v6.0.0.beta.3

Because v6.0.0-beta.2 performed extremely poorly, most of the code was rolled back to v6.0.0-beta.1, but some bugs that existed in v6.0.0-beta.1 were fixed.

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因 v6.0.0-beta.2 性能下降幅度过大，故将大部分的代码回滚到 v6.0.0-beta.1，但是修复了一些存在于 v6.0.0-beta.1 的 bug。