te_nsqjs/lib/framebuffer.js

NodeJS client for NSQ

// Generated by CoffeeScript 1.12.3
var FrameBuffer, _;

_ = require('underscore');

FrameBuffer = (function() {
  function FrameBuffer() {}

  FrameBuffer.prototype.consume = function(raw) {
    return this.buffer = Buffer.concat(_.compact([this.buffer, raw]));
  };

  FrameBuffer.prototype.nextFrame = function() {
    var frame, nextOffset;
    if (!this.buffer) {
      return;
    }
    if (!(this.frameSize(0) && this.frameSize(0) <= this.buffer.length)) {
      return;
    }
    frame = this.pluckFrame();
    nextOffset = this.nextOffset();
    this.buffer = this.buffer.slice(nextOffset);
    if (!this.buffer.length) {
      delete this.buffer;
    }
    return frame;
  };

  FrameBuffer.prototype.pluckFrame = function(offset) {
    var frame, frameId;
    if (offset == null) {
      offset = 0;
    }
    frame = this.buffer.slice(offset, offset + this.frameSize(offset));
    frameId = frame.readInt32BE(4);
    return [frameId, frame.slice(8)];
  };

  FrameBuffer.prototype.nextOffset = function(offset) {
    var size;
    if (offset == null) {
      offset = 0;
    }
    size = this.frameSize(offset);
    if (size) {
      return offset + size;
    }
  };

  FrameBuffer.prototype.frameSize = function(offset) {
    if (!(this.buffer && this.buffer.length > 4)) {
      return;
    }
    if (offset + 4 <= this.buffer.length) {
      return 4 + this.buffer.readInt32BE(offset);
    }
  };

  return FrameBuffer;

})();

module.exports = FrameBuffer;