Diagnostic Visitors

Microsoft.Azure.Cosmos/src/Batch/BatchAsyncContainerExecutor.cs

@@ -11,6 +11,7 @@ namespace Microsoft.Azure.Cosmos
     using System.IO;
     using System.Threading;
     using System.Threading.Tasks;
+    using Microsoft.Azure.Cosmos.Diagnostics;
     using Microsoft.Azure.Cosmos.Routing;
     using Microsoft.Azure.Documents;
 

Microsoft.Azure.Cosmos/src/Diagnostics/BackendMetricsExtractor.cs

@@ -0,0 +1,61 @@
+// ------------------------------------------------------------
+// Copyright (c) Microsoft Corporation.  All rights reserved.
+// ------------------------------------------------------------
+
+namespace Microsoft.Azure.Cosmos.Diagnostics
+{
+    using Microsoft.Azure.Cosmos.Query.Core.Metrics;
+
+    /// <summary>
+    /// Extracts the aggregated <see cref="BackendMetrics"/> from a <see cref="CosmosDiagnostics"/>.
+    /// </summary>
+    internal sealed class BackendMetricsExtractor : CosmosDiagnosticsInternalVisitor<(bool, BackendMetrics)>
+    {
+        public static readonly BackendMetricsExtractor Singleton = new BackendMetricsExtractor();
+
+        private BackendMetricsExtractor()
+        {
+            // Private default constructor.
+        }
+
+        public override (bool, BackendMetrics) Visit(PointOperationStatistics pointOperationStatistics)
+        {
+            return (false, default);
+        }
+
+        public override (bool, BackendMetrics) Visit(CosmosDiagnosticsContext cosmosDiagnosticsContext)
+        {
+            return cosmosDiagnosticsContext.ContextList.Accept(this);
+        }
+
+        public override (bool, BackendMetrics) Visit(CosmosDiagnosticScope cosmosDiagnosticScope)
+        {
+            return (false, default);
+        }
+
+        public override (bool, BackendMetrics) Visit(CosmosDiagnosticsContextList cosmosDiagnosticsContextList)
+        {
+            BackendMetrics.Accumulator accumulator = default;
+            foreach (CosmosDiagnosticsInternal cosmosDiagnostics in cosmosDiagnosticsContextList)
+            {
+                (bool gotBackendMetric, BackendMetrics backendMetrics) = cosmosDiagnostics.Accept(this);
+                if (gotBackendMetric)
+                {
+                    accumulator = accumulator.Accumulate(backendMetrics);
+                }
+            }
+
+            return (true, BackendMetrics.Accumulator.ToBackendMetrics(accumulator));
+        }
+
+        public override (bool, BackendMetrics) Visit(QueryPageDiagnostics queryPageDiagnostics)
+        {
+            if (!BackendMetrics.TryParseFromDelimitedString(queryPageDiagnostics.QueryMetricText, out BackendMetrics backendMetrics))
+            {
+                return (false, default);
+            }
+
+            return (true, backendMetrics);
+        }
+    }
+}

Microsoft.Azure.Cosmos/src/Diagnostics/CosmosDiagnosticScope.cs

@@ -2,7 +2,7 @@
 // Copyright (c) Microsoft Corporation.  All rights reserved.
 //------------------------------------------------------------
 
-namespace Microsoft.Azure.Cosmos
+namespace Microsoft.Azure.Cosmos.Diagnostics
 {
     using System;
     using System.Collections.Generic;
@@ -15,28 +15,34 @@ namespace Microsoft.Azure.Cosmos
     /// A scope is a section of code that is important to track.
     /// For example there is a scope for serialization, retry handlers, etc..
     /// </summary>
-    internal class CosmosDiagnosticScope : CosmosDiagnosticWriter, IDisposable
+    internal sealed class CosmosDiagnosticScope : CosmosDiagnosticsInternal, IDisposable
     {
-        private readonly string Id;
-
         private readonly Stopwatch ElapsedTimeStopWatch;
-
         private readonly Action<TimeSpan> ElapsedTimeCallback;
-
-        internal TimeSpan? ElapsedTime { get; private set; }
-
         private bool isDisposed = false;
-        
-        internal CosmosDiagnosticScope(
+
+        public CosmosDiagnosticScope(
             string name,
             Action<TimeSpan> elapsedTimeCallback = null)
         {
             this.Id = name;
             this.ElapsedTimeStopWatch = Stopwatch.StartNew();
-            this.ElapsedTime = null;
             this.ElapsedTimeCallback = elapsedTimeCallback;
         }
 
