pack: add flb_msgpack_get_char_from_obj

[nokute78]

Bin type and Str type of msgpack represent string. This function is to get a pointer of string in unified manner.

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Enter [N/A] in the box, if an item is not applicable to your change.

Testing Before we can approve your change; please submit the following in a comment:

• [N/A] Example configuration file for the change
• [X] Debug log output from testing the change

• [X] Attached Valgrind output that shows no leaks or memory corruption was found

If this is a change to packaging of containers or native binaries then please confirm it works for all targets.

• [N/A] Run local packaging test showing all targets (including any new ones) build.
• [N/A] Set ok-package-test label to test for all targets (requires maintainer to do).

Documentation

• [N/A] Documentation required for this feature

Backporting

• [N/A] Backport to latest stable release.

Debug/Valgrind output

$ valgrind --leak-check=full bin/flb-it-pack 
==27047== Memcheck, a memory error detector
==27047== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==27047== Using Valgrind-3.18.1 and LibVEX; rerun with -h for copyright info
==27047== Command: bin/flb-it-pack
==27047== 
Test json_pack...                               [ OK ]
==27047== Warning: invalid file descriptor -1 in syscall close()
Test json_pack_iter...                          [ OK ]
==27047== Warning: invalid file descriptor -1 in syscall close()
Test json_pack_mult...                          [ OK ]
==27047== Warning: invalid file descriptor -1 in syscall close()
Test json_pack_mult_iter...                     [ OK ]
==27047== Warning: invalid file descriptor -1 in syscall close()
Test json_macros...                             [ OK ]
==27047== Warning: invalid file descriptor -1 in syscall close()
Test json_dup_keys...                           [ OK ]
==27047== Warning: invalid file descriptor -1 in syscall close()
Test json_pack_bug342...                        [ OK ]
==27047== Warning: invalid file descriptor -1 in syscall close()
Test json_pack_bug1278...                       
test 0 out => "one\u0007two"
test 1 out => "one\btwo"
test 2 out => "one\ttwo"
test 3 out => "one\ntwo"
test 4 out => "one\u000btwo"
test 5 out => "one\ftwo"
test 6 out => "one\rtwo"
test 7 out => "\\n"
[ OK ]
==27047== Warning: invalid file descriptor -1 in syscall close()
Test json_pack_nan...                           [ OK ]
==27047== Warning: invalid file descriptor -1 in syscall close()
Test json_pack_bug5336...                       [ OK ]
==27047== Warning: invalid file descriptor -1 in syscall close()
Test json_date_iso8601...                       [ OK ]
==27047== Warning: invalid file descriptor -1 in syscall close()
Test json_date_double...                        [ OK ]
==27047== Warning: invalid file descriptor -1 in syscall close()
Test json_date_java_sql...                      [ OK ]
==27047== Warning: invalid file descriptor -1 in syscall close()
Test json_date_epoch...                         [ OK ]
==27047== Warning: invalid file descriptor -1 in syscall close()
Test json_date_epoch_ms...                      [ OK ]
==27047== Warning: invalid file descriptor -1 in syscall close()
Test utf8_to_json...                            [ OK ]
==27047== Warning: invalid file descriptor -1 in syscall close()
Test msgpack_get_char...                        [ OK ]
==27047== Warning: invalid file descriptor -1 in syscall close()
SUCCESS: All unit tests have passed.
==27047== 
==27047== HEAP SUMMARY:
==27047==     in use at exit: 0 bytes in 0 blocks
==27047==   total heap usage: 15,183 allocs, 15,183 frees, 6,184,825 bytes allocated
==27047== 
==27047== All heap blocks were freed -- no leaks are possible
==27047== 
==27047== For lists of detected and suppressed errors, rerun with: -s
==27047== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)

---

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.

[github-actions[bot]]

This PR is stale because it has been open 45 days with no activity. Remove stale label or comment or this will be closed in 10 days.

[nokute78]

ping

[github-actions[bot]]

This PR is stale because it has been open 45 days with no activity. Remove stale label or comment or this will be closed in 10 days.

[nokute78]

ping

[github-actions[bot]]

This PR is stale because it has been open 45 days with no activity. Remove stale label or comment or this will be closed in 10 days.

[nokute78]

ping

[github-actions[bot]]

This PR is stale because it has been open 45 days with no activity. Remove stale label or comment or this will be closed in 10 days.