If we're connecting to the peer which might support
transaction reconciliation, we announce we want to reconcile
with them.
We store the reconciliation salt so that when the peer
responds with their salt, we are able to compute the
full reconciliation salt.
This behavior is enabled with a CLI flag.
Assigning TIME_INIT to nTime was needed to fully re-initialize a dirty
object where the deserialization might skip nTime.
See https://github.com/bitcoin/bitcoin/pull/19020/files#r427620111
Now that the without-nTime logic is removed in commit
dbcb5742c4 and commit
e08770bed1, the logic here can be removed
as well.
Also, remove confusing and redundant preprocessor code.
Also, remove no longer needed version.h include, which was needed for
INIT_PROTO_VERSION.
Historically, the VERSION message contains an "addrMe" and an "addrYou". As
these are sent before version negotiation is complete, the protocol version is
INIT_PROTO_VERSION (209), and in that protocol, CAddress is serialized without
nTime.
This is in fact the only situation left where a CAddress is (de)serialized
without nTime. As it's such a simple structure (CService for ip/port + uint64_t
for nServices), just inline that structure in the few places where it occurs,
and remove the logic for dealing with missing nTime from CAddress.
Before this commit, CAddress disk serialization was messy. It stored
CLIENT_VERSION in the first 4 bytes, optionally OR'ed with ADDRV2_FORMAT.
- All bits except ADDRV2_FORMAT were ignored, making it hard to use for actual
future format changes.
- ADDRV2_FORMAT determines whether or not nServices is serialized in LE64
format or in CompactSize format.
- Whether or not the embedded CService is serialized in V1 or V2 format is
determined by the stream's version having ADDRV2_FORMAT (as opposed to the
nServices encoding, which is determined by the disk version).
To improve the situation, this commit introduces the following disk
serialization format, compatible with earlier versions, but better defined for
future changes:
- The first 4 bytes store a format version number. Its low 19 bits are ignored
(as it historically stored the CLIENT_VERSION), but its high 13 bits specify
the serialization exactly:
- 0x00000000: LE64 encoding for nServices, V1 encoding for CService
- 0x20000000: CompactSize encoding for nServices, V2 encoding for CService
- Any other value triggers an unsupported format error on deserialization,
and can be used for future format changes.
- The ADDRV2_FORMAT flag in the stream's version does not impact the actual
serialization format; it only determines whether V2 encoding is permitted;
whether it's actually enabled depends solely on the disk version number.
Operationally the changes to the deserializer are:
- Failure when the stored format version number is unexpected.
- The embedded CService's format is determined by the stored format version
number rather than the stream's version number.
These do no introduce incompatibilities, as no code versions exist that write
any value other than 0 or 0x20000000 in the top 13 bits, and no code paths
where the stream's version differs from the stored version.
