improve SimilarsMap implementation

[zhoney]

Change-Id: If98cd1df039bac5d2ca80819e550a7b4501b041d

[codecov]

Codecov Report

Merging #1523 (42d1e93) into master (f22d03f) will decrease coverage by 0.01%.
The diff coverage is n/a.

@@             Coverage Diff              @@
##             master    #1523      +/-   ##
============================================
- Coverage     59.66%   59.65%   -0.02%     
  Complexity     6150     6150              
============================================
  Files           410      410              
  Lines         33255    33255              
  Branches       4591     4591              
============================================
- Hits          19843    19838       -5     
- Misses        11336    11346      +10     
+ Partials       2076     2071       -5     

Impacted Files	Coverage Δ
...va/com/baidu/hugegraph/auth/HugeAuthenticator.java	34.78% <0.00%> (-5.44%)	⬇️
...in/java/com/baidu/hugegraph/auth/HugeResource.java	77.92% <0.00%> (-1.30%)	⬇️
.../java/com/baidu/hugegraph/auth/RolePermission.java	90.58% <0.00%> (-1.18%)	⬇️
...c/main/java/com/baidu/hugegraph/task/HugeTask.java	72.00% <0.00%> (+0.30%)	⬆️
...ain/java/com/baidu/hugegraph/task/TaskManager.java	71.94% <0.00%> (+1.43%)	⬆️
...va/com/baidu/hugegraph/task/ServerInfoManager.java	74.15% <0.00%> (+2.80%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update f22d03f...42d1e93. Read the comment docs.