Add runtime stats for normalizeIdentifier

Author: agrawalreetika

presto-common/src/main/java/com/facebook/presto/common/RuntimeMetricName.java

@@ -58,6 +58,7 @@ private RuntimeMetricName()
     public static final String GET_CANONICAL_INFO_TIME_NANOS = "getCanonicalInfoTimeNanos";
     public static final String FRAGMENT_PLAN_TIME_NANOS = "fragmentPlanTimeNanos";
     public static final String GET_LAYOUT_TIME_NANOS = "getLayoutTimeNanos";
+    public static final String GET_IDENTIFIER_NORMALIZATION_TIME_NANOS = "getIdentifierNormalizationTimeNanos";
     public static final String REWRITE_AGGREGATION_IF_TO_FILTER_APPLIED = "rewriteAggregationIfToFilterApplied";
     // Time between task creation and start.
     public static final String TASK_QUEUED_TIME_NANOS = "taskQueuedTimeNanos";

presto-main-base/src/main/java/com/facebook/presto/metadata/MetadataManager.java

@@ -108,6 +108,7 @@
 
 import static com.facebook.airlift.concurrent.MoreFutures.toListenableFuture;
 import static com.facebook.presto.SystemSessionProperties.isIgnoreStatsCalculatorFailures;
+import static com.facebook.presto.common.RuntimeMetricName.GET_IDENTIFIER_NORMALIZATION_TIME_NANOS;
 import static com.facebook.presto.common.RuntimeMetricName.GET_LAYOUT_TIME_NANOS;
 import static com.facebook.presto.common.RuntimeMetricName.GET_MATERIALIZED_VIEW_STATUS_TIME_NANOS;
 import static com.facebook.presto.common.RuntimeUnit.NANO;
@@ -1491,13 +1492,18 @@ public void addConstraint(Session session, TableHandle tableHandle, TableConstra
     @Override
     public String normalizeIdentifier(Session session, String catalogName, String identifier)
     {
+        long startTime = System.nanoTime();
+        String normalizedString = identifier.toLowerCase(ENGLISH);
         Optional<CatalogMetadata> catalogMetadata = getOptionalCatalogMetadata(session, transactionManager, catalogName);
         if (catalogMetadata.isPresent()) {
             ConnectorId connectorId = catalogMetadata.get().getConnectorId();
             ConnectorMetadata metadata = catalogMetadata.get().getMetadataFor(connectorId);
-            return metadata.normalizeIdentifier(session.toConnectorSession(connectorId), identifier);
+            normalizedString = metadata.normalizeIdentifier(session.toConnectorSession(connectorId), identifier);
+            session.getRuntimeStats().addMetricValue(GET_IDENTIFIER_NORMALIZATION_TIME_NANOS, NANO, System.nanoTime() - startTime);
+            return normalizedString;
         }
-        return identifier.toLowerCase(ENGLISH);
+        session.getRuntimeStats().addMetricValue(GET_IDENTIFIER_NORMALIZATION_TIME_NANOS, NANO, System.nanoTime() - startTime);
+        return normalizedString;
     }
 
     private ViewDefinition deserializeView(String data)