[syncd]: Only query queue counters that are needed by the application (sonic-net#261)

The previous hardcoded for loop to iterate items defined in the SAI
header file was not ideal. Update the logic here so that only needed
attributes are checked for the support.

Signed-off-by: Shu0T1an ChenG <[email protected]>

Author: Shuotian Cheng

syncd/syncd_flex_counter.cpp

@@ -27,6 +27,11 @@ FlexCounter::QueueAttrIds::QueueAttrIds(
 {
 }
 
+/* The current implementation of 'setPortCounterList' and 'setQueueCounterList' are
+ * not the same. Need to refactor these two functions to have the similar logic.
+ * Either the full SAI attributes are queried once, or each of the needed counters
+ * will be queried when they are set.
+ */
 void FlexCounter::setPortCounterList(
         _In_ sai_object_id_t portVid,
         _In_ sai_object_id_t portId,
@@ -90,11 +95,7 @@ void FlexCounter::setQueueCounterList(
 
     FlexCounter &fc = getInstance(pollInterval);
 
-    // Initialize the supported counters list before setting
-    if (fc.m_supportedQueueCounters.size() == 0)
-    {
-        fc.saiUpdateSupportedQueueCounters(queueId);
-    }
+    fc.saiUpdateSupportedQueueCounters(queueId, counterIds);
 
     // Remove unsupported counters
     std::vector<sai_queue_stat_t> supportedIds;
@@ -579,25 +580,30 @@ void FlexCounter::saiUpdateSupportedPortCounters(sai_object_id_t portId)
     }
 }
 
-void FlexCounter::saiUpdateSupportedQueueCounters(sai_object_id_t queueId)
+void FlexCounter::saiUpdateSupportedQueueCounters(
+        _In_ sai_object_id_t queueId,
+        _In_ const std::vector<sai_queue_stat_t> &counterIds)
 {
     uint64_t value;
-    for (int cntr_id = SAI_QUEUE_STAT_PACKETS; cntr_id <= SAI_QUEUE_STAT_SHARED_WATERMARK_BYTES; ++cntr_id)
-    {
-        sai_queue_stat_t counter = static_cast<sai_queue_stat_t>(cntr_id);
+    m_supportedQueueCounters.clear();
 
+    for (auto &counter : counterIds)
+    {
         sai_status_t status = sai_metadata_sai_queue_api->get_queue_stats(queueId, 1, &counter, &value);
 
         if (status != SAI_STATUS_SUCCESS)
         {
-            SWSS_LOG_WARN("Counter %s is not supported on port RID %s: %s",
+            SWSS_LOG_WARN("Counter %s is not supported on queue %s, rv: %s",
                     sai_serialize_queue_stat(counter).c_str(),
                     sai_serialize_object_id(queueId).c_str(),
                     sai_serialize_status(status).c_str());
 
             continue;
         }
+        else
+        {
+            m_supportedQueueCounters.insert(counter);
+        }
 
-        m_supportedQueueCounters.insert(counter);
     }
 }

syncd/syncd_flex_counter.h

@@ -93,7 +93,7 @@ class FlexCounter
         void endFlexCounterThread(void);
 
         void saiUpdateSupportedPortCounters(sai_object_id_t portId);
-        void saiUpdateSupportedQueueCounters(sai_object_id_t queueId);
+        void saiUpdateSupportedQueueCounters(sai_object_id_t queueId, const std::vector<sai_queue_stat_t> &counterIds);
         bool isPortCounterSupported(sai_port_stat_t counter) const;
         bool isQueueCounterSupported(sai_queue_stat_t counter) const;