[perf] disabling _populateCache() in loader in favor of an on-demand process to create internal module info based on the raw meta when the module is needed #1581

caridy · 2014-01-24T23:57:50Z

Initial analysis:

For a very basic page with all necessary modules in the page upfront, and a YUI().use(‘json-stringify’) call, will run under 20ms in chrome/desktop, but it takes more than 100ms in safari iPad3.

For a more complex example, adding more modules (app level modules), we can clearly see more degradation of the initialization, even though none of those modules are "used". Here is an example using modules from screen.yahoo.com (almost 400 new modules + the 407 modules from yui core):

http://jsbin.com/iPOriSAS/1/edit

For what we can see in the profiling, _populateCache(), which is executed once per Y instance, it will do a one time operation to digest all the raw metadata from YUI.Env.modules, passing them thru addModule() method that will do a basic expansion of the meta without doing the recursive computation to expand the dependencies, that happens on demand.

By using the loader built of this branch, we seed a good deal of improvement, and overall a constant time to use despited the number of extra modules added thru the metas, which is exactly what we are looking for.

Changes:

Loader keeps a member called moduleInfo, which is a hash with the internal meta for every module. This structure is used within the loader and from yui.js as well. This PR is proposing a shim on top of that structure to se can populate the cache for each individual module from the raw meta structure YUI.Env.modules when we needed. This will help to not have to walk thousand of modules as part of the initialization of the first YUI instance.

A quirk on this new way of initialization is that conditional modules are not requested by any other module in the require chain, which means they will have to be analyzed before applying any operation to compute dependencies, for that, we are just warming up the conditional cache (which is normally 16 entries for yui core), instead of just initializing all core modules (400+).

Performance tests

command: yb src/loader/tests/performance/loader-tests.js --phantom --ref v3.14.1 --ref v3.15.0

loader resolve core modules

┌───────────┬───────────────────────────┬───────────────────────────────────┬───────────────────────────┐
│           │  Safari (7.0.1) / Mac OS  │  Chrome (33.0.1750.117) / Mac OS  │  Firefox (27.0) / Mac OS  │
├───────────┼───────────────────────────┼───────────────────────────────────┼───────────────────────────┤
│  v3.14.1  │  44.788  ±3.7%            │  44.546  ±3.8%                    │  21.736  ±4.6%            │
│  Working  │  189.414  ±4.4%  +323%    │  127.738  ±8.9%  +187%            │  86.822  ±3.8%  +299%     │
│  v3.15.0  │  157.768  ±3.9%  +252%    │  109.642  ±4.7%  +146%            │  80.497  ±3.9%  +270%     │
└───────────┴───────────────────────────┴───────────────────────────────────┴───────────────────────────┘

loader resolve application modules

┌───────────┬───────────────────────────┬───────────────────────────────────┬───────────────────────────┐
│           │  Safari (7.0.1) / Mac OS  │  Chrome (33.0.1750.117) / Mac OS  │  Firefox (27.0) / Mac OS  │
├───────────┼───────────────────────────┼───────────────────────────────────┼───────────────────────────┤
│  v3.14.1  │  595.568  ±5.7%           │  245.833  ±7.7%                   │  231.745  ±5.0%           │
│  Working  │  6.721k  ±3.3%  +1029%    │  3.450k  ±7.1%  +1304%            │  2.500k  ±4.3%  +979%     │
│  v3.15.0  │  696.895  ±3.0%  +17%     │  279.307  ±4.9%  +14%             │  260.851  ±3.8%  +13%     │
└───────────┴───────────────────────────┴───────────────────────────────────┴───────────────────────────┘

caculate dependecies

┌───────────┬───────────────────────────┬───────────────────────────────────┬───────────────────────────┐
│           │  Safari (7.0.1) / Mac OS  │  Chrome (33.0.1750.117) / Mac OS  │  Firefox (27.0) / Mac OS  │
├───────────┼───────────────────────────┼───────────────────────────────────┼───────────────────────────┤
│  v3.14.1  │  87.696  ±3.8%            │  78.881  ±4.2%                    │  44.247  ±4.4%            │
│  Working  │  306.211  ±3.0%  +249%    │  217.144  ±8.9%  +175%            │  154.839  ±3.1%  +250%    │
│  v3.15.0  │  224.967  ±2.7%  +157%    │  132.550  ±7.0%  +68%             │  110.696  ±3.9%  +150%    │
└───────────┴───────────────────────────┴───────────────────────────────────┴───────────────────────────┘

