chunker/index.js

Chunk/split your stream without eating the splitter char.

// Generated by CoffeeScript 1.6.3
var __hasProp = {}.hasOwnProperty,
  __extends = function(child, parent) { for (var key in parent) { if (__hasProp.call(parent, key)) child[key] = parent[key]; } function ctor() { this.constructor = child; } ctor.prototype = parent.prototype; child.prototype = new ctor(); child.__super__ = parent.prototype; return child; };

module.exports = (function() {
  var Chunker, stream;
  stream = require('stream');
  return Chunker = (function(_super) {
    __extends(Chunker, _super);

    Chunker.prototype.leftover = null;

    Chunker.prototype.matcher = new Buffer('\r\n');

    function Chunker(options) {
      Chunker.__super__.constructor.call(this, options);
      if (options && options.matcher) {
        this.matcher = options.matcher;
        if (typeof this.matcher === 'string') {
          this.matcher = new Buffer(this.matcher);
        }
      }
    }

    Chunker.prototype._transform = function(chunk, encoding, callback) {
      var i, j, match, matched, part, pivot, skip, start, _i, _j, _ref, _ref1;
      pivot = this.matcher[this.matcher.length - 1];
      matched = false;
      match = -1;
      start = 0;
      skip = 0;
      if (this.leftover) {
        chunk = Buffer.concat([this.leftover, chunk], this.leftover.length + chunk.length);
        skip = this.leftover.length - this.matcher.length;
        this.leftover = null;
      }
      for (i = _i = skip, _ref = chunk.length; _i < _ref; i = _i += 1) {
        if (chunk[i] !== pivot) {
          continue;
        }
        match = i;
        for (j = _j = i, _ref1 = i - this.matcher.length; _j > _ref1; j = _j += -1) {
          if (chunk[j] === this.matcher[this.matcher.length - i + j - 1]) {
            continue;
          }
          match = -1;
        }
        if (match > -1) {
          part = chunk.slice(start, match + 1);
          start = match + 1;
          this.leftover = chunk.slice(start);
          this.push(part);
          this.emit('chunk', part);
        }
      }
      this.leftover = chunk.slice(start);
      return callback(null);
    };

    return Chunker;

  })(stream.Transform);
})();