Changeset 246615 in webkit

Timestamp:

Jun 19, 2019, 4:36:35 PM (7 years ago)

Author:

commit-queue@webkit.org

Message:

DownloadMonitor::measuredThroughputRate should approach zero with no throughput
​https://bugs.webkit.org/show_bug.cgi?id=198981
<rdar://problem/51456914>

Patch by Alex Christensen <​achristensen@webkit.org> on 2019-06-19
Reviewed by Geoffrey Garen.

When the timer fires to approximate the download rate, add a new timestamp with 0 bytes received since the last time we received bytes.
Then, if there's only one timestamp, assume the throughput rate is 0 instead of infinite.
This will prevent false positives estimating large download rates based on old data when the throughput drops to 0.

• NetworkProcess/Downloads/DownloadMonitor.cpp:

(WebKit::DownloadMonitor::measuredThroughputRate const):
(WebKit::DownloadMonitor::timerFired):

Location:

trunk/Source/WebKit

Files:

• ChangeLog (modified) (1 diff)
• NetworkProcess/Downloads/DownloadMonitor.cpp (modified) (2 diffs)

trunk/Source/WebKit/ChangeLog

@@ +1 @@
+2019-06-19  Alex Christensen  <achristensen@webkit.org>
+
+        DownloadMonitor::measuredThroughputRate should approach zero with no throughput
+        https://bugs.webkit.org/show_bug.cgi?id=198981
+        <rdar://problem/51456914>
+
+        Reviewed by Geoffrey Garen.
+
+        When the timer fires to approximate the download rate, add a new timestamp with 0 bytes received since the last time we received bytes.
+        Then, if there's only one timestamp, assume the throughput rate is 0 instead of infinite.
+        This will prevent false positives estimating large download rates based on old data when the throughput drops to 0.
+
+        * NetworkProcess/Downloads/DownloadMonitor.cpp:
+        (WebKit::DownloadMonitor::measuredThroughputRate const):
+        (WebKit::DownloadMonitor::timerFired):
+
 2019-06-19  Sihui Liu  <sihui_liu@apple.com>
 

trunk/Source/WebKit/NetworkProcess/Downloads/DownloadMonitor.cpp

@@ -79 +79 @@
     double seconds = timeDifference.seconds();
     if (!seconds)
-        return std::numeric_limits<double>::max();
+        return 0;
     return bytes / seconds;
 }
@@ -114 +114 @@
 void DownloadMonitor::timerFired()
 {
+    downloadReceivedBytes(0);
+
     RELEASE_ASSERT(m_interval < WTF_ARRAY_LENGTH(throughputIntervals));
     if (measuredThroughputRate() < throughputIntervals[m_interval].bytesPerSecond) {