perf: avoid using delete operator

[SukkaW]

What does it do?

https://v8.dev/blog/fast-properties

In short, the delete operator has a potential performance impact (related with v8 hidden class, and delete could cause v8 to degrade object process). By replacing delete operator it could gain performance.

Screenshots

Benchmark result:

master branch

Cold processing
┌──────────────────────────────┬───────────────┐
│           (index)            │ Cost time (s) │
├──────────────────────────────┼───────────────┤
│ Load Plugin/Scripts/Database │    '0.41s'    │
│        Process Source        │    '3.60s'    │
│         Render Posts         │    '3.36s'    │
│         Render Files         │    '7.27s'    │
│        Save Database         │    '0.35s'    │
│          Total time          │   '14.99s'    │
└──────────────────────────────┴───────────────┘
Hot processing
┌──────────────────────────────┬───────────────┐
│           (index)            │ Cost time (s) │
├──────────────────────────────┼───────────────┤
│ Load Plugin/Scripts/Database │    '1.20s'    │
│        Process Source        │    '1.41s'    │
│         Render Files         │    '7.23s'    │
│        Save Database         │    '0.35s'    │
│          Total time          │   '10.20s'    │
└──────────────────────────────┴───────────────┘
Another Cold processing
┌──────────────────────────────┬───────────────┐
│           (index)            │ Cost time (s) │
├──────────────────────────────┼───────────────┤
│ Load Plugin/Scripts/Database │    '0.41s'    │
│        Process Source        │    '3.43s'    │
│         Render Posts         │    '3.31s'    │
│         Render Files         │    '7.38s'    │
│        Save Database         │    '0.34s'    │
│          Total time          │   '14.87s'    │
└──────────────────────────────┴───────────────┘

After the PR:

Cold processing
Cold processing
┌──────────────────────────────┬───────────────┐
│           (index)            │ Cost time (s) │
├──────────────────────────────┼───────────────┤
│ Load Plugin/Scripts/Database │    '0.36s'    │
│        Process Source        │    '3.32s'    │
│         Render Posts         │    '3.22s'    │
│         Render Files         │    '6.94s'    │
│        Save Database         │    '0.33s'    │
│          Total time          │   '14.17s'    │
└──────────────────────────────┴───────────────┘
Hot processing
┌──────────────────────────────┬───────────────┐
│           (index)            │ Cost time (s) │
├──────────────────────────────┼───────────────┤
│ Load Plugin/Scripts/Database │    '1.07s'    │
│        Process Source        │    '1.38s'    │
│         Render Files         │    '6.80s'    │
│        Save Database         │    '0.34s'    │
│          Total time          │    '9.59s'    │
└──────────────────────────────┴───────────────┘
Another Cold processing
┌──────────────────────────────┬───────────────┐
│           (index)            │ Cost time (s) │
├──────────────────────────────┼───────────────┤
│ Load Plugin/Scripts/Database │    '0.38s'    │
│        Process Source        │    '3.32s'    │
│         Render Posts         │    '3.14s'    │
│         Render Files         │    '6.82s'    │
│        Save Database         │    '0.35s'    │
│          Total time          │   '14.01s'    │
└──────────────────────────────┴───────────────┘

Performance improved by 7% after the PR.

Pull request tasks

• Add test cases for the changes.
• Passed the CI test.

[coveralls]

Coverage remained the same at 98.282% when pulling 9170b79 on SukkaW:perf-avoid-using-delete-operator into eef2eac on hexojs:master.

[jiangtj]

👍