379213 - Very high transfer rate when resuming a paused download

Status: RESOLVED DUPLICATE of bug 227516

(Toolkit :: Downloads API, defect)

Description

[Kamil Kulczynski]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; pl; rv:1.8.1.3) Gecko/20070309 Firefox/2.0.0.3
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; pl; rv:1.8.1.3) Gecko/20070309 Firefox/2.0.0.3

If I pause a download and then resume it, very high transfer rate (kb/s) is shown. It gets to its actual level after a while.

Reproducible: Always

Steps to Reproduce:
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Comment 1

[Samuel Sidler (old account; do not CC)]

Dupe of bug 245725? It was marked as fixed, but that seems to be the most relevant bug...

Comment 2

[Shawn Wilsher :sdwilsh]

Not a dupe.

So, the speed is calculated here (currently, close to here if changes happen to the file):
http://mxr.mozilla.org/seamonkey/source/toolkit/components/downloads/src/nsDownloadManager.cpp#1377

The way I see it, you would see slow speeds at first if the time was when you paused it (small number of bytes over a large time).  So, my guess is that the server is just giving you a larger burst of data (just like when you first start a download) when you resume it, hence the faster speed.

Maybe biesi can shed more light on this.

Comment 3

[Samuel Sidler (old account; do not CC)]

Shawn, is this a valid bug then? (I can just hear it shouting "Confirm me!")

Comment 4

[Shawn Wilsher :sdwilsh]

It might be valid, but it's not a bug.  I'm betting the server is just sending a lot of data right away then throttling down.  I'm not 100% certain of this though.

Comment 5

[Shawn Wilsher :sdwilsh]

Ah, found the original bug!