mdoc: Analytics mode

Added -statistics CLI argument with required parameter <path>.
Statistics module counts how many namespaces/types/members are added/removed/total.
If <path> parameter just points to a folder the default filename "statistics.txt" is appended. If the path can't be resolved a warning message is printed ("mdoc: Unable to save statistics file: Could not find a part of the path 'Z:\'.")
Unit tests for new classes are added; "check-monodocer-fx-statistics-remove" integration test is added, 2 other tests check statistics result file as well.
Closes #100

15 files changed, 485 insertions, 83 deletions

diff --git a/mdoc/Makefile b/mdoc/Makefile
index 5bb56f29..e1d23a7e 100644
--- a/mdoc/Makefile
+++ b/mdoc/Makefile
@@ -227,6 +227,7 @@ check-monodocer-dropns-multi-withexisting:
 
 check-monodocer-dropns-delete: 
 	-rm -Rf Test/en.actual
+	-rm -Rf Test/actual_statistics.txt
 	rm -Rf Test/DocTest-DropNS-classic-deletetest.dll
 	rm -Rf Test/DocTest-DropNS-unified-deletetest.dll
 	$(MAKE) Test/DocTest-DropNS-classic-deletetest.dll
@@ -236,8 +237,9 @@ check-monodocer-dropns-delete:
 	$(MAKE) Test/DocTest-DropNS-classic-deletetest-V2.dll
 	$(MONO) $(PROGRAM) update --delete --exceptions=all -o Test/en.actual Test/DocTest-DropNS-classic-deletetest.dll --api-style=classic
 	$(MAKE) Test/DocTest-DropNS-unified-deletetest-V2.dll
-	$(MONO) $(PROGRAM) update --delete --exceptions=all -o Test/en.actual Test/DocTest-DropNS-unified-deletetest.dll --api-style=unified --dropns Test/DocTest-DropNS-unified-deletetest.dll=MyFramework
+	$(MONO) $(PROGRAM) update --delete --exceptions=all -o Test/en.actual Test/DocTest-DropNS-unified-deletetest.dll --api-style=unified --dropns Test/DocTest-DropNS-unified-deletetest.dll=MyFramework -statistics Test/actual_statistics.txt
 	$(DIFF) Test/en.expected-dropns-delete Test/en.actual
+	$(DIFF) Test/expected_remove_statistics.txt Test/actual_statistics.txt
 
 check-monodocer-dropns-classic-withsecondary: 
 	# tests case where a secondary assembly is included with a --dropns parameter
@@ -364,6 +366,7 @@ check-monodocer-importecmadoc:
 check-monodocer-import-fx-work: Test/DocTest.dll-v1 Test/DocTest-DropNS-classic-secondary.dll Test/DocTest-DropNS-classic.dll
 	rm -Rf Test/en.actual
 	rm -Rf Test/fx-import
+	rm -Rf Test/actual_statistics.txt
 	mkdir Test/fx-import
 	mkdir Test/fx-import/one
 	mkdir Test/fx-import/two
@@ -375,7 +378,25 @@ check-monodocer-import-fx-work: Test/DocTest.dll-v1 Test/DocTest-DropNS-classic-
 	cp Test/DocTest.xml Test/fx-import/TestEcmaDocs.xml
 	cp Test/CLILibraryTypes.dtd Test/fx-import/
 	cp Test/fx-import-configuration.xml Test/fx-import/frameworks.xml
+	$(MONO) $(PROGRAM) update -o Test/en.actual -frameworks Test/fx-import -statistics Test/actual_statistics.txt
+	$(DIFF) Test/expected_statistics.txt Test/actual_statistics.txt
+	
+	
+check-monodocer-fx-statistics-remove:
+	rm -Rf Test/en.actual
+	rm -Rf Test/fx-import
+	rm -Rf Test/actual_statistics.txt
+	mkdir Test/fx-import
+	mkdir Test/fx-import/one
+	cp Test/fx-statistics-remove-configuration.xml Test/fx-import/frameworks.xml
+	$(MAKE) Test/DocTest-DropNS-unified-deletetest.dll
+	cp Test/DocTest-DropNS-unified-deletetest.dll Test/fx-import/one/DocTest.dll
 	$(MONO) $(PROGRAM) update -o Test/en.actual -frameworks Test/fx-import
+	$(MAKE) Test/DocTest-DropNS-unified.dll
+	rm -rf Test/fx-import/one/DocTest.dll
+	cp Test/DocTest-DropNS-unified.dll Test/fx-import/one/DocTest.dll
+	$(MONO) $(PROGRAM) update -o Test/en.actual -frameworks Test/fx-import -statistics Test/actual_statistics.txt
+	$(DIFF) Test/expected_fx_remove_statistics.txt Test/actual_statistics.txt
 
 .PHONY: check-monodocer-import-fx
 check-monodocer-import-fx: check-monodocer-import-fx-work
@@ -498,7 +519,8 @@ check-doc-tools: check-monodocer-since \
 	check-monodocer-frameworks \
 	check-monodocer-frameworks-inheritance \
 	check-monodocer-docid \
-	check-monodocer-operators
+	check-monodocer-operators \
+	check-monodocer-fx-statistics-remove
 
 check-doc-tools-update: check-monodocer-since-update \
 	check-monodocer-importecmadoc-update \
diff --git a/mdoc/Mono.Documentation/MDocUpdater.cs b/mdoc/Mono.Documentation/MDocUpdater.cs
index d789e9af..8a347c72 100644
--- a/mdoc/Mono.Documentation/MDocUpdater.cs
+++ b/mdoc/Mono.Documentation/MDocUpdater.cs
@@ -12,14 +12,15 @@ using System.Xml.XPath;
 
 using Mono.Cecil;
 using Mono.Documentation.Updater;
-using Mono.Documentation.Updater.Frameworks;

