forked from antimatter15/bzip2.js
/
node-test.js
131 lines (116 loc) · 3.01 KB
/
node-test.js
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var fs = require('fs');
var bz2 = require('./bzip2.js');
var bufferSize = 1;
var reader = fs.createReadStream('test.txt.bz2', { bufferSize: bufferSize });
process.on('unhandledRejection', error => {
throw error;
});
// var blockSize;
// reader.on('data', function (data) {
// var bitReader = bz2.array(data);
// if (!blockSize) {
// blockSize = bz2.header(bitReader);
// }
// console.log( bz2.decompress(bitReader, blockSize) );
// });
// var bit = 0, readBytes = 0;
// var BITMASK = [0, 0x01, 0x03, 0x07, 0x0F, 0x1F, 0x3F, 0x7F, 0xFF ];
// var buffer = new Buffer(0)
// var hasBytes = 0;
// var blockOffset = 0;
// var blockSize = 0;
// function bitReader(n){
// var result = 0;
// while(n > 0){
// var left = 8 - bit;
// var currentByte = buffer[readBytes - blockOffset];
// if(n >= left){
// result <<= left;
// result |= (BITMASK[left] & currentByte);
// readBytes++;
// bit = 0;
// n -= left;
// }else{
// result <<= n;
// result |= ((currentByte & (BITMASK[n] << (8 - n - bit))) >> (8 - n - bit));
// bit += n;
// n = 0;
// }
// }
// return result;
// }
// reader.on('data', function (data) {
// var newData = data.length;
// blockOffset = readBytes;
// var newBuffer = new Buffer(hasBytes - readBytes + newData); //create a buffer for all the unread bytes
// buffer.copy(newBuffer, 0, hasBytes - readBytes);
// data.copy(newBuffer, hasBytes - readBytes);
// buffer = newBuffer;
// hasBytes += data.length;
// if(hasBytes - readBytes > blockSize){
// if(!blockSize){
// blockSize = bz2.header(bitReader);
// }else{
// bz2.decompress(bitReader, blockSize)
// }
// }
// })
var bit = 0, readBytes = 0, readOffset = 0;
var BITMASK = [0, 0x01, 0x03, 0x07, 0x0F, 0x1F, 0x3F, 0x7F, 0xFF ];
var bufferQueue = [];
var buffer = [];
async function bitReader (n){
var result = 0;
while(n > 0){
var left = 8 - bit;
if(buffer.length == readBytes - readOffset){
readOffset = readBytes;
buffer = bufferQueue.shift();
}
var currentByte = buffer[readBytes - readOffset];
if(n >= left){
result <<= left;
result |= (BITMASK[left] & currentByte);
readBytes++;
bit = 0;
n -= left;
}else{
result <<= n;
result |= ((currentByte & (BITMASK[n] << (8 - n - bit))) >> (8 - n - bit));
bit += n;
n = 0;
}
}
return result;
}
var blockSize = 0;
var fullFile = '';
async function decompressBlock(){
if(!blockSize){
blockSize = await bz2.header(bitReader);
console.log("got header of", blockSize)
}else{
var chunk = await bz2.decompress(bitReader, blockSize);
if(chunk == -1){
if (fullFile !== fs.readFileSync('LICENSE.md', 'utf8')) {
throw new Error('not a match')
}
console.log('done')
}else{
fullFile += chunk
console.log(chunk)
}
}
}
var hasBytes = 0;
reader.on('data', function (data) {
bufferQueue.push(data);
hasBytes += data.length;
if(hasBytes - readBytes > (100000 * blockSize || 10)){
console.log('decompressing with ', hasBytes)
decompressBlock()
}
})
reader.on('end', function (data) {
decompressBlock()
})