aaribaud/ESPSomfy-RTS
0
0
Fork 0
mirror of https://github.com/rstrouse/ESPSomfy-RTS.git synced 2026-10-31 13:52:15 +01:00
Code Issues Projects Releases Packages Wiki Activity

test: prove no read item can outgrow the snapshot unit

Browse source 
The read routes leave out a room, shade, group or linked shade that
doesn't fit the 3 KB unit, without telling the client (KNOWN_ISSUES.md).
test_snapshot_limits fills a snapshot with the largest possible items and
checks every read document written with the real unit is identical to
the same document written with an unlimited one. The largest item, a
shade, is 1,097 bytes. The unit is now SNAPSHOT_UNIT_SIZE in
ModelSnapshot.h, used by Web.cpp and the tests.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
This commit is contained in:
cjkas 2026-10-17 23:29:04 +02:00
parent 29211630f2
commit 89d3713d86
5 changed files with 153 additions and 6 deletions
Download patch file Download diff file Expand all files Collapse all files

8
docs/KNOWN_ISSUES.md
View file

@ -19,18 +19,18 @@ The handlers that changed the shade model on the web server task (adding, saving
### Still open
- Command replies (`/shadeCommand`, `/tiltCommand`, `/unpairShade`, `/setRollingCode`, ...) still copy the one item they report from the live shade model on async_tcp, so a reply can show a value from the middle of a change. `/room`, `/shade`, `/group` and `/groupOptions` also check on the live model whether the item exists, because the status goes out before the snapshot is filled.
- The read routes leave out an item that doesn't fit their 3 KB unit, see [Oversized read items are left out](#oversized-read-items-are-left-out).
- The read routes would leave out an item that didn't fit their 3 KB unit; a test now proves none can, see [Oversized read items are left out](#oversized-read-items-are-left-out).
## Oversized read items are left out
**Status:** open
**Location:** `SnapshotWriter::overflowed` in [src/ModelSnapshot.cpp](../src/ModelSnapshot.cpp).
**Status:** guarded by a test (fix option (b)). It can't happen with today's fields, and a change that would make it happen fails `test_snapshot_limits`.
**Location:** `SnapshotWriter::overflowed` in [src/ModelSnapshot.cpp](../src/ModelSnapshot.cpp); the unit is `SNAPSHOT_UNIT_SIZE` in [src/ModelSnapshot.h](../src/ModelSnapshot.h).
### Summary
Every read route builds each room, shade, group and linked shade into a 3 KB unit before sending it. When one doesn't fit, the writer logs an `ESP_LOGE` line, skips that item and carries on, so the document stays valid JSON. The client gets no sign that anything is missing: the item just isn't in the list. Before step 2 only `/controller` did this; `/discovery`, `/shades` and the rest grew their buffer instead.
A shade with every linked remote populated is about 1.5 KB today, so nothing overflows yet. It becomes a silent loss as soon as a change to the shade, room or group fields pushes an item past 3 KB.
`test_snapshot_limits` fills a snapshot with the largest possible items: 20-character names of control characters (each escaped to `\u00XX`), all 7 linked remotes, 32 members in every group, and the widest value of every number. It checks that every read document written with the real unit is identical to the same document written with an unlimited one. The largest items are a shade at 1,097 bytes, a linked shade at 345, a group at 333 and a room at 159, against 3,072. The log line stays as a backstop.
### Concrete failure modes