Concentrate

Produce binary data with a neat DSL.

Overview

Concentrate allows you to efficiently create buffers by chaining together calls to write numbers, strings and even other buffers! Concentrate is also easily extendable so you can implement your own custom types.

If you want to parse binary data, might I suggest dissolve?

Features

• Accurate handling of [u]int{8,16,32} numbers in both signed and unsigned variants using fast, built-in Buffer methods
• Fast and reliable operation through lazy compilation of results
• Tiny (<150 LoC) implementation, allowing for easy debugging
• Stream interface with explicit flushing for maximum speeeeeeed (inspired by felixge, so you know it's good!)

Installation

Available via npm:

$ npm install concentrate

Or via git:

$ git clone git://github.com/deoxxa/concentrate.git node_modules/concentrate

Usage

Also see example.js and example-complex.js.

#!/usr/bin/env node
 
var Concentrate = require("./index");
 
var data = Concentrate().uint8(1).uint8(2).uint32be(555).string("hi there", "utf8").result();
 
console.log(data);

<Buffer 01 02 00 00 02 2b 68 69 20 74 68 65 72 65 40 06 66 66 40 00 cc cc cc cc cc cd>

Oh look! Streams! Also see example-stream.js.

#!/usr/bin/env node
 
var Concentrate = require("./index");
 
var c = Concentrate();
 
c.on("end", function() {
  console.log("ended");
});
 
c.on("readable", function() {
  var e;
  while (e = c.read()) {
    console.log(e);
  }
});
 
c.uint8(1).uint8(2).uint32be(555).string("hi there", "utf8").floatbe(2.1).doublebe(2.1).flush();
c.uint8(5).uint8(6);
c.uint8(7);
c.uint8(30);
c.flush().end();

<Buffer 01 02 00 00 02 2b 68 69 20 74 68 65 72 65 40 06 66 66 40 00 cc cc cc cc cc cd>
<Buffer 05 06 07 1e>
ended

Methods

All methods aside from result are chainable and all except copy return the same Concentrate instance they were called on.

Execution Methods

• copy() - returns a new copy of the current Concentrate instance, copying the state of the current job list
• reset() - resets the job list
• result() - compiles the job list into a buffer and returns that buffer
• flush() - compiles the current job list, emits it via the stream API, then clears the current job list
• end() - ends the stream part of Concentrate (basically makes it emit "end")

Writing methods

• buffer(data)
• string(data, encoding) - write a string with the given encoding
• int8(data) - signed 8 bit integer
• sint8(data) - signed 8 bit integer
• uint8(data) - unsigned 8 bit integer
• int16(data) - signed, little endian 16 bit integer
• int16le(data) - signed, little endian 16 bit integer
• int16be(data) - signed, big endian 16 bit integer
• sint16(data) - signed, little endian 16 bit integer
• sint16le(data) - signed, little endian 16 bit integer
• sint16be(data) - signed, big endian 16 bit integer
• uint16(data) - unsigned, little endian 16 bit integer
• uint16le(data) - unsigned, little endian 16 bit integer
• uint16be(data) - unsigned, big endian 16 bit integer
• int32(data) - signed, little endian 32 bit integer
• int32le(data) - signed, little endian 32 bit integer
• int32be(data) - signed, big endian 32 bit integer
• sint32(data) - signed, little endian 32 bit integer
• sint32le(data) - signed, little endian 32 bit integer
• sint32be(data) - signed, big endian 32 bit integer
• uint32(data) - unsigned, little endian 32 bit integer
• uint32le(data) - unsigned, little endian 32 bit integer
• uint32be(data) - unsigned, big endian 32 bit integer
• floatbe(data) - big endian 32 bit float
• floatle(data) - little endian 32 bit float
• doublebe(data) - big endian 64 bit double
• doublele(data) - little endian 64 bit double

License

3-clause BSD. A copy is included with the source.

Contact

• GitHub (deoxxa)
• Twitter (@deoxxa)
• ADN (@deoxxa)
• Email ([e-mail])