88 lines
2.6 KiB
Markdown
88 lines
2.6 KiB
Markdown
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node-packet-reader
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==================
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Handy little well tested module for reading length-prefixed binary packets.
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Since buffers come off a socket in randomly sized chunks you can't expect them to cleanly
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break on packet boundaries. This module allows you to push buffers in and read
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full packets out the other side, so you can get to parsing right away and not have
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to manage concatenating partial buffers and searching through them for packets.
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## install
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` $ npm install packet-reader `
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## example
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```js
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var Reader = require('packet-reader')
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var reader = new Reader()
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//assuming you have a socket emitting `data` events
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socket.on('data', function(buffer) {
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reader.addChunk(buffer)
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var packet = reader.read()
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while(packet) {
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//do something with fully parsed packet
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}
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})
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```
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here's a more full featured example:
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let's assume our "packet" for our protocol is 32-bit Big Endian length-prefixed strings
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so a "hello world" packet would look something like [length, string]
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`[0, 0, 0 0x0B, h, e, l, l, o, w, o, r, l, d]`
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```js
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var Transform = require('stream').Transform
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var Reader = require('packet-reader')
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var reader = new Reader()
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var parser = new Transform()
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parser._transform = function(chunk, encoding, cb) {
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reader.addChunk(chunk)
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var packet = reader.read()
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while(packet) {
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this.push(packet.toString('utf8'))
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packet = reader.read()
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}
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cb()
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}
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var server = net.createServer(function(socket) {
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socket.pipe(parser).pipe(stdout)
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})
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```
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There are a few config options for setting optional pre-length padding byte. Read the tests for details.
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## License
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MIT
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Copyright 2015 Brian M. Carlson
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All rights reserved.
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Permission is hereby granted, free of charge, to any person
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obtaining a copy of this software and associated documentation
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files (the "Software"), to deal in the Software without
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restriction, including without limitation the rights to use,
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copy, modify, merge, publish, distribute, sublicense, and/or sell
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copies of the Software, and to permit persons to whom the
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Software is furnished to do so, subject to the following
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conditions:
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The above copyright notice and this permission notice shall be
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included in all copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
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OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
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HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
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WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
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OTHER DEALINGS IN THE SOFTWARE.
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