1 files changed, 19 insertions, 0 deletions
diff --git a/mailnews/db/gloda/modules/indexer.js b/mailnews/db/gloda/modules/indexer.js
index e75b6796b9..f6c9395306 100644
--- a/mailnews/db/gloda/modules/indexer.js
+++ b/mailnews/db/gloda/modules/indexer.js
@@ -1006,6 +1006,10 @@ var GlodaIndexer = {
       //     make ourselves less responsive by drawing out the period of time we
       //     are dominating the main thread.
       this._perfIndexStopwatch.start();
+      // For telemetry purposes, we want to know how many messages we've been
+      //  processing during that batch, and how long it took, pauses included.
+      let t0 = Date.now();
+      this._indexedMessageCount = 0;
       batchCount = 0;
       while (batchCount < this._indexTokens) {
         if ((this._callbackHandle.activeIterator === null) &&
@@ -1146,6 +1150,21 @@ var GlodaIndexer = {
         }
       }
 
+      // All pauses have been taken, how effective were we? Report!
+      // XXX: there's possibly a lot of fluctuation since we go through here
+      // every 5 messages or even less
+      if (this._indexedMessageCount > 0) {
+        let delta = (Date.now() - t0)/1000; // in seconds
+        let v = Math.round(this._indexedMessageCount/delta);
+        try {
+          let h = Services.telemetry
+            .getHistogramById("THUNDERBIRD_INDEXING_RATE_MSG_PER_S");
+          h.add(v);
+        } catch (e) {
+          this._log.warn("Couldn't report telemetry", e, v);
+        }
+      }
+
       if (batchCount > 0) {
         let totalTime = this._perfIndexStopwatch.realTimeSeconds * 1000;
         let timePerToken = totalTime / batchCount;