libubox: add convenience functions, cleanup

[pprindeville]

You might not always want to populate JSON serially, so a way to save/restore the cursor through a convenience function is handy.

Also, adding anonymous (unnamed) strings to an array isn't obvious, so added a convenience function for that.

Lastly, some minor cleanup to show what the parameters are to functions, etc.

Requires PR #16.

[pprindeville]

@nbd168 Can I get a review please? I need some of these changes to help with a migration from ISC-DHCP to Kea.

[pprindeville]

cc: @Ansuel @dangowrt @neheb @stintel @jow-

[pprindeville]

@jow- Can you please look this over?

[jow-]

Most (all?) existing functions use reference style returns (caller passes a destination variable name, function populates it and uses it's numeric return value to signify success/error) while your new functions introduce echo style returns requiring calling code to use ugly subshell invocations.

Personally I would also change the naming like that:

• json_get_pos -> json_get_position
• json_set_pos -> json_move_to
• json_get_parent -> json_move_up
• json_add_anon_string -> json_push_string

[pprindeville]

Most (all?) existing functions use reference style returns (caller passes a destination variable name, function populates it and uses it's numeric return value to signify success/error) while your new functions introduce echo style returns requiring calling code to use ugly subshell invocations.

Personally I would also change the naming like that:

• json_get_pos -> json_get_position
• json_set_pos -> json_move_to
• json_get_parent -> json_move_up
• json_add_anon_string -> json_push_string

Thanks, making those changes now.

By json_get_pos you meant json_get_cur, and that should become json_get_position?

And json_set_cur should become json_move_to? Or json_set_position (for symmetry)?

Where do the functions _get_var and _set_var get used? I can only find references to _json_get_var and _json_set_var...

json_get_parent isn't meant to move the cursor explicitly. It's a way to get the parent of a node if you need to do something like query the parent's type (array, table, etc).

For instance, you could implement json_select ".." as:

    local parent
    json_get_parent parent
    json_set_position "$parent"

if json_select ".." didn't exist.

[pprindeville]

Casting a wider net

cc: @blogic

[pprindeville]

Creating 2nd PR (#12) without the positioning getter/setting commit which seems to be stalled.

[pprindeville]

Most (all?) existing functions use reference style returns (caller passes a destination variable name, function populates it and uses it's numeric return value to signify success/error) while your new functions introduce echo style returns requiring calling code to use ugly subshell invocations.

Personally I would also change the naming like that:

• json_get_pos -> json_get_position
• json_set_pos -> json_move_to
• json_get_parent -> json_move_up
• json_add_anon_string -> json_push_string

@jow- I believe I've made these changes as requested. Can you please re-review?

[pprindeville]

@jow- I believe I've addressed the comments you made. Can I get a merge please or a re-review?

[pprindeville]

@nbd168 Can I get a review please? I need some of these changes to help with a migration from ISC-DHCP to Kea.

Still blocked on improvements to libubox before I can merge these this migration tool to Kea.

[Neustradamus]

This migration is really important from ISC DHCP to Kea.

[systemcrash]

I figure you have commit rights to fix this @pprindeville

[pprindeville]

I figure you have commit rights to fix this @pprindeville

No, my rights are only for openwrt/packages.

[systemcrash]

Get the test formalities fixed and then we can ping a maintainer.

[pprindeville]

Get the test formalities fixed and then we can ping a maintainer.

Do you know how to write test scripts? I've not dug into it.

[systemcrash]

?

: Commit subject line MUST start with '<package name>: ' (jshn.sh: Add getters for the cursor and its parent)

[pprindeville]

?

: Commit subject line MUST start with '<package name>: ' (jshn.sh: Add getters for the cursor and its parent)

Is that a new requirement?

ca3f6d0 udebug: fix file descriptor initialization for __udebug_buf_map
6339204 CMakeLists.txt: bump minimum cmake version
c1be505 udebug: fix crash in udebug_entry_vprintf with longer strings
a2fce00 CI: add build test run
12bda4b CI: add CodeQL workflow tests
eb9bcb6 ustream: prevent recursive calls to the read callback
3868f47 blob: constify attr argument to blob_memdup
b7acc8e remove compatibility code for older json-c versions
a1acd99 udebug: remove obsolete debug message
49056d1 udebug: fix issue with snapshot of remote ring
eeb6fcf examples: CMakeLists: update cmake minimum required version to 3.10
c163d7a lua: build: require CMake >= 3.10 due to dropped legacy support
7a3863a lua: CMakeLists: drop redundant cmake_minimum_required
61cc1e6 examples: CMakeLists: drop redundant cmake_minimum_required
7d6b9d9 add debian/ directory
9caf555 (origin/master) github: improve CI build

[pprindeville]

Get the test formalities fixed and then we can ping a maintainer.

Do you know how to write test scripts? I've not dug into it.

Sorry, misread. Thought you were suggesting we add test coverage as well. Which doesn’t seem like a bad idea.