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Bug 18963 - Provide a mechanism for rate limiting appending
Summary: Provide a mechanism for rate limiting appending
Status: RESOLVED FIXED
Alias: None
Product: HTML WG
Classification: Unclassified
Component: Media Source Extensions (show other bugs)
Version: unspecified
Hardware: PC Windows 3.1
: P1 normal
Target Milestone: ---
Assignee: Aaron Colwell (c)
QA Contact: HTML WG Bugzilla archive list
URL:
Whiteboard: tpac2012
Keywords:
Depends on:
Blocks: 20253
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Reported: 2012-09-21 22:28 UTC by Aaron Colwell (c)
Modified: 2012-12-06 01:57 UTC (History)
3 users (show)

See Also:


Attachments

Description Aaron Colwell (c) 2012-09-21 22:28:51 UTC
This bug is the result of discussions around Bug 16998

http://lists.w3.org/Archives/Public/public-html-media/2012Jul/0074.html
http://www.w3.org/2012/07/31-html-media-minutes.html#item05

Currently there is no mechanism for the UA to signal that it wants the web application to stop appending for a while. A UA might want to do this in a memory constrained environment to help the web application avoid appending "too far ahead" which might trigger media segment eviction (Section 2.10). 

It could be useful to have a mechanism that notifies the application when further appends will trigger evictions so the web application could use remove() (https://www.w3.org/Bugs/Public/show_bug.cgi?id=18709) to control what time ranges get removed. When the UA determines that enough data has been removed to allow appending again it can notify the application with an event.
Comment 1 Aaron Colwell (c) 2012-12-05 19:09:02 UTC
Based on discussions at TPAC (http://www.w3.org/2012/11/01-html-wg-minutes.html), it was decided to have append() throw an exception when the SourceBuffer is full. The application can use remove() to free up space in the buffer and try again.

I plan on updating the spec text for append() to say that a QUOTA_EXCEEDED_ERR should be thrown if the SourceBuffer doesn't have space available to accommodate the data in the append.
Comment 2 Aaron Colwell (c) 2012-12-06 01:57:00 UTC
Changes committed
http://dvcs.w3.org/hg/html-media/rev/43be42e69533