+using Mono.Documentation.Updater.Frameworks;
+using Mono.Documentation.Updater.Statistics;
 using Mono.Documentation.Util;
 using Mono.Options;
 
 using MyXmlNodeList = System.Collections.Generic.List<System.Xml.XmlNode>;
 using StringList = System.Collections.Generic.List<string>;
 using StringToXmlNodeMap = System.Collections.Generic.Dictionary<string, System.Xml.XmlNode>;
-

+
 namespace Mono.Documentation
 {
     class MDocUpdater : MDocCommand
@@ -63,6 +64,8 @@ namespace Mono.Documentation
 
         public static string droppedNamespace = string.Empty;
 
+        private HashSet<string> memberSet;
+
         public static bool HasDroppedNamespace (TypeDefinition forType)
         {
             return HasDroppedNamespace (forType.Module);
@@ -102,11 +105,16 @@ namespace Mono.Documentation
         string FrameworksPath = string.Empty;
         FrameworkIndex frameworks;
         FrameworkIndex frameworksCache;
+        IEnumerable<XDocument> oldFrameworkXmls;
+
+        private StatisticsCollector statisticsCollector = new StatisticsCollector();
 
         static List<string> droppedAssemblies = new List<string> ();
 
         public string PreserveTag { get; set; }
         public bool DisableSearchDirectoryRecurse = false;
+        private bool statisticsEnabled = false;
+        private string statisticsFilePath;
         public static MDocUpdater Instance { get; private set; }
         public static bool SwitchingToMagicTypes { get; private set; }
 
@@ -129,7 +137,10 @@ namespace Mono.Documentation
                 "             for NEW types/members\n" +
                 "If nothing is specified, then only exceptions from the member will " +
                 "be listed.",
-                v => exceptions = ParseExceptionLocations (v) },
+                v =>
+                {
+                    exceptions = ParseExceptionLocations(v);
+                } },
             { "f=",
                 "Specify a {FLAG} to alter behavior.  See later -f* options for available flags.",
                 v => {
@@ -205,6 +216,15 @@ namespace Mono.Documentation
             { "disable-searchdir-recurse",
                 "Default behavior for adding search directories ('-L') is to recurse them and search in all subdirectories. This disables that",
                 v => DisableSearchDirectoryRecurse = true },
+            {
+                "statistics=",
+                "Save statistics to the specified file",
+                v =>
+                {
+                    statisticsEnabled = true;
+                    if (!string.IsNullOrEmpty(v))
+                        statisticsFilePath = v;
+                } },
         };
             var assemblyPaths = Parse (p, args, "update",
                     "[OPTIONS]+ ASSEMBLIES",
@@ -235,6 +255,17 @@ namespace Mono.Documentation
                                   })
                                   .Where (f => Directory.Exists (f.Path));
 
+                oldFrameworkXmls = fxconfig.Root
+                                               .Elements("Framework")
+                                               .Select(f => new
+                                               {
+                                                   Name = f.Attribute("Name").Value,
+                                                   Source = f.Attribute("Source").Value,
+                                                   XmlPath = Path.Combine(srcPath, "FrameworksIndex", f.Attribute("Source").Value + ".xml"),
+                                               })
+                                               .Where(f => File.Exists(f.XmlPath))
+                                               .Select(f => XDocument.Load(f.XmlPath));
+
                 Func<string, string, IEnumerable<string>> getFiles = (string path, string filters) =>
                 {
                     return filters
@@ -327,6 +358,18 @@ namespace Mono.Documentation
             if (!string.IsNullOrWhiteSpace (FrameworksPath))
                 frameworks.WriteToDisk (srcPath);
 
+            if (statisticsEnabled)
+            {
+                try
+                {
+                    StatisticsSaver.Save(statisticsCollector, statisticsFilePath);
+                }
+                catch (Exception exception)
+                {
+                    Warning($"Unable to save statistics file: {exception.Message}");
+                }
+            }
+
             Console.WriteLine ("Members Added: {0}, Members Deleted: {1}", additions, deletions);
         }
 
@@ -554,6 +597,10 @@ namespace Mono.Documentation
                 {
                     foreach (AssemblyDefinition assembly in assemblySet.Assemblies)
                     {
+                        var typeSet = new HashSet<string> ();
+                        var namespacesSet = new HashSet<string> ();
+                        memberSet = new HashSet<string> ();
+
                         var frameworkEntry = frameworks.StartProcessingAssembly (assembly, assemblySet.Importers);
 
                         foreach (TypeDefinition type in docEnum.GetDocumentationTypes (assembly, typenames))
@@ -571,7 +618,14 @@ namespace Mono.Documentation
 
                             index.Add (assembly);
                             index.Add (type);
+
+                            namespacesSet.Add (type.Namespace);
+                            typeSet.Add (type.FullName);
                         }
+
+                        statisticsCollector.AddMetric (frameworkEntry.Name, StatisticsItem.Types, StatisticsMetrics.Total, typeSet.Count);
+                        statisticsCollector.AddMetric (frameworkEntry.Name, StatisticsItem.Namespaces, StatisticsMetrics.Total, namespacesSet.Count);
+                        statisticsCollector.AddMetric (frameworkEntry.Name, StatisticsItem.Members, StatisticsMetrics.Total, memberSet.Count);
                     }
                 }
             }
@@ -579,6 +633,7 @@ namespace Mono.Documentation
             if (index != null)
                 index.Write ();
 
+
             if (ignore_missing_types)
                 return;
 
@@ -664,8 +719,8 @@ namespace Mono.Documentation
 
             // Find the file, if it exists
             string[] searchLocations = new string[] {
-            nsname
-        };
+                nsname
+            };
 
             if (MDocUpdater.HasDroppedNamespace (type))
             {
@@ -914,8 +969,11 @@ namespace Mono.Documentation
 
         private void DoUpdateAssembly (AssemblySet assemblySet, AssemblyDefinition assembly, XmlElement index_types, string source, string dest, HashSet<string> goodfiles)
         {
-            var frameworkEntry = frameworks.StartProcessingAssembly (assembly, assemblySet.Importers);
+            var namespacesSet = new HashSet<string> ();
+            var typeSet = new HashSet<string> ();
+            memberSet = new HashSet<string> ();
 
+            var frameworkEntry = frameworks.StartProcessingAssembly (assembly, assemblySet.Importers);
             foreach (TypeDefinition type in docEnum.GetDocumentationTypes (assembly, null))
             {
                 string typename = GetTypeFileName (type);
@@ -939,6 +997,7 @@ namespace Mono.Documentation
                 }
                 string onsdoc = DocUtils.PathCombine (dest, namespaceToUse + ".xml");
                 string nsdoc = DocUtils.PathCombine (dest, "ns-" + namespaceToUse + ".xml");
+                namespacesSet.Add (namespaceToUse);
                 if (File.Exists (onsdoc))
                 {
                     File.Move (onsdoc, nsdoc);
@@ -946,12 +1005,17 @@ namespace Mono.Documentation
 
                 if (!File.Exists (nsdoc))
                 {
+                    statisticsCollector.AddMetric (frameworkEntry.Name, StatisticsItem.Namespaces, StatisticsMetrics.Added);
                     Console.WriteLine ("New Namespace File: " + type.Namespace);
                     WriteNamespaceStub (namespaceToUse, dest);
                 }
 
                 goodfiles.Add (reltypepath);
+                typeSet.Add (type.FullName);
             }
+            statisticsCollector.AddMetric (frameworkEntry.Name, StatisticsItem.Types, StatisticsMetrics.Total, typeSet.Count);
+            statisticsCollector.AddMetric (frameworkEntry.Name, StatisticsItem.Namespaces, StatisticsMetrics.Total, namespacesSet.Count);
+            statisticsCollector.AddMetric (frameworkEntry.Name, StatisticsItem.Members, StatisticsMetrics.Total, memberSet.Count);
         }
 
         private static void SortIndexEntries (XmlElement indexTypes)
@@ -1068,6 +1132,7 @@ namespace Mono.Documentation
                         XmlDocument doc = new XmlDocument ();
                         doc.Load (typefile.FullName);
                         XmlElement e = doc.SelectSingleNode ("/Type") as XmlElement;
+                        var typeFullName = e.GetAttribute("FullName");
                         var assemblyNameNode = doc.SelectSingleNode ("/Type/AssemblyInfo/AssemblyName");
                         if (assemblyNameNode == null)
                         {
@@ -1102,6 +1167,23 @@ namespace Mono.Documentation
                             try { System.IO.File.Delete (newname); } catch (Exception) { Warning ("Unable to delete existing file: {0}", newname); }
                             try { typefile.MoveTo (newname); } catch (Exception) { Warning ("Unable to rename to: {0}", newname); }
                             Console.WriteLine ("Class no longer present; file renamed: " + Path.Combine (nsdir.Name, typefile.Name));
+
+                            // Here we don't know the framwork which contained the removed type. So, we determine it by the old frameworks XML-file
+                            // If there is only one framework, use it as a default value
+                            var defaultFramework = frameworks.Frameworks.SingleOrDefault();
+                            // If there is no frameworks (no frameworks mode) or there is more than one framework
+                            if (defaultFramework == null)
+                                // Use FrameworkEntry.Empty as the default value (as well as in FrameworkIndex/StartProcessingAssembly)
+                                defaultFramework = FrameworkEntry.Empty;
+                            var frameworkName = defaultFramework.Name;
+                            // Try to find the removed type in the old frameworks XML-file
+                            var frameworkXml = oldFrameworkXmls?.FirstOrDefault
+                                (i => i.XPathSelectElements($"Framework/Namespace/Type[@Name='{typeFullName}']").Any());
+                            var frameworkNameAttribute = frameworkXml?.Root?.Attribute ("Name");
+                            // If the removed type is found in the old frameworks XML-file, use this framework name
+                            if (frameworkNameAttribute != null)
+                                frameworkName = frameworkNameAttribute.Value;
+                            statisticsCollector.AddMetric (frameworkName, StatisticsItem.Types, StatisticsMetrics.Removed);
                         };
 
                         if (string.IsNullOrWhiteSpace (PreserveTag))
@@ -1242,7 +1324,6 @@ namespace Mono.Documentation
         public void DoUpdateType2 (string message, XmlDocument basefile, TypeDefinition type, FrameworkTypeEntry typeEntry, string output, bool insertSince)
         {
             Console.WriteLine (message + ": " + type.FullName);
-
             StringToXmlNodeMap seenmembers = new StringToXmlNodeMap ();
 
