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Gus 2019-06-24 19:00:17 -05:00 committed by Gus Caplan
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tests
test.js
test.html

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Copyright 2019 SheetJS LLC
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.

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# bz2
bzip2 library for JavaScript
```js
import { decompress } from 'bz2';
const output = decompress(input);
```
Available from the npm registry as `bz2`
and from the GitHub registry as `@sheetjs/bz2`.
Try out the [demo](https://http://sheetjs.com/bz2/demo).
## API
### `decompress(data, crc)`
* `data`: `Uint8Array` - The data to be decompressed.
* `crc`: `boolean` - Check data using CRC32. Default: `true`.
* **Returns**: `Uint8Array`
Decompresses `data`.

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<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>BZ2 Test</title>
<style>
#drop {
border: 2px dashed #bbb;
-moz-border-radius: 5px;
-webkit-border-radius: 5px;
border-radius: 5px;
padding: 25px;
text-align: center;
font: 20pt bold, "Vollkorn";
color: #bbb;
}
</style>
</head>
<body>
<h1>bz2 Live Demo</h1>
<h5>This demo decompresses bz2 archives in your web browser. No data is sent to an external server.</h5>
<a href="https://github.com/sheetjs/bz2">Source code on GitHub</a>
<div id="drop">
<p>Drag a bzip2 file into this area to see the contents</p>
</div>
<input type="checkbox" id="download"> Download decompressed output (Recommended for .tar.bz2 and other compressed binary data)
<pre id="out"></pre>
<script type="module">
import { decompress } from 'https://unpkg.com/bz2?module';
document.querySelector('#drop').addEventListener('drop', (event) => {
event.preventDefault();
let file;
if (event.dataTransfer.items) {
file = event.dataTransfer.items[0].getAsFile();
} else {
file = event.dataTransfer.files[0];
}
const download = document.querySelector('#download').checked;
const reader = new FileReader();
reader.addEventListener('load', (e) => {
const bytes = decompress(new Uint8Array(reader.result));
const result = new TextDecoder('utf8').decode(bytes);
if (download) {
const blob = new Blob([result], { type: 'application/octet-stream' });
document.location = URL.createObjectURL(blob);
} else {
document.querySelector('#out').textContent = result;
}
});
reader.readAsArrayBuffer(file);
});
document.querySelector('#drop').addEventListener('dragover', (event) => {
event.preventDefault();
});
</script>
</body>
</html>

