net: Provide block templates to peers on request #33191

1. 
   ajtowns commented at 10:33 pm on August 14, 2025: contributor

   Implements the sending side of SENDTEMPLATE, GETTEMPLATE, TEMPLATE message scheme for sharing block templates with peers via compact block encoding/reconstruction.
2. DrahtBot added the label P2P on Aug 14, 2025
3. 
   DrahtBot commented at 10:33 pm on August 14, 2025: contributor

   The following sections might be updated with supplementary metadata relevant to reviewers and maintainers.

   Code Coverage & Benchmarks

   For details see: https://corecheck.dev/bitcoin/bitcoin/pulls/33191.

   Reviews

   See the guideline for information on the review process. A summary of reviews will appear here.

4. node/miner: drop node/context include 5935551b24
5. node/miner: Log via MINER debug category

   This removes "CreateNewBlock" messages from logs by default. Also changes
   "-printpriority" argument to automatically enable -debug=miner logging.

   d6f4d3ed47
6. blockencoding: Move mempool to InitData argument

   This allows default initialisation of a PartiallyDownloadedBlock.

   9c28f7d3d1
7. protocol.h: Define template sharing protocol messages

   Also covers functional test setup.

   e6b2db2f0b
8. net_processing: add support for template sharing

   This adds suport for SENDTEMPLATE, GETTEMPLATE, TEMPLATE p2p messages to generate
   and send block templates to our peers. It does not support requesting templates from
   our peers.

   fc52a0a487
9. blockencodings: Generalise vExtraTxns

   Allows extra transactions to be provided from structures other than a
   vector of CTransactionRefs.

   4a6233dd57
10. net: use our own old templates to help reconstruct blocks 08a6c4872e
11. rpc/net: provide experimental gettemplateinfo c0eae62830
12. net_processing: drop dummy coinbase from templates

    Shared templates can never predict a future block's coinbase, so don't
    waste bandwidth including it; likewise don't include the first transaction
    in the compact block prefill when it's not a coinbase.

    355e0b2665
13. ajtowns force-pushed on Aug 15, 2025
14. DrahtBot added the label CI failed on Aug 15, 2025
15. 
    DrahtBot commented at 0:47 am on August 15, 2025: contributor

    🚧 At least one of the CI tasks failed. Task lint: https://github.com/bitcoin/bitcoin/runs/48132397637 LLM reason (✨ experimental): The CI failure is caused by a circular dependency detected during lint checks.

    Try to run the tests locally, according to the documentation. However, a CI failure may still happen due to a number of reasons, for example:

    • Possibly due to a silent merge conflict (the changes in this pull request being incompatible with the current code in the target branch). If so, make sure to rebase on the latest commit of the target branch.

    • A sanitizer issue, which can only be found by compiling with the sanitizer and running the affected test.

    • An intermittent issue.

    Leave a comment here, if you need help tracking down a confusing failure.

16. DrahtBot removed the label CI failed on Aug 15, 2025

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