artifact.path))
if(!validateLocal(libItm.to, 'sha1', libItm.hash)){
dlSize += (libItm.size*1)
libDlQueue.push(libItm)
}
}
cb()
}, function(err){
instance.libraries = new DLTracker(libDlQueue, dlSize)
instance.totaldlsize += dlSize
fulfill()
})
})
}
/**
* Public miscellaneous mojang file validation function.
*/
validateMiscellaneous = function(versionData, basePath){
return new Promise(async function(fulfill, reject){
await validateClient(versionData, basePath)
await validateLogConfig(versionData, basePath)
fulfill()
})
}
//Validate client - artifact renamed from client.jar to '{version}'.jar.
validateClient = function(versionData, basePath, force = false){
return new Promise(function(fulfill, reject){
const clientData = versionData.downloads.client
const version = versionData.id
const targetPath = path.join(basePath, 'versions', version)
const targetFile = version + '.jar'
let client = new Asset(version + ' client', clientData.sha1, clientData.size, clientData.url, path.join(targetPath, targetFile))
if(!validateLocal(client.to, 'sha1', client.hash) || force){
instance.files.dlqueue.push(client)
instance.files.dlsize += client.size*1
fulfill()
} else {
fulfill()
}
})
}
//Validate log config.
validateLogConfig = function(versionData, basePath){
return new Promise(function(fulfill, reject){
const client = versionData.logging.client
const file = client.file
const targetPath = path.join(basePath, 'assets', 'log_configs')
let logConfig = new Asset(file.id, file.sha1, file.size, file.url, path.join(targetPath, file.id))
if(!validateLocal(logConfig.to, 'sha1', logConfig.hash)){
instance.files.dlqueue.push(logConfig)
instance.files.dlsize += client.size*1
fulfill()
} else {
fulfill()
}
})
}
processDlQueues = function(identifiers = [{id:'assets', limit:20}, {id:'libraries', limit:5}, {id:'files', limit:5}]){
this.progress = 0;
let win = remote.getCurrentWindow()
let shouldFire = true
for(let i=0; i<identifiers.length; i++){
let iden = identifiers[i]
let r = startAsyncProcess(iden.id, iden.limit)
if(r) shouldFire = false
}
if(shouldFire){
instance.emit('dlcomplete')
}
}
module.exports = {
loadVersionData,
validateAssets,
validateLibraries,
validateMiscellaneous,
processDlQueues,
instance,
Asset,
Library
}