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/*! bz2 (C) 2019-present SheetJS LLC */
'use strict';
// https://www.ncbi.nlm.nih.gov/IEB/ToolBox/CPP_DOC/lxr/source/src/util/compress/bzip2/crctable.c
const crc32Table = [
0x00000000, 0x04c11db7, 0x09823b6e, 0x0d4326d9, 0x130476dc, 0x17c56b6b, 0x1a864db2, 0x1e475005,
0x2608edb8, 0x22c9f00f, 0x2f8ad6d6, 0x2b4bcb61, 0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd,
0x4c11db70, 0x48d0c6c7, 0x4593e01e, 0x4152fda9, 0x5f15adac, 0x5bd4b01b, 0x569796c2, 0x52568b75,
0x6a1936c8, 0x6ed82b7f, 0x639b0da6, 0x675a1011, 0x791d4014, 0x7ddc5da3, 0x709f7b7a, 0x745e66cd,
0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039, 0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5,
0xbe2b5b58, 0xbaea46ef, 0xb7a96036, 0xb3687d81, 0xad2f2d84, 0xa9ee3033, 0xa4ad16ea, 0xa06c0b5d,
0xd4326d90, 0xd0f37027, 0xddb056fe, 0xd9714b49, 0xc7361b4c, 0xc3f706fb, 0xceb42022, 0xca753d95,
0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1, 0xe13ef6f4, 0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d,
0x34867077, 0x30476dc0, 0x3d044b19, 0x39c556ae, 0x278206ab, 0x23431b1c, 0x2e003dc5, 0x2ac12072,
0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16, 0x018aeb13, 0x054bf6a4, 0x0808d07d, 0x0cc9cdca,
0x7897ab07, 0x7c56b6b0, 0x71159069, 0x75d48dde, 0x6b93dddb, 0x6f52c06c, 0x6211e6b5, 0x66d0fb02,
0x5e9f46bf, 0x5a5e5b08, 0x571d7dd1, 0x53dc6066, 0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba,
0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e, 0xbfa1b04b, 0xbb60adfc, 0xb6238b25, 0xb2e29692,
0x8aad2b2f, 0x8e6c3698, 0x832f1041, 0x87ee0df6, 0x99a95df3, 0x9d684044, 0x902b669d, 0x94ea7b2a,
0xe0b41de7, 0xe4750050, 0xe9362689, 0xedf73b3e, 0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2,
0xc6bcf05f, 0xc27dede8, 0xcf3ecb31, 0xcbffd686, 0xd5b88683, 0xd1799b34, 0xdc3abded, 0xd8fba05a,
0x690ce0ee, 0x6dcdfd59, 0x608edb80, 0x644fc637, 0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb,
0x4f040d56, 0x4bc510e1, 0x46863638, 0x42472b8f, 0x5c007b8a, 0x58c1663d, 0x558240e4, 0x51435d53,
0x251d3b9e, 0x21dc2629, 0x2c9f00f0, 0x285e1d47, 0x36194d42, 0x32d850f5, 0x3f9b762c, 0x3b5a6b9b,
0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff, 0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623,
0xf12f560e, 0xf5ee4bb9, 0xf8ad6d60, 0xfc6c70d7, 0xe22b20d2, 0xe6ea3d65, 0xeba91bbc, 0xef68060b,
0xd727bbb6, 0xd3e6a601, 0xdea580d8, 0xda649d6f, 0xc423cd6a, 0xc0e2d0dd, 0xcda1f604, 0xc960ebb3,
0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7, 0xae3afba2, 0xaafbe615, 0xa7b8c0cc, 0xa379dd7b,
0x9b3660c6, 0x9ff77d71, 0x92b45ba8, 0x9675461f, 0x8832161a, 0x8cf30bad, 0x81b02d74, 0x857130c3,
0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640, 0x4e8ee645, 0x4a4ffbf2, 0x470cdd2b, 0x43cdc09c,
0x7b827d21, 0x7f436096, 0x7200464f, 0x76c15bf8, 0x68860bfd, 0x6c47164a, 0x61043093, 0x65c52d24,
0x119b4be9, 0x155a565e, 0x18197087, 0x1cd86d30, 0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec,
0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088, 0x2497d08d, 0x2056cd3a, 0x2d15ebe3, 0x29d4f654,
0xc5a92679, 0xc1683bce, 0xcc2b1d17, 0xc8ea00a0, 0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb, 0xdbee767c,
0xe3a1cbc1, 0xe760d676, 0xea23f0af, 0xeee2ed18, 0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4,
0x89b8fd09, 0x8d79e0be, 0x803ac667, 0x84fbdbd0, 0x9abc8bd5, 0x9e7d9662, 0x933eb0bb, 0x97ffad0c,
0xafb010b1, 0xab710d06, 0xa6322bdf, 0xa2f33668, 0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4,
];
// generated from 1 << i, except for 32
const masks = [
0x00000000, 0x00000001, 0x00000003, 0x00000007,
0x0000000f, 0x0000001f, 0x0000003f, 0x0000007f,
0x000000ff, 0x000001ff, 0x000003ff, 0x000007ff,
