Implemented pause/resume

Streams starting with node 0.10 are expected to implement the stream.pause method

See https://nodejs.org/api/stream.html#stream_compatibility_with_older_node_js_versions

Author: Cactusbone

lib/sax.js

@@ -183,6 +183,7 @@
     this._parser = new SAXParser(strict, opt)
     this.writable = true
     this.readable = true
+    this.paused = false
 
     var me = this
 
@@ -238,7 +239,7 @@
 
     this._parser.write(data.toString())
     this.emit('data', data)
-    return true
+    return !this.paused
   }
 
   SAXStream.prototype.end = function (chunk) {
@@ -249,6 +250,17 @@
     return true
   }
 
+  SAXStream.prototype.pause = function () {
+    this.paused = true
+  }
+
+  SAXStream.prototype.resume = function () {
+    if (this.paused) {
+      this.paused = false
+      this.emit('drain')
+    }
+  }
+
   SAXStream.prototype.on = function (ev, handler) {
     var me = this
     if (!me._parser['on' + ev] && streamWraps.indexOf(ev) !== -1) {

test/pause_resume_stream.js

@@ -0,0 +1,26 @@
+var tap = require('tap')
+
+// pausable stream that will understand and handle push returning false
+var Readable = require('stream').Readable
+var inputStream = new Readable()
+var saxStream = require('../lib/sax').createStream()
+
+var paused = true
+saxStream.pause()
+
+saxStream.on('data', function () {
+  tap.equal(false, paused, 'Received data while paused')
+})
+
+inputStream.pipe(saxStream)
+
+inputStream.push('<test><a>')
+inputStream.push('</a><b>')
+inputStream.push('</b><c>')
+inputStream.push('</c>')
+inputStream.push('<d>')
+inputStream.push('</d></test>')
+inputStream.push(null)
+
+paused = false
+saxStream.resume()