1246969 - nsIBufferedStreams implementation inflates (measured?) IO

Status: NEW

(Core :: Networking: File, enhancement, P5)

Description

[Gian-Carlo Pascutto [:gcp]]

Background story in bug https://bugzilla.mozilla.org/show_bug.cgi?id=1244259.

https://bugzilla.mozilla.org/show_bug.cgi?id=1244259#c12
https://bugzilla.mozilla.org/show_bug.cgi?id=1244259#c37
https://bugzilla.mozilla.org/show_bug.cgi?id=1244259#c40

This seems to be caused by bug 1211090. Introducing BufferedInputStream and BufferedOutputStream with a 64k buffer has made the measured IO of writing a 16 byte file go up to 64k.

Is this an issue with xpref?

Is there something fishy with the BufferedStream implementation?

Did we miss something in the SafeBrowsing code/fallocate changes?

This was all measured on Windows 7.

Comment 1

[Gian-Carlo Pascutto [:gcp]]

There's a mitigation in place by making sure the buffer size <= file size, so this isn't very urgent to fix.

Comment 2

[Firefox Bug Husbandry Bot]

Bulk change to priority: https://bugzilla.mozilla.org/show_bug.cgi?id=1399258

Comment 3

[Firefox Bug Husbandry Bot]

Bulk change to priority: https://bugzilla.mozilla.org/show_bug.cgi?id=1399258

Comment 4

[Jens Stutte [:jstutte]]

Bulk-downgrade of unassigned, >=3 years untouched DOM/Storage bug's priority.

If you have reason to believe this is wrong, please write a comment and ni :jstutte.