0x00000fff, 0x00001fff, 0x00003fff, 0x00007fff,
0x0000ffff, 0x0001ffff, 0x0003ffff, 0x0007ffff,
0x000fffff, 0x001fffff, 0x003fffff, 0x007fffff,
0x00ffffff, 0x01ffffff, 0x03ffffff, 0x07ffffff,
0x0fffffff, 0x1fffffff, 0x3fffffff, -0x80000000,
];
function createOrderedHuffmanTable(lengths) {
const z = [];
for (let i = 0; i < lengths.length; i += 1) {
z.push([i, lengths[i]]);
}
z.push([lengths.length, -1]);
const table = [];
let start = z[0][0];
let bits = z[0][1];
for (let i = 0; i < z.length; i += 1) {
const finish = z[i][0];
const endbits = z[i][1];
if (bits) {
for (let code = start; code < finish; code += 1) {
table.push({ code, bits, symbol: undefined });
}
}
start = finish;
bits = endbits;
if (endbits === -1) {
break;
}
}
table.sort((a, b) => ((a.bits - b.bits) || (a.code - b.code)));
let tempBits = 0;
let symbol = -1;
const fastAccess = [];
let current;
for (let i = 0; i < table.length; i += 1) {
const t = table[i];
symbol += 1;
if (t.bits !== tempBits) {
symbol <<= t.bits - tempBits;
tempBits = t.bits;
current = fastAccess[tempBits] = {};
}
t.symbol = symbol;
current[symbol] = t;
}
return {
table,
fastAccess,
};
}
function bwtReverse(src, primary) {
if (primary < 0 || primary >= src.length) {
throw RangeError('Out of bound');
}
const unsorted = src.slice();
src.sort((a, b) => a - b);
const start = {};
for (let i = src.length - 1; i >= 0; i -= 1) {
start[src[i]] = i;
}
const links = [];
for (let i = 0; i < src.length; i += 1) {
links.push(start[unsorted[i]]++); // eslint-disable-line no-plusplus
}
let i;
const first = src[i = primary];
const ret = [];
for (let j = 1; j < src.length; j += 1) {
const x = src[i = links[i]];
if (x === undefined) {
ret.push(255);
} else {
ret.push(x);
}
}
ret.push(first);
ret.reverse();
return ret;
}
function decompress(bytes, checkCRC = false) {
let index = 0;
let bitfield = 0;
let bits = 0;
const read = (n) => {
if (n >= 32) {
const nd = n >> 1;
return read(nd) * (1 << nd) + read(n - nd);
}
while (bits < n) {
bitfield = (bitfield << 8) + bytes[index];
index += 1;
bits += 8;
}
const m = masks[n];
const r = (bitfield >> (bits - n)) & m;
bits -= n;
bitfield &= ~(m << bits);
return r;
};
const magic = read(16);
if (magic !== 0x425A) { // 'BZ'
throw new Error('Invalid magic');
}
const method = read(8);
if (method !== 0x68) { // h for huffman
throw new Error('Invalid method');
}
let blocksize = read(8);
if (blocksize >= 49 && blocksize <= 57) { // 1..9
blocksize -= 48;
} else {
throw new Error('Invalid blocksize');
}
let out = new Uint8Array(bytes.length * 1.5);
let outIndex = 0;
let newCRC = -1;
while (true) {
const blocktype = read(48);
const crc = read(32) | 0;
if (blocktype === 0x314159265359) {
if (read(1)) {
throw new Error('do not support randomised');
}
const pointer = read(24);
const used = [];
const usedGroups = read(16);
for (let i = 1 << 15; i > 0; i >>= 1) {
if (!(usedGroups & i)) {
for (let j = 0; j < 16; j += 1) {
used.push(false);
}
continue; // eslint-disable-line no-continue
}
const usedChars = read(16);
for (let j = 1 << 15; j > 0; j >>= 1) {
used.push(!!(usedChars & j));
}
}
const groups = read(3);
if (groups < 2 || groups > 6) {
throw new Error('Invalid number of huffman groups');
}
const selectorsUsed = read(15);
const selectors = [];
const mtf = Array.from({ length: groups }, (_, i) => i);
for (let i = 0; i < selectorsUsed; i += 1) {
let c = 0;
while (read(1)) {
c += 1;
if (c >= groups) {
throw new Error('MTF table out of range');
}
}
const v = mtf[c];
for (let j = c; j > 0; mtf[j] = mtf[--j]) { // eslint-disable-line no-plusplus
// nothing
}
selectors.push(v);
mtf[0] = v;
}
const symbolsInUse = used.reduce((a, b) => a + b, 0) + 2;
const tables = [];
for (let i = 0; i < groups; i += 1) {