loader constructor with global cache

┌───────────┬───────────────────────────┬───────────────────────────────────┬───────────────────────────┐
│           │  Safari (7.0.1) / Mac OS  │  Chrome (33.0.1750.117) / Mac OS  │  Firefox (27.0) / Mac OS  │
├───────────┼───────────────────────────┼───────────────────────────────────┼───────────────────────────┤
│  v3.14.1  │  1.159k  ±4.6%            │  402.577  ±4.5%                   │  419.501  ±4.0%           │
│  Working  │  35.813k  ±3.5%  +2990%   │  9.923k  ±7.8%  +2365%            │  12.131k  ±3.6%  +2792%   │
│  v3.15.0  │  1.203k  ±3.0%  +4%       │  406.346  ±4.1%  +1%              │  435.124  ±3.6%  +4%      │
└───────────┴───────────────────────────┴───────────────────────────────────┴───────────────────────────┘

loader constructor without cache

┌───────────┬───────────────────────────┬───────────────────────────────────┬───────────────────────────┐
│           │  Safari (7.0.1) / Mac OS  │  Chrome (33.0.1750.117) / Mac OS  │  Firefox (27.0) / Mac OS  │
├───────────┼───────────────────────────┼───────────────────────────────────┼───────────────────────────┤
│  v3.14.1  │  143.610  ±8.3%           │  127.687  ±5.7%                   │  95.255  ±7.2%            │
│  Working  │  4.830k  ±2.9%  +3263%    │  3.451k  ±12.1%  +2603%           │  2.972k  ±3.7%  +3020%    │
│  v3.15.0  │  138.078  ±8.1%  -4%      │  135.419  ±6.8%  +6%              │  91.891  ±5.6%  -4%       │
└───────────┴───────────────────────────┴───────────────────────────────────┴───────────────────────────┘

…to addModules to the metas when they are really needed

caridy · 2014-01-30T18:52:21Z

This is proven to be worth it, bumping the priority of this one. A clean up is needed! /cc @ekashida

ekashida · 2014-01-31T00:25:23Z

src/loader/js/loader.js

+    * @param {string} name of the module
+    * @private
+    */
+    _getModuleInfo: function(name) {


Should the accessor to the public moduleInfo property be private?

good question. It seems that moduleInfo was public, but we were not expecting people to use it. That sounds off! http://yuilibrary.com/yui/docs/api/classes/Loader.html#property_moduleInfo

We could make getModuleInfo public, and make moduleInfo private (at least in the docs).

ekashida · 2014-02-04T22:05:59Z

src/loader/js/loader.js

+        var rawMetaModules = META.modules,
+            globalConditions = GLOBAL_ENV._conditions,
+            globalRenderedMods = GLOBAL_ENV._renderedMods,
+            internal = this._internal;


Need to change this semicolon to a comma.

… is analyzed before addModule is called.

…hat those are taken in consideration even when those modules are not added thru addModule() call

… to support when: after

caridy · 2014-03-14T22:09:23Z

This PR is ready for a formal review.

caridy · 2014-03-14T22:11:43Z

src/loader/js/loader.js

-            for (i in cache) {
-                if (cache.hasOwnProperty(i)) {
-                    self.moduleInfo[i] = Y.merge(cache[i]);
+    _getModuleInfo: function(name) {


This is the new accessor for module info, although, in some places we are intentionally using the internal hash this.moduleInfo to avoid the penalty of the function call, even though there is a short circuit in this method for that case. Ideally, we can test this and simply drop the property in favor of the accessor, or we can replace the property with a define property (when that feature is available), and that will help us to control this better.

ezequiel · 2014-03-21T18:18:21Z

I think this pull request inadvertently fixes #768 and #769.

ericf · 2014-03-21T21:31:02Z

src/loader/js/loader.js

-                if (cache.hasOwnProperty(i)) {
-                    self.moduleInfo[i] = Y.merge(cache[i]);
+        if (this.moduleInfo[name]) {
+            return this.moduleInfo[name];


You could optimize this lookup by not doing it twice, but once and bind it to a local var.

ericf · 2014-03-21T22:03:49Z

This should be in a 3.x release because it changes the public moduleInfo. We should have a way for people to opt back into eagerly populating moduleInfo.

ericf · 2014-03-26T20:06:52Z

src/loader/js/loader.js

-            defaults = META.modules,
-            cache = GLOBAL_ENV._renderedMods,
-            i;
+    getModuleInfo: function(name) {


Is this staying private even though the method name does not start with an underscore?

I think it is ok to make it public, as the accessor for module info.

The API doc comment should be updated then.

ericf · 2014-03-26T20:32:47Z

The updates look good. I added a comment about whether getModuleInfo() is meant to be public or private.

ezequiel · 2014-03-27T05:41:58Z

src/loader/js/loader.js

-                delete mod.langCache;
-                delete mod.skinCache;
+                mod.langCache = undefined;
+                mod.skinCache = undefined;


Why? Setting a property to undefined is different than deleteing it.

most js engines will go crazy about deleting a member of an object, part of the micro optimizations they do thru the synthetic classes. Deleting a member of a module meta object will simply throw the class away and will require extra work to access any member.

