expose the index of the metadata log processor

lib/metadata.js

@@ -85,19 +85,19 @@ var handleCommand = function (meta, line) {
 
 Meta.createLineHandler = function (ref, errorHandler) {
     ref.meta = {};
+    ref.index = 0;
 
-    var index = 0;
     return function (err, line) {
         if (err) {
             return void errorHandler('METADATA_HANDLER_LINE_ERR', {
                 error: err,
-                index: index,
+                index: ref.index,
                 line: JSON.stringify(line),
             });
         }
 
         if (Array.isArray(line)) {
-            index++;
+            ref.index++;
             try {
                 handleCommand(ref.meta, line);
             } catch (err2) {
@@ -109,8 +109,8 @@ Meta.createLineHandler = function (ref, errorHandler) {
             return;
         }
 
-        if (index === 0 && typeof(line) === 'object') {
+        if (ref.index === 0 && typeof(line) === 'object') {
-            index++;
+            ref.index++;
             // special case!
             ref.meta = line;
             return;
@@ -118,7 +118,7 @@ Meta.createLineHandler = function (ref, errorHandler) {
 
         errorHandler("METADATA_HANDLER_WEIRDLINE", {
             line: line,
-            index: index++,
+            index: ref.index++,
         });
     };
 };