transparent-http-compress

transparent-http-compress

transparent-http-compress creates a stream based on the accept-encoding HTTP header which transparently compresses the data written to it while being fully compatible to original response

Usage

For normal usage, just call httpCompress.compress and use the return value as new response:

const http = require('http');
const httpCompress = require('transparent-http-compress');

http.createServer((request, response) =>
{
	let compressedResponse = httpCompress.compress(request, response);

	//compressedResponse is connected and fully compatible to the original response
	//and can be used as it would be the real response
	compressedResponse.setHeader('x-foo', 'bar');

	compressedResponse.writeHead(403,
		{
			'x-bar': 'foo'
		}
	);
	compressedResponse.write('Hello HTTP');
	compressedResponse.end();
});

If you want to add new compression libraries or replace or disable existing ones, either set or extend the variable httpCompress.libraries to set the default for all future responses, or pass an object to httpCompress.compress which then will then be merged into the default libraries in httpCompress.libraries for that response:

const http = require('http');
const httpCompress = require('transparent-http-compress');

const myZLib = require('./my-zlib');

//Add/replace the 'deflate' library
httpCompress.libraries.deflate = () => myZLib.createDeflate();

http.createServer((request, response) =>
{
	let compressedResponse = httpCompress.compress(request, response,
		{
			gzip: null, //As this object is merged
						//into the default libraries,
						//gzip will be disabled for this response
		}
	);


	compressedResponse.write('Hello HTTP');
	compressedResponse.end();
});

It's also possible, to pass the Accept-Encoding header manually instead of the whole request object. This also allows to pass a single compression method and if available, that one will be used:

const http = require('http');
const httpCompress = require('transparent-http-compress');

http.createServer((request, response) =>
{
	let compressedResponse = httpCompress.compress('deflate, gzip', response);

	compressedResponse.write('Hello HTTP');
	compressedResponse.end();
});

Supported compression methods

Default compression methods

Following compression methods can be used without any dependencies as they're done using the NodeJS core packages. These are enabled by default:

• deflate: Using NodeJS zlib
• gzip: Using NodeJS zlib
• br (brotli): Using NodeJS 11+ zlib

Compressions with dependencies

Some compression methods are provided by other packages not included in NodeJS. transparent-http-compress doesn't have this dependencies listed in package.json so users don't have to download huge dependency-trees if they don't use the features. If you want to use a compression listed here, just install the dependency and transparent-http-compress will automatically use it.

• br (brotli): When below NodeJS 11.7, depends on npm package iltorb

API

compress(request, response, [additionalLibraries])

arguments

• request (http.IncommingMessage or compatible)
• response (http.ServerResponse or compatible)
• additionalLibraries (object) in format { LIBNAME: () => return STREAMINSTANCE };

returns

• object fully compatible to response