audiobookshelf/server/libs/libarchive/wasm-module.js

235 lines
7.5 KiB
JavaScript

/**
* Modified from https://github.com/nika-begiashvili/libarchivejs
*/
const Path = require('path')
const libarchive = require('./wasm-libarchive')
const TYPE_MAP = {
32768: 'FILE',
16384: 'DIR',
40960: 'SYMBOLIC_LINK',
49152: 'SOCKET',
8192: 'CHARACTER_DEVICE',
24576: 'BLOCK_DEVICE',
4096: 'NAMED_PIPE',
}
class ArchiveReader {
/**
* archive reader
* @param {WasmModule} wasmModule emscripten module
*/
constructor(wasmModule) {
this._wasmModule = wasmModule
this._runCode = wasmModule.runCode
this._file = null
this._passphrase = null
}
/**
* open archive, needs to closed manually
* @param {File} file
*/
open(file) {
if (this._file !== null) {
console.warn('Closing previous file')
this.close()
}
const { promise, resolve, reject } = this._promiseHandles()
this._file = file
this._loadFile(file, resolve, reject)
return promise
}
/**
* close archive
*/
close() {
this._runCode.closeArchive(this._archive)
this._wasmModule._free(this._filePtr)
this._file = null
this._filePtr = null
this._archive = null
}
/**
* detect if archive has encrypted data
* @returns {boolean|null} null if could not be determined
*/
hasEncryptedData() {
this._archive = this._runCode.openArchive(this._filePtr, this._fileLength, this._passphrase)
this._runCode.getNextEntry(this._archive)
const status = this._runCode.hasEncryptedEntries(this._archive)
if (status === 0) {
return false
} else if (status > 0) {
return true
} else {
return null
}
}
/**
* set passphrase to be used with archive
* @param {*} passphrase
*/
setPassphrase(passphrase) {
this._passphrase = passphrase
}
/**
* get archive entries
* @param {boolean} skipExtraction
* @param {string} except don't skip this entry
*/
*entries(skipExtraction = false, except = null) {
this._archive = this._runCode.openArchive(this._filePtr, this._fileLength, this._passphrase)
let entry
while (true) {
entry = this._runCode.getNextEntry(this._archive)
if (entry === 0) break
const entryData = {
size: this._runCode.getEntrySize(entry),
path: this._runCode.getEntryName(entry),
type: TYPE_MAP[this._runCode.getEntryType(entry)],
ref: entry,
}
if (entryData.type === 'FILE') {
let fileName = entryData.path.split('/')
entryData.fileName = fileName[fileName.length - 1]
}
if (skipExtraction && except !== entryData.path) {
this._runCode.skipEntry(this._archive)
} else {
const ptr = this._runCode.getFileData(this._archive, entryData.size)
if (ptr < 0) {
throw new Error(this._runCode.getError(this._archive))
}
entryData.fileData = this._wasmModule.HEAP8.slice(ptr, ptr + entryData.size)
this._wasmModule._free(ptr)
}
yield entryData
}
}
_loadFile(fileBuffer, resolve, reject) {
try {
const array = new Uint8Array(fileBuffer)
this._fileLength = array.length
this._filePtr = this._runCode.malloc(this._fileLength)
this._wasmModule.HEAP8.set(array, this._filePtr)
resolve()
} catch (error) {
reject(error)
}
}
_promiseHandles() {
let resolve = null, reject = null
const promise = new Promise((_resolve, _reject) => {
resolve = _resolve
reject = _reject
})
return { promise, resolve, reject }
}
}
class WasmModule {
constructor() {
this.preRun = []
this.postRun = []
this.totalDependencies = 0
}
print(...text) {
console.log(text)
}
printErr(...text) {
console.error(text)
}
initFunctions() {
this.runCode = {
// const char * get_version()
getVersion: this.cwrap('get_version', 'string', []),
// void * archive_open( const void * buffer, size_t buffer_size)
// retuns archive pointer
openArchive: this.cwrap('archive_open', 'number', ['number', 'number', 'string']),
// void * get_entry(void * archive)
// return archive entry pointer
getNextEntry: this.cwrap('get_next_entry', 'number', ['number']),
// void * get_filedata( void * archive, size_t bufferSize )
getFileData: this.cwrap('get_filedata', 'number', ['number', 'number']),
// int archive_read_data_skip(struct archive *_a)
skipEntry: this.cwrap('archive_read_data_skip', 'number', ['number']),
// void archive_close( void * archive )
closeArchive: this.cwrap('archive_close', null, ['number']),
// la_int64_t archive_entry_size( struct archive_entry * )
getEntrySize: this.cwrap('archive_entry_size', 'number', ['number']),
// const char * archive_entry_pathname( struct archive_entry * )
getEntryName: this.cwrap('archive_entry_pathname', 'string', ['number']),
// __LA_MODE_T archive_entry_filetype( struct archive_entry * )
/*
#define AE_IFMT ((__LA_MODE_T)0170000)
#define AE_IFREG ((__LA_MODE_T)0100000) // Regular file
#define AE_IFLNK ((__LA_MODE_T)0120000) // Sybolic link
#define AE_IFSOCK ((__LA_MODE_T)0140000) // Socket
#define AE_IFCHR ((__LA_MODE_T)0020000) // Character device
#define AE_IFBLK ((__LA_MODE_T)0060000) // Block device
#define AE_IFDIR ((__LA_MODE_T)0040000) // Directory
#define AE_IFIFO ((__LA_MODE_T)0010000) // Named pipe
*/
getEntryType: this.cwrap('archive_entry_filetype', 'number', ['number']),
// const char * archive_error_string(struct archive *);
getError: this.cwrap('archive_error_string', 'string', ['number']),
/*
* Returns 1 if the archive contains at least one encrypted entry.
* If the archive format not support encryption at all
* ARCHIVE_READ_FORMAT_ENCRYPTION_UNSUPPORTED is returned.
* If for any other reason (e.g. not enough data read so far)
* we cannot say whether there are encrypted entries, then
* ARCHIVE_READ_FORMAT_ENCRYPTION_DONT_KNOW is returned.
* In general, this function will return values below zero when the
* reader is uncertain or totally incapable of encryption support.
* When this function returns 0 you can be sure that the reader
* supports encryption detection but no encrypted entries have
* been found yet.
*
* NOTE: If the metadata/header of an archive is also encrypted, you
* cannot rely on the number of encrypted entries. That is why this
* function does not return the number of encrypted entries but#
* just shows that there are some.
*/
// __LA_DECL int archive_read_has_encrypted_entries(struct archive *);
entryIsEncrypted: this.cwrap('archive_entry_is_encrypted', 'number', ['number']),
hasEncryptedEntries: this.cwrap('archive_read_has_encrypted_entries', 'number', ['number']),
// __LA_DECL int archive_read_add_passphrase(struct archive *, const char *);
addPassphrase: this.cwrap('archive_read_add_passphrase', 'number', ['number', 'string']),
//this.stringToUTF(str), //
string: (str) => this.allocate(this.intArrayFromString(str), 'i8', 0),
malloc: this.cwrap('malloc', 'number', ['number']),
free: this.cwrap('free', null, ['number']),
}
}
monitorRunDependencies() { }
locateFile(path /* ,prefix */) {
const wasmFilepath = Path.join(__dirname, `../../../client/dist/libarchive/wasm-gen/${path}`)
return wasmFilepath
}
}
module.exports.getArchiveReader = (cb) => {
libarchive(new WasmModule()).then((module) => {
module.initFunctions()
cb(new ArchiveReader(module))
})
}