Bug 491436 - Some logging improvements to update service. r=rstrong

toolkit/mozapps/update/src/nsUpdateService.js.in

@@ -363,8 +363,11 @@ function getUpdatesDir(key) {
   }
   updateDir.append(DIR_UPDATES);
   updateDir.append("0");
-  if (!updateDir.exists() && !key)
+  if (!updateDir.exists() && !key) {
+    LOG("General", "getUpdatesDir - update directory " + updateDir.path +
+        " doesn't exist, creating...");
     updateDir.create(Ci.nsILocalFile.DIRECTORY_TYPE, PERMS_DIRECTORY);
+  }
   return updateDir;
 }
 
@@ -378,8 +381,10 @@ function getUpdatesDir(key) {
 function readStatusFile(dir) {
   var statusFile = dir.clone();
   statusFile.append(FILE_UPDATE_STATUS);
-  LOG("General", "readStatusFile - Reading Status File: " + statusFile.path);
-  return readStringFromFile(statusFile) || STATE_NONE;
+  var status = readStringFromFile(statusFile) || STATE_NONE;
+  LOG("General", "readStatusFile - status: " + status + ", path: " +
+      statusFile.path);
+  return status;
 }
 
 /**
@@ -470,6 +475,8 @@ function cleanUpUpdatesDir(key) {
         updateDir.path + " - This is almost always bad. Exception = " + e);
     throw e;
   }
+  LOG("General", "cleanUpUpdatesDir - successfully removed update directory: " +
+      updateDir.path);
 }
 
 /**
@@ -640,8 +647,10 @@ function readStringFromFile(file) {
   var fis = Cc["@mozilla.org/network/file-input-stream;1"].
             createInstance(Ci.nsIFileInputStream);
   var modeFlags = MODE_RDONLY;
-  if (!file.exists())
+  if (!file.exists()) {
+    LOG("General", "readStringFromFile - file doesn't exist: " + file.path);
     return null;
+  }
   fis.init(file, modeFlags, PERMS_FILE, 0);
   var sis = Cc["@mozilla.org/scriptableinputstream;1"].
             createInstance(Ci.nsIScriptableInputStream);