+        public string Id { get; }
+
+        public bool TryGetElapsedTime(out TimeSpan elapsedTime)
+        {
+            if (!this.isDisposed)
+            {
+                return false;
+            }
+
+            elapsedTime = this.ElapsedTimeStopWatch.Elapsed;
+            return true;
+        }
+
         public void Dispose()
         {
             if (this.isDisposed)
@@ -45,28 +51,18 @@ public void Dispose()
             }
 
             this.ElapsedTimeStopWatch.Stop();
-            this.ElapsedTime = this.ElapsedTimeStopWatch.Elapsed;
-            this.ElapsedTimeCallback?.Invoke(this.ElapsedTime.Value);
+            this.ElapsedTimeCallback?.Invoke(this.ElapsedTimeStopWatch.Elapsed);
             this.isDisposed = true;
         }
 
-        internal override void WriteJsonObject(JsonWriter jsonWriter)
+        public override void Accept(CosmosDiagnosticsInternalVisitor cosmosDiagnosticsInternalVisitor)
         {
-            jsonWriter.WriteStartObject();
-            jsonWriter.WritePropertyName("Id");
-            jsonWriter.WriteValue(this.Id);
-            jsonWriter.WritePropertyName("ElapsedTime");
-
-            if (this.ElapsedTime.HasValue)
-            {
-                jsonWriter.WriteValue(this.ElapsedTime.Value);
-            }
-            else
-            {
-                jsonWriter.WriteValue("Timer Never Stopped.");
-            }
+            cosmosDiagnosticsInternalVisitor.Visit(this);
+        }
 
-            jsonWriter.WriteEndObject();
+        public override TResult Accept<TResult>(CosmosDiagnosticsInternalVisitor<TResult> visitor)
+        {
+            return visitor.Visit(this);
         }
     }
 }

Microsoft.Azure.Cosmos/src/Diagnostics/CosmosDiagnosticSummary.cs

@@ -5,9 +5,7 @@
 namespace Microsoft.Azure.Cosmos
 {
     using System;
-    using System.Collections.Generic;
     using System.Globalization;
-    using System.Text;
     using Newtonsoft.Json;
 
     internal sealed class CosmosDiagnosticSummary
@@ -93,7 +91,6 @@ internal void Append(CosmosDiagnosticSummary newSummary)
 
         internal void WriteJsonProperty(JsonWriter writer)
         {
-            writer.WritePropertyName("Summary");
             writer.WriteStartObject();
             writer.WritePropertyName("StartUtc");
             writer.WriteValue(this.StartUtc.ToString("o", CultureInfo.InvariantCulture));

Microsoft.Azure.Cosmos/src/Diagnostics/CosmosDiagnosticsContext.cs

@@ -6,6 +6,7 @@ namespace Microsoft.Azure.Cosmos
     using System;
     using System.IO;
     using System.Text;
+    using Microsoft.Azure.Cosmos.Diagnostics;
     using Newtonsoft.Json;
 
     /// <summary>
@@ -14,24 +15,27 @@ namespace Microsoft.Azure.Cosmos
     /// through the pipeline appending information as it goes into a list
     /// where it is lazily converted to a JSON string.
     /// </summary>
-    internal sealed class CosmosDiagnosticsContext : CosmosDiagnostics
+    internal sealed class CosmosDiagnosticsContext : CosmosDiagnosticsInternal
     {
-        // Summary contains the high level overview of operations
-        // like start time, retries, and other aggregated information
-        internal CosmosDiagnosticSummary Summary { get; }
+        private bool isOverallScopeSet;
 
-        // Context list is detailed view of all the operations
-        internal CosmosDiagnosticsContextList ContextList { get; }
-
-        private bool isOverallScopeSet = false;
-
-        internal CosmosDiagnosticsContext()
+        public CosmosDiagnosticsContext()
         {
             this.Summary = new CosmosDiagnosticSummary(DateTime.UtcNow);
             this.ContextList = new CosmosDiagnosticsContextList();
         }
 
-        internal CosmosDiagnosticScope CreateOverallScope(string name)
+        /// <summary>
+        /// Contains the high level overview of operations like start time, retries, and other aggregated information
+        /// </summary>
+        public CosmosDiagnosticSummary Summary { get; }
+
+        /// <summary>
+        /// Detailed view of all the operations.
+        /// </summary>
+        public CosmosDiagnosticsContextList ContextList { get; }
+
+        public CosmosDiagnosticScope CreateOverallScope(string name)
         {
             CosmosDiagnosticScope scope;
             // If overall is already set then let the original set the elapsed time.
@@ -57,26 +61,7 @@ internal CosmosDiagnosticScope CreateScope(string name)
             return scope;
         }
 
