I have added a section that includes the four compiler options that Carlos mentioned. If there are more that, when used, reduce output size, they should go there. I have not populated the descriptions, as a smart person should do that.
a On Fri, Nov 20, 2020 at 3:23 PM Andrew Wetmore <[email protected]> wrote: > Yes, that page is a good location. Should we start a subsection for these > options which have the benefit of reducing output size? > > a > > On Fri, Nov 20, 2020 at 1:48 PM Carlos Rovira <[email protected]> > wrote: > >> Hi Josh, >> >> thanks for working on this. I finally could get here after weeks of hard >> work in other things with almost not time. >> I tried in Tour de Jewel with: >> >> -export-public-symbols=false >> -prevent-rename-protected-symbols=false >> -prevent-rename-internal-symbols=false >> -prevent-rename-public-static-methods=false >> -prevent-rename-public-instance-methods=false >> >> (for what I read that's the set it can be used without breaking app) >> >> and a downsize from 1045kb to 910kb so amazing! :) >> >> I'll try to add to TodoMVC as well and see what happens ;) >> >> @Andrew I think you and Josh can add this doc to the Royale Docs compiler >> options page here [1] >> >> [1] https://apache.github.io/royale-docs/compiler/compiler-options >> >> >> >> El mar, 10 nov 2020 a las 23:36, Josh Tynjala (<[email protected] >> >) >> escribió: >> >> > Hi Andrew, >> > >> > Yes, I can help with that! >> > >> > -- >> > Josh Tynjala >> > Bowler Hat LLC <https://bowlerhat.dev> >> > >> > >> > On Mon, Nov 9, 2020 at 3:22 PM Andrew Wetmore <[email protected]> >> wrote: >> > >> > > Josh, this is very interesting. I would like to include an actionable >> > > amount of this information in our user documentation. If I create a >> page >> > in >> > > the help docs for it, can you help me populate instructions based on >> your >> > > researchs? >> > > >> > > Thanks! >> > > >> > > Andrew >> > > >> > > On Mon, Nov 9, 2020 at 6:16 PM Josh Tynjala < >> [email protected]> >> > > wrote: >> > > >> > > > Hi all, >> > > > >> > > > Some of you have probably been wondering about my changes to the >> > compiler >> > > > over the last year or more. I apologize again for occasionally >> breaking >> > > > things for short periods. It's been quite a challenge getting this >> > stuff >> > > > working, but I'm excited to finally be able to report some real >> > > > improvements that pretty much anyone should be able to take >> advantage >> > of >> > > > when building a Royale app. >> > > > >> > > > First some background. A while back, Harbs asked me to look into >> ways >> > of >> > > > reducing the file size of release builds. As you may know, we use >> > > Google's >> > > > Closure compiler to optimize our generated JavaScript. Closure can >> be >> > > very >> > > > aggressive in its optimizations, by renaming symbols (things like >> > > variable >> > > > and function names) and removing "dead code" that is detected as >> never >> > > > being called. >> > > > >> > > > Closure's optimizations are good, but they also require developers >> to >> > be >> > > > very careful about how they write their JavaScript code. When you >> > enable >> > > > Closure's full optimizations, you are not allowed to use certain >> > > JavaScript >> > > > features because Closure cannot analyze them properly. For instance, >> > > > consider the following code: >> > > > >> > > > var propName= "myProp"; >> > > > var value = obj[propName]; >> > > > >> > > > When you dynamically access a property with a string, Closure cannot >> > > > reliably know that the property exists and will be accessed at >> runtime. >> > > It >> > > > may decide to rename or remove that property, which would break >> things >> > at >> > > > runtime. >> > > > >> > > > ActionScript supports many of the same restricted dynamic features >> too, >> > > so >> > > > if you want to support the entire AS3 language, we can't let >> Closure do >> > > its >> > > > full optimization. Luckily, Closure also provides a bit of a >> backdoor: >> > it >> > > > allows you to "export" symbols, which means that they won't be >> renamed >> > > and >> > > > they won't be removed as dead code. Traditionally, we have made >> heavy >> > use >> > > > of this exporting feature in Royale. >> > > > >> > > > Harbs wanted to know if we absolutely needed to export everything >> that >> > we >> > > > currently export, and if we could potentially allow developers to >> turn >> > > off >> > > > exporting entirely, as long as they follow the stricter rules >> required >> > by >> > > > Closure. >> > > > >> > > > I won't go into all of the details, but over the last several >> months, >> > > I've >> > > > been changing the compiler to give developers more control over >> release >> > > > builds. In particular, control over which symbols get exported, but >> > also >> > > > the ability to block Closure from renaming symbols that haven't been >> > > > exported. >> > > > >> > > > Now, for some of the results. I'm going to share the output file >> size >> > of >> > > > the release build for