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Re: Lazy Blob

From: Florian Bösch <pyalot@gmail.com>
Date: Thu, 2 Aug 2012 19:09:31 +0200
Message-ID: <CAOK8ODixHU1Xxm69pLLa3MEvxYFU96rGQ=DpYFgpGFbH3h_TbQ@mail.gmail.com>
To: Glenn Adams <glenn@skynav.com>
Cc: Robin Berjon <robin@berjon.com>, Glenn Maynard <glenn@zewt.org>, WebApps WG <public-webapps@w3.org>, Jungkee Song <jungkee.song@samsung.com>
On Thu, Aug 2, 2012 at 6:37 PM, Glenn Adams <glenn@skynav.com> wrote:

> I am not proposing a "particular browser supported semantic" for a
> "specific implementation on the server". I have suggested, by way of
> example, two particular patterns be supported independently of any such
> implementation. I did not restrict the results to just those patterns in
> case someone wishes to generalize. That is little different from the
> proposed or implied XHR patterns being discussed.

So I'll take a stab, the remote blob resource/range protocol over WS 1.0:

1) A websocket to a URL is opened by the browser, the path and query of the
URL is interpreted to specify a resource.
2) During the lifetime of a websocket session onto a wsblob resource, the
resource is guaranteed to be reflected unchanged to the session, it cannot
be changed, appended or removed.
3) The client has to send these bytes "<handshake>" as a first message
4) The server has to respond with a "<handshake><length>" message to
indicate that he understands this protocol and indicate the byte length of
the resource.
5) after successful setup the client may request ranges from the server by
sending this message: "<range><start><end>", start and end have to be in
range of the byte resource.
6) The server will respond to each range request in the form of
"<range><start><end><bytes>" in case that a range request is valid, the
length of <bytes> has to be start - end. In case a range is not valid the
server will respond with "<invalid><start><end>.

These are the protocol field definitions:
handshake := "wsblob"
length := unsigned int 4 bytes
start := unsigned int 4 bytes
end := unsigned int 4 bytes
bytes := string of bytes
range := 0x01
invalid := 0x02
Received on Friday, 3 August 2012 01:32:59 UTC

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