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denoland-deno/std/archive/tar.ts
2020-10-19 13:33:51 +02:00

639 lines
15 KiB
TypeScript

/**
* Ported and modified from: https://github.com/beatgammit/tar-js and
* licensed as:
*
* (The MIT License)
*
* Copyright (c) 2011 T. Jameson Little
* Copyright (c) 2019 Jun Kato
* Copyright (c) 2020 the Deno authors
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
import { MultiReader } from "../io/readers.ts";
import { PartialReadError } from "../io/bufio.ts";
import { assert } from "../_util/assert.ts";
type Reader = Deno.Reader;
type Seeker = Deno.Seeker;
const recordSize = 512;
const ustar = "ustar\u000000";
// https://pubs.opengroup.org/onlinepubs/9699919799/utilities/pax.html#tag_20_92_13_06
// eight checksum bytes taken to be ascii spaces (decimal value 32)
const initialChecksum = 8 * 32;
async function readBlock(
reader: Deno.Reader,
p: Uint8Array,
): Promise<number | null> {
let bytesRead = 0;
while (bytesRead < p.length) {
const rr = await reader.read(p.subarray(bytesRead));
if (rr === null) {
if (bytesRead === 0) {
return null;
} else {
throw new PartialReadError();
}
}
bytesRead += rr;
}
return bytesRead;
}
/**
* Simple file reader
*/
class FileReader implements Reader {
private file?: Deno.File;
constructor(private filePath: string) {}
public async read(p: Uint8Array): Promise<number | null> {
if (!this.file) {
this.file = await Deno.open(this.filePath, { read: true });
}
const res = await Deno.read(this.file.rid, p);
if (res === null) {
Deno.close(this.file.rid);
this.file = undefined;
}
return res;
}
}
/**
* Remove the trailing null codes
* @param buffer
*/
function trim(buffer: Uint8Array): Uint8Array {
const index = buffer.findIndex((v): boolean => v === 0);
if (index < 0) return buffer;
return buffer.subarray(0, index);
}
/**
* Initialize Uint8Array of the specified length filled with 0
* @param length
*/
function clean(length: number): Uint8Array {
const buffer = new Uint8Array(length);
buffer.fill(0, 0, length - 1);
return buffer;
}
function pad(num: number, bytes: number, base?: number): string {
const numString = num.toString(base || 8);
return "000000000000".substr(numString.length + 12 - bytes) + numString;
}
enum FileTypes {
"file" = 0,
"link" = 1,
"symlink" = 2,
"character-device" = 3,
"block-device" = 4,
"directory" = 5,
"fifo" = 6,
"contiguous-file" = 7,
}
/*
struct posix_header { // byte offset
char name[100]; // 0
char mode[8]; // 100
char uid[8]; // 108
char gid[8]; // 116
char size[12]; // 124
char mtime[12]; // 136
char chksum[8]; // 148
char typeflag; // 156
char linkname[100]; // 157
char magic[6]; // 257
char version[2]; // 263
char uname[32]; // 265
char gname[32]; // 297
char devmajor[8]; // 329
char devminor[8]; // 337
char prefix[155]; // 345
// 500
};
*/
const ustarStructure: Array<{ field: string; length: number }> = [
{
field: "fileName",
length: 100,
},
{
field: "fileMode",
length: 8,
},
{
field: "uid",
length: 8,
},
{
field: "gid",
length: 8,
},
{
field: "fileSize",
length: 12,
},
{
field: "mtime",
length: 12,
},
{
field: "checksum",
length: 8,
},
{
field: "type",
length: 1,
},
{
field: "linkName",
length: 100,
},
{
field: "ustar",
length: 8,
},
{
field: "owner",
length: 32,
},
{
field: "group",
length: 32,
},
{
field: "majorNumber",
length: 8,
},
{
field: "minorNumber",
length: 8,
},
{
field: "fileNamePrefix",
length: 155,
},
{
field: "padding",
length: 12,
},
];
/**
* Create header for a file in a tar archive
*/
function formatHeader(data: TarData): Uint8Array {
const encoder = new TextEncoder(),
buffer = clean(512);
let offset = 0;
ustarStructure.forEach(function (value): void {
const entry = encoder.encode(data[value.field as keyof TarData] || "");
buffer.set(entry, offset);
offset += value.length; // space it out with nulls
});
return buffer;
}
/**
* Parse file header in a tar archive
* @param length
*/
function parseHeader(buffer: Uint8Array): { [key: string]: Uint8Array } {
const data: { [key: string]: Uint8Array } = {};
let offset = 0;
ustarStructure.forEach(function (value): void {
const arr = buffer.subarray(offset, offset + value.length);
data[value.field] = arr;
offset += value.length;
});
