WIP: perf(router): avoid calling `set` when the generated data unmodified

[yoshinorin]

What does it do?

When any file is modified, even unchanged routes are updated (the set method is called). Additionally, in the set method, EventEmitter's emit is called. So, events to be fired many times (number of assets) whenever a single file is updated.

Maybe, it should be fine to call the set method only for the modified files.

Screenshots

N/A

Pull request tasks

• [ ] Add test cases for the changes.
• [x] Passed the CI test.

[github-actions[bot]]

How to test

git clone -b perf/router-refresh https://github.com/hexojs/hexo.git
cd hexo
npm install
npm test

[github-actions[bot]]

Flamegraph

https://c364a668e1e10e5ea65d2aa332677e6be4f3a292-14-hexo.surge.sh/flamegraph.html https://c364a668e1e10e5ea65d2aa332677e6be4f3a292-16-hexo.surge.sh/flamegraph.html https://c364a668e1e10e5ea65d2aa332677e6be4f3a292-18-hexo.surge.sh/flamegraph.html

[yoshinorin]

The test cases for the watcher are failing.

Now green. Use unique files for each test for watch. Because using the same files (test.txt) as other tests caused failures. Perhaps caused by caching or something similar, but I'm not sure.

[coveralls]

Pull Request Test Coverage Report for Build 8870147837

Details

• 5 of 5 (100.0%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 98.978%

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Totals
Change from base Build 8800035659:	0.0%
Covered Lines:	9297
Relevant Lines:	9393

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💛 - Coveralls

[yoshinorin]

I've noticed that when db.json exists before hexo s execution, CSS files and others aren't registered to the route in this PR. This is likely related to the tests failing when the file test.txt is used. I'll investigate.

[yoshinorin]

I've noticed that when db.json exists before hexo s execution, CSS files and others aren't registered to the route in this PR. This is likely related to the tests failing when the file test.txt is used. I'll investigate.

It seems that the _routerRefresh method is called not only for updating the router but also for initializing the router. Therefore, it seems necessary to make changes such as separating the method for initialization and updating.