Every ephemeral OfflineSyncDatabase shares one context but initializes a
recorder of its own, and each rebuilt the projections of every space
when the context's first initialize had changed the registry: on every
session and every merge, until the process stopped (upstream #150). A
new device, or one whose app changed its synced tables, spent about 3 s
of every inbound merge on it with a library of 8,000 cards, a server
after such a migration as much on every request.
The context now runs the rebuild once (Once): wrappers initializing
while it runs await the same run, later ones skip it, and a failed run
is tried again by the next.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
projectionValuesEqual took a Uint8List (how a bytea column arrives) down
its List branch and compared it byte by byte, and tryUuidValue parsed
every value as a UUID by throwing and catching an error when it was none.
Each byte of a payload thus cost a thrown TypeError, about 18 µs: two
payloads of 2 KB took 36 ms to compare. A sync whose projection loaded a
few thousand rows with payloads kept the server's isolate busy for
minutes, during which it answered no other request and the client's
method stream timed out, so the client sent the same changes again.
Byte values are now compared as bytes, and tryUuidValue only parses what
can hold a UUID (a UuidValue, 16 bytes, a 36-character string), returning
null for anything else without throwing. A UUID compares with its string
and its bytes as before. Longer byte values are no longer read as the
UUID of their first 16 bytes, which made canonicalProjectionValue group
payloads with the same beginning together.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MMm7usAo6q9ZZRoPkWjoxi
