kv: add flb_kv_get_all_key_values function

[iypetrov]

Add flb_kv_get_all_key_values function for mk_list.

Addresses #11776 (1/3 sub-task)

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Testing
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• Backport to latest stable release.

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Fluent Bit is licensed under Apache 2.0, by submitting this pull request I understand that this code will be released under the terms of that license.

<!-- This is an auto-generated comment: release notes by coderabbit.ai -->
## Summary by CodeRabbit

* **New Features**
  * Added an API to retrieve all key/value entries from a collection as an allocated array, returning NULL for empty/invalid input and reporting the item count; includes allocation and error handling.

* **Tests**
  * Added unit tests validating empty and populated collection behavior, returned count, and returned entries.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

[coderabbitai]

📝 Walkthrough

Walkthrough

This pull request adds a public API, flb_kv_get_all_key_values, that returns all flb_kv entries from a mk_list as a newly allocated array and reports the element count; it includes implementation, header declaration, and a unit test with cleanup.

Changes

Key-Value Array Retrieval API

Layer / File(s)	Summary
Public API Contract include/fluent-bit/flb_kv.h	Function declaration for flb_kv_get_all_key_values added, returning struct flb_kv** and accepting int *out_count.
Core Implementation src/flb_kv.c	Function validates the input list, allocates an array sized to mk_list_size(list), populates it with existing flb_kv pointers, sets *out_count, and returns the array or NULL on failure.
Tests & Support tests/internal/kv.c	Added #include <fluent-bit/flb_mem.h>; unit test test_kv_get_all_key_values verifies NULL/count==0 for empty list, correct array of three pairs for populated list, frees returned array, and registers the test in TEST_LIST.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Suggested labels

docs-required

Poem

🐰 A tiny hop, a clever trace,
Keys and values find their place,
I gather pairs in tidy rows,
Count them true before I close,
Tests applaud the tidy chase.

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% 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 pull request title directly and accurately summarizes the main change: adding a new function flb_kv_get_all_key_values to the kv API.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[coderabbitai]

Actionable comments posted: 2

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@include/fluent-bit/flb_kv.h`:
- Line 44: flb_kv_get_all_key_values currently returns a pointer array without
length metadata, making callers unsafe to iterate; modify its signature to
include an output count (e.g., add a size_t *out_count parameter) or change the
return to a small struct { struct flb_kv **items; size_t count; } so callers can
know the array length; update the function implementation and all call sites
that use flb_kv_get_all_key_values to set/read the count and to free/iterate
correctly (search for references to flb_kv_get_all_key_values to update usage).

In `@tests/internal/kv.c`:
- Around line 49-61: The test accesses pairs[0..2] without ensuring the
underlying list contains three items; change the check so after verifying pairs
is non-NULL you also assert mk_list_size(&list) == 3 (or equivalent size check
against the list used to build pairs) before indexing pairs[0], pairs[1], and
pairs[2]; reference the list used when calling flb_kv_item_set() and use that
size guard so the subsequent TEST_CHECK(strcmp(...)) validations only run when
the list actually has three entries.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

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ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: 96ef314f-ede6-4b61-9703-2e217b4ad117

📥 Commits

Reviewing files that changed from the base of the PR and between 7299905 and 24549d4.

📒 Files selected for processing (3)

• include/fluent-bit/flb_kv.h
• src/flb_kv.c
• tests/internal/kv.c

[coderabbitai]

🧹 Nitpick comments (1)

tests/internal/kv.c (1)

44-46: ⚡ Quick win

Check each flb_kv_item_set result explicitly

Please assert each insertion succeeds, so failures are reported at the source rather than only via downstream count/content checks.

Suggested patch

-    flb_kv_item_set(&list, "host", "localhost");
-    flb_kv_item_set(&list, "port", "8080");
-    flb_kv_item_set(&list, "path", "/api");
+    TEST_CHECK(flb_kv_item_set(&list, "host", "localhost") != NULL);
+    TEST_CHECK(flb_kv_item_set(&list, "port", "8080") != NULL);
+    TEST_CHECK(flb_kv_item_set(&list, "path", "/api") != NULL);

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@tests/internal/kv.c` around lines 44 - 46, Each flb_kv_item_set call should
have its return value checked and asserted immediately so insertion failures are
reported at the source; update the three calls to flb_kv_item_set(&list, "host",
"localhost"), flb_kv_item_set(&list, "port", "8080"), and flb_kv_item_set(&list,
"path", "/api") to capture their returns into distinct variables (e.g.,
ret_host/ret_port/ret_path) and add assertions that each return indicates
success (match the test framework's success condition) before proceeding to
later count/content checks.

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Nitpick comments:
In `@tests/internal/kv.c`:
- Around line 44-46: Each flb_kv_item_set call should have its return value
checked and asserted immediately so insertion failures are reported at the
source; update the three calls to flb_kv_item_set(&list, "host", "localhost"),
flb_kv_item_set(&list, "port", "8080"), and flb_kv_item_set(&list, "path",
"/api") to capture their returns into distinct variables (e.g.,
ret_host/ret_port/ret_path) and add assertions that each return indicates
success (match the test framework's success condition) before proceeding to
later count/content checks.

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ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: 2ccc1540-93cc-41e1-98ac-1dd74658090e

📥 Commits

Reviewing files that changed from the base of the PR and between dd48761 and ff54e1a.

📒 Files selected for processing (1)

• tests/internal/kv.c

[cosmo0920]

Looks good to me.