Question: Performance improvements possible?

[cebe]

Currently composer queries bower.json for versions that it is never going to install because of version constraints. Is it somehow possible to avoid these requests?

Having the latest version of composer and the composer-asset-plugin and run the following command:

composer create-project --prefer-dist --stability=rc yiisoft/yii2-app-basic basic

Installing yiisoft/yii2-app-basic (2.0.0-rc)
  - Installing yiisoft/yii2-app-basic (2.0.0-rc)
    Loading from cache

Created project in basic
Loading composer repositories with package information
Installing dependencies (including require-dev)

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Reading bower.json of bower-asset/jquery (1.8.3)^C   

As you can see it is trying to get bower.json for jquery 1.8.3 which is not installable anyway because of the version constraint "2.1.*@stable | 1.11.*@stable". Is it possible to avoid these requests somehow?

[francoispluchino]

Alas, this is not possible, and for good reason, it's the Solver wishing retrieve package dependencies via the method getRequire. Even with the lazy loader package, once the Solver want to compare versions, the complete loading of packages to compare is performed.

You'll have more details in the issue #5 to this comment.

Regarding your composer.json file, all versions of jquery >=1.7 are got, because as several dependencies have this constraint, and given that the Solver is a Solver SAT, it will get the contents of all the versions allowed by this constraint.

List of dependencies:

• bower-asset/jquery.inputmask: jquery >=1.7
• bower-asset/yii2-pjax: jquery >=1.8
• bower-asset/typeahead.js: jquery >=1.7
• bower-asset/boostrap: jquery >=1.9.0

You will find that with the option -v, there is only the packages of jquery >=1.7 that are recovered (and not all versions).

However, 2 issues on improving performance for Composer were created:

• For the Remote File System (see Increase performance of the remote file system composer/composer#3282)
• For the Solver (see Increase performance of Sover composer/composer#3283)

For the Solver, after discussion, it is not possible because of the type of Solver (SAT).

The performance could be much better (especially for VCS repositories), by using curl without the follow redirects, and to do manually the redirection (up to 6x faster).

[cebe]

Great, thank your very much for the detailed answer! :)

[francoispluchino]

The issue #52 improves significantly the performance for the update.