cscg24-guacamole

CSCG 2024 Challenge 'Guacamole Mashup'
git clone https://git.sinitax.com/sinitax/cscg24-guacamole
Log | Files | Refs | sfeed.txt

BufferPool.js (1775B)

      1/*!
      2 * ws: a node.js websocket client
      3 * Copyright(c) 2011 Einar Otto Stangvik <einaros@gmail.com>
      4 * MIT Licensed
      5 */
      6
      7var util = require('util');
      8
      9function BufferPool(initialSize, growStrategy, shrinkStrategy) {
     10  if (this instanceof BufferPool === false) {
     11    throw new TypeError("Classes can't be function-called");
     12  }
     13
     14  if (typeof initialSize === 'function') {
     15    shrinkStrategy = growStrategy;
     16    growStrategy = initialSize;
     17    initialSize = 0;
     18  }
     19  else if (typeof initialSize === 'undefined') {
     20    initialSize = 0;
     21  }
     22  this._growStrategy = (growStrategy || function(db, size) {
     23    return db.used + size;
     24  }).bind(null, this);
     25  this._shrinkStrategy = (shrinkStrategy || function(db) {
     26    return initialSize;
     27  }).bind(null, this);
     28  this._buffer = initialSize ? new Buffer(initialSize) : null;
     29  this._offset = 0;
     30  this._used = 0;
     31  this._changeFactor = 0;
     32  this.__defineGetter__('size', function(){
     33    return this._buffer == null ? 0 : this._buffer.length;
     34  });
     35  this.__defineGetter__('used', function(){
     36    return this._used;
     37  });
     38}
     39
     40BufferPool.prototype.get = function(length) {
     41  if (this._buffer == null || this._offset + length > this._buffer.length) {
     42    var newBuf = new Buffer(this._growStrategy(length));
     43    this._buffer = newBuf;
     44    this._offset = 0;
     45  }
     46  this._used += length;
     47  var buf = this._buffer.slice(this._offset, this._offset + length);
     48  this._offset += length;
     49  return buf;
     50}
     51
     52BufferPool.prototype.reset = function(forceNewBuffer) {
     53  var len = this._shrinkStrategy();
     54  if (len < this.size) this._changeFactor -= 1;
     55  if (forceNewBuffer || this._changeFactor < -2) {
     56    this._changeFactor = 0;
     57    this._buffer = len ? new Buffer(len) : null;
     58  }
     59  this._offset = 0;
     60  this._used = 0;
     61}
     62
     63module.exports = BufferPool;