Performance: Fixes query improvement to load values lazily

Microsoft.Azure.Cosmos/src/Query/Core/Metrics/QueryMetrics.cs

@@ -24,20 +24,31 @@ sealed class QueryMetrics
         /// QueryMetrics that with all members having default (but not null) members.
         /// </summary>
         public static readonly QueryMetrics Empty = new QueryMetrics(
-            backendMetrics: BackendMetrics.Empty,
+            deliminatedString: string.Empty,
             indexUtilizationInfo: IndexUtilizationInfo.Empty,
             clientSideMetrics: ClientSideMetrics.Empty);
 
         public QueryMetrics(
-            BackendMetrics backendMetrics,
-            IndexUtilizationInfo indexUtilizationInfo,
-            ClientSideMetrics clientSideMetrics)
+        BackendMetrics backendMetrics,
+        IndexUtilizationInfo indexUtilizationInfo,
+        ClientSideMetrics clientSideMetrics)
         {
             this.BackendMetrics = backendMetrics ?? throw new ArgumentNullException(nameof(backendMetrics));
             this.IndexUtilizationInfo = indexUtilizationInfo ?? throw new ArgumentNullException(nameof(indexUtilizationInfo));
             this.ClientSideMetrics = clientSideMetrics ?? throw new ArgumentNullException(nameof(clientSideMetrics));
         }
 
+        public QueryMetrics(
+            string deliminatedString,
+            IndexUtilizationInfo indexUtilizationInfo,
+            ClientSideMetrics clientSideMetrics)
+            : this(!String.IsNullOrWhiteSpace(deliminatedString) &&
+                    BackendMetricsParser.TryParse(deliminatedString, out BackendMetrics backendMetrics)
+                ? backendMetrics
+                : BackendMetrics.Empty, indexUtilizationInfo, clientSideMetrics)
+        {
+        }
+
         public BackendMetrics BackendMetrics { get; }
 
         public IndexUtilizationInfo IndexUtilizationInfo { get; }

Microsoft.Azure.Cosmos/src/Query/Core/Pipeline/CrossPartition/OrderBy/OrderByCrossPartitionQueryPipelineStage.cs

@@ -19,6 +19,7 @@ namespace Microsoft.Azure.Cosmos.Query.Core.Pipeline.CrossPartition.OrderBy
     using Microsoft.Azure.Cosmos.Query.Core.Monads;
     using Microsoft.Azure.Cosmos.Query.Core.Pipeline.CrossPartition.Parallel;
     using Microsoft.Azure.Cosmos.Query.Core.Pipeline.Pagination;
+    using Microsoft.Azure.Cosmos.Query.Core.QueryClient;
     using Microsoft.Azure.Cosmos.Tracing;
     using ResourceId = Documents.ResourceId;
 
@@ -1108,7 +1109,9 @@ private static (string leftFilter, string targetFilter, string rightFilter) GetF
                 // If there is a tie in the sort order the documents should be in _rid order in the same direction as the index (given by the backend)
                 ResourceId rid = ResourceId.Parse(orderByResult.Rid);
                 int ridOrderCompare = continuationRid.Document.CompareTo(rid.Document);
-                if ((orderByQueryPage.Page.CosmosQueryExecutionInfo == null) || orderByQueryPage.Page.CosmosQueryExecutionInfo.ReverseRidEnabled)
+
+                Lazy<CosmosQueryExecutionInfo> cosmosQueryExecutionInfo = orderByQueryPage.Page.CosmosQueryExecutionInfo;
+                if ((cosmosQueryExecutionInfo == null) || cosmosQueryExecutionInfo.Value.ReverseRidEnabled)
                 {
                     // If reverse rid is enabled on the backend then fallback to the old way of doing it.
                     if (sortOrders[0] == SortOrder.Descending)
@@ -1119,7 +1122,7 @@ private static (string leftFilter, string targetFilter, string rightFilter) GetF
                 else
                 {
                     // Go by the whatever order the index wants
-                    if (orderByQueryPage.Page.CosmosQueryExecutionInfo.ReverseIndexScan)
+                    if (cosmosQueryExecutionInfo.Value.ReverseIndexScan)
                     {
                         ridOrderCompare = -ridOrderCompare;
                     }

