var fs = require('fs'); 
var util = require('util'); 
var Buffer = require('buffer').Buffer; 
var path = "/tmp/wt.dat"; 
var tsize = 1000 * 1048576; 
var bsizes = [1024, 4096, 8192, 16384, 32768, 65536] ; 
function bufit(size){ 
var buf = new Buffer(size); 
for (var i = 0; 
i < _AN_Read_length("length", buf); i += 1){ 
buf[i] = 33; 
} 
return buf; 
} 
function once(emitter, name, cb){ 
function incb(){ 
cb.apply(undefined, arguments); 
emitter.removeListener(name, incb); 
} 
emitter.addListener(name, incb); 
} 
c = 0; 
function writetest(size, bsize){ 
var s = fs.createWriteStream(path, { 
'flags': 'w',
'mode': 420}
); 
var remaining = size; 
var buf = bufit(bsize); 
function dowrite(){ 
var rv = _AN_Call_write('write', s, buf); 
remaining -= _AN_Read_length('length', buf); 
if (remaining > 0) { 
} 
 else { 
s.emit('done'); 
s.end(); 
} 
} 
s.on('drain', function (){ 
dowrite(); 
if (c++  % 2000 == 0) util.print("."); 
} 
); 
dowrite(); 
return s; 
} 
function readtest(size, bsize){ 
var s = fs.createReadStream(path, { 
'flags': 'r',
'encoding': 'binary',
'mode': 420,
'bufferSize': bsize}
); 
s.addListener("data", function (chunk){ 
} 
); 
return s; 
} 
function wt(tsize, bsize, done){ 
var start = Date.now(); 
s = writetest(tsize, bsize); 
s.addListener('close', function (){ 
var end = Date.now(); 
var diff = end - start; 
console.log('Wrote ' + tsize + ' bytes in ' + diff / 1000 + 's using ' + bsize + ' byte buffers: ' + ((tsize / (diff / 1000)) / 1048576) + ' mB/s'); 
done(); 
} 
); 
} 
function rt(tsize, bsize, done){ 
var start = Date.now(); 
s = readtest(tsize, bsize); 
s.addListener('close', function (){ 
var end = Date.now(); 
var diff = end - start; 
console.log('Read ' + tsize + ' bytes in ' + diff / 1000 + 's using ' + bsize + ' byte buffers: ' + ((tsize / (diff / 1000)) / 1048576) + ' mB/s'); 
done(); 
} 
); 
} 
var bs = 0; 
function nextwt(){ 
if (_AN_Read_length('length', bsizes) <= bs) { 
bs = 0; 
nextrt(); 
return ; 
} 
wt(tsize, bsizes[bs], nextwt); 
bs += 1; 
} 
function nextrt(){ 
if (_AN_Read_length('length', bsizes) <= bs) { 
fs.unlink(path, function (err){ 
if (err) throw err
console.log('All done!'); 
} 
); 
return ; 
} 
rt(tsize, bsizes[bs], nextrt); 
bs += 1; 
} 
nextwt();