return data;
}
interface TarHeader {
[key: string]: Uint8Array;
}
export interface TarData {
fileName?: string;
fileNamePrefix?: string;
fileMode?: string;
uid?: string;
gid?: string;
fileSize?: string;
mtime?: string;
checksum?: string;
type?: string;
ustar?: string;
owner?: string;
group?: string;
}
export interface TarDataWithSource extends TarData {
/**
* file to read
*/
filePath?: string;
/**
* buffer to read
*/
reader?: Reader;
}
export interface TarInfo {
fileMode?: number;
mtime?: number;
uid?: number;
gid?: number;
owner?: string;
group?: string;
type?: string;
}
export interface TarOptions extends TarInfo {
/**
* append file
*/
filePath?: string;
/**
* append any arbitrary content
*/
reader?: Reader;
/**
* size of the content to be appended
*/
contentSize?: number;
}
export interface TarMeta extends TarInfo {
fileName: string;
fileSize?: number;
}
// eslint-disable-next-line @typescript-eslint/no-empty-interface
interface TarEntry extends TarMeta {}
/**
* A class to create a tar archive
*/
export class Tar {
data: TarDataWithSource[];
constructor() {
this.data = [];
}
/**
* Append a file to this tar archive
* @param fn file name
* e.g., test.txt; use slash for directory separators
* @param opts options
*/
async append(fn: string, opts: TarOptions): Promise<void> {
if (typeof fn !== "string") {
throw new Error("file name not specified");
}
let fileName = fn;
// separate file name into two parts if needed
let fileNamePrefix: string | undefined;
if (fileName.length > 100) {
let i = fileName.length;
while (i >= 0) {
i = fileName.lastIndexOf("/", i);
if (i <= 155) {
fileNamePrefix = fileName.substr(0, i);
fileName = fileName.substr(i + 1);
break;
}
i--;
}
const errMsg =
"ustar format does not allow a long file name (length of [file name" +
"prefix] + / + [file name] must be shorter than 256 bytes)";
if (i < 0 || fileName.length > 100) {
throw new Error(errMsg);
} else {
assert(fileNamePrefix != null);
if (fileNamePrefix.length > 155) {
throw new Error(errMsg);
}
}
}
opts = opts || {};
// set meta data
let info: Deno.FileInfo | undefined;
if (opts.filePath) {
info = await Deno.stat(opts.filePath);
if (info.isDirectory) {
info.size = 0;
opts.reader = new Deno.Buffer();
}
}
const mode = opts.fileMode || (info && info.mode) ||
parseInt("777", 8) & 0xfff,
mtime = Math.floor(
opts.mtime ?? (info?.mtime ?? new Date()).valueOf() / 1000,
),
uid = opts.uid || 0,
gid = opts.gid || 0;
if (typeof opts.owner === "string" && opts.owner.length >= 32) {
throw new Error(
"ustar format does not allow owner name length >= 32 bytes",
);
}
if (typeof opts.group === "string" && opts.group.length >= 32) {
throw new Error(
"ustar format does not allow group name length >= 32 bytes",
);
}
const fileSize = info?.size ?? opts.contentSize;
assert(fileSize != null, "fileSize must be set");
const type = opts.type
? FileTypes[opts.type as keyof typeof FileTypes]
: (info?.isDirectory ? FileTypes.directory : FileTypes.file);
const tarData: TarDataWithSource = {
fileName,
fileNamePrefix,
fileMode: pad(mode, 7),
uid: pad(uid, 7),
gid: pad(gid, 7),
fileSize: pad(fileSize, 11),
mtime: pad(mtime, 11),
checksum: " ",
type: type.toString(),
ustar,
owner: opts.owner || "",
group: opts.group || "",
filePath: opts.filePath,
reader: opts.reader,
};
// calculate the checksum
let checksum = 0;
const encoder = new TextEncoder();
Object.keys(tarData)
.filter((key): boolean => ["filePath", "reader"].indexOf(key) < 0)
.forEach(function (key): void {
checksum += encoder
.encode(tarData[key as keyof TarData])
.reduce((p, c): number => p + c, 0);
});
tarData.checksum = pad(checksum, 6) + "\u0000 ";
this.data.push(tarData);
}
/**
* Get a Reader instance for this tar data
*/
getReader(): Reader {
const readers: Reader[] = [];
this.data.forEach((tarData): void => {
let { reader } = tarData;
const { filePath } = tarData;
const headerArr = formatHeader(tarData);
readers.push(new Deno.Buffer(headerArr));
if (!reader) {
assert(filePath != null);
reader = new FileReader(filePath);
}
readers.push(reader);
// to the nearest multiple of recordSize
assert(tarData.fileSize != null, "fileSize must be set");
readers.push(
new Deno.Buffer(
clean(
recordSize -