             // Update type metadata
@@ -1308,6 +1389,7 @@ namespace Mono.Documentation
                         continue;
 
                     DeleteMember ("Member Removed", output, oldmember, todelete, type);
+                    statisticsCollector.AddMetric(typeEntry.Framework.Name, StatisticsItem.Members, StatisticsMetrics.Removed);
                     continue;
                 }
 
@@ -1319,13 +1401,16 @@ namespace Mono.Documentation
                         // ignore, already seen
                     }
                     else
+                    {
                         DeleteMember ("Duplicate Member Found", output, oldmember, todelete, type);
-
+                        statisticsCollector.AddMetric(typeEntry.Framework.Name, StatisticsItem.Members, StatisticsMetrics.Removed);
+                    }
                     continue;
                 }
 
                 // Update signature information
                 UpdateMember (info, typeEntry);
+                memberSet.Add (info.Member.FullName);
 
                 // get all apistyles of sig from info.Node
                 var styles = oldmember.GetElementsByTagName ("MemberSignature").Cast<XmlElement> ()
@@ -1394,6 +1479,8 @@ namespace Mono.Documentation
                         mm.AddApiStyle (ApiStyle.Unified);
                     }
 
+                    statisticsCollector.AddMetric (typeEntry.Framework.Name, StatisticsItem.Members, StatisticsMetrics.Added);
+                    memberSet.Add (m.FullName);
                     Console.WriteLine ("Member Added: " + mm.SelectSingleNode ("MemberSignature/@Value").InnerText);
                     additions++;
                 }
@@ -1686,6 +1773,7 @@ namespace Mono.Documentation
             var frameworkEntry = frameworks.StartProcessingAssembly (type.Module.Assembly, importers);
             var typeEntry = frameworkEntry.ProcessType (type);
             DoUpdateType2 ("New Type", doc, type, typeEntry, output, true);
+            statisticsCollector.AddMetric (typeEntry.Framework.Name, StatisticsItem.Types, StatisticsMetrics.Added);
 
