Memory usage improvement

[popduke]

1. Reduced memory consumption in dist worker
2. Reduced memory overhead during split/merge/snapshot installation process

[coveralls]

Pull Request Test Coverage Report for Build 18059875195

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 301 unchanged lines in 24 files lost coverage.
• Overall coverage increased (+0.3%) to 64.062%

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Files with Coverage Reduction	New Missed Lines	%
org/apache/bifromq/basekv/localengine/rocksdb/RocksDBKVSpaceSnapshot.java	1	33.33%
org/apache/bifromq/basekv/store/range/KVRange.java	1	91.27%
org/apache/bifromq/basescheduler/Batcher.java	1	84.75%
org/apache/bifromq/dist/worker/schema/cache/GroupMatchingCache.java	1	92.31%
org/apache/bifromq/dist/worker/schema/cache/NormalMatchingCache.java	1	92.31%
org/apache/bifromq/dist/worker/schema/cache/ReceiverCache.java	1	85.71%
org/apache/bifromq/dist/worker/schema/cache/RouteDetailCache.java	1	98.53%
org/apache/bifromq/basekv/raft/RaftNodeStateLeader.java	2	85.54%
org/apache/bifromq/dist/server/DistService.java	2	91.67%
org/apache/bifromq/basehlc/HLC.java	3	54.32%

Totals
Change from base Build 17993887957:	0.3%
Covered Lines:	24725
Relevant Lines:	37276

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💛 - Coveralls