[SAI-PTF] Enhance the function for getting counters in sai_adapter.py

[richardyu-ms]

Description

For the auto-generated adapter, need to add a parameter for which counter_id/counter_ids we want, in order to compatiable with current code and reduce the modification, we can define a constant parameter as the list of counter_ids, and use this constant as the default.

Resolve issue

#1614

Before

    def sai_thrift_get_bfd_session_stats(client,
                                         bfd_session_oid):

        counter_ids = []
        counter_ids.append(SAI_BFD_SESSION_STAT_IN_PACKETS)
        counter_ids.append(SAI_BFD_SESSION_STAT_OUT_PACKETS)
        counter_ids.append(SAI_BFD_SESSION_STAT_DROP_PACKETS)

        counters = [0] * 3
        global status
        status = SAI_STATUS_SUCCESS

After the refactor

sai_get_bfd_session_stats_counter_ids = []
sai_get_bfd_session_stats_counter_ids_dict = dict()
sai_get_bfd_session_stats_counter_ids.append(SAI_BFD_SESSION_STAT_IN_PACKETS)
sai_get_bfd_session_stats_counter_ids_dict[SAI_BFD_SESSION_STAT_IN_PACKETS] = "SAI_BFD_SESSION_STAT_IN_PACKETS"
sai_get_bfd_session_stats_counter_ids.append(SAI_BFD_SESSION_STAT_OUT_PACKETS)
sai_get_bfd_session_stats_counter_ids_dict[SAI_BFD_SESSION_STAT_OUT_PACKETS] = "SAI_BFD_SESSION_STAT_OUT_PACKETS"
sai_get_bfd_session_stats_counter_ids.append(SAI_BFD_SESSION_STAT_DROP_PACKETS)
sai_get_bfd_session_stats_counter_ids_dict[SAI_BFD_SESSION_STAT_DROP_PACKETS] = "SAI_BFD_SESSION_STAT_DROP_PACKETS"

def sai_thrift_get_bfd_session_stats(client,
                                     bfd_session_oid,
                                     counter_ids=sai_get_bfd_session_stats_counter_ids):
...

    stats = dict()

    for index, item in enumerate(counter_ids):
        stats[sai_get_bfd_session_stats_counter_ids_dict[item]] = counters[index]


    return stats

Usage

        ids = []    
        ids.append(SAI_QUEUE_STAT_PACKETS)
        pre_cpu_queue_state = sai_thrift_get_queue_stats(self.client, self.cpu_queue0, counter_ids=ids)[

[richardyu-ms]

@ravi861 Could you please help to make a review. Thanks

[ravi861]

pre_cpu_queue_state["SAI_QUEUE_STAT_PACKETS"]
You can now get the counter value using above dict?

[richardyu-ms]

pre_cpu_queue_state["SAI_QUEUE_STAT_PACKETS"] You can now get the counter value using above dict?

Yes. By specifying what's the excatlly attributes need to use, I can get the value from the dict.
Have to confirm if that attribute/counter is supported in advance, anyway.