             return root;
         }
diff --git a/mdoc/Mono.Documentation/Updater/Statistics/StatisticsCollector.cs b/mdoc/Mono.Documentation/Updater/Statistics/StatisticsCollector.cs
new file mode 100644
index 00000000..c5200f10
--- /dev/null
+++ b/mdoc/Mono.Documentation/Updater/Statistics/StatisticsCollector.cs
@@ -0,0 +1,33 @@
+using System.Collections.Generic;
+
+namespace Mono.Documentation.Updater.Statistics
+{
+    /// <summary>
+    /// The class stores statistics for different frameworks
+    /// </summary>
+    public class StatisticsCollector
+    {
+        /// <summary>
+        /// Collected statistics for each framework
+        /// </summary>
+        public Dictionary<string, StatisticsStorage> Storages { get; } =
+            new Dictionary<string, StatisticsStorage>();
+
+        /// <summary>
+        /// Change metric value for the item
+        /// </summary>
+        /// <param name="framework">The framework name which statistics is being collected</param>
+        /// <param name="item">The item which metrics value is changing</param>
+        /// <param name="metrics">The metrics which value is changing</param>
+        /// <param name="delta">The value by which the metrics value should be changed</param>
+        public void AddMetric(string framework, StatisticsItem item, StatisticsMetrics metrics, int delta = 1)
+        {
+            if (!Storages.ContainsKey(framework))
+            {
+                Storages[framework] = new StatisticsStorage();
+            }
+
+            Storages[framework].AddMetric(item, metrics, delta);
+        }
+    }
+}
\ No newline at end of file
diff --git a/mdoc/Mono.Documentation/Updater/Statistics/StatisticsFormatter.cs b/mdoc/Mono.Documentation/Updater/Statistics/StatisticsFormatter.cs
new file mode 100644
index 00000000..430807c4
--- /dev/null
+++ b/mdoc/Mono.Documentation/Updater/Statistics/StatisticsFormatter.cs
@@ -0,0 +1,31 @@
+using System.Collections.Generic;
+using System.Text;
+
+namespace Mono.Documentation.Updater.Statistics
+{
+    public static class StatisticsFormatter
+    {
+        public static string Format(Dictionary<string, StatisticsStorage> input)
+        {
+            var result = new StringBuilder();
+            foreach (var statisticsStoragePair in input)
+            {
+                var framework = statisticsStoragePair.Key;
+                var statisticsStorage = statisticsStoragePair.Value;
+                result.AppendLine($"Framework: {framework}");
+                result.AppendLine("--------");
+                foreach (var statistics in statisticsStorage.Values)
+                {
+                    var staticsItem = statistics.Key;
+                    foreach (var statisticsValuePair in statistics.Value)
+                    {
+                        result.AppendLine($"{staticsItem} {statisticsValuePair.Key}: {statisticsValuePair.Value}");
+                    }
+                    result.AppendLine();
+                }
+            }
+
+            return result.ToString();
+        }
+    }
+}
\ No newline at end of file
diff --git a/mdoc/Mono.Documentation/Updater/Statistics/StatisticsItem.cs b/mdoc/Mono.Documentation/Updater/Statistics/StatisticsItem.cs
new file mode 100644
index 00000000..68ff2e22
--- /dev/null
+++ b/mdoc/Mono.Documentation/Updater/Statistics/StatisticsItem.cs
@@ -0,0 +1,9 @@
+namespace Mono.Documentation.Updater.Statistics
+{
+    public enum StatisticsItem
+    {
+        Types,
+        Namespaces,
+        Members
+    }
+}
\ No newline at end of file
diff --git a/mdoc/Mono.Documentation/Updater/Statistics/StatisticsMetrics.cs b/mdoc/Mono.Documentation/Updater/Statistics/StatisticsMetrics.cs
new file mode 100644
index 00000000..cef043d7
--- /dev/null
+++ b/mdoc/Mono.Documentation/Updater/Statistics/StatisticsMetrics.cs
@@ -0,0 +1,9 @@
+namespace Mono.Documentation.Updater.Statistics
+{
+    public enum StatisticsMetrics
+    {
+        Added,
+        Removed,
+        Total
+    }
+}
\ No newline at end of file
diff --git a/mdoc/Mono.Documentation/Updater/Statistics/StatisticsSaver.cs b/mdoc/Mono.Documentation/Updater/Statistics/StatisticsSaver.cs
new file mode 100644
index 00000000..d8c9cc23
--- /dev/null
+++ b/mdoc/Mono.Documentation/Updater/Statistics/StatisticsSaver.cs
@@ -0,0 +1,23 @@
+using System;
+using System.IO;
+
+namespace Mono.Documentation.Updater.Statistics
+{
+    public static class StatisticsSaver
+    {
+        private const string DefaltStatisticsFileName = "statistics.txt";
+
+        /// <summary>
+        /// Save statistics to the file
+        /// </summary>
+        /// <param name="statisticsCollector">Statistics values which should be saved</param>
+        /// <param name="statisticsFilePath">Path to the file where statistics should be saved</param>
+        public static void Save(StatisticsCollector statisticsCollector, string statisticsFilePath)
+        {
+            if (Directory.Exists(statisticsFilePath))
+                statisticsFilePath = Path.Combine(statisticsFilePath, DefaltStatisticsFileName);
+            File.WriteAllText(statisticsFilePath, StatisticsFormatter.Format(statisticsCollector.Storages));
+            Console.WriteLine($"Statistics saved to {statisticsFilePath}");
+        }
+    }
+}
\ No newline at end of file
diff --git a/mdoc/Mono.Documentation/Updater/Statistics/StatisticsStorage.cs b/mdoc/Mono.Documentation/Updater/Statistics/StatisticsStorage.cs
new file mode 100644
index 00000000..d7bac0da
--- /dev/null
+++ b/mdoc/Mono.Documentation/Updater/Statistics/StatisticsStorage.cs
@@ -0,0 +1,30 @@
+using System;
+using System.Collections.Generic;
+
+namespace Mono.Documentation.Updater.Statistics
+{
+    /// <summary>
+    /// The class stores statistics: int value for each StatisticsItem-StatisticsMetrics pair
+    /// </summary>
+    public class StatisticsStorage
+    {
+        public Dictionary<StatisticsItem, Dictionary<StatisticsMetrics, int>> Values { get; } = new Dictionary<StatisticsItem, Dictionary<StatisticsMetrics, int>>();
+
+        public StatisticsStorage()
+        {
+            foreach (var statisticsItem in Enum.GetValues(typeof(StatisticsItem)))
+            {
+                var metrics = Values[(StatisticsItem)statisticsItem] = new Dictionary<StatisticsMetrics, int>();
+                foreach (var statisticsMetrics in Enum.GetValues(typeof(StatisticsMetrics)))
+                {
+                    metrics[(StatisticsMetrics) statisticsMetrics] = 0;
+                }
+            }
+        }
+
+        public void AddMetric(StatisticsItem item, StatisticsMetrics metrics, int delta = 1)
+        {
+            Values[item][metrics] += delta;
+        }
+    }
+}
\ No newline at end of file
