This ensures the transaction cannot be processed on a chain
that forked before that ID. It will also provide a basis for
expiration constraints. A client may want their transaction
to expire, and the generators may want to reject transactions
that have been floating in the ether for years.
Before this change, the logger's send channel could quickly be
flooded with Tick events. Those events should only be passed to
a writer.
Also, the log_event() function no longer sends entries. That
functionality moved to the new process_events() function. This
will allow us to initialize the with the genesis block without
flooding the send channel with events the historian won't read.
Before this change, a client could spend funds before the accountant
processed a previous spend. With this change in place, the accountant
updates balances immediately, but that comes at an architectural cost.
The accountant now verifies signatures on behalf of the historian, so
that it can ensure logging will not fail.
The log crate was starting to be the catch-all for all things
related to entries, events, signatures, and hashes. This split
shows us that:
* Event depends only on signatures, not on hashes [directly]
* All event testing was done via log testing (shame on me)
* Accounting depends only on events
Unlike a Discovery event, a Claim event associates a public key
with a hash. It's intended to to be used to claim ownership of
some hashable data. For example, a graphic designer could claim
copyright by hashing some image they created, signing it with
their private key, and publishing the hash-signature pair via
the historian. If someone else tries to claim it as their own,
the designer can point to the historian's log as cryptographically
secure evidence that the designer's copy existed before anyone
else's.
Note there's nothing here that verifies the first claim is the actual
content owner, only that the first claim almost certainly happened
before a second.
From the perspective of the log, when some data's hash is added,
that data is "discovered" by the historian. Another event
might be a "claim" that some signed data belongs to the owner of a
public key.
Hasher will generate different hashes for the same input if it
had already generated a hash.
Also add a binary to ensure the example in the README works.
Greg Fitzgerald