The background of this commit is an ongoing effort to decouple the
libbitcoinkernel library from code that is not strictly required by it.
The settings code belongs into the common library and namespace, since
the kernel library should not depend on it. See doc/design/libraries.md
for more information on this rationale.
Changing the namespace of the moved functions is scripted in the
following commit.
This commit effectively moves the definition of these constants
out of the chainparamsbase to their own file.
Using the ChainType enums provides better type safety compared to
passing around strings.
The commit is part of an ongoing effort to decouple the libbitcoinkernel
library from the ArgsManager and other functionality that should not be
part of the kernel library.
The fs.* files are already part of the libbitcoin_util library. With the
introduction of the fs_helpers.* it makes sense to move fs.* into the
util/ directory as well.
Add interfaces::Node methods to give GUI finer grained control over
settings.json file. Update method is used to write settings to the file,
getPersistent and isIgnored methods are used to find out about settings
file and command line option interactions.
Persistent settings are used in followup PRs #15936 to unify gui settings
between bitcoin-qt and bitcoind, and #15937 to add a load_on_startup flag to
the loadwallet RPC and maintain a dynamic list of wallets that should be loaded
on startup that also can be shared between bitcoind and bitcoin-qt.
Implement merging of settings from different sources (command line and config
file) separately from parsing code in system.cpp, so it is easier to add new
sources.
Document current inconsistent merging behavior without changing it.
This commit only adds new settings code without using it. The next commit calls
the new code to replace existing code in system.cpp.
Co-authored-by: John Newbery <john@johnnewbery.com>