Microsoft.Azure.Cosmos/src/Query/Core/Pipeline/Pagination/QueryPage.cs

@@ -11,6 +11,7 @@ namespace Microsoft.Azure.Cosmos.Query.Core.Pipeline.Pagination
     using Microsoft.Azure.Cosmos.CosmosElements;
     using Microsoft.Azure.Cosmos.Pagination;
     using Microsoft.Azure.Cosmos.Query.Core.QueryClient;
+    using Newtonsoft.Json;
 
     internal sealed class QueryPage : Page<QueryState>
     {
@@ -25,7 +26,7 @@ public QueryPage(
             double requestCharge,
             string activityId,
             long responseLengthInBytes,
-            CosmosQueryExecutionInfo cosmosQueryExecutionInfo,
+            Lazy<CosmosQueryExecutionInfo> cosmosQueryExecutionInfo,
             string disallowContinuationTokenMessage,
             IReadOnlyDictionary<string, string> additionalHeaders,
             QueryState state)
@@ -41,7 +42,7 @@ public QueryPage(
 
         public long ResponseLengthInBytes { get; }
 
-        public CosmosQueryExecutionInfo CosmosQueryExecutionInfo { get; }
+        public Lazy<CosmosQueryExecutionInfo> CosmosQueryExecutionInfo { get; }
 
         public string DisallowContinuationTokenMessage { get; }
 

Microsoft.Azure.Cosmos/src/Query/v2Query/DefaultDocumentQueryExecutionContext.cs

@@ -107,7 +107,7 @@ protected override async Task<DocumentFeedResponse<CosmosElement>> ExecuteIntern
                                 {
                                     partitionIdentifier,
                                     new QueryMetrics(
-                                        BackendMetrics.ParseFromDelimitedString(response.ResponseHeaders[HttpConstants.HttpHeaders.QueryMetrics]),
+                                        response.ResponseHeaders[HttpConstants.HttpHeaders.QueryMetrics],
                                         IndexUtilizationInfo.CreateFromString(response.ResponseHeaders[HttpConstants.HttpHeaders.IndexUtilization]),
                                         new ClientSideMetrics(
                                             this.retries,

Microsoft.Azure.Cosmos/src/Query/v3Query/CosmosQueryClientCore.cs

@@ -285,12 +285,13 @@ private static TryCatch<QueryPage> GetCosmosElementResponse(
             {
                 using (cosmosResponseMessage)
                 {
-                    if (
-                        cosmosResponseMessage.Headers.QueryMetricsText != null &&
-                        BackendMetricsParser.TryParse(cosmosResponseMessage.Headers.QueryMetricsText, out BackendMetrics backendMetrics))
+                    if (cosmosResponseMessage.Headers.QueryMetricsText != null)
                     {
                         QueryMetricsTraceDatum datum = new QueryMetricsTraceDatum(
-                            new QueryMetrics(backendMetrics, IndexUtilizationInfo.Empty, ClientSideMetrics.Empty));
+                            new Lazy<QueryMetrics>(() => new QueryMetrics(
+                                cosmosResponseMessage.Headers.QueryMetricsText, 
+                                IndexUtilizationInfo.Empty, 
+                                ClientSideMetrics.Empty)));
                         trace.AddDatum("Query Metrics", datum);
                     }
 
@@ -317,16 +318,6 @@ private static TryCatch<QueryPage> GetCosmosElementResponse(
                         resourceType,
                         requestOptions.CosmosSerializationFormatOptions);
 
-                    CosmosQueryExecutionInfo cosmosQueryExecutionInfo;
-                    if (cosmosResponseMessage.Headers.TryGetValue(QueryExecutionInfoHeader, out string queryExecutionInfoString))
-                    {
-                        cosmosQueryExecutionInfo = JsonConvert.DeserializeObject<CosmosQueryExecutionInfo>(queryExecutionInfoString);
-                    }
-                    else
-                    {
-                        cosmosQueryExecutionInfo = default;
-                    }
-
                     QueryState queryState;
                     if (cosmosResponseMessage.Headers.ContinuationToken != null)
                     {
@@ -346,6 +337,14 @@ private static TryCatch<QueryPage> GetCosmosElementResponse(
                         }
                     }
 
+                    Lazy<CosmosQueryExecutionInfo> cosmosQueryExecutionInfo = default;
+                    if (cosmosResponseMessage.Headers.TryGetValue(QueryExecutionInfoHeader, out string queryExecutionInfoString))
+                    {
+                        cosmosQueryExecutionInfo = 
+                            new Lazy<CosmosQueryExecutionInfo>(
+                                () => JsonConvert.DeserializeObject<CosmosQueryExecutionInfo>(queryExecutionInfoString));
+                    }
+
                     QueryPage response = new QueryPage(
                         documents,
                         cosmosResponseMessage.Headers.RequestCharge,

