Re: Prefs overhaul
The old code read the entire file into memory before starting parsing. In one place it did this with URLPreloader::ReadZip() (for default pref files), and in another place it did this with URLPreloader::ReadFile() (for user pref files). It was simplest to leave that code unchanged. Nick On Mon, Mar 12, 2018 at 9:16 PM, David Teller wrote: > Out of curiosity, why is the read handled by C++ code? > > On 12/03/2018 10:38, Nicholas Nethercote wrote: > > I don't know. But libpref's file-reading is done by C++ code, which > passes > > a string to the Rust code for parsing. > > > > Nick > > ___ > > 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 > ___ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
Re: Prefs overhaul
Out of curiosity, why is the read handled by C++ code? On 12/03/2018 10:38, Nicholas Nethercote wrote: > I don't know. But libpref's file-reading is done by C++ code, which passes > a string to the Rust code for parsing. > > Nick > ___ > 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: Prefs overhaul
On Sun, Mar 11, 2018 at 4:24 AM, ISHIKAWA,chiaki wrote: > > I have noticed that you mentioned rewrite in Rust. > > Does the I/O primitive Rust uses handle the following "short read" case > niciely? > I don't know. But libpref's file-reading is done by C++ code, which passes a string to the Rust code for parsing. Nick ___ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
Re: Prefs overhaul
On 2018/03/07 12:08, Nicholas Nethercote wrote: Hi, I've been doing a lot of work to improve libpref recently, and there is more in the pipeline. I've written a brief roadmap that might be of interest to people: https://wiki.mozilla.org/Platform/PrefsOverhaul I'd be happy to hear feedback, via this list or other means. Thanks. Nick I have noticed that you mentioned rewrite in Rust. Does the I/O primitive Rust uses handle the following "short read" case niciely? Suppose, prefs file (user profile) is stored on a remote file server. Based on the network congestion and/or server load, the remote file server may end up returning shorter than requested octet strings. (This can happen for real.) Under linux, the I/O primitive does not read the remaining octets. Under Windows, the I/O primitive seems to automagically handles the reading of remaining octets as far as the remote file server is CIFS. (I don't know about NFS.) Does libpres under linux handles such short-read cases? I have filed a few bugzilla for TB's failure to tackle this situation (under linux), but I have noticed the issue is deep within M-C portion of the code, too. Bugzilla: Bug 1170646 - A few M-C fixes to handle short read in Cache code ( from [META] Failure to deal with short read) and related bugs there. Bug 1170578 - RFC: Buggy NSS dbm code ought to be updated 1170606 <--- this is C-C TB side noted below. Bug 1170668 - Failure to handle short read: the case of reading a JSON file into JavaScript 'String' type. ( [META] Failure to deal with short read) 1172304 <-- fixed. On the purely C-C TB side: Bug 1170606 - C-C T-B fixes to take care of short read (part of [META] Failure to deal with short read) and 1170646 mentioned there. cf. My comment about short write of PR_Write() in the currently last comment of https://bugzilla.mozilla.org/show_bug.cgi?id=1170564 may be misguided. I found that PR_Write() is automatically retried even under Linux. PPS: MS-Windows seems to handle this under the hood: the I/O routines are mapped to MS syscalls and they seem to handle the short read issue on the OS side very well. ___ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
Re: Prefs overhaul
This looks like great work - I'm very glad to see us investing in improvements to core infrastructure like this. Thanks Nick! On Tue, Mar 6, 2018 at 7:08 PM, Nicholas Nethercote wrote: > Hi, > > I've been doing a lot of work to improve libpref recently, and there is > more in the pipeline. I've written a brief roadmap that might be of > interest to people: https://wiki.mozilla.org/Platform/PrefsOverhaul > > I'd be happy to hear feedback, via this list or other means. Thanks. > > Nick > ___ > 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: Prefs overhaul
On Wed, Mar 07, 2018 at 02:08:59PM +1100, Nicholas Nethercote wrote: Hi, I've been doing a lot of work to improve libpref recently, and there is more in the pipeline. I've written a brief roadmap that might be of interest to people: https://wiki.mozilla.org/Platform/PrefsOverhaul I'd be happy to hear feedback, via this list or other means. Thanks. Related to this (and particularly in the light of bug 1425613), I've been thinking it's about time to migrate the preference service bindings to WebIDL, and kill the XPIDL/XPCOM bindings altogether. The XPC overhead on the JS side is pretty bad given how much we use the service, and a WebIDL implementation would make it easier to add certain optimizations (like native lazy pref getters) on top of the ones we'd automatically get from the conversion. From the native side, accessing the pref service via do_GetService adds a bunch of get service overhead, and then a bunch of virtual call overhead for each method call. We do have already have a non-virtual API. We should just make that the only option. ___ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
Prefs overhaul
Hi, I've been doing a lot of work to improve libpref recently, and there is more in the pipeline. I've written a brief roadmap that might be of interest to people: https://wiki.mozilla.org/Platform/PrefsOverhaul I'd be happy to hear feedback, via this list or other means. Thanks. Nick ___ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
