KYLIN-3597, fix the critical bug reported by sonar: Make sure this ex…

[Aaaaaaron]

…pression can't be zero before doing this division.

[asfgit]

Can one of the admins verify this patch?

[Aaaaaaron]

Hi @mingmwang, there's a critical bug reported by sonar, and I offer a fix, can you take a look and confirm the change? Thanks.

[coveralls]

Pull Request Test Coverage Report for Build 3836

• 0 of 1 (0.0%) changed or added relevant line in 1 file are covered.
• 5 unchanged lines in 1 file lost coverage.
• Overall coverage decreased (-0.003%) to 23.613%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
cache/src/main/java/net/spy/memcached/RefinedKetamaNodeLocator.java	0	1	0.0%

Files with Coverage Reduction	New Missed Lines	%
core-cube/src/main/java/org/apache/kylin/cube/inmemcubing/MemDiskStore.java	5	77.81%

Totals
Change from base Build 3832:	-0.003%
Covered Lines:	16809
Relevant Lines:	71186

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💛 - Coveralls

[codecov-io]

Codecov Report

Merging #326 into master will decrease coverage by 0.01%.
The diff coverage is 0%.

@@             Coverage Diff              @@
##             master     #326      +/-   ##
============================================
- Coverage     21.55%   21.54%   -0.02%     
+ Complexity     4579     4577       -2     
============================================
  Files          1112     1112              
  Lines         71186    71186              
  Branches      10284    10285       +1     
============================================
- Hits          15343    15334       -9     
- Misses        54373    54379       +6     
- Partials       1470     1473       +3

Impacted Files	Coverage Δ	Complexity Δ
...va/net/spy/memcached/RefinedKetamaNodeLocator.java	24.17% <0%> (ø)	8 <0> (ø)	⬇️
...org/apache/kylin/rest/util/QueryRequestLimits.java	35.71% <0%> (-4.77%)	5% <0%> (-1%)
...rg/apache/kylin/cube/inmemcubing/MemDiskStore.java	69.3% <0%> (-1.83%)	7% <0%> (ø)
...a/org/apache/kylin/dict/Number2BytesConverter.java	81.74% <0%> (-0.8%)	17% <0%> (-1%)

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[Aaaaaaron]

When "totalWeight" is 0, means there are no nodes, so "thisWeight" is 0 too.

[shaofengshi]

LGTM