(parseInt(tarData.fileSize, 8) % recordSize || recordSize),
),
),
);
});
// append 2 empty records
readers.push(new Deno.Buffer(clean(recordSize * 2)));
return new MultiReader(...readers);
}
}
class TarEntry implements Reader {
#header: TarHeader;
#reader: Reader | (Reader & Deno.Seeker);
#size: number;
#read = 0;
#consumed = false;
#entrySize: number;
constructor(
meta: TarMeta,
header: TarHeader,
reader: Reader | (Reader & Deno.Seeker),
) {
Object.assign(this, meta);
this.#header = header;
this.#reader = reader;
// File Size
this.#size = this.fileSize || 0;
// Entry Size
const blocks = Math.ceil(this.#size / recordSize);
this.#entrySize = blocks * recordSize;
}
get consumed(): boolean {
return this.#consumed;
}
async read(p: Uint8Array): Promise<number | null> {
// Bytes left for entry
const entryBytesLeft = this.#entrySize - this.#read;
const bufSize = Math.min(
// bufSize can't be greater than p.length nor bytes left in the entry
p.length,
entryBytesLeft,
);
if (entryBytesLeft <= 0) {
this.#consumed = true;
return null;
}
const block = new Uint8Array(bufSize);
const n = await readBlock(this.#reader, block);
const bytesLeft = this.#size - this.#read;
this.#read += n || 0;
if (n === null || bytesLeft <= 0) {
if (n === null) this.#consumed = true;
return null;
}
// Remove zero filled
const offset = bytesLeft < n ? bytesLeft : n;
p.set(block.subarray(0, offset), 0);
return offset < 0 ? n - Math.abs(offset) : offset;
}
async discard(): Promise<void> {
// Discard current entry
if (this.#consumed) return;
this.#consumed = true;
if (typeof (this.#reader as Seeker).seek === "function") {
await (this.#reader as Seeker).seek(
this.#entrySize - this.#read,
Deno.SeekMode.Current,
);
this.#read = this.#entrySize;
} else {
await Deno.readAll(this);
}
}
}
/**
* A class to extract a tar archive
*/
export class Untar {
reader: Reader;
block: Uint8Array;
#entry: TarEntry | undefined;
constructor(reader: Reader) {
this.reader = reader;
this.block = new Uint8Array(recordSize);
}
#checksum = (header: Uint8Array): number => {
let sum = initialChecksum;
for (let i = 0; i < 512; i++) {
if (i >= 148 && i < 156) {
// Ignore checksum header
continue;
}
sum += header[i];
}
return sum;
};
#getHeader = async (): Promise<TarHeader | null> => {
await readBlock(this.reader, this.block);
const header = parseHeader(this.block);
// calculate the checksum
const decoder = new TextDecoder();
const checksum = this.#checksum(this.block);
if (parseInt(decoder.decode(header.checksum), 8) !== checksum) {
if (checksum === initialChecksum) {
// EOF
return null;
}
throw new Error("checksum error");
}
const magic = decoder.decode(header.ustar);
if (magic.indexOf("ustar")) {
throw new Error(`unsupported archive format: ${magic}`);
}
return header;
};
#getMetadata = (header: TarHeader): TarMeta => {
const decoder = new TextDecoder();
// get meta data
const meta: TarMeta = {
fileName: decoder.decode(trim(header.fileName)),
};
const fileNamePrefix = trim(header.fileNamePrefix);
if (fileNamePrefix.byteLength > 0) {
meta.fileName = decoder.decode(fileNamePrefix) + "/" + meta.fileName;
}
(["fileMode", "mtime", "uid", "gid"] as [
"fileMode",
"mtime",
"uid",
"gid",
]).forEach((key): void => {
const arr = trim(header[key]);
if (arr.byteLength > 0) {
meta[key] = parseInt(decoder.decode(arr), 8);
}
});
(["owner", "group", "type"] as ["owner", "group", "type"]).forEach(
(key): void => {
const arr = trim(header[key]);
if (arr.byteLength > 0) {
meta[key] = decoder.decode(arr);
}
},
);
meta.fileSize = parseInt(decoder.decode(header.fileSize), 8);
meta.type = FileTypes[parseInt(meta.type!)] ?? meta.type;
return meta;
};
async extract(): Promise<TarEntry | null> {
if (this.#entry && !this.#entry.consumed) {
// If entry body was not read, discard the body
// so we can read the next entry.
await this.#entry.discard();
}
const header = await this.#getHeader();
if (header === null) return null;
const meta = this.#getMetadata(header);
this.#entry = new TarEntry(meta, header, this.reader);
return this.#entry;
}
async *[Symbol.asyncIterator](): AsyncIterableIterator<TarEntry> {
while (true) {
const entry = await this.extract();
if (entry === null) return;
yield entry;
}
}
}