Implements core NIP-26 delegated event functionality. Events can
include a `delegation` tag that provides a signature and restrictions
on which events can be delegated.
Notable points on the implementation so far:
* Schema has been upgraded to include an index and new column.
* Basic rune parsing/evaluation to implement the example event in the
NIP, but no more.
* No special logic for deletion.
* No migration logic for determining delegated authors for
already-stored events.
Schema upgrades were buggy from 4->5 (the v5 would be skipped). This
change also refactors the logic slightly so that future additions can
be clearer (no need to have if and else-if combinations).
NIP-01 prefix search, and NIP-12 generic tags are no longer marked as
experimental.
NIP-11 relay info advertises NIP-09 event deletion and NIP-12 generic
tag search support.
The `reject_future_limits` option can now be disabled, and is by
default.
NIP-11 advertises support for created_at limits.
The message for future-dated events has been modified, to be closer to
the recommended example in the NIP.
Only lowercase and even-length tag values are stored as binary BLOBs.
Previously there was an error which search results from being returned
if the tag value was mixed-case and could be interpreted as hex.
A new database migration has been created to repair the `tag` table
for existing relays.
fixes: https://todo.sr.ht/~gheartsfield/nostr-rs-relay/37
The original implementation of subscription limit applied to the
entire query, instead of the specific filter. Now, each filter gets
its own query limit. When a limit is applied, the most recent N
events will be returned, otherwise the default is to return the
earliest events (in order), for all matching events.
This was quickly sneaked in by fiatjaf per my request[0], it makes many
queries more efficient and allows for paging when combined with until.
It is a bit weird to have multiple limits on each filter... for now we
just choose any or the last limit seen.
[0]: a4aea5337f
Signed-off-by: William Casarin <jb55@jb55.com>
