Merge #19334: wallet: Introduce WalletDatabase abstract class

d416ae560e46a4846a3fd5990b7d390d2ef30ec8 walletdb: Introduce WalletDatabase abstract class (Andrew Chow)
2179dbcbcd0b9bef7ad9c907b85294b9a1bccf0f walletdb: Add BerkeleyDatabase::Open dummy function (Andrew Chow)
71d28e7cdca1c8553531bb3a4725d7916363ec5c walletdb: Introduce AddRef and RemoveRef functions (Andrew Chow)
27b27663849932971eb5deadb1f19234b9cd97ea walletdb: Move BerkeleyDatabase::Flush(true) to Close() (Andrew Chow)

Pull request description:

  A `WalletDatabase` abstract class is created from `BerkeleyDatabase` and is implemented by `BerkeleyDatabase`. First, to get to the point that this is possible, 4 functions need to be added to `BerkeleyDatabase`: `AddRef`, `RemoveRef`, `Open`, and `Close`.

  First the increment and decrement of `mapFileUseCount` is refactored into separate functions `AddRef` and `RemoveRef`.

  `Open` is introduced as a dummy function. This will raise an exception so that it always fails.

  `Close` is refactored from `Flush`. The `shutdown` argument in `Flush` is removed and instead `Flush(true)` is now the `Close` function.

  Split from #18971

  Requires #19325

ACKs for top commit:
  ryanofsky:
    Code review ACK d416ae560e46a4846a3fd5990b7d390d2ef30ec8. Only changes since last review were rebasing after base PR #19334 merge, and adding cs_db lock in BerkeleyDatabase destructor, which should avoid races accessing env->m_databases and env->m_fileids
  fjahr:
    Code review ACK d416ae560e46a4846a3fd5990b7d390d2ef30ec8
  meshcollider:
    Code review & test run ACK d416ae560e46a4846a3fd5990b7d390d2ef30ec8

Tree-SHA512: 98d05ec093d7446c4488e2b0914584222a331e9a2f4d5be6af98e3f6d78fdd8e75526c12f91a8a52d4820c25bce02aa02aabe92d38bee7eb2fce07d0691b7b0d

0 files changed, 0 insertions, 0 deletions