Intent to implement and ship: Performance.translateTime
Summary: A new method on Performance that allows translating a timestamp from one timeline to another. The idea is that you can take a performance.now() value or performance mark from some other global and convert them to the timeline of your global. It works like this: var myTime = Performance.translateTime(otherTime, otherGlobal); where otherGlobal is a Window, Worker, SharedWorker, or ServiceWorker. Bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1169068 Spec: http://w3c.github.io/hr-time/ Target release: 45 State in other UAs: Chrome plans to implement, unclear on the others. -Boris P.S. I'm not doing the impl work, just the paperwork. ___ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
Re: Intent to implement and ship: Performance.translateTime
This API doesn't seem to work for nested workers (which Blink doesn't implement), does it? Since there's no way in the window to get hold of a reference of a sub-sub-worker. It also doesn't seem possible for a worker to convert to the timeline of a parent window, since there's no object representing the parent of a worker. / Jonas On Thu, Nov 19, 2015 at 2:11 PM, Boris Zbarsky wrote: > Summary: A new method on Performance that allows translating a timestamp > from one timeline to another. The idea is that you can take a > performance.now() value or performance mark from some other global and > convert them to the timeline of your global. It works like this: > > var myTime = Performance.translateTime(otherTime, otherGlobal); > > where otherGlobal is a Window, Worker, SharedWorker, or ServiceWorker. > > Bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1169068 > > Spec: http://w3c.github.io/hr-time/ > > Target release: 45 > > State in other UAs: Chrome plans to implement, unclear on the others. > > -Boris > > P.S. I'm not doing the impl work, just the paperwork. > ___ > dev-platform mailing list > dev-platform@lists.mozilla.org > https://lists.mozilla.org/listinfo/dev-platform ___ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
Re: Intent to implement and ship: Performance.translateTime
On 11/19/15 5:39 PM, Jonas Sicking wrote: This API doesn't seem to work for nested workers (which Blink doesn't implement), does it? Since there's no way in the window to get hold of a reference of a sub-sub-worker. While true, there is also no way to directly get a message from a sub-sub-worker, right? The only way to get one is via the intermediate worker. So you have a window create worker W1, W1 creates W2. W2 does something, posts a message back to W1 with some timestamps. W1 translates those into its timeline and posts message back to the window, which translates into its timeline. It also doesn't seem possible for a worker to convert to the timeline of a parent window, since there's no object representing the parent of a worker. That's true. If you want to ship timestamps from a window to a worker, there's no convenient way to do that, though you can hack it together like so: w.postMessage(myTimeStamp - Performance.translateTime(0, w)) It seemed to me when this was being discussed that typically your timestamps would flow the other way, but maybe that's a bad assumption? -Boris ___ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
Re: Intent to implement and ship: Performance.translateTime
On Thu, Nov 19, 2015 at 2:48 PM, Boris Zbarsky wrote: > On 11/19/15 5:39 PM, Jonas Sicking wrote: >> >> This API doesn't seem to work for nested workers (which Blink doesn't >> implement), does it? Since there's no way in the window to get hold of >> a reference of a sub-sub-worker. > > While true, there is also no way to directly get a message from a > sub-sub-worker, right? The only way to get one is via the intermediate > worker. You can actually create a MessageChannel and then send one of the ports to a sub-sub-worker. Unfortunately the other port can't be used as something that represents the sub-sub-worker since even after a port has started getting used, it can be sent around again. > So you have a window create worker W1, W1 creates W2. W2 does something, > posts a message back to W1 with some timestamps. W1 translates those into > its timeline and posts message back to the window, which translates into its > timeline. Yes, this is possible. It's not great, but it's probably a fine enough solution. >> It also doesn't seem possible for a worker to convert to the timeline >> of a parent window, since there's no object representing the parent of >> a worker. > > That's true. If you want to ship timestamps from a window to a worker, > there's no convenient way to do that, though you can hack it together like > so: > > w.postMessage(myTimeStamp - Performance.translateTime(0, w)) > > It seemed to me when this was being discussed that typically your timestamps > would flow the other way, but maybe that's a bad assumption? I suspect having a worker which takes care of coordinating network traffic to a server is likely to be a good design. Especially having a sharedworker or serviceworker take care of coordinating the network traffic if the website expects the user to have multiple tabs open. Though Service Workers do actually have a 'client' object which represent window objects. So we could enable passing those as global to the translate function. / Jonas ___ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
Re: Intent to implement and ship: Performance.translateTime
On 11/19/15 6:57 PM, Jonas Sicking wrote: You can actually create a MessageChannel and then send one of the ports to a sub-sub-worker. Ah, good point. Unfortunately the other port can't be used as something that represents the sub-sub-worker since even after a port has started getting used, it can be sent around again. Right. There's really no good solution here short of introducing something that represents an arbitrary worker to an arbitrary window or worker, right? That's unfortunate... Though Service Workers do actually have a 'client' object which represent window objects. So we could enable passing those as global to the translate function. That's a good idea. Want to raise it with the webperf WG? Seems like it wouldn't be that hard to implement. -Boris ___ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
Re: Intent to implement and ship: Performance.translateTime
On Thu, Nov 19, 2015 at 5:38 PM, Boris Zbarsky wrote: >> Though Service Workers do actually have a 'client' object which >> represent window objects. So we could enable passing those as global >> to the translate function. > > That's a good idea. Want to raise it with the webperf WG? Seems like it > wouldn't be that hard to implement. I'd be quite happy if someone else would :) / Jonas ___ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
Re: Intent to implement and ship: Performance.translateTime
On Fri, Nov 20, 2015 at 9:49 AM, Jonas Sicking wrote: > I'd be quite happy if someone else would :) Filed https://github.com/w3c/hr-time/issues/22 on the general nested worker problem. Filed https://github.com/w3c/hr-time/issues/23 on the Client object thing. -- https://annevankesteren.nl/ ___ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
