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'use strict';
var common = require('../common');
var assert = require('assert');
if (!common.hasCrypto) {
console.log('1..0 # Skipped: missing crypto');
return;
}
var crypto = require('crypto');
var stream = require('stream');
var Stream = stream.Stream;
var util = require('util');
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 = Buffer.allocUnsafe(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');
});
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