Merge bitcoin/bitcoin#28385: [refactor] rewrite DisconnectedBlockTransactions to not use boost

4313c77400eb8eaa8586db39a7e29a861772ea80 make DisconnectedBlockTransactions responsible for its own memory management (glozow)
cf5f1faa037e9a40a5029cc7dd4ee61454b62466 MOVEONLY: DisconnectedBlockTransactions to its own file (glozow)
2765d6f3434c101fe2d46e9313e540aa680fbd77 rewrite DisconnectedBlockTransactions as a list + map (glozow)
79ce9f0aa46de8ff742be83fd6f68eab40e073ec add std::list to memusage (glozow)
59a35a7398f5bcb3e3805d1e4f363e4c2fb336b3 [bench] DisconnectedBlockTransactions (glozow)
925bb723ca71aa76380b769d8926c7c2ad9bbb7b [refactor] batch-add transactions to DisconnectedBlockTransactions (glozow)

Pull request description:

  Motivation
  - I think it's preferable to use stdlib data structures instead of depending on boost if we can achieve the same thing.
  - Also see #28335 for further context/motivation. This PR simplifies that one.

  Things done in this PR:
  - Add a bench for `DisconnectedBlockTransactions` where we reorg and the new chain has {100%, 90%, 10%} of the same transactions. AFAIU in practice, it's usually close to 100%.
  - Rewrite `DisconnectedBlockTransactions` as a `std::list` + `unordered_map` instead of a boost multi index container.
    - On my machine, the bench suggests the performance is very similar.
  - Move `DisconnectedBlockTransactions` from txmempool.h to its own kernel/disconnected_transactions.h. This struct isn't used by txmempool and doesn't have much to do with txmempool. My guess is that it's been living there for convenience since the boost includes are there.

ACKs for top commit:
  ismaelsadeeq:
    Tested ACK 4313c77400eb8eaa8586db39a7e29a861772ea80
  stickies-v:
    ACK 4313c77400eb8eaa8586db39a7e29a861772ea80
  TheCharlatan:
    ACK 4313c77400eb8eaa8586db39a7e29a861772ea80

Tree-SHA512: 273c80866bf3acd39b2a039dc082b7719d2d82e0940e1eb6c402f1c0992e997256722b85c7e310c9811238a770cfbdeb122ea4babbc23835d17128f214a1ef9e

1 files changed, 1 insertions, 1 deletions

diff --git a/src/validation.h b/src/validation.h
index f1ff6bb671..6640bb5b50 100644
--- a/src/validation.h
+++ b/src/validation.h
@@ -50,7 +50,7 @@ class Chainstate;
 class CTxMemPool;
 class ChainstateManager;
 struct ChainTxData;
-struct DisconnectedBlockTransactions;
+class DisconnectedBlockTransactions;
 struct PrecomputedTransactionData;
 struct LockPoints;
 struct AssumeutxoData;