Background analysis support

src/OmniSharp.Abstractions/Models/Events/EventTypes.cs

@@ -11,5 +11,7 @@ public static class EventTypes
         public const string PackageRestoreFinished = nameof(PackageRestoreFinished);
         public const string UnresolvedDependencies = nameof(UnresolvedDependencies);
         public const string ProjectConfiguration = nameof(ProjectConfiguration);
+        public const string ProjectDiagnosticStatus = nameof(ProjectDiagnosticStatus);
+
     }
 }

src/OmniSharp.Abstractions/Models/Events/ProjectAnalyzeStatusMessage.cs

@@ -0,0 +1,9 @@
+namespace OmniSharp.Models.Events
+{
+    public class ProjectDiagnosticStatusMessage
+    {
+        public ProjectDiagnosticStatus Status { get; set; }
+        public string ProjectFilePath { get; set; }
+        public string Type = "background";
+    }
+}

src/OmniSharp.Abstractions/Models/Events/ProjectDiagnosticStatus.cs

@@ -0,0 +1,8 @@
+namespace OmniSharp.Models.Events
+{
+    public enum ProjectDiagnosticStatus
+    {
+        Started = 0,
+        Ready = 1
+    }
+}

src/OmniSharp.Abstractions/Models/v1/ReAnalyze/ReanalyzeRequest.cs

@@ -0,0 +1,13 @@
+using OmniSharp.Mef;
+using OmniSharp.Models;
+
+namespace OmniSharp.Abstractions.Models.V1.ReAnalyze
+{
+    [OmniSharpEndpoint(OmniSharpEndpoints.ReAnalyze, typeof(ReAnalyzeRequest), typeof(ReanalyzeResponse))]
+    public class ReAnalyzeRequest: IRequest
+    {
+        // This document path is used as context to resolve which project should be analyzed. Simplifies
+        // clients since they don't have to figure out what is correct project for current open file.
+        public string CurrentOpenFilePathAsContext { get; set; }
+    }
+}

src/OmniSharp.Abstractions/Models/v1/ReAnalyze/ReanalyzeResponse.cs

@@ -0,0 +1,9 @@
+using OmniSharp.Models;
+
+namespace OmniSharp.Abstractions.Models.V1.ReAnalyze
+{
+    public class ReanalyzeResponse : IAggregateResponse
+    {
+        public IAggregateResponse Merge(IAggregateResponse response) { return response; }
+    }
+}

src/OmniSharp.Abstractions/OmniSharpEndpoints.cs

@@ -43,6 +43,8 @@ public static class OmniSharpEndpoints
         public const string Close = "/close";
         public const string Diagnostics = "/diagnostics";
 
+        public const string ReAnalyze = "/reanalyze";
+
         public static class V2
         {
             public const string GetCodeActions = "/v2/getcodeactions";

src/OmniSharp.Roslyn.CSharp/Services/Diagnostics/ReAnalyzeService.cs

@@ -0,0 +1,81 @@
+using System;
+using System.Collections.Immutable;
+using System.Composition;
+using System.IO;
+using System.Linq;
+using System.Threading.Tasks;
+using Microsoft.CodeAnalysis;
+using Microsoft.Extensions.Logging;
+using OmniSharp.Abstractions.Models.V1.ReAnalyze;
+using OmniSharp.Mef;
+using OmniSharp.Models;
+using OmniSharp.Models.Diagnostics;
+using OmniSharp.Roslyn.CSharp.Workers.Diagnostics;
+
+namespace OmniSharp.Roslyn.CSharp.Services.Diagnostics
+{
+    [OