Re: File API: Blob and underlying file changes.

On Wed, Jan 27, 2010 at 01:16, Robert O'Callahan <robert@ocallahan.org> wrote:
> On Wed, Jan 27, 2010 at 5:38 AM, Juan Lanus <juan.lanus@gmail.com> wrote:
>>
>> Quite right Bob. But still the lock is the way to go. At least as of
>> today.
>>
>> HTML5 might be mainstream for the next 10 years, starting rather soon.
>>
>> In the meanwhile OSs will also evolve, in a way that we can't tell
>> now. But if there are common issues, like this one, somebody will come
>> up with a smart solution maybe soon.
>> For example feeding an image of the file as of the instant it was
>> opened (like relational databases do to provide stable queries) by
>> keeping a temporary map to the original disk segments that comprised
>> the file before it was changed.
>> For example Apple is encouraging advisory locks
>>
>> http://developer.apple.com/mac/library/technotes/tn/tn2037.html#OSSolutions
>> asking developers to design in an environment-aware mood.
>
> In my experience, almost no code uses advisory locking unless it is being
> explicitly designed for some kind of concurrent usage, i.e., Apple's advice
> is not being followed. If that's not going to suddenly change --- and I see
> no evidence it will --- then asking the UA to apply a mandatory lock is
> asking the UA to do something impossible, which is generally not a good
> idea.
> Rob

Right, not talking about locks any more because it would be telling
HOW the UA should do it, and what is best for the UA developers is to
be told WHAT to do.
Not writing a tutorial but a specification. Let the developer find out
how to do it, this year, and with the tools that will be available by
2020.

Now, out of the locks subject, what I want to be sure of is that the
specification does not specify the "mutating blob", the origin of this
thread.
--
Juan


> "He was pierced for our transgressions, he was crushed for our iniquities;
> the punishment that brought us peace was upon him, and by his wounds we are
> healed. We all, like sheep, have gone astray, each of us has turned to his
> own way; and the LORD has laid on him the iniquity of us all." [Isaiah
> 53:5-6]
Indeed.

Received on Wednesday, 27 January 2010 12:41:08 UTC