diff --git a/mdoc/Test/expected_fx_remove_statistics.txt b/mdoc/Test/expected_fx_remove_statistics.txt
new file mode 100644
index 00000000..82b80e4d
--- /dev/null
+++ b/mdoc/Test/expected_fx_remove_statistics.txt
@@ -0,0 +1,14 @@
+Framework: One
+--------
+Types Added: 0
+Types Removed: 1
+Types Total: 2
+
+Namespaces Added: 0
+Namespaces Removed: 0
+Namespaces Total: 1
+
+Members Added: 0
+Members Removed: 5
+Members Total: 5
+
diff --git a/mdoc/Test/expected_remove_statistics.txt b/mdoc/Test/expected_remove_statistics.txt
new file mode 100644
index 00000000..6ba550d0
--- /dev/null
+++ b/mdoc/Test/expected_remove_statistics.txt
@@ -0,0 +1,14 @@
+Framework: Empty
+--------
+Types Added: 0
+Types Removed: 1
+Types Total: 3
+
+Namespaces Added: 0
+Namespaces Removed: 0
+Namespaces Total: 1
+
+Members Added: 1
+Members Removed: 6
+Members Total: 10
+
diff --git a/mdoc/Test/expected_statistics.txt b/mdoc/Test/expected_statistics.txt
new file mode 100644
index 00000000..aea1339d
--- /dev/null
+++ b/mdoc/Test/expected_statistics.txt
@@ -0,0 +1,28 @@
+Framework: one
+--------
+Types Added: 31
+Types Removed: 0
+Types Total: 31
+
+Namespaces Added: 4
+Namespaces Removed: 0
+Namespaces Total: 4
+
+Members Added: 127
+Members Removed: 0
+Members Total: 127
+
+Framework: two
+--------
+Types Added: 3
+Types Removed: 0
+Types Total: 3
+
+Namespaces Added: 2
+Namespaces Removed: 0
+Namespaces Total: 2
+
+Members Added: 9
+Members Removed: 0
+Members Total: 9
+
diff --git a/mdoc/Test/fx-statistics-remove-configuration.xml b/mdoc/Test/fx-statistics-remove-configuration.xml
new file mode 100644
index 00000000..47c3a1f5
--- /dev/null
+++ b/mdoc/Test/fx-statistics-remove-configuration.xml
@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Frameworks>
+  <Framework Name="One" Source="One">
+    <assemblySearchPath>One</assemblySearchPath>
+  </Framework>
+</Frameworks>
\ No newline at end of file
diff --git a/mdoc/mdoc.Test/StatisticsTests.cs b/mdoc/mdoc.Test/StatisticsTests.cs
new file mode 100644
index 00000000..222e2ea0
--- /dev/null
+++ b/mdoc/mdoc.Test/StatisticsTests.cs
@@ -0,0 +1,88 @@
+using System.Collections.Generic;
+using NUnit.Framework;
+
+using Mono.Documentation.Updater.Statistics;
+
+namespace mdoc.Test
+{
+    [TestFixture()]
+    public class StatisticsTests
+    {
+        const string FRAMEWORK_NAME = "frameworkName";
+        
+        [Test()]
+        public void StatisticsStorage_Increment()
+        {
+            var statisticsStorage = new StatisticsStorage();
+
+            statisticsStorage.AddMetric(StatisticsItem.Members, StatisticsMetrics.Added);
+
+            Assert.AreEqual(statisticsStorage.Values[StatisticsItem.Members][StatisticsMetrics.Added], 1);
+            Assert.AreEqual(statisticsStorage.Values[StatisticsItem.Members][StatisticsMetrics.Removed], 0);
+            Assert.AreEqual(statisticsStorage.Values[StatisticsItem.Namespaces][StatisticsMetrics.Added], 0);
+            Assert.AreEqual(statisticsStorage.Values[StatisticsItem.Namespaces][StatisticsMetrics.Removed], 0);
+        }
+
+        [Test()]
+        public void StatisticsStorage_ManyIncrements()
+        {
+            var statisticsStorage = new StatisticsStorage();
+
+            statisticsStorage.AddMetric(StatisticsItem.Members, StatisticsMetrics.Added);
+            statisticsStorage.AddMetric(StatisticsItem.Members, StatisticsMetrics.Added);
+            statisticsStorage.AddMetric(StatisticsItem.Members, StatisticsMetrics.Added);
+
+            Assert.AreEqual(statisticsStorage.Values[StatisticsItem.Members][StatisticsMetrics.Added], 3);
+            Assert.AreEqual(statisticsStorage.Values[StatisticsItem.Members][StatisticsMetrics.Removed], 0);
+            Assert.AreEqual(statisticsStorage.Values[StatisticsItem.Namespaces][StatisticsMetrics.Added], 0);
+            Assert.AreEqual(statisticsStorage.Values[StatisticsItem.Namespaces][StatisticsMetrics.Removed], 0);
+        }
+
+        [Test()]
+        public void StatisticsStorage_IncrementDelta()
+        {
+            var statisticsStorage = new StatisticsStorage();
+
+            statisticsStorage.AddMetric(StatisticsItem.Members, StatisticsMetrics.Added, 5);
+
+            Assert.AreEqual(statisticsStorage.Values[StatisticsItem.Members][StatisticsMetrics.Added], 5);
+            Assert.AreEqual(statisticsStorage.Values[StatisticsItem.Members][StatisticsMetrics.Removed], 0);
+            Assert.AreEqual(statisticsStorage.Values[StatisticsItem.Namespaces][StatisticsMetrics.Added], 0);
+            Assert.AreEqual(statisticsStorage.Values[StatisticsItem.Namespaces][StatisticsMetrics.Removed], 0);
+        }
+
+        [Test()]
+        public void StatisticsCollector_Increment()
+        {
+            var statisticsCollector = new StatisticsCollector();
+
+            statisticsCollector.AddMetric(FRAMEWORK_NAME, StatisticsItem.Members, StatisticsMetrics.Added);
+
+            Assert.AreEqual(
+                statisticsCollector.Storages[FRAMEWORK_NAME].Values[StatisticsItem.Members][StatisticsMetrics.Added], 1);
+            Assert.AreEqual(
+                statisticsCollector.Storages[FRAMEWORK_NAME].Values[StatisticsItem.Members][StatisticsMetrics.Removed], 0);
+            Assert.AreEqual(
+                statisticsCollector.Storages[FRAMEWORK_NAME].Values[StatisticsItem.Namespaces][StatisticsMetrics.Added], 0);
+            Assert.AreEqual(
+                statisticsCollector.Storages[FRAMEWORK_NAME].Values[StatisticsItem.Namespaces][StatisticsMetrics.Removed], 0);
+        }
+
+        [Test()]
+        public void StatisticsCollector_IncrementDelta()
+        {
+            var statisticsCollector = new StatisticsCollector();
+
+            statisticsCollector.AddMetric(FRAMEWORK_NAME, StatisticsItem.Members, StatisticsMetrics.Added, 7);
+
+            Assert.AreEqual(
+                statisticsCollector.Storages[FRAMEWORK_NAME].Values[StatisticsItem.Members][StatisticsMetrics.Added], 7);
+            Assert.AreEqual(
+                statisticsCollector.Storages[FRAMEWORK_NAME].Values[StatisticsItem.Members][StatisticsMetrics.Removed], 0);
+            Assert.AreEqual(
+                statisticsCollector.Storages[FRAMEWORK_NAME].Values[StatisticsItem.Namespaces][StatisticsMetrics.Added], 0);
+            Assert.AreEqual(
+                statisticsCollector.Storages[FRAMEWORK_NAME].Values[StatisticsItem.Namespaces][StatisticsMetrics.Removed], 0);
+        }
+    }
+}
\ No newline at end of file
diff --git a/mdoc/mdoc.Test/mdoc.Test.csproj b/mdoc/mdoc.Test/mdoc.Test.csproj
index 1278af31..a610b28f 100644
--- a/mdoc/mdoc.Test/mdoc.Test.csproj
+++ b/mdoc/mdoc.Test/mdoc.Test.csproj
@@ -1,77 +1,78 @@
-<?xml version="1.0" encoding="utf-8"?>

