Usage in Deno
import * as mod from "node:zlib";
The node:zlib module provides compression functionality implemented using
Gzip, Deflate/Inflate, and Brotli.
To access it:
import zlib from 'node:zlib';
Compression and decompression are built around the Node.js Streams API.
Compressing or decompressing a stream (such as a file) can be accomplished by
piping the source stream through a zlib Transform stream into a destination
stream:
import { createGzip } from 'node:zlib';
import { pipeline } from 'node:stream';
import {
createReadStream,
createWriteStream,
} from 'node:fs';
const gzip = createGzip();
const source = createReadStream('input.txt');
const destination = createWriteStream('input.txt.gz');
pipeline(source, gzip, destination, (err) => {
if (err) {
console.error('An error occurred:', err);
process.exitCode = 1;
}
});
// Or, Promisified
import { promisify } from 'node:util';
const pipe = promisify(pipeline);
async function do_gzip(input, output) {
const gzip = createGzip();
const source = createReadStream(input);
const destination = createWriteStream(output);
await pipe(source, gzip, destination);
}
do_gzip('input.txt', 'input.txt.gz')
.catch((err) => {
console.error('An error occurred:', err);
process.exitCode = 1;
});
It is also possible to compress or decompress data in a single step:
import { deflate, unzip } from 'node:zlib';
const input = '.................................';
deflate(input, (err, buffer) => {
if (err) {
console.error('An error occurred:', err);
process.exitCode = 1;
}
console.log(buffer.toString('base64'));
});
const buffer = Buffer.from('eJzT0yMAAGTvBe8=', 'base64');
unzip(buffer, (err, buffer) => {
if (err) {
console.error('An error occurred:', err);
process.exitCode = 1;
}
console.log(buffer.toString());
});
// Or, Promisified
import { promisify } from 'node:util';
const do_unzip = promisify(unzip);
do_unzip(buffer)
.then((buf) => console.log(buf.toString()))
.catch((err) => {
console.error('An error occurred:', err);
process.exitCode = 1;
});
f
f
f
f
f
crc32
Computes a 32-bit Cyclic Redundancy Check checksum of data.
If value is specified, it is used as the starting value of the checksum, otherwise, 0 is used as the starting value.
f
f
f
f
f
f
f
f
f
f
f
f
f
f
f
f
f
f
f
f
f
f
f
N
T
T
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v
v