text: /*!
   * ws: a node.js websocket client
   * Copyright(c) 2011 Einar Otto Stangvik <einaros@gmail.com>
   * MIT Licensed
   */
  
  var util = require('util');
  
  function BufferPool(initialSize, growStrategy, shrinkStrategy) {
    if (this instanceof BufferPool === false) {
      throw new TypeError("Classes can't be function-called");
    }
  
    if (typeof initialSize === 'function') {
      shrinkStrategy = growStrategy;
      growStrategy = initialSize;
      initialSize = 0;
    }
    else if (typeof initialSize === 'undefined') {
      initialSize = 0;
    }
    this._growStrategy = (growStrategy || function(db, size) {
      return db.used + size;
    }).bind(null, this);
    this._shrinkStrategy = (shrinkStrategy || function(db) {
      return initialSize;
    }).bind(null, this);
    this._buffer = initialSize ? Buffer.alloc(initialSize) : null;
    this._offset = 0;
    this._used = 0;
    this._changeFactor = 0;
    this.__defineGetter__('size', function(){
      return this._buffer == null ? 0 : this._buffer.length;
    });
    this.__defineGetter__('used', function(){
      return this._used;
    });
  }
  
  BufferPool.prototype.get = function(length) {
    if (this._buffer == null || this._offset + length > this._buffer.length) {
      var newBuf = Buffer.alloc(this._growStrategy(length));
      this._buffer = newBuf;
      this._offset = 0;
    }
    this._used += length;
    var buf = this._buffer.slice(this._offset, this._offset + length);
    this._offset += length;
    return buf;
  }
  
  BufferPool.prototype.reset = function(forceNewBuffer) {
    var len = this._shrinkStrategy();
    if (len < this.size) this._changeFactor -= 1;
    if (forceNewBuffer || this._changeFactor < -2) {
      this._changeFactor = 0;
      this._buffer = len ? Buffer.alloc(len) : null;
    }
    this._offset = 0;
    this._used = 0;
  }
  
  module.exports = BufferPool;
  