[Offline Pages] Expanding event logger to be used by harness.

chrome/android/java/src/org/chromium/chrome/browser/offlinepages/evaluation/OfflinePageEvaluationBridge.java

Index: chrome/android/java/src/org/chromium/chrome/browser/offlinepages/evaluation/OfflinePageEvaluationBridge.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/offlinepages/evaluation/OfflinePageEvaluationBridge.java b/chrome/android/java/src/org/chromium/chrome/browser/offlinepages/evaluation/OfflinePageEvaluationBridge.java
index 1dced8029edb9da52d7f6914942ec023e194b006..5be2a6e165ea8b6c057b03c09a77915a3d49e004 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/offlinepages/evaluation/OfflinePageEvaluationBridge.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/offlinepages/evaluation/OfflinePageEvaluationBridge.java
@@ -5,6 +5,7 @@
 package org.chromium.chrome.browser.offlinepages.evaluation;
 
 import org.chromium.base.Callback;
+import org.chromium.base.Log;
 import org.chromium.base.ObserverList;
 import org.chromium.base.ThreadUtils;
 import org.chromium.base.annotations.CalledByNative;
@@ -14,8 +15,17 @@ import org.chromium.chrome.browser.offlinepages.OfflinePageItem;
 import org.chromium.chrome.browser.offlinepages.SavePageRequest;
 import org.chromium.chrome.browser.profiles.Profile;
 
+import java.io.File;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.io.OutputStreamWriter;
+
+import java.text.SimpleDateFormat;
+
 import java.util.ArrayList;
+import java.util.Date;
 import java.util.List;
+import java.util.Locale;
 
 /**
  * Class used for offline page evaluation testing tools.
@@ -65,11 +75,14 @@ public class OfflinePageEvaluationBridge {
         return nativeGetBridgeForProfile(profile, useEvaluationScheduler);
     }
 
+    private static final String TAG = "OPEvalBridge";
     private long mNativeOfflinePageEvaluationBridge;
     private boolean mIsOfflinePageModelLoaded;
     private ObserverList<OfflinePageEvaluationObserver> mObservers =
             new ObserverList<OfflinePageEvaluationObserver>();
 
+    private OutputStreamWriter mLogOutput;
+
     /**
      * Creates an offline page evalutaion bridge for a given profile.
      */
@@ -152,6 +165,10 @@ public class OfflinePageEvaluationBridge {
         nativeRemoveRequestsFromQueue(mNativeOfflinePageEvaluationBridge, ids, callback);
     }
 
+    public void setLogOutputFile(File outputFile) throws IOException {
+        mLogOutput = new FileWriter(outputFile);
+    }
+
     /**
      * @return True if the offline page model has fully loaded.
      */
@@ -160,6 +177,27 @@ public class OfflinePageEvaluationBridge {
     }
 
     @CalledByNative
+    public void log(String sourceTag, String message) {
+        try {
+            Date date = new Date(System.currentTimeMillis());
+            SimpleDateFormat formatter =
+                    new SimpleDateFormat("MM-dd HH:mm:ss.SSS", Locale.getDefault());
+            mLogOutput.write(formatter.format(date) + ": " + sourceTag + " | " + message
+                    + System.getProperty("line.separator"));
+        } catch (IOException e) {
+            Log.e(TAG, e.getMessage(), e);

[fgorski, 2016/11/30 17:30:47]

Wouldn't it be easier (and more widely applicable) to use Log class everywhere
and then learn to properly parse it... so that we can get relevant evaluation
statements in production code and interpret any run, not just evaluation run?

[romax, 2016/12/01 01:47:52]

yes that's a more reasonable way and it would be easier to keep Logs even in
production code.
However this patch wasn't prepared for that scope and was only aiming for the
evaluation run. I currently have no idea how the logs are used in Chromium
production code.
My quick thought is we're logging everything in logcat and we redirect the
output stream to a file, then we parse the logs to get whatever we want(maybe
with our TAGs). I guess in this way we might have to add many log statements in
production code which I'm not seeing very often (maybe I just missed).
Or am I totally misunderstanding your idea...?

+        }
+    }
+
+    public void closeLog() {
+        try {
+            mLogOutput.close();
+        } catch (IOException e) {
+            Log.e(TAG, e.getMessage(), e);
+        }
+    }
+
+    @CalledByNative
     void savePageRequestAdded(SavePageRequest request) {
         for (OfflinePageEvaluationObserver observer : mObservers) {
             observer.savePageRequestAdded(request);