This is obviously not relevant for dictionaries/hashes, which is not the case here.

ezequiel · 2014-03-27T21:03:58Z

👍

ericf · 2014-03-28T14:34:10Z

What do the coverage numbers look like for the code that was changed in this diff? Since this is loader I want us to be extra cautious. We might want to add some tests, especially for the new getModuleInfo() method.

Also we need may need User Guide updates.

ericf · 2014-03-28T14:42:08Z

👍

caridy added 3 commits January 24, 2014 18:50

disabling _populateCache() in loader in favor of an ondemand process …

420f042

…to addModules to the metas when they are really needed

fixing typo

4924186

improving fallback from global modules

b2b4be9

ekashida reviewed Jan 31, 2014
View reviewed changes

adding internal flag when needed for raw modules

5efec76

ekashida reviewed Feb 4, 2014
View reviewed changes

fixing typo

7668152

caridy mentioned this pull request Feb 26, 2014

New loader sort breaks config changes on sub-dependencies #1656

Open

ezequiel self-assigned this Mar 4, 2014

ezequiel added this to the Sprint 13 milestone Mar 4, 2014

ezequiel added the Loader label Mar 8, 2014

ezequiel removed their assignment Mar 12, 2014

caridy added 7 commits March 12, 2014 16:53

merging upstream and resolving conflicts after 3.15

c553a05

skipping the short-circuit on css detection routine if the css module…

e2ef327

… is analyzed before addModule is called.

adding a note for the docs on skip parameter when detecting css modules

4f2edc0

adding conditions as part of the loader initialization to guarantee t…

643b0fd

…hat those are taken in consideration even when those modules are not added thru addModule() call

adding a temporary patch on the test until @ezequiel fixes the laoder…

c96a667

… to support when: after

I hate trailing spaces

b978f6b

adding perf tests for the loader constructor

d2cd2a0

cleaning up docs

b616ab0

caridy reviewed Mar 14, 2014
View reviewed changes

caridy added 2 commits March 14, 2014 19:59

rolling back the patch for the test now that we figure the issue

dc12a55

some extra improvements, removing unnecessarily copies of conditions

2978af2

okuryu assigned apipkin and unassigned apipkin Mar 16, 2014

caridy mentioned this pull request Mar 18, 2014

[bz5894189] research on Y.use('*') #1714

Open

ericf reviewed Mar 21, 2014
View reviewed changes

caridy added 3 commits March 21, 2014 18:53

Merge branch 'dev-3.x' of github.com:yui/yui3 into module-info

e7b9232

Merge branch 'dev-3.x' of github.com:yui/yui3 into module-info

f4fc272

review feedback for yui#1581

4e7e031

ericf reviewed Mar 26, 2014
View reviewed changes

caridy added 2 commits March 26, 2014 16:55

making getModuleInfo() public

0f1f265

adding history entry for PR yui#1581

77fa118

ezequiel reviewed Mar 27, 2014
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review feedback from @ezequiel

0829ca1

caridy merged commit 0829ca1 into yui:dev-3.x Mar 28, 2014

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[perf] disabling _populateCache() in loader in favor of an on-demand process to create internal module info based on the raw meta when the module is needed #1581

[perf] disabling _populateCache() in loader in favor of an on-demand process to create internal module info based on the raw meta when the module is needed #1581

caridy commented Jan 24, 2014

caridy commented Jan 30, 2014

ekashida Jan 31, 2014

caridy Jan 31, 2014

ekashida Feb 4, 2014

caridy commented Mar 14, 2014

caridy Mar 14, 2014

ezequiel commented Mar 21, 2014

ericf Mar 21, 2014

ericf commented Mar 21, 2014

ericf Mar 26, 2014

caridy Mar 26, 2014

ericf Mar 28, 2014

ericf commented Mar 26, 2014

ezequiel Mar 27, 2014

caridy Mar 27, 2014

ezequiel commented Mar 27, 2014

ericf commented Mar 28, 2014

ericf commented Mar 28, 2014

[perf] disabling _populateCache() in loader in favor of an on-demand process to create internal module info based on the raw meta when the module is needed #1581

[perf] disabling _populateCache() in loader in favor of an on-demand process to create internal module info based on the raw meta when the module is needed #1581

Conversation

caridy commented Jan 24, 2014

Initial analysis:

Changes:

Performance tests

loader resolve core modules

loader resolve application modules

caculate dependecies

loader constructor with global cache

loader constructor without cache

caridy commented Jan 30, 2014

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