let length = read(5);
const lengths = [];
for (let j = 0; j < symbolsInUse; j += 1) {
if (length < 0 || length > 20) {
throw new Error('Huffman group length outside range');
}
while (read(1)) {
length -= (read(1) * 2) - 1;
}
lengths.push(length);
}
tables.push(createOrderedHuffmanTable(lengths));
}
const favourites = [];
for (let i = 0; i < used.length - 1; i += 1) {
if (used[i]) {
favourites.push(i);
}
}
let decoded = 0;
let selectorPointer = 0;
let t;
let r;
let repeat = 0;
let repeatPower = 0;
const buffer = [];
while (true) {
decoded -= 1;
if (decoded <= 0) {
decoded = 50;
if (selectorPointer <= selectors.length) {
t = tables[selectors[selectorPointer]];
selectorPointer += 1;
}
}
for (const b in t.fastAccess) {
if (!Object.prototype.hasOwnProperty.call(t.fastAccess, b)) {
continue; // eslint-disable-line no-continue
}
if (bits < b) {
bitfield = (bitfield << 8) + bytes[index];
index += 1;
bits += 8;
}
r = t.fastAccess[b][bitfield >> (bits - b)];
if (r) {
bitfield &= masks[bits -= b];
r = r.code;
break;
}
}
if (r >= 0 && r <= 1) {
if (repeat === 0) {
repeatPower = 1;
}
repeat += repeatPower << r;
repeatPower <<= 1;
continue; // eslint-disable-line no-continue
} else {
const v = favourites[0];
for (; repeat > 0; repeat -= 1) {
buffer.push(v);
}
}
if (r === symbolsInUse - 1) {
break;
} else {
const v = favourites[r - 1];
// eslint-disable-next-line no-plusplus
for (let j = r - 1; j > 0; favourites[j] = favourites[--j]) {
// nothing
}
favourites[0] = v;
buffer.push(v);
}
}
const nt = bwtReverse(buffer, pointer);
let i = 0;
while (i < nt.length) {
const c = nt[i];
let count = 1;
if ((i < nt.length - 4)
&& nt[i + 1] === c
&& nt[i + 2] === c
&& nt[i + 3] === c) {
count = nt[i + 4] + 4;
i += 5;
} else {
i += 1;
}
if (outIndex + count >= out.length) {
const old = out;
out = new Uint8Array(old.length * 2);
out.set(old);
}
for (let j = 0; j < count; j += 1) {
if (checkCRC) {
newCRC = (newCRC << 8) ^ crc32Table[((newCRC >> 24) ^ c) & 0xff];
}
out[outIndex] = c;
outIndex += 1;
}
}
if (checkCRC) {
const calculatedCRC = newCRC ^ -1;
if (calculatedCRC !== crc) {
throw new Error(`CRC mismatch: ${calculatedCRC} !== ${crc}`);
}
newCRC = -1;
}
} else if (blocktype === 0x177245385090) {
read(bits & 0x07); // pad align
break;
} else {
throw new Error('Invalid bz2 blocktype');
}
}
return out.subarray(0, outIndex);
}
module.exports = { decompress };

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{
"name": "bz2",
"version": "1.0.0",
"description": "bzip2 for JavaScript",
"main": "index.js",
"directories": {
"test": "tests"
},
"scripts": {
"test": "node test.js"
},
"repository": {
"type": "git",
"url": "git+https://github.com/sheetjs/bz2.git"
},
"author": "gus@sheetjs.com",
"license": "MIT",
"bugs": {
"url": "https://github.com/sheetjs/bz2/issues"
},
"homepage": "https://github.com/sheetjs/bz2#readme"
}

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'use strict';
const { readFileSync, writeFileSync, readdirSync } = require('fs');
const { deepStrictEqual } = require('assert');
const { decompress } = require('.');
const [input, out] = process.argv.slice(2);
if (input) {
writeFileSync(out, decompress(readFileSync(input)));
} else {
const tests = readdirSync('./tests')
.filter((x) => x.endsWith('.bz2'));
tests.forEach((test) => {
const name = test.split('.')[0];
console.log(name);
const result = decompress(readFileSync(`./tests/${name}.bz2`), true);
const original = new Uint8Array(readFileSync(`./tests/${name}.out`));
deepStrictEqual(result, original);
});
}

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a

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hello world

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