shell bypass 403
var inherits = require('util').inherits;
var Transform = require('stream').Transform;
var TokenBucket = require('limiter').TokenBucket;
/*
* Throttle is a throttled stream implementing the stream.Transform interface.
* Options:
* rate (mandatory): the throttling rate in bytes per second.
* chunksize (optional): the maximum chunk size into which larger writes are decomposed.
* Any other options are passed to stream.Transform.
*/
function Throttle(opts, group) {
if (group === undefined)
group = new ThrottleGroup(opts);
this.bucket = group.bucket;
this.chunksize = group.chunksize;
Transform.call(this, opts);
}
inherits(Throttle, Transform);
Throttle.prototype._transform = function(chunk, encoding, done) {
process(this, chunk, 0, done);
};
function process(self, chunk, pos, done) {
var slice = chunk.slice(pos, pos + self.chunksize);
if (!slice.length) {
// chunk fully consumed
done();
return;
}
self.bucket.removeTokens(slice.length, function(err) {
if (err) {
done(err);
return;
}
self.push(slice);
process(self, chunk, pos + self.chunksize, done);
});
}
/*
* ThrottleGroup throttles an aggregate of streams.
* Options are the same as for Throttle.
*/
function ThrottleGroup(opts) {
if (!(this instanceof ThrottleGroup))
return new ThrottleGroup(opts);
opts = opts || {};
if (opts.rate === undefined)
throw new Error('throttle rate is a required argument');
if (typeof opts.rate !== 'number' || opts.rate <= 0)
throw new Error('throttle rate must be a positive number');
if (opts.chunksize !== undefined && (typeof opts.chunksize !== 'number' || opts.chunksize <= 0)) {
throw new Error('throttle chunk size must be a positive number');
}
this.rate = opts.rate;
this.chunksize = opts.chunksize || this.rate/10;
this.bucket = new TokenBucket(this.rate, this.rate, 'second', null);
}
/*
* Create a new stream in the throttled group and returns it.
* Any supplied options are passed to the Throttle constructor.
*/
ThrottleGroup.prototype.throttle = function(opts) {
return new Throttle(opts, this);
};
module.exports = {
Throttle: Throttle,
ThrottleGroup: ThrottleGroup
};