Add:Scanner extracts cover from comic files #1837 and ComicInfo.xml parser

server/libs/libarchive/archive.js

@@ -0,0 +1,262 @@
+/**
+ * Modified from https://github.com/nika-begiashvili/libarchivejs
+ */
+
+const Path = require('path')
+const { Worker } = require('worker_threads')
+
+/**
+ * Represents compressed file before extraction
+ */
+class CompressedFile {
+
+    constructor(name, size, path, archiveRef) {
+        this._name = name
+        this._size = size
+        this._path = path
+        this._archiveRef = archiveRef
+    }
+
+    /**
+     * file name
+     */
+    get name() {
+        return this._name
+    }
+    /**
+     * file size
+     */
+    get size() {
+        return this._size
+    }
+
+    /**
+     * Extract file from archive
+     * @returns {Promise<File>} extracted file
+     */
+    extract() {
+        return this._archiveRef.extractSingleFile(this._path)
+    }
+
+}
+
+class Archive {
+    /**
+     * Creates new archive instance from browser native File object
+     * @param {Buffer} fileBuffer
+     * @param {object} options
+     * @returns {Archive}
+     */
+    static open(fileBuffer) {
+        const arch = new Archive(fileBuffer, { workerUrl: Path.join(__dirname, 'libarchiveWorker.js') })
+        return arch.open()
+    }
+
+    /**
+     * Create new archive
+     * @param {File} file 
+     * @param {Object} options 
+     */
+    constructor(file, options) {
+        this._worker = new Worker(options.workerUrl)
+        this._worker.on('message', this._workerMsg.bind(this))
+
+        this._callbacks = []
+        this._content = {}
+        this._processed = 0
+        this._file = file
+    }
+
+    /**
+     * Prepares file for reading
+     * @returns {Promise<Archive>} archive instance
+     */
+    async open() {
+        await this._postMessage({ type: 'HELLO' }, (resolve, reject, msg) => {
+            if (msg.type === 'READY') {
+                resolve()
+            }
+        })
+        return await this._postMessage({ type: 'OPEN', file: this._file }, (resolve, reject, msg) => {
+            if (msg.type === 'OPENED') {
+                resolve(this)
+            }
+        })
+    }
+
+    /**
+     * Terminate worker to free up memory
+     */
+    close() {
+        this._worker.terminate()
+        this._worker = null
+    }
+
+    /**
+     * detect if archive has encrypted data
+     * @returns {boolean|null} null if could not be determined
+     */
+    hasEncryptedData() {
+        return this._postMessage({ type: 'CHECK_ENCRYPTION' },
+            (resolve, reject, msg) => {
+                if (msg.type === 'ENCRYPTION_STATUS') {
+                    resolve(msg.status)
+                }
+            }
+        )
+    }
+
+    /**
+     * set password to be used when reading archive
+     */
+    usePassword(archivePassword) {
+        return this._postMessage({ type: 'SET_PASSPHRASE', passphrase: archivePassword },
+            (resolve, reject, msg) => {
+                if (msg.type === 'PASSPHRASE_STATUS') {
+                    resolve(msg.status)
+                }
+            }
+        )
+    }
+
+    /**
+     * Returns object containing directory structure and file information 
+     * @returns {Promise<object>}
+     */
+    getFilesObject() {
+        if (this._processed > 0) {
+            return Promise.resolve().then(() => this._content)
+        }
+        return this._postMessage({ type: 'LIST_FILES' }, (resolve, reject, msg) => {
+            if (msg.type === 'ENTRY') {
+                const entry = msg.entry
+                const [target, prop] = this._getProp(this._content, entry.path)
+                if (entry.type === 'FILE') {
+                    target[prop] = new CompressedFile(entry.fileName, entry.size, entry.path, this)
+                }
+                return true
+            } else if (msg.type === 'END') {
+                this._processed = 1
+                resolve(this._cloneContent(this._content))
+            }
+        })
+    }
+
+    getFilesArray() {
+        return this.getFilesObject().then((obj) => {
+            return this._objectToArray(obj)
+        })
+    }
+
+    extractSingleFile(target) {
+        // Prevent extraction if worker already terminated
+        if (this._worker === null) {
+            throw new Error("Archive already closed")
+        }
+
+        return this._postMessage({ type: 'EXTRACT_SINGLE_FILE', target: target },
+            (resolve, reject, msg) => {
+                if (msg.type === 'FILE') {
+                    resolve(msg.entry)
+                }
+            }
+        )
+    }
+
+    /**
+     * Returns object containing directory structure and extracted File objects 
+     * @param {Function} extractCallback
+     * 
+     */
+    extractFiles(extractCallback) {
+        if (this._processed > 1) {
+            return Promise.resolve().then(() => this._content)
+        }
+        return this._postMessage({ type: 'EXTRACT_FILES' }, (resolve, reject, msg) => {
+            if (msg.type === 'ENTRY') {
+                const [target, prop] = this._getProp(this._content, msg.entry.path)
+                if (msg.entry.type === 'FILE') {
+                    target[prop] = msg.entry
+                    if (extractCallback !== undefined) {
+                        setTimeout(extractCallback.bind(null, {
+                            file: target[prop],
+                            path: msg.entry.path,
+                        }))
+                    }
+                }
+                return true
+            } else if (msg.type === 'END') {
+                this._processed = 2
+                this._worker.terminate()
+                resolve(this._cloneContent(this._content))
+            }
+        })
+    }
+
+    _cloneContent(obj) {
+        if (obj instanceof CompressedFile || obj === null) return obj
+        const o = {}
+        for (const prop of Object.keys(obj)) {
+            o[prop] = this._cloneContent(obj[prop])
+        }
+        return o
+    }
+
+    _objectToArray(obj, path = '') {
+        const files = []
+        for (const key of Object.keys(obj)) {
+            if (obj[key] instanceof CompressedFile || obj[key] === null) {
+                files.push({
+                    file: obj[key] || key,
+                    path: path
+                })
+            } else {
+                files.push(...this._objectToArray(obj[key], `${path}${key}/`))
+            }
+        }
+        return files
+    }
+
+    _getProp(obj, path) {
+        const parts = path.split('/')
+        if (parts[parts.length - 1] === '') parts.pop()
+        let cur = obj, prev = null
+        for (const part of parts) {
+            cur[part] = cur[part] || {}
+            prev = cur
+            cur = cur[part]
+        }
+        return [prev, parts[parts.length - 1]]
+    }
+
+    _postMessage(msg, callback) {
+        this._worker.postMessage(msg)
+        return new Promise((resolve, reject) => {
+            this._callbacks.push(this._msgHandler.bind(this, callback, resolve, reject))
+        })
+    }
+
+    _msgHandler(callback, resolve, reject, msg) {
+        if (!msg) {
+            reject('invalid msg')
+            return
+        }
+        if (msg.type === 'BUSY') {
+            reject('worker is busy')
+        } else if (msg.type === 'ERROR') {
+            reject(msg.error)
+        } else {
+            return callback(resolve, reject, msg)
+        }
+    }
+
+    _workerMsg(msg) {
+        const callback = this._callbacks[this._callbacks.length - 1]
+        const next = callback(msg)
+        if (!next) {
+            this._callbacks.pop()
+        }
+    }
+
+}
+module.exports = Archive