215675 - Download speed flawed when starting a partially completed download

Status: RESOLVED DUPLICATE of bug 151810

(SeaMonkey :: Download & File Handling, defect)

Description

[Adam Anderson]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.5a) Gecko/20030728 Mozilla Firebird/0.6.1
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.5a) Gecko/20030728 Mozilla Firebird/0.6.1

When starting a download that is partially cached, the download speed is far
higher than the actual speed, and the ETA is extremely slow.  I suspect that
this is a product of the way speed and ETA are calculated.  From what it seems,
the process used to calculate the download speed and ETA takes into account the
previous amount of data downloaded, but not the amount of time that it took to
download.  I may not be doing a very good job of explaining this, so the
reproduction instructions might show the problem better than I can explain it.

Reproducible: Always

Steps to Reproduce:
1. Go to a website and start a fairly large download.  I did this all at
mozilla.org downloading Mozilla 1.4.
2. Wait until the download is partially completed, say, maybe 50% or so (it
doesn't really matter as long as it is not close to the beginning or end).
3. Cancel the download.
4. Start the same download again.  It should start from the point where it left off.
5. After the download dialog appears, notice the download speed (it should be
absurdly high), and the ETA (it should be absurdly slow-moving).
Actual Results:  
The download speed and ETA were completely out of whack in the download dialog.

Expected Results:  
Mozilla should have considered the amount of time that it took the first half of
the download to complete, and factored that into the speed and ETA calculations
after completing the download.

WinXP on a 650 Mhz AMD Athalon, 512 RAM

Comment 1

[Ray Birks]

Confirming with FireBird 0.6.1+ (20030901) on WinME.

1st download attempt of latest Mozilla Win32 nightly build (around 11 MB) shows
my download speed at a fairly constant 183.3 KB/second. After cancelling that
download around 50% and then re-starting, the download speed indicator starts
out at 862 KB/second and was re-calculated downward with each re-display to 730
KB/s, 567 KB/s, 505 KB/s, 449 KB/s, etc.

On the initial download process, the Time Left indicator seems to progress
normally, i.e., display is decremented from a meaningful starting value (1
minute and 10 seconds or so) by a few seconds corresponding to real time elapsed
seconds. However, on the re-started download, the Time Left indicator starts out
 at a very unreasonable 3 seconds, slowly increments up to 11 seconds, drops
down some to around 8 seconds, and is generally undependable.

Have not checked similar in recent Mozilla 1.5b build.

Comment 2

[Ray Birks]

Reporter, I recommend changing product to "Browser" from "Firebird" since
behavior occurs in Mozilla 1.5b as well, build 20030906, on WinME.

Comment 3

[Adam Anderson]

Product containing bug changed to Browser.

Comment 4

[Charles Fenwick]

*** This bug has been marked as a duplicate of 151810 ***