Library source code organization #15732

(copied from #15638 (comment) by @ryanofsky) Here is how I am thinking about the organization:

• libbitcoin_server.a, libbitcoin_wallet.a, and libbitcoinqt.a should all be terminal dependencies. They should be able to depend on other symbols in other libraries, but no other libraries should depend on symbols in them (and they shouldn't depend on each other).

• libbitcoin_consensus.a should be a standalone library that doesn't depend on symbols in other libraries mentioned here

• libbitcoin_common.a and libbitcoin_util.a seem very interchangeable right now and mutually depend on each other. I think we should either merge them into one library, or create a new top-level src/common/ directory complementing src/util/, and start to distinguish general purpose utility code (like argument parsing) from bitcoin-specific utility code (like formatting bip32 paths and using ChainParams). Both these libraries can be depended on by libbitcoin_server.a, libbitcoin_wallet.a, and libbitcoinqt.a, and they can depend on libbitcoin_consensus.a. If we want to split util and common up, as opposed to merging them together, then util shouldn't depend on libconsensus, but common should.

Over time, I think it'd be nice if source code organization reflected library organization . I think it'd be nice if all libbitcoin_util source files lived in src/util, all libbitcoin_consensus.a source files lived in src/consensus, and all libbitcoin_server.a code lived in src/node (and maybe the library was called libbitcoin_node.a).

See also:

• Source code organization for standalone (util) functions and types #14721

libbitcoin_common.a and libbitcoin_util.a seem very interchangeable right now and mutually depend on each other

interesting—util is linked by:

bitcoind
bitcoin-cli
bitcoin-tx
bitcoin-wallet
bench/bench_bitcoin
qt/bitcoin-qt
qt/test/test_bitcoin-qt
test/test_bitcoin

whereas common is linked by:

bitcoind
bitcoin-tx
bitcoin-wallet
bench/bench_bitcoin
qt/bitcoin-qt
qt/test/test_bitcoin-qt
test/test_bitcoin

The only difference being bitcoin-cli. Yes, with this I'd say it makes sense to merge them, unless the current split avoids pulling in some dependencies for bitcoin-cli (@luke-jr might be able to comment w.r.t. gentoo). This can't be true if there are bidirectional dependencies between them.

Concept ACK on the organization plan above.

I feel that there is place for a distinction between common and util, through the question "bitcoin specific logic". For example, transaction signing seems to belong in a very different place than command-line handling logic, and bitcoin-cli shouldn't need to include the former.

However it seems that in practice this distinction isn't really followed, so it may be better to just merge common and util to remove the mutual dependency, and the later carve out the real "util" parts.

it'd be nice if source code organization reflected library organization

Concept ACK.

Concept ACK

See also #24303