| // Copyright Joyent, Inc. and other Node contributors. |
| // |
| // Permission is hereby granted, free of charge, to any person obtaining a |
| // copy of this software and associated documentation files (the |
| // "Software"), to deal in the Software without restriction, including |
| // without limitation the rights to use, copy, modify, merge, publish, |
| // distribute, sublicense, and/or sell copies of the Software, and to permit |
| // persons to whom the Software is furnished to do so, subject to the |
| // following conditions: |
| // |
| // The above copyright notice and this permission notice shall be included |
| // in all copies or substantial portions of the Software. |
| // |
| // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS |
| // OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF |
| // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN |
| // NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, |
| // DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR |
| // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE |
| // USE OR OTHER DEALINGS IN THE SOFTWARE. |
| |
| var common = require('../common'); |
| var crypto = require('crypto'); |
| var stream = require('stream'); |
| var Stream = stream.Stream; |
| var util = require('util'); |
| var assert = require('assert'); |
| var zlib = require('zlib'); |
| |
| |
| |
| // emit random bytes, and keep a shasum |
| function RandomReadStream(opt) { |
| Stream.call(this); |
| |
| this.readable = true; |
| this._paused = false; |
| this._processing = false; |
| |
| this._hasher = crypto.createHash('sha1'); |
| opt = opt || {}; |
| |
| // base block size. |
| opt.block = opt.block || 256 * 1024; |
| |
| // total number of bytes to emit |
| opt.total = opt.total || 256 * 1024 * 1024; |
| this._remaining = opt.total; |
| |
| // how variable to make the block sizes |
| opt.jitter = opt.jitter || 1024; |
| |
| this._opt = opt; |
| |
| this._process = this._process.bind(this); |
| |
| process.nextTick(this._process); |
| } |
| |
| util.inherits(RandomReadStream, Stream); |
| |
| RandomReadStream.prototype.pause = function() { |
| this._paused = true; |
| this.emit('pause'); |
| }; |
| |
| RandomReadStream.prototype.resume = function() { |
| // console.error("rrs resume"); |
| this._paused = false; |
| this.emit('resume'); |
| this._process(); |
| }; |
| |
| RandomReadStream.prototype._process = function() { |
| if (this._processing) return; |
| if (this._paused) return; |
| |
| this._processing = true; |
| |
| if (!this._remaining) { |
| this._hash = this._hasher.digest('hex').toLowerCase().trim(); |
| this._processing = false; |
| |
| this.emit('end'); |
| return; |
| } |
| |
| // figure out how many bytes to output |
| // if finished, then just emit end. |
| var block = this._opt.block; |
| var jitter = this._opt.jitter; |
| if (jitter) { |
| block += Math.ceil(Math.random() * jitter - (jitter / 2)); |
| } |
| block = Math.min(block, this._remaining); |
| var buf = new Buffer(block); |
| for (var i = 0; i < block; i++) { |
| buf[i] = Math.random() * 256; |
| } |
| |
| this._hasher.update(buf); |
| |
| this._remaining -= block; |
| |
| console.error('block=%d\nremain=%d\n', block, this._remaining); |
| this._processing = false; |
| |
| this.emit('data', buf); |
| process.nextTick(this._process); |
| }; |
| |
| |
| // a filter that just verifies a shasum |
| function HashStream() { |
| Stream.call(this); |
| |
| this.readable = this.writable = true; |
| this._hasher = crypto.createHash('sha1'); |
| } |
| |
| util.inherits(HashStream, Stream); |
| |
| HashStream.prototype.write = function(c) { |
| // Simulate the way that an fs.ReadStream returns false |
| // on *every* write like a jerk, only to resume a |
| // moment later. |
| this._hasher.update(c); |
| process.nextTick(this.resume.bind(this)); |
| return false; |
| }; |
| |
| HashStream.prototype.resume = function() { |
| this.emit('resume'); |
| process.nextTick(this.emit.bind(this, 'drain')); |
| }; |
| |
| HashStream.prototype.end = function(c) { |
| if (c) { |
| this.write(c); |
| } |
| this._hash = this._hasher.digest('hex').toLowerCase().trim(); |
| this.emit('data', this._hash); |
| this.emit('end'); |
| }; |
| |
| |
| |
| |
| var inp = new RandomReadStream({ total: 1024, block: 256, jitter: 16 }); |
| var out = new HashStream(); |
| var gzip = zlib.createGzip(); |
| var gunz = zlib.createGunzip(); |
| |
| inp.pipe(gzip).pipe(gunz).pipe(out); |
| |
| inp.on('data', function(c) { |
| console.error('inp data', c.length); |
| }); |
| |
| gzip.on('data', function(c) { |
| console.error('gzip data', c.length); |
| }); |
| |
| gunz.on('data', function(c) { |
| console.error('gunz data', c.length); |
| }); |
| |
| out.on('data', function(c) { |
| console.error('out data', c.length); |
| }); |
| |
| var didSomething = false; |
| out.on('data', function(c) { |
| didSomething = true; |
| console.error('hash=%s', c); |
| assert.equal(c, inp._hash, 'hashes should match'); |
| }); |
| |
| process.on('exit', function() { |
| assert(didSomething, 'should have done something'); |
| }); |