feat: peer automatically injects existing task metadata to scheduler upon restart

[BruceAko]

Description

Handle AnnouncePeersRequest, store Peer into scheduler.

Related Issue

Resolve #3387

Motivation and Context

Rust's dfdaemon stores the task's metadata in RocksDB at the beginning of the download. Add a new rpc interface: AnnounceTask() to the v2 scheduler. dfdaemon of Rust will fetch the metadata of downloaded tasks (including the metadata of tasks and pieces) from RocksDB at each startup, filter out all the completed tasks, call AnnounceTask() to the schedulerscheduler to add the metadata of Task and Peer to the Manager for subsequent scheduling.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation Update (if none of the other choices apply)

Checklist

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.

Test doc

https://www.yuque.com/baimo/fv9qk8/vw6mgd2aw0ksv0c8

[codecov]

Codecov Report

Attention: Patch coverage is 67.39130% with 30 lines in your changes missing coverage. Please review.

Project coverage is 52.07%. Comparing base (2c0ae78) to head (d353508).
Report is 4 commits behind head on main.

Files with missing lines	Patch %	Lines
scheduler/service/service_v2.go	70.45%	25 Missing and 1 partial ⚠️
scheduler/rpcserver/scheduler_server_v2.go	0.00%	4 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3385      +/-   ##
==========================================
- Coverage   52.11%   52.07%   -0.04%     
==========================================
  Files         188      188              
  Lines       20242    20332      +90     
==========================================
+ Hits        10549    10588      +39     
- Misses       8894     8940      +46     
- Partials      799      804       +5     

Flag	Coverage Δ
unittests	52.07% <67.39%> (-0.04%)	⬇️

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

Files with missing lines	Coverage Δ
scheduler/metrics/metrics.go	8.24% <ø> (ø)
scheduler/rpcserver/scheduler_server_v2.go	2.56% <0.00%> (-0.14%)	⬇️
scheduler/service/service_v2.go	81.40% <70.45%> (-1.00%)	⬇️

... and 5 files with indirect coverage changes

[gaius-qi]

PeerCountLimitForTask

[BruceAko]

PeerCountLimitForTask

resolved