Spool4

[gortiz]

This PR is a continuation (and should be merged after) of #14507 and the next step on #14196.

Here we introduce a new exchange that buffers data on the heap. This is a cheap implementation. In future we may decide add an offheap implementation.

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 71.08014% with 83 lines in your changes missing coverage. Please review.

Project coverage is 64.02%. Comparing base (59551e4) to head (5d81c6a).
Report is 1478 commits behind head on master.

Files with missing lines	Patch %	Lines
...ry/runtime/operator/exchange/BufferedExchange.java	52.94%	22 Missing and 2 partials ⚠️
...hysical/colocated/GreedyShuffleRewriteVisitor.java	0.00%	19 Missing ⚠️
...query/runtime/operator/exchange/BlockExchange.java	48.38%	10 Missing and 6 partials ⚠️
...me/operator/utils/BlockingMultiStreamConsumer.java	0.00%	9 Missing ⚠️
...ery/planner/physical/MailboxAssignmentVisitor.java	90.62%	4 Missing and 2 partials ⚠️
...requesthandler/MultiStageBrokerRequestHandler.java	0.00%	2 Missing ⚠️
...inot/query/planner/serde/PlanNodeDeserializer.java	60.00%	1 Missing and 1 partial ⚠️
...apache/pinot/query/mailbox/GrpcSendingMailbox.java	50.00%	2 Missing ⚠️
...he/pinot/query/planner/logical/PlanFragmenter.java	85.71%	0 Missing and 1 partial ⚠️
.../pinot/query/planner/serde/PlanNodeSerializer.java	87.50%	0 Missing and 1 partial ⚠️
... and 1 more

Additional details and impacted files

@@             Coverage Diff              @@
##             master   #14672      +/-   ##
============================================
+ Coverage     61.75%   64.02%   +2.27%     
- Complexity      207     1603    +1396     
============================================
  Files          2436     2705     +269     
  Lines        133233   149091   +15858     
  Branches      20636    22844    +2208     
============================================
+ Hits          82274    95453   +13179     
- Misses        44911    46637    +1726     
- Partials       6048     7001     +953     

Flag	Coverage Δ
custom-integration1	100.00% <ø> (+99.99%)	⬆️
integration	100.00% <ø> (+99.99%)	⬆️
integration1	100.00% <ø> (+99.99%)	⬆️
integration2	0.00% <ø> (ø)
java-11	64.00% <71.08%> (+2.29%)	⬆️
java-21	34.40% <2.78%> (-27.23%)	⬇️
skip-bytebuffers-false	64.01% <71.08%> (+2.27%)	⬆️
skip-bytebuffers-true	34.38% <2.78%> (+6.65%)	⬆️
temurin	64.02% <71.08%> (+2.27%)	⬆️
unittests	64.01% <71.08%> (+2.27%)	⬆️
unittests1	56.33% <70.52%> (+9.44%)	⬆️
unittests2	34.41% <2.78%> (+6.68%)	⬆️

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

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.