A code-quality pass over the table. The latest sequence number of
each journal, which readers compare their cursors with without the
shard's lock, was an atomic inside the journal under the lock with
the table holding the other end of an Arc to it, stored on every
route; it is now in a slot beside each shard's lock, `ShardSlot`,
stored once a shard a change while the write guard is still held and
before the readers are woken. "One of each kind of journal" is one
type, `ByKind<T>`, where three hand-written dispatchers and an array
index were. `Reader::poll` is the loop skeleton over `resync_step`
and `follow_pass`; the journal's `tidy` is three named stages;
`live`'s nested Option is an enum that says what an entry says; the
place of a cursor in a journal is found by one function for both the
time chosen for a pass and the pass itself. The attribute set's four
byte-readers share one walk over the raw attributes, with the next
hop decoded once for both of its readers. `best` returns a `Route`
like the other lookups. Docs that described an earlier design (the
reader's `seen`, "every method takes &self", a `Routes::is_empty`
that could not be true) are put right.
Testing: new tests pin the lock-free skip, which nothing checked
directly before: the number equals the journal's after every kind of
change, with and without readers of each kind; a shard passed over is
read again once it has news, from a reader of the whole table and
from one that starts now. The OTC flag and the received-attributes
interning gain tests. The crate's tests, both proptests included, the
server tests, the integration tests, the kernel tests and every lab
phase pass.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
