fast.js

gistfile1.txt

var WriteStream = require('fs').WriteStream;

var BUF_SIZE = 1 * 1024 * 1024;
var CHUNK_MAX = 100 * 1024;

WriteStream.prototype.__write = WriteStream.prototype.write;
WriteStream.prototype.__end = WriteStream.prototype.end;

WriteStream.prototype.__flush = function() {
  if (this.__writeBehindBuffer &&
      this.__writeBehindUsed) {
    this.__write(this.__writeBehindBuffer.slice(0, this.__writeBehindUsed));
    
    this.__writeBehindBuffer = null;
    this.__writeBehindUsed = 0;
  }
}

WriteStream.prototype.write = function(chunk, encoding, cb) {
  if (typeof chunk === 'function') {
    cb = chunk;
    chunk = null;
    encoding = null;
  } else if (typeof encoding === 'function') {
    cb = encoding;
    encoding = null;
  }
  
  // No string support for now
  // Also if the chunk is very big, don't buffer
  if (!Buffer.isBuffer(chunk) ||
      chunk.length > CHUNK_MAX) {
    this.__flush();
    return this.__write(chunk, encoding, cb);
  }
  
  var left = this.__writeBehindBuffer ? 
                this.__writeBehindBuffer.length - this.__writeBehindUsed : 0
  
  if (left < chunk.length) {
    this.__flush();
    this.__writeBehindBuffer = new Buffer(BUF_SIZE);
    this.__writeBehindUsed = 0;
  }
  
  chunk.copy(this.__writeBehindBuffer, this.__writeBehindUsed);
  this.__writeBehindUsed += chunk.length;
}

WriteStream.prototype.end = function(chunk, encoding, cb) {
  if (typeof chunk === 'function') {
    cb = chunk;
    chunk = null;
    encoding = null;
  } else if (typeof encoding === 'function') {
    cb = encoding;
    encoding = null;
  }
  
  if (chunk)
    this.write(chunk, encoding);
    
  this.__flush();
  this.__end(cb);
}