several Royale projects with various different >> > > > compiler options. >> > > > >> > > > For the example projects included with Royale, I built royale-asjs >> > commit >> > > > 94f12ed0e564b0b443834400dc2fc06d61b90a8a from October 26, 2020. If >> you >> > > want >> > > > to try building these examples yourself, the file sizes of release >> > builds >> > > > may be slightly different, if you use a different commit. >> > > > >> > > > SpectrumBrowser is a project developed by Harbs and his team. I used >> > > commit >> > > > d25a3def972b15ec029ae838f1a8a677d2d158bd from October 20 for the >> > results >> > > > below. Repo: https://github.com/unhurdle/spectrum-royale/ >> > > > >> > > > To establish a baseline, I built all of these projects with the >> older >> > > > Royale 0.9.7 compiler first. >> > > > >> > > > ========== >> > > > Baseline: royale-compiler 0.9.7 >> > > > ========== >> > > > >> > > > HelloWorld: 68 KB >> > > > ASDoc: 231 KB >> > > > TourDeJewel: 1074 KB >> > > > SpectrumBrowser: 900 KB >> > > > >> > > > Again, I am building the same AS3/MXML code every time, but these >> first >> > > > numbers are from building with the older compiler. All apps build >> and >> > run >> > > > successfully. >> > > > >> > > > ----- >> > > > >> > > > The rest of the results are built with royale-compiler commit >> > > > df8bd9f686f1bbf89539e545377b2797c646172c from November 3. >> > > > >> > > > All results below include the difference in KB and %. These values >> are >> > > > always in comparison to the baseline numbers above. >> > > > >> > > > ========== >> > > > Result 1: 0.9.8 default options >> > > > ========== >> > > > >> > > > HelloWorld: 84 KB (+10 KB / +24%) >> > > > ASDoc: 254 KB (+23 KB / +10%) >> > > > TourDeJewel: 1105 KB (+31 KB / +3%) >> > > > SpectrumBrowser: 936 KB (+36 KB / +4%) >> > > > >> > > > These examples are slightly larger when built with the newer >> compiler. >> > > > That's expected. It's not ideal, but in the process of testing a >> > > multitude >> > > > of things to be sure that nothing had broken after my compiler >> > changes, I >> > > > discovered some cases where exporting a symbol didn't actually work >> > > > correctly in 0.9.7! To properly fix the bug and export these >> symbols, >> > > there >> > > > was no choice but to make the file size a bit larger. >> > > > >> > > > ========== >> > > > Result 2: Disable export >> > > > ========== >> > > > >> > > > HelloWorld: 74 KB (+6 KB / +9%) >> > > > ASDoc: 227 KB (-4 KB / -2%) >> > > > TourDeJewel: 942 KB (-132 KB / -12%) >> > > > SpectrumBrowser: 882 KB (-18 KB / -2%) >> > > > >> > > > In this round, I added the *-export-public-symbols=false* compiler >> > > option. >> > > > You may recall that I said earlier that I also modified the >> compiler to >> > > > allow a symbol not to be exported, but still prevent it from being >> > > renamed. >> > > > With that in mind, -export-public-symbols=false basically tells the >> > > > compiler that it still can't rename things, but it is allowed to >> remove >> > > > what it perceives as dead code. >> > > > >> > > > HelloWorld is still slightly larger than 0.9.7, but the three other >> > > > examples are now slightly smaller than 0.9.7. >> > > > >> > > > Most developers should be able to safely add >> > -export-public-symbols=false >> > > > to their compiler options when building a Royale app. The only time >> > that >> > > > you might still want this exporting is if you have external >> JavaScript >> > in >> > > > your page that isn't part of your Royale app, but it needs to call >> > > > functions/classes in your Royale app. >> > > > >> > > > ========== >> > > > Result 3: Allow non-public things to be renamed >> > > > ========== >> > > > >> > > > HelloWorld: 72 KB (+4 KB / +6%) >> > > > ASDoc: 221 KB (-10 KB / -4%) >> > > > TourDeJewel: 918 KB (-156 KB / -15%) >> > > > SpectrumBrowser: 861 KB (-39 KB / -4%) >> > > > >> > > > In this round, I used the following compiler options: >> > > > >> > > > -export-public-symbols=false >> > > > >> > > > >> > > > >> > > >> > >> *-prevent-rename-protected-symbols=false-prevent-rename-internal-symbols=false* >> > > > >> > > > The two new options allow Closure compiler to rename protected and >> > > internal >> > > > symbols. Once again, HelloWorld is still slightly larger than 0.9.7, >> > but >> > > > the other three examples have gotten smaller again. >> > > > >> > > > While -prevent-rename-public-symbols=false exists too, we cannot use >> > it. >> > > > The examples would not work correctly at runtime. This option would >> > > > probably work in a pure AS3 app, but our implementation of MXML in >> > Royale >> > > > uses dynamic language features that Closure restricts. Unless that >> is >> > > > fixed, we need to avoid renaming certain public symbols. >> > > > >> > > > Again, most developers should be able to add >> > > > -prevent-rename-protected-symbols=false >> > > > and -prevent-rename-internal-symbols=false to their Royale app's >> > compiler >> > > > options. You might need to prevent renaming of protected/internal >> > symbols >> > > > if you access them dynamically. However, in my experience, people >> are >> > > much >> > > > more likely to access public symbols dynamically. >> > > > >> > > > ----- >> > > > >> > > > ========== >> > > > Result 4: Allow public methods to be renamed >> > > > ========== >> > > > >> > > > HelloWorld: 64 KB (-4 KB / -6%) >> > > > ASDoc: 206 KB (-25 KB / -11%) >> > > > TourDeJewel: 881 KB (-193 KB / -18%) >> > > > SpectrumBrowser: 828 KB (-72 KB / -8%) >> > > > >> > > > In this round, I used the following compiler options: >> > > > >> > > > -export-public-symbols=false >> > > > -prevent-rename-protected-symbols=false >> > > > -prevent-rename-internal-symbols=false >> > > > >> > > > >> > > > >> > > >> > >> *-prevent-rename-public-static-methods=false-prevent-rename-public-instance-methods=false >> > > > * >> > > > >> > > > The two new options allow Closure to rename methods that are public. >> > Now, >> > > > all four examples are smaller than 0.9.7, and the file size >> difference >> > is >> > > > getting even more dramatic. >> > > > >> > > > Once again, -prevent-rename-public-static-methods=false and >> > > > -prevent-rename-public-instance-methods=false should be safe for >> most >> > > > developers to enable when compiling their Royale app. In my >> experience, >> > > > calling methods dynamically is rare. >> > > > >> > > > ========== >> > > > More new compiler options >> > > > ========== >> > > > >> > > > There are some additional new compiler options available, but using >> > them >> > > is >> > > > likely to break most Royale apps. >> > > > >> > > > -prevent-rename-public-static-variables=false >> > > > -prevent-rename-public-instance-variables=false >> > > > -prevent-rename-public-static-accessors=false >> > > > -prevent-rename-public-instance-accessors=false >> > > > >> > > > These options control whether Closure allows variables or accessors >> > > > (getters and setters) to be renamed. There are also similarly-named >> > > options >> > > > for protected and internal symbols, if you want more control over >> those >> > > > too, instead of using -prevent-rename-protected-symbols=false and >> > > > -prevent-rename-internal-symbols=false. >> > > > >> > > > Unfortunately, renaming public variables/accessors is usually not >> > > possible >> > > > without breaking the app at runtime. In some apps, you might be >> able to >> > > > allow public static members to be renamed. However, in my >> experience, >> > > > binding to static constants is pretty common, and renaming breaks >> those >> > > > bindings. >> > > > >> > > > ========== >> > > > Next Steps >> > > > ========== >> > > > >> > > > Ideally, I'd like to make it possible for developers to be able to >> tell >> > > > Closure that it's allowed to rename all symbols, including public >> > ones. I >> > > > believe that we could see even more file size savings in release >> builds >> > > if >> > > > Closure works with full optimizations for all symbols. Obviously, >> > > > ActionScript developers would be required to strictly follow >> Closure's >> > > > rules, if they opt into renaming of public symbols, but that's a >> choice >> > > > that they should be allowed to make. >> > > > >> > > > As I mentioned above, our implementation of MXML and binding uses >> > dynamic >> > > > access, which is not compatible with Closure's full optimizations. >> To >> > > > support those optimizations, I will need to explore changes to how >> we >> > > > generate JS for MXML, and how it gets parsed at runtime. >> > > > >> > > > We previously discussed this subject a bit in this older thread from >> > > > January 2020: >> > > > >> > > > >> > > > >> > > >> > >> https://lists.apache.org/thread.html/r843e55252e37967b71b1430a2a904719791d698f3e5e2a79de74e493%40%3Cdev.royale.apache.org%3E >> > > > >> > > > At the time, I tried out some ideas that we came up with while >> > > > brainstorming, but all had various downsides that didn't make for an >> > > > obvious winner. In the end, I decided to set further investigation >> > aside >> > > > and first focus on exporting/renaming stuff. Now, I'm ready to take >> a >> > > > second look with a fresh perspective, and maybe we'll have some new >> > ideas >> > > > to try. >> > > > >> > > > ----- >> > > > >> > > > That was really long, so thank you for reading, if you made it to >> the >> > > end! >> > > > >> > > > TL;DR: By enabling certain, new compiler options, most Royale >> > developers >> > > > can make their app release builds smaller. Additionally, I plan to >> keep >> > > > investigating, and I expect to find more ways to reduce file size in >> > the >> > > > future. >> > > > >> > > > -- >> > > > Josh Tynjala >> > > > Bowler Hat LLC <https://bowlerhat.dev> >> > > > >> > > >> > > >> > > -- >> > > Andrew Wetmore >> > > >> > > http://cottage14.blogspot.com/ >> > > >> > >> >> >> -- >> Carlos Rovira >> Apache Member & Apache Royale PMC >> *Apache Software Foundation* >> http://about.me/carlosrovira >> > > > -- > Andrew Wetmore > > http://cottage14.blogspot.com/ > > > > > -- Andrew Wetmore http://cottage14.blogspot.com/
