Improve download performance statistics.

content/browser/download/download_stats.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/download/download_stats.h"
 
 #include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "content/browser/download/download_resource_handler.h"
 #include "content/public/browser/download_interrupt_reasons.h"
@@ skipping 288 matching lines @@
                               size,
                               0/*min*/,
                               (1 << 10)/*max*/,
                               64/*num_buckets*/);
 }
 
 void RecordContiguousWriteTime(base::TimeDelta time_blocked) {
   UMA_HISTOGRAM_TIMES("Download.FileThreadBlockedTime", time_blocked);
 }
 
-void RecordNetworkBandwidth(size_t length,
-                            base::TimeDelta elapsed_time,
-                            base::TimeDelta paused_time) {
-  size_t non_pause_time_ms = (elapsed_time - paused_time).InMilliseconds();
-  if (0u == non_pause_time_ms)
-    non_pause_time_ms = 1;
+// Record what percentage of the time we have the network flow controlled.
+void RecordNetworkBlockage(base::TimeDelta resource_handler_lifetime,
+                           base::TimeDelta resource_handler_blocked_time) {
+  int percentage = 0;
+  // Avoid division by zero errors.
+  if (resource_handler_blocked_time != base::TimeDelta()) {
+    percentage =
+        resource_handler_blocked_time * 100 / resource_handler_lifetime;
+  }
 
-  // Note that this will be somewhat higher than sustainable network
-  // bandwidth because of buffering in the kernel during pauses.
-  // Using Bytes/s rather than bits/s so that this value is easily
-  // comparable with BandwidthOverall and BandwidthDisk.
-  UMA_HISTOGRAM_CUSTOM_COUNTS(
-      "Download.BandwidthNetworkBytesPerSecond",
-      (1000 * length / non_pause_time_ms),
-      1, 100000000, 50);
+  UMA_HISTOGRAM_COUNTS_100("Download.ResourceHandlerBlockedPercentage",
+                           percentage);
 }
 
 void RecordFileBandwidth(size_t length,
                          base::TimeDelta disk_write_time,
                          base::TimeDelta elapsed_time) {
   size_t elapsed_time_ms = elapsed_time.InMilliseconds();
   if (0u == elapsed_time_ms)
     elapsed_time_ms = 1;
   size_t disk_write_time_ms = disk_write_time.InMilliseconds();
   if (0u == disk_write_time_ms)
     disk_write_time_ms = 1;
 
   UMA_HISTOGRAM_CUSTOM_COUNTS(
       "Download.BandwidthOverallBytesPerSecond",
       (1000 * length / elapsed_time_ms), 1, 50000000, 50);
   UMA_HISTOGRAM_CUSTOM_COUNTS(
       "Download.BandwidthDiskBytesPerSecond",
       (1000 * length / disk_write_time_ms), 1, 50000000, 50);
+  UMA_HISTOGRAM_COUNTS_100("Download.DiskBandwidthUsedPercentage",
+                           disk_write_time_ms * 100 / elapsed_time_ms);
 }
 
 void RecordSavePackageEvent(SavePackageEvent event) {
   UMA_HISTOGRAM_ENUMERATION("Download.SavePackage",
                             event,
                             SAVE_PACKAGE_LAST_ENTRY);
 }
 
 }  // namespace download_stats