that are otherwise private:
- CConnman::m_nodes
- CConnman::ConnectNodes()
- CConnman::AlreadyConnectedToAddress()
and update the #include headers per iwyu.
Before this commit, there are only two possibly outcomes for the "more" prediction
in Transport::GetBytesToSend():
* true: the transport itself has more to send, so the answer is certainly yes.
* false: the transport has nothing further to send, but if vSendMsg has more message(s)
left, that still will result in more wire bytes after the next
SetMessageToSend().
For the BIP324 v2 transport, there will arguably be a third state:
* definitely not: the transport has nothing further to send, but even if vSendMsg has
more messages left, they can't be sent (right now). This happens
before the handshake is complete.
To implement this, we move the entire decision logic to the Transport, by adding a
boolean to GetBytesToSend(), called have_next_message, which informs the transport
whether more messages are available. The return values are still true and false, but
they mean "definitely yes" and "definitely no", rather than "yes" and "maybe".
This also cleans up the addrman (de)serialization code paths to only
allow `Disk` serialization. Some unit tests previously forced a
`Network` serialization, which does not make sense, because Bitcoin Core
in production will always `Disk` serialize.
This cleanup idea was suggested by Pieter Wuille and implemented by Anthony
Towns.
Co-authored-by: Pieter Wuille <pieter@wuille.net>
Co-authored-by: Anthony Towns <aj@erisian.com.au>
This furthers transport abstraction by removing the assumption that a message
can always immediately be converted to wire bytes. This assumption does not hold
for the v2 transport proposed by BIP324, as no messages can be sent before the
handshake completes.
This is done by only keeping (complete) CSerializedNetMsg objects in vSendMsg,
rather than the resulting bytes (for header and payload) that need to be sent.
In SocketSendData, these objects are handed to the transport as permitted by it,
and sending out the bytes the transport tells us to send. This also removes the
nSendOffset member variable in CNode, as keeping track of how much has been sent
is now a responsability of the transport.
This is not a pure refactor, and has the following effects even for the current
v1 transport:
* Checksum calculation now happens in SocketSendData rather than PushMessage.
For non-optimistic-send messages, that means this computation now happens in
the network thread rather than the message handler thread (generally a good
thing, as the message handler thread is more of a computational bottleneck).
* Checksum calculation now happens while holding the cs_vSend lock. This is
technically unnecessary for the v1 transport, as messages are encoded
independent from one another, but is untenable for the v2 transport anyway.
* Statistics updates about per-message sent bytes now happen when those bytes
are actually handed to the OS, rather than at PushMessage time.
This makes the sending side of P2P transports mirror the receiver side: caller provides
message (consisting of type and payload) to be sent, and then asks what bytes must be
sent. Once the message has been fully sent, a new message can be provided.
This removes the assumption that P2P serialization of messages follows a strict structure
of header (a function of type and payload), followed by (unmodified) payload, and instead
lets transports decide the structure themselves.
It also removes the assumption that a message must always be sent at once, or that no
bytes are even sent on the wire when there is no message. This opens the door for
supporting traffic shaping mechanisms in the future.
This allows state that is shared between both directions to be encapsulated
into a single object. Specifically the v2 transport protocol introduced by
BIP324 has sending state (the encryption keys) that depends on received
messages (the DH key exchange). Having a single object for both means it can
hide logic from callers related to that key exchange and other interactions.
cd0c8eeb09 [net] Pass nRecvFloodSize to CNode (dergoegge)
860402ef2e [net] Remove trivial GetConnectionType() getter (dergoegge)
b5a85b365a [net] Delete CNetMessage copy constructor/assignment op (dergoegge)
Pull request description:
Follow-up PR for #27257
* Deletes the copy constructor/assignment operator of `CNetMessage`
* Removes trivial getter for the connection type
* Avoids passing `nRecvFloodSize` to CNode methods by passing it to `CNode` on creation
ACKs for top commit:
jnewbery:
utACK cd0c8eeb09
theStack:
ACK cd0c8eeb09
Tree-SHA512: 673a758668617f69fba77e61f0eaa1538da27a4849c82c98742436692baa2d7f001129af3e7a66b160e599d12109dac08137a146f10ff9b9ebdc5c2237311d41
At the time when
```cpp
pnode->vProcessMsg.splice(pnode->vProcessMsg.end(), pnode->vRecvMsg, pnode->vRecvMsg.begin(), it);
```
is called, `it` is certainly `pnode->vRecvMsg.end()` which makes the
call equivalent to:
```cpp
pnode->vProcessMsg.splice(pnode->vProcessMsg.end(), pnode->vRecvMsg, pnode->vRecvMsg.begin(), pnode->vRecvMsg.end());
```
which is equivalent to:
```cpp
pnode->vProcessMsg.splice(pnode->vProcessMsg.end(), pnode->vRecvMsg);
```
Thus, use the latter. Further, maybe irrelevant, but the latter has
constant complexity while the original code is `O(length of vRecvMsg)`.
