Get_next is called many time before get_object, when CLI command is executed twice

CDB and CDB API
1

Guys I am totally stuck with this issue.

I have two elements to print. Example item1 and item2

  1. When the command is executed from CLI once, then everything works smoothly. get_next calls twice with -1, then it calls with valid next address
    i.e. get_next(-1) -> get_next(-1) -> get_next(item1 address) -> get_object() -> get_next(item2 address) -> get_object

  2. If I execute the CLI command again within a second after the previous command. Then get_next is called twice with -1 then get_next twice again wth valid value
    i.e. get_next(-1) -> get_next(-1) -> get_next(item1 address) -> get_next(item2 address) -> get_object()

Summary get_next is called many time even before get_object is called

2

While I agree that it might be confusing, the data provider should not assume any particular sequence of callbacks. There are many reasons why get_elem or get_object (and others) can be called seemingly out of band, the data provider really needs to be able to respond to any (valid) DP callback.

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3

That means if twice the time I received data with get_next, then its get_next job to handle it properly.

My thought (assumption) was when get_next is finished then get_object should always be called.

My code was like this. I have linked list.
get_next receive first element and reply with next element using confd_data_reply_next_key
get_object receive those and process

since get_next is called twice for non -1 values before get_object, every thing was messed up.

Now I handled in get_next the scenario and not assuming get_object will alway call just after get_next.

Thanks and please let me know my understanding is correct

4

That is correct. The “no assumptions” approach is the best one for a data provider application.

When using a CLI human-to-machine interface, for example, ConfD will not only have to do data provider calls for the values when the user hits “enter”, but also for tab completes, etc.

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