From d3bc7474996322030bc83ea76e1c377d52f76199 Mon Sep 17 00:00:00 2001
From: Han Qi <qihan.dev@gmail.com>
Date: Sun, 23 Apr 2017 13:32:39 -0700
Subject: [PATCH] Add LearnerObserver. This enables usage of BIDViz

---
 src/main/scala/BIDMach/Learner.scala | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/main/scala/BIDMach/Learner.scala b/src/main/scala/BIDMach/Learner.scala
index 5648164d..93a85ac3 100755
--- a/src/main/scala/BIDMach/Learner.scala
+++ b/src/main/scala/BIDMach/Learner.scala
@@ -135,6 +135,9 @@ case class Learner(
         if (opts.updateAll) {
           model.dobatchg(mats, ipass, here);
           if (mixins != null) mixins map (_ compute(mats, here));
+          if (opts.observer != null) {
+            opts.observer.notify(ipass, model, mats)
+          }
           if (updater != null) updater.update(ipass, here, gprogress);
         }
         val scores = model.evalbatchg(mats, ipass, here);
@@ -144,6 +147,9 @@ case class Learner(
       } else {
         model.dobatchg(mats, ipass, here)
         if (mixins != null) mixins map (_ compute(mats, here))
+        if (opts.observer != null) {
+          opts.observer.notify(ipass, model, mats)
+        }
         if (updater != null) updater.update(ipass, here, gprogress)
       }
       if (datasource.opts.putBack >= 0) datasource.putBack(mats, datasource.opts.putBack)
@@ -814,6 +820,11 @@ class ParLearnerF(
 }
 
 object Learner {
+  trait LearnerObserver {
+    def init = {}
+    def cleanup = {}
+    def notify(ipass:Int, model:Model, minibatch:Array[Mat]) = {}
+  }
 
   class Options extends BIDMat.Opts {
   	var npasses = 2;
@@ -827,6 +838,7 @@ object Learner {
     var cumScore = 0;
     var checkPointFile:String = null;
     var checkPointInterval = 0f;
+    var observer: LearnerObserver = null;
   }
 
   def numBytes(mat:Mat):Long = {