-<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">

-  <PropertyGroup>

-    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>

-    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>

-    <ProjectGuid>{5ADDEFB6-930C-46BC-8B2B-FDE5C7E3B5AD}</ProjectGuid>

-    <OutputType>Library</OutputType>

-    <RootNamespace>mdoc.Test</RootNamespace>

-    <AssemblyName>mdoc.Test</AssemblyName>

-    <TargetFrameworkVersion>v4.6.1</TargetFrameworkVersion>

-  </PropertyGroup>

-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">

-    <DebugSymbols>true</DebugSymbols>

-    <DebugType>full</DebugType>

-    <Optimize>false</Optimize>

-    <OutputPath>bin\Debug</OutputPath>

-    <DefineConstants>DEBUG;</DefineConstants>

-    <ErrorReport>prompt</ErrorReport>

-    <WarningLevel>4</WarningLevel>

-  </PropertyGroup>

-  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">

-    <Optimize>true</Optimize>

-    <OutputPath>bin\Release</OutputPath>

-    <ErrorReport>prompt</ErrorReport>

-    <WarningLevel>4</WarningLevel>

-  </PropertyGroup>

-  <ItemGroup>

-    <Reference Include="System" />

-    <Reference Include="nunit.framework">

-      <HintPath>..\..\packages\NUnit.2.6.4\lib\nunit.framework.dll</HintPath>

-    </Reference>

-        <Reference Include="Mono.Cecil, Version=0.10.0.0, Culture=neutral, PublicKeyToken=50cebf1cceb9d05e, processorArchitecture=MSIL">

-      <HintPath>..\..\packages\Mono.Cecil.0.10.0-beta5\lib\net40\Mono.Cecil.dll</HintPath>

-    </Reference>

-    <Reference Include="Mono.Cecil.Mdb, Version=0.10.0.0, Culture=neutral, PublicKeyToken=50cebf1cceb9d05e, processorArchitecture=MSIL">

-      <HintPath>..\..\packages\Mono.Cecil.0.10.0-beta5\lib\net40\Mono.Cecil.Mdb.dll</HintPath>

-    </Reference>

-    <Reference Include="Mono.Cecil.Pdb, Version=0.10.0.0, Culture=neutral, PublicKeyToken=50cebf1cceb9d05e, processorArchitecture=MSIL">

-      <HintPath>..\..\packages\Mono.Cecil.0.10.0-beta5\lib\net40\Mono.Cecil.Pdb.dll</HintPath>

-    </Reference>

-    <Reference Include="Mono.Cecil.Rocks, Version=0.10.0.0, Culture=neutral, PublicKeyToken=50cebf1cceb9d05e, processorArchitecture=MSIL">

-      <HintPath>..\..\packages\Mono.Cecil.0.10.0-beta5\lib\net40\Mono.Cecil.Rocks.dll</HintPath>

