A very fast streaming multipart parser for node.js
npm install dicer
Description
===========
A very fast streaming multipart parser for node.js.
Benchmarks can be found here.
Requirements
============
* node.js -- v10.0.0 or newer
Install
============
npm install dicer
Examples
========
* Parse an HTTP form upload
``js
const { inspect } = require('util');
const http = require('http');
const Dicer = require('dicer');
// Quick and dirty way to parse multipart boundary
const RE_BOUNDARY =
/^multipart\/.+?(?:; boundary=(?:(?:"(.+)")|(?:([^\s]+))))$/i;
const HTML = Buffer.from(
);
const PORT = 8080;http.createServer((req, res) => {
let m;
if (req.method === 'POST'
&& req.headers['content-type']
&& (m = RE_BOUNDARY.exec(req.headers['content-type']))) {
const d = new Dicer({ boundary: m[1] || m[2] });
d.on('part', (p) => {
console.log('New part!');
p.on('header', (header) => {
for (const h in header) {
console.log(
Part header: k: ${inspect(h)}, v: ${inspect(header[h])}
);
}
});
p.on('data', (data) => {
console.log();
});
p.on('end', () => {
console.log('End of part\n');
});
});
d.on('finish', () => {
console.log('End of parts');
res.writeHead(200);
res.end('Form submission successful!');
});
req.pipe(d);
} else if (req.method === 'GET' && req.url === '/') {
res.writeHead(200);
res.end(HTML);
} else {
res.writeHead(404);
res.end();
}
}).listen(PORT, () => {
console.log(Listening for requests on port ${PORT});
});
`
API
===
_Dicer_ is a _Writable_ stream
Dicer (special) events
----------------------
* finish() - Emitted when all parts have been parsed and the Dicer instance has been ended.
* part(< _PartStream_ >stream) - Emitted when a new part has been found.
* preamble(< _PartStream_ >stream) - Emitted for preamble if you should happen to need it (can usually be ignored).
* trailer(< _Buffer_ >data) - Emitted when trailing data was found after the terminating boundary (as with the preamble, this can usually be ignored too).
Dicer methods
-------------
* (constructor)(< _object_ >config) - Creates and returns a new Dicer instance with the following valid
settings: * boundary - _string_ - This is the boundary used to detect the beginning of a new part.
* headerFirst - _boolean_ - If true, preamble header parsing will be performed first.
* maxHeaderPairs - _integer_ - The maximum number of header key=>value pairs to parse Default: 2000 (same as node's http).
* setBoundary(< _string_ >boundary) - _(void)_ - Sets the boundary to use for parsing and performs some initialization needed for parsing. You should only need to use this if you set
headerFirst` to true in the constructor and are parsing the boundary from the preamble header._PartStream_ is a _Readable_ stream
PartStream (special) events
---------------------------
* header(< _object_ >header) - An object containing the header for this particular part. Each property value is an _array_ of one or more string values.