Stratum v2 Template Provider common functionality

[Sjors]

Moved from bitcoin#30475.

Based on:

• Noise encryption Sv2 noise #66
• Messages and transport layer Stratum v2 Transport #67
• Sv2Connman Stratum v2 connman #50

And the following interface changes:

• Introduce waitTipChanged() mining interface, replace RPCNotifyBlockChange, drop CRPCSignals & g_best_block bitcoin/bitcoin#30409
• Mining interface: getCoinbaseMerklePath() and submitSolution() bitcoin/bitcoin#30955
• Have createNewBlock() wait for tip, make rpc handle shutdown during long poll and wait methods bitcoin/bitcoin#31785 (not needed, this PR has a workaround)
• Add waitNext() to BlockTemplate interface bitcoin/bitcoin#31283
  • Make m_tip_block std::optional bitcoin/bitcoin#31325
• refactor: mining interface 30955 followups bitcoin/bitcoin#31197
• Drop script_pub_key arg from createNewBlock bitcoin/bitcoin#31318
• Prune mining interface bitcoin/bitcoin#31196
• Add destroy to BlockTemplate schema bitcoin/bitcoin#31288
• Set notifications m_tip_block in LoadChainTip() bitcoin/bitcoin#31346
• Have createNewBlock() return a BlockTemplate interface bitcoin/bitcoin#30440

As well as:

• miner: timelock the coinbase to the mined block's height bitcoin/bitcoin#32155
  • opt-out with -coinbaselocktime=0

This contains all Template Provider functionality that can be used by both #68 and the IPC based sidecar alternative #48.

[Sjors]

Updated to the latest interface changes proposed in bitcoin#30409 and #53.

[Sjors]

Rebased for CMake

[Sjors]

One test still seems brittle:

src/test/sv2_template_provider_tests.cpp(256): fatal error: in "sv2_template_provider_tests/client_tests": critical check tester.GetBlockTemplateCount() == 3 has failed [2 != 3]

[Sjors]

Moved TemplateProvider from node to common so that in #48 bitcoin-mine does not depend on bitcoin-node.

[Sjors]

Rebased after bitcoin#31325, bitcoin#31581.

The rebase includes bitcoin#31376 which ensures that new templates account for the timewarp rule (important on testnet4 because of the MTP drift).

The rebase also includes bitcoin#31583 which makes getmininginfo a lot more useful! E.g. if displays the difficulty and target for the next block.

Using the latest version of bitcoin#31283 which has waitNext() return a new template once testnet difficulty drops after 20 minutes. It also requires a small refactor.

In anticipation of bitcoin#31384 I changed the block_reserved_weight calculation.

[Sjors]

Rebased and included #45 / stratum-mining/sv2-spec#86.

[Sjors]

Possible thread issue, found by CI in #68: https://cirrus-ci.com/task/5072000852426752?logs=ci#L3303

[Sjors]

Rebased after bitcoin#31384.

[Sjors]

Rebased in hopes of making #80 magically go away.

[Sjors]

I squashed 4c132d067586ede434f6d28d40b7de9d666efa9e "Incrementally update sv2 block template" into 61eeca1fc63779f5b22017db48bcb5d9d2d1404d "Sv2: construct and submit block templates" and then refactored the combined commit ad3120b to fix #80. Every client now has its own thread in the TemplateProvider.

It could be improved further, e.g. the handshake is blocking and we're not using optimistic send, but I'm going to wait to see what @theuni comes up with in terms of an alternative approach to Connman.

[Sjors]

Occasional failing on CentOS probably means the tests need to be made more robust. https://cirrus-ci.com/task/5262823086882816

[Sjors]

Rebased after bitcoin#31785 landed, which completes the interface changes needed for the Template Provider. Dropped the use of waitTipChanged() on startup and added a shutdown check in ThreadSv2ClientHandler().

[Sjors]

CI fails because since bitcoin#29307 we have to fclose files. I'll update 9e6d5d6485a108f938fe2333c2d17b3113956695 to do that.

[Sjors]

Note to self for the next update, apply:

diff --git a/src/sv2/template_provider.cpp b/src/sv2/template_provider.cpp
index a4331c6cb3..d83b86be69 100644
--- a/src/sv2/template_provider.cpp
+++ b/src/sv2/template_provider.cpp
@@ -66,7 +66,7 @@ Sv2TemplateProvider::Sv2TemplateProvider(interfaces::Mining& mining) : m_mining{
     version_pubkey_bytes[1] = 0;
     m_authority_pubkey = XOnlyPubKey(authority_key.GetPubKey());
     std::copy(m_authority_pubkey.begin(), m_authority_pubkey.end(), version_pubkey_bytes.begin() + 2);
-    LogInfo("Template Provider authority key: %s\n", EncodeBase58Check(version_pubkey_bytes));
+    LogPrintLevel(BCLog::SV2, BCLog::Level::Info, "Template Provider authority key: %s\n", EncodeBase58Check(version_pubkey_bytes));
     LogTrace(BCLog::SV2, "Authority key: %s\n", HexStr(m_authority_pubkey));

[Sjors]

Last rebase before I'm going to split off the sv2 functionality into a fresh codebase.

[Sjors]

This code is now part of https://github.com/Sjors/sv2-tp; feedback and pull requests are welcome there!