Close #1929 zlib Respond to 'resume' events properly

lib/zlib.js

@@ -254,6 +254,7 @@ Zlib.prototype._process = function() {
       this._needDrain = false;
       this.emit('drain');
     }
+    // nothing to do, waiting for more data at this point.
     return;
   }
 
@@ -312,7 +313,7 @@ Zlib.prototype._process = function() {
       var newReq = self._binding.write(self._flush,
                                        chunk,
                                        inOff,
-                                       availInAfter,
+                                       availInBefore,
                                        self._buffer,
                                        self._offset,
                                        self._chunkSize);
@@ -336,7 +337,7 @@ Zlib.prototype.pause = function() {
 
 Zlib.prototype.resume = function() {
   this._paused = false;
-  this.emit('resume');
+  this._process();
 };
 
 util.inherits(Deflate, Zlib);

test/simple/test-zlib-random-byte-pipes.js

@@ -0,0 +1,143 @@
+
+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);
+
+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');
+})