Add custom nvs namespace feature.

[h2zero]

Adds the function set_nvs_namespace(const char*) for users to switch bond data stores.

Fixes #959
Fixes #1102

Summary by CodeRabbit

• New Features

  • Non-volatile storage namespace can now be customized at runtime instead of being fixed at compile time.
  • Added a runtime API to change the active namespace with C/C++ compatibility.

• Bug Fixes

  • Input validation prevents too-long or NULL namespace values; invalid inputs log an error and revert to the default.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: a9d82cf2-6087-4f4f-8795-6ba92cdb987e

📥 Commits

Reviewing files that changed from the base of the PR and between 9e9daac and 8e60f7c.

📒 Files selected for processing (2)

• src/nimble/nimble/host/store/config/src/ble_store_nvs.c
• src/nimconfig.h

🚧 Files skipped from review as they are similar to previous changes (2)

• src/nimconfig.h
• src/nimble/nimble/host/store/config/src/ble_store_nvs.c

---

📝 Walkthrough

Walkthrough

Replaced the compile-time NVS namespace with a runtime-configurable namespace and added set_nimble_nvs_namespace(const char *ns) to change it (with length validation and fallback to the default). nimconfig.h exports the function with C linkage when compiled as C++ under ESP_PLATFORM.

Changes

Cohort / File(s)	Summary
NVS namespace implementation src/nimble/nimble/host/store/config/src/ble_store_nvs.c	Replaced fixed NIMBLE_NVS_NAMESPACE with a mutable variable initialized from NIMBLE_NVS_DEFAULT_NAMESPACE. Added set_nimble_nvs_namespace(const char *ns) which validates length, copies into an internal buffer, logs on error, and reverts to default when needed. All NVS opens use the runtime namespace.
Public declaration src/nimconfig.h	Added C-linkage declaration extern "C" void set_nimble_nvs_namespace(const char *ns); under #ifdef ESP_PLATFORM when compiled as C++.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Poem

⚓️ Avast! A namespace set to roam,

A tiny flag no longer glued to home,
Switch yer bonds and sail anew,
Names aplenty on the blue,
Yarrr — configurations bid adieu!

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 50.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately reflects the main change: introducing a custom NVS namespace feature for managing separate bond stores.
Linked Issues check	✅ Passed	The implementation provides the requested namespace-switching mechanism via set_nimble_nvs_namespace(), directly addressing requirements from issues #959 and #1102.
Out of Scope Changes check	✅ Passed	All changes are scoped to implementing the custom NVS namespace feature; no unrelated modifications detected.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch nvs-custom-namespace

---

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

[coderabbitai]

Actionable comments posted: 2

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@src/nimble/nimble/host/store/config/src/ble_store_nvs.c`:
- Around line 65-69: The current branch treats a NULL ns the same as an overly
long string and logs "Namespace string is too long", which is misleading; update
the conditional in the setter so you first check if ns == NULL and in that case
quietly assign NIMBLE_NVS_NAMESPACE = NIMBLE_NVS_DEFAULT_NAMESPACE (or log at
debug/verbose level), otherwise validate strlen(ns) against
NIMBLE_NVS_STR_NAME_MAX_LEN and only log an ESP_LOGE via LOG_TAG when the length
check fails before assigning the default; reference the symbols ns,
NIMBLE_NVS_NAMESPACE, NIMBLE_NVS_DEFAULT_NAMESPACE, NIMBLE_NVS_STR_NAME_MAX_LEN
and LOG_TAG when making this change.
- Around line 62-71: set_nvs_namespace currently stores the caller's pointer
into NIMBLE_NVS_NAMESPACE which can lead to dangling pointers; change it to copy
the incoming string into a static buffer and point NIMBLE_NVS_NAMESPACE at that
buffer (ensure the buffer size uses NIMBLE_NVS_STR_NAME_MAX_LEN, always
null-terminate, and fall back to NIMBLE_NVS_DEFAULT_NAMESPACE on overflow);
validate ns != NULL and strlen(ns) < NIMBLE_NVS_STR_NAME_MAX_LEN before copying,
log via ESP_LOGE(LOG_TAG) on overflow and use the static buffer contents
thereafter so callers may pass stack or heap strings safely.

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 2bece196-cfc6-4b74-8f9b-673b941bd580

📥 Commits

Reviewing files that changed from the base of the PR and between 4746c60 and 9e9daac.

📒 Files selected for processing (2)

• src/nimble/nimble/host/store/config/src/ble_store_nvs.c
• src/nimconfig.h