Improve the performance when sending on macOS

[LinuxSuRen]

• Support order insensitive of the sender or receiver
• Increase the udp buffer on darwin
• Improve the performance when sending on macOS

[codecov-commenter]

Codecov Report

❗ No coverage uploaded for pull request base (master@cb262e1). Click here to learn what that means.
The diff coverage is n/a.

@@            Coverage Diff            @@
##             master       #4   +/-   ##
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  Coverage          ?   22.08%           
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  Files             ?        6           
  Lines             ?      335           
  Branches          ?        0           
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  Hits              ?       74           
  Misses            ?      260           
  Partials          ?        1           

Flag	Coverage Δ
unittests	22.08% <0.00%> (?)

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