feat(controller-status): libxce xcecli_ctrlstatus any-node read + decode + free (task 3.1)

This commit is contained in:
Rongsong Shen 2026-06-20 05:18:04 +00:00
parent e56409cbd4
commit 691cd9199e
12 changed files with 285 additions and 1 deletions

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@ -27,7 +27,7 @@
- _Depends: 2.1_
- [ ] 3. libxce client API
- [ ] 3.1 Add the failover-aware any-node status call
- [x] 3.1 Add the failover-aware any-node status call
- Add the opcode-only request sender, the send-and-decode call, and the failover-aware client read (retryable, non-write) that returns whatever reachable node answers, plus the free helper. On no reachable controller, return a typed failure without a partial/empty success.
- TDD: a round-trip test decodes every status field from a handler reply; a no-reachable-controller test returns a typed failure.
- Observable: the client decodes all fields from a live/loopback handler reply and surfaces a typed error when no controller is reachable.
@ -69,3 +69,4 @@
- The authoritative redirect (3.2) is what makes wait-primary trustworthy (no stale-standby false success) — it is the resolution of the design-review decision; do not collapse it back into a plain any-node read for wait-primary.
- 1.1 LEARNING (affects later tasks): the `$C.mapname(...)` capnp types are NOT auto-generated in this schema — the generated `controller.capnp.c` references HAND-AUTHORED C typedefs in `src/include/typemap.h` (same convention as `xce_clusterconf_t`). So `xce_ctrlstatus_t`/`xce_ctrlpeer_t` (and the `xce_reply_t.data.ctrlstatus` union member) live in `typemap.h`, verified field-for-field against the regenerated codec. `OPCode_ctrlstatus = 40`, `RequestReply_data_ctrlstatus = 12`. `configChecksum` is `xce_data_t*`. The handler/libxce tasks build/encode against these typemap.h types.
- 2.1 LEARNING + SCHEMA AMENDMENT: capnp `Data` in THIS schema maps to the project's STRUCTURED `xce_data_t` union (table-switched), NOT raw bytes — `encode_Data_ptr` can't serialize a SHA-256 blob. So `configChecksum @6` was changed `Data → Text` (a 64-char lowercase-hex string of the full 32-byte `config_sha256`); typemap member is `char*`; freed in `ctrlstatus_free_fields`. Ordinal @6 unchanged, no released decoder yet → safe. Handler lives in NEW `src/controller/ctrlstatus.c` (`ctrlstatus_fill`/`ctrlstatus_free_fields`/`handle_ctrlstatus`), proto in `src/controller/include/cluster.h`, routed at `cluster.c` opcode switch, test `src/controller/testsuite/test_ctrlstatus.c` (registered in `controller_test.c`, built via `controller/meson.build`). `primary_host` read under `ha->lock`; peer name/host strings are BORROWED from myconf (not freed). The libxce client (3.x) decodes `configChecksum` as Text.
- 3.1 LEARNING: the ctx-side reply union `xce_ctx_t.reply.u` (in `src/include/xcectx.h`) is SEPARATE from `xce_reply_t.data` (typemap.h) — the decode path needs BOTH a `ctrlstatus` member there AND a `case OPCode_ctrlstatus` in `xcectx.c` handle_reply (mirror clusterconf). Free: clusterconf's `xce_free_clusterconf` macro is a LATENT-BROKEN alias (undefined symbol, never expanded); use the REAL generated free — `xce_free_ctrlstatus(s) → free_CtrlStatus(s)`, `xcecli_free_ctrlstatus(s) → xce_free_ctrlstatus(s)` (any TU expanding it must include the generated `controller.capnp.h`). `xcecli_ctrlstatus` is is_write=false; NULL ctx → `-EINVAL`.