1388768 - reduce body stream copying in some interception paths

Status: RESOLVED DUPLICATE of bug 1204254

(Core :: DOM: Service Workers, enhancement, P3)

Description

[Ben Kelly [:bkelly, not reviewing]]

Currently the nsIInterceptedChannel interface exposes a responseBody writable stream.  When the channel is intercepted the synthesized body must be written to this stream.  We are pretty much always reading from another stream, though, which means we always have a copying step during interception.

Instead of copying to an output stream, we should change nsIInterceptedChannel to consume an nsIInputStream instead.  It may internally copy for some configurations, but for others it can pass the stream on directly.

In particular, we will have to continue to copy for non-e10s because of the way it uses a fake http cache entry.  We must write into the entry.  For e10s, though, we may be able to avoid any copying.

Comment 1

[Ben Kelly [:bkelly, not reviewing]]

I'm going to end up doing this in bug 1204254.