Microsoft.Azure.Cosmos/src/Tracing/TraceData/QueryMetricsTraceDatum.cs

@@ -9,12 +9,14 @@ namespace Microsoft.Azure.Cosmos.Tracing.TraceData
 
     internal sealed class QueryMetricsTraceDatum : TraceDatum
     {
-        public QueryMetricsTraceDatum(QueryMetrics queryMetrics)
+        private readonly Lazy<QueryMetrics> LazyQueryMetrics;
+
+        public QueryMetricsTraceDatum(Lazy<QueryMetrics> queryMetrics)
         {
-            this.QueryMetrics = queryMetrics ?? throw new ArgumentNullException(nameof(queryMetrics));
+            this.LazyQueryMetrics = queryMetrics ?? throw new ArgumentNullException(nameof(queryMetrics));
         }
 
-        public QueryMetrics QueryMetrics { get; }
+        public QueryMetrics QueryMetrics => this.LazyQueryMetrics.Value;
 
         internal override void Accept(ITraceDatumVisitor traceDatumVisitor)
         {

Microsoft.Azure.Cosmos/tests/Microsoft.Azure.Cosmos.EmulatorTests/QueryTests.cs

@@ -2287,7 +2287,7 @@ private async Task ValidateQueryMetricsHeadersOverContinuations(
                             string indexUtilization = response.ResponseHeaders[WFConstants.BackendHeaders.IndexUtilization];
 
                             QueryMetrics queryMetrics = new QueryMetrics(
-                                BackendMetrics.ParseFromDelimitedString(responseQueryMetrics),
+                                responseQueryMetrics,
                                 IndexUtilizationInfo.CreateFromString(indexUtilization),
                                 ClientSideMetrics.Empty);
                             this.ValidateQueryMetrics(queryMetrics);

Microsoft.Azure.Cosmos/tests/Microsoft.Azure.Cosmos.Tests/BaselineTest/TestBaseline/TraceWriterBaselineTests.TraceData.xml

@@ -137,10 +137,10 @@
     using (rootTrace = TraceForBaselineTesting.GetRootTrace())
     {
         QueryMetricsTraceDatum datum = new QueryMetricsTraceDatum(
-            new QueryMetrics(
+            new Lazy<QueryMetrics>(() => new QueryMetrics(
                 BackendMetricsTests.MockBackendMetrics,
                 IndexUtilizationInfoTests.MockIndexUtilizationInfo,
-                ClientSideMetricsTests.MockClientSideMetrics));
+                ClientSideMetricsTests.MockClientSideMetrics)));
         rootTrace.AddDatum("Query Metrics", datum);
     }
 ]]></Setup>

Microsoft.Azure.Cosmos/tests/Microsoft.Azure.Cosmos.Tests/Tracing/TraceWriterBaselineTests.cs

@@ -40,10 +40,10 @@ namespace Microsoft.Azure.Cosmos.Tests.Tracing
     [TestClass]
     public sealed class TraceWriterBaselineTests : BaselineTests<TraceWriterBaselineTests.Input, TraceWriterBaselineTests.Output>
     {
-        private static readonly QueryMetrics MockQueryMetrics = new QueryMetrics(
+        private static readonly Lazy<QueryMetrics> MockQueryMetrics = new Lazy<QueryMetrics>(() => new QueryMetrics(
             BackendMetricsTests.MockBackendMetrics,
             IndexUtilizationInfoTests.MockIndexUtilizationInfo,
-            ClientSideMetricsTests.MockClientSideMetrics);
+            ClientSideMetricsTests.MockClientSideMetrics));
 
         private static readonly Documents.PartitionKeyDefinition partitionKeyDefinition = new Documents.PartitionKeyDefinition()
         {
@@ -315,10 +315,10 @@ public void TraceData()
                 using (rootTrace = TraceForBaselineTesting.GetRootTrace())
                 {
                     QueryMetricsTraceDatum datum = new QueryMetricsTraceDatum(
-                        new QueryMetrics(
+                        new Lazy<QueryMetrics>(() => new QueryMetrics(
                             BackendMetricsTests.MockBackendMetrics,
                             IndexUtilizationInfoTests.MockIndexUtilizationInfo,
-                            ClientSideMetricsTests.MockClientSideMetrics));
+                            ClientSideMetricsTests.MockClientSideMetrics)));
                     rootTrace.AddDatum("Query Metrics", datum);
                 }
                 endLineNumber = GetLineNumber();