Added codec for built-in type tid

[fantix]

Fixed issue that SELECT ctid, * FROM xxx and SELECT * FROM xxx WHERE ctid = $1 are not working, by adding a new codec for tid. Now tid values are output as a two-item tuple, and both tuple and list with exactly two items are accepted for input.

asyncpg.protocol.protocol.BufferError: unexpected trailing 2 bytes in buffer

(Because tid has 6 bytes, current asyncpg consumes only 4.)

References:

• https://www.postgresql.org/docs/10/static/ddl-system-columns.html
• https://www.postgresql.org/docs/10/static/datatype-oid.html
• https://github.com/postgres/postgres/blob/c7cc9b7d408063c04482efb6bdd3c822fc3455ce/src/backend/utils/adt/tid.c

[elprans]

Excellent! Thank you!

[fantix]

Thanks for merging!

[fantix]

@elprans Apologies, looks like pg is using unsigned integers for presentation. I’ve fixed this in a new commit, even though previous patch worked anyway (consistent encode and decode should do, just mismatched pg presentation). Please let me know if the fix is okay and should I create a new PR. Thanks for your time!

[elprans]

@fantix No worries, please make a followup PR.