-        public override string ToString()
-        {
-            StringBuilder sb = new StringBuilder();
-            StringWriter sw = new StringWriter(sb);
-
-            using (JsonWriter jsonWriter = new JsonTextWriter(sw))
-            {
-                jsonWriter.WriteStartObject();
-                this.Summary.WriteJsonProperty(jsonWriter);
-                jsonWriter.WritePropertyName("Context");
-                jsonWriter.WriteStartArray();
-                this.ContextList.WriteJsonObject(jsonWriter);
-                jsonWriter.WriteEndArray();
-                jsonWriter.WriteEndObject();
-            }
-
-            return sb.ToString();
-        }
-
-        internal void AddContextWriter(CosmosDiagnosticWriter diagnosticWriter)
+        internal void AddContextWriter(CosmosDiagnosticsInternal diagnosticWriter)
         {
             this.ContextList.AddWriter(diagnosticWriter);
         }
@@ -92,5 +77,15 @@ internal void Append(CosmosDiagnosticsContext newContext)
 
             this.ContextList.Append(newContext.ContextList);
         }
+
+        public override void Accept(CosmosDiagnosticsInternalVisitor cosmosDiagnosticsInternalVisitor)
+        {
+            cosmosDiagnosticsInternalVisitor.Visit(this);
+        }
+
+        public override TResult Accept<TResult>(CosmosDiagnosticsInternalVisitor<TResult> visitor)
+        {
+            return visitor.Visit(this);
+        }
     }
 }

Microsoft.Azure.Cosmos/src/Diagnostics/CosmosDiagnosticsContextList.cs

@@ -1,37 +1,54 @@
 //------------------------------------------------------------
 // Copyright (c) Microsoft Corporation.  All rights reserved.
 //------------------------------------------------------------
-namespace Microsoft.Azure.Cosmos
+namespace Microsoft.Azure.Cosmos.Diagnostics
 {
+    using System;
+    using System.Collections;
     using System.Collections.Generic;
-    using System.Text;
-    using Newtonsoft.Json;
 
-    internal sealed class CosmosDiagnosticsContextList : CosmosDiagnosticWriter
+    internal sealed class CosmosDiagnosticsContextList : CosmosDiagnosticsInternal, IEnumerable<CosmosDiagnosticsInternal>
     {
-        private List<CosmosDiagnosticWriter> contextList { get; }
+        private List<CosmosDiagnosticsInternal> contextList { get; }
 
-        internal CosmosDiagnosticsContextList()
+        public CosmosDiagnosticsContextList(List<CosmosDiagnosticsInternal> contextList)
         {
-            this.contextList = new List<CosmosDiagnosticWriter>();
+            this.contextList = contextList ?? throw new ArgumentNullException(nameof(contextList));
         }
 
-        internal void AddWriter(CosmosDiagnosticWriter diagnosticWriter)
+        public CosmosDiagnosticsContextList()
+            : this(new List<CosmosDiagnosticsInternal>())
+        {
+        }
+
+        public void AddWriter(CosmosDiagnosticsInternal diagnosticWriter)
         {
             this.contextList.Add(diagnosticWriter);
         }
 
-        internal void Append(CosmosDiagnosticsContextList newContext)
+        public void Append(CosmosDiagnosticsContextList newContext)
         {
             this.contextList.Add(newContext);
         }
 
-        internal override void WriteJsonObject(JsonWriter jsonWriter)
+        public override void Accept(CosmosDiagnosticsInternalVisitor cosmosDiagnosticsInternalVisitor)
+        {
+            cosmosDiagnosticsInternalVisitor.Visit(this);
+        }
+
+        public override TResult Accept<TResult>(CosmosDiagnosticsInternalVisitor<TResult> visitor)
+        {
+            return visitor.Visit(this);
+        }
+
+        public IEnumerator<CosmosDiagnosticsInternal> GetEnumerator()
+        {
+            return this.contextList.GetEnumerator();
+        }
+
+        IEnumerator IEnumerable.GetEnumerator()
         {
-            foreach (CosmosDiagnosticWriter writer in this.contextList)
-            {
-                writer.WriteJsonObject(jsonWriter);
-            }
+            return this.contextList.GetEnumerator();
         }
     }
 }

Microsoft.Azure.Cosmos/src/Diagnostics/CosmosDiagnosticsInternal.cs

@@ -0,0 +1,31 @@
+//------------------------------------------------------------
+// Copyright (c) Microsoft Corporation.  All rights reserved.
+//------------------------------------------------------------
+
+namespace Microsoft.Azure.Cosmos.Diagnostics
+{
+    using System.IO;
+
+    /// <summary>
+    /// Extends <see cref="CosmosDiagnostics"/> to expose internal APIs.
+    /// </summary>
+    internal abstract class CosmosDiagnosticsInternal : CosmosDiagnostics
+    {
+        public abstract void Accept(CosmosDiagnosticsInternalVisitor visitor);
+
+        public abstract TResult Accept<TResult>(CosmosDiagnosticsInternalVisitor<TResult> visitor);
+
+        public override string ToString()
+        {
+            StringWriter stringWriter = new StringWriter();
+            this.WriteTo(stringWriter);
+            return stringWriter.ToString();
+        }
+
+        public void WriteTo(TextWriter textWriter)
+        {
+            CosmosDiagnosticsSerializerVisitor cosmosDiagnosticsSerializerVisitor = new CosmosDiagnosticsSerializerVisitor(textWriter);
+            this.Accept(cosmosDiagnosticsSerializerVisitor);
+        }
+    }
+}