[improve][broker] Pin executor to dispatcher and StreamingEntryReader to cache the string hashing

[AnonHxy]

Motivation

Inspired by #18078, Instead of hashing the string each, pin the thread and always use the same, for a given dispatcher instance, also StreamingEntryReader.

Modifications

Instead of hashing the string each, pin the thread and always use the same, for a given dispatcher instance, also StreamingEntryReader.

Verifying this change

• Make sure that the change passes the CI checks.

Documentation

• doc
• doc-required
• doc-not-needed
• doc-complete

Matching PR in forked repository

PR in forked repository: AnonHxy#18

[mattisonchao]

LGTM

[AnonHxy]

@Jason918 @merlimat @Technoboy- PTAL

[codecov-commenter]

Codecov Report

Merging #18566 (0d4220f) into master (b579bb8) will increase coverage by 2.08%.
The diff coverage is 25.00%.

@@             Coverage Diff              @@
##             master   #18566      +/-   ##
============================================
+ Coverage     47.51%   49.60%   +2.08%     
- Complexity    10520    10803     +283     
============================================
  Files           698      698              
  Lines         68079    68084       +5     
  Branches       7280     7280              
============================================
+ Hits          32351    33774    +1423     
+ Misses        32151    30654    -1497     
- Partials       3577     3656      +79     

Flag	Coverage Δ
unittests	49.60% <25.00%> (+2.08%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...ersistentStreamingDispatcherMultipleConsumers.java	0.00% <0.00%> (ø)
...istentStreamingDispatcherSingleActiveConsumer.java	0.00% <0.00%> (ø)
...ervice/streamingdispatch/StreamingEntryReader.java	0.00% <0.00%> (ø)
...tent/PersistentDispatcherSingleActiveConsumer.java	59.37% <75.00%> (-0.50%)	⬇️
...ar/broker/loadbalance/impl/BundleSplitterTask.java	60.00% <0.00%> (-17.78%)	⬇️
.../apache/pulsar/broker/admin/impl/PackagesBase.java	54.12% <0.00%> (-13.77%)	⬇️
.../pulsar/broker/service/SharedConsumerAssignor.java	68.51% <0.00%> (-9.26%)	⬇️
...lsar/broker/loadbalance/impl/ThresholdShedder.java	38.56% <0.00%> (-9.16%)	⬇️
...er/mledger/impl/ManagedLedgerFactoryMBeanImpl.java	63.41% <0.00%> (-4.88%)	⬇️
...ction/buffer/impl/TransactionBufferClientImpl.java	76.74% <0.00%> (-4.66%)	⬇️
... and 104 more