-    </Reference>

-  </ItemGroup>

-  <ItemGroup>

-    <Compile Include="FormatterTests.cs" />

-    <Compile Include="SampleClasses\TestClass.cs" />

-    <Compile Include="SampleClasses\TestPrivateClass.cs" />

-    <Compile Include="SampleClasses\TestClassTwo.cs" />

-  </ItemGroup>

-  <ItemGroup>

-    <None Include="packages.config" />

-    <None Include="cppcli\cppcli\cppcli.h">

-      <Link>SampleClasses\cppcli.h</Link>

-    </None>

-  </ItemGroup>

-  <ItemGroup>

-    <ProjectReference Include="..\mdoc.csproj">

-      <Project>{7DA7CD97-614F-4BCD-A2FA-B379590CEA48}</Project>

-      <Name>mdoc</Name>

-    </ProjectReference>

-    <ProjectReference Include="..\..\monodoc\monodoc.csproj">

-      <Project>{6E644802-B579-4037-9809-9CF4C7172C9D}</Project>

-      <Name>monodoc</Name>

-    </ProjectReference>

-  </ItemGroup>

+<?xml version="1.0" encoding="utf-8"?>
+<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <ProjectGuid>{5ADDEFB6-930C-46BC-8B2B-FDE5C7E3B5AD}</ProjectGuid>
+    <OutputType>Library</OutputType>
+    <RootNamespace>mdoc.Test</RootNamespace>
+    <AssemblyName>mdoc.Test</AssemblyName>
+    <TargetFrameworkVersion>v4.6.1</TargetFrameworkVersion>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
+    <DebugSymbols>true</DebugSymbols>
+    <DebugType>full</DebugType>
+    <Optimize>false</Optimize>
+    <OutputPath>bin\Debug</OutputPath>
+    <DefineConstants>DEBUG;</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
+    <Optimize>true</Optimize>
+    <OutputPath>bin\Release</OutputPath>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <ItemGroup>
+    <Reference Include="System" />
+    <Reference Include="nunit.framework">
+      <HintPath>..\..\packages\NUnit.2.6.4\lib\nunit.framework.dll</HintPath>
+    </Reference>
+    <Reference Include="Mono.Cecil, Version=0.10.0.0, Culture=neutral, PublicKeyToken=50cebf1cceb9d05e, processorArchitecture=MSIL">
+      <HintPath>..\..\packages\Mono.Cecil.0.10.0-beta5\lib\net40\Mono.Cecil.dll</HintPath>
+    </Reference>
+    <Reference Include="Mono.Cecil.Mdb, Version=0.10.0.0, Culture=neutral, PublicKeyToken=50cebf1cceb9d05e, processorArchitecture=MSIL">
+      <HintPath>..\..\packages\Mono.Cecil.0.10.0-beta5\lib\net40\Mono.Cecil.Mdb.dll</HintPath>
+    </Reference>
+    <Reference Include="Mono.Cecil.Pdb, Version=0.10.0.0, Culture=neutral, PublicKeyToken=50cebf1cceb9d05e, processorArchitecture=MSIL">
+      <HintPath>..\..\packages\Mono.Cecil.0.10.0-beta5\lib\net40\Mono.Cecil.Pdb.dll</HintPath>
+    </Reference>
+    <Reference Include="Mono.Cecil.Rocks, Version=0.10.0.0, Culture=neutral, PublicKeyToken=50cebf1cceb9d05e, processorArchitecture=MSIL">
+      <HintPath>..\..\packages\Mono.Cecil.0.10.0-beta5\lib\net40\Mono.Cecil.Rocks.dll</HintPath>
+    </Reference>
+  </ItemGroup>
+  <ItemGroup>
+    <Compile Include="FormatterTests.cs" />
+    <Compile Include="SampleClasses\TestClass.cs" />
+    <Compile Include="SampleClasses\TestPrivateClass.cs" />
+    <Compile Include="SampleClasses\TestClassTwo.cs" />
+    <Compile Include="StatisticsTests.cs" />
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="packages.config" />
+    <None Include="cppcli\cppcli\cppcli.h">
+      <Link>SampleClasses\cppcli.h</Link>
+    </None>
+  </ItemGroup>
+  <ItemGroup>
+    <ProjectReference Include="..\mdoc.csproj">
+      <Project>{7DA7CD97-614F-4BCD-A2FA-B379590CEA48}</Project>
+      <Name>mdoc</Name>
+    </ProjectReference>
+    <ProjectReference Include="..\..\monodoc\monodoc.csproj">
+      <Project>{6E644802-B579-4037-9809-9CF4C7172C9D}</Project>
+      <Name>monodoc</Name>
+    </ProjectReference>
+  </ItemGroup>
   <ItemGroup>

     <Folder Include="SampleClasses\" />

   </ItemGroup>

-  <ItemGroup>

-    <Content Include="cppcli\Debug\cppcli.dll">

-      <Link>SampleClasses\cppcli.dll</Link>

-      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>

-    </Content>

-  </ItemGroup>

-  <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />

+  <ItemGroup>
+    <Content Include="cppcli\Debug\cppcli.dll">
+      <Link>SampleClasses\cppcli.dll</Link>
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </Content>
+  </ItemGroup>
+  <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />
 </Project>
\ No newline at end of file
diff --git a/mdoc/mdoc.csproj b/mdoc/mdoc.csproj
index a1b2ea59..bcf3a3a5 100644
--- a/mdoc/mdoc.csproj
+++ b/mdoc/mdoc.csproj
@@ -77,6 +77,12 @@
     <Compile Include="Mono.Documentation\Updater\EcmaDocumentationEnumerator.cs" />

     <Compile Include="Mono.Documentation\Updater\DocumentationEnumerator.cs" />

     <Compile Include="Mono.Documentation\Updater\DocsNodeInfo.cs" />

+    <Compile Include="Mono.Documentation\Updater\Statistics\StatisticsCollector.cs" />

+    <Compile Include="Mono.Documentation\Updater\Statistics\StatisticsFormatter.cs" />

+    <Compile Include="Mono.Documentation\Updater\Statistics\StatisticsItem.cs" />

+    <Compile Include="Mono.Documentation\Updater\Statistics\StatisticsMetrics.cs" />

+    <Compile Include="Mono.Documentation\Updater\Statistics\StatisticsSaver.cs" />

+    <Compile Include="Mono.Documentation\Updater\Statistics\StatisticsStorage.cs" />

     <Compile Include="Mono.Documentation\Util\ApiStyle.cs" />

     <Compile Include="Mono.Documentation\Updater\DocUtils.cs" />

     <Compile Include="Mono.Documentation\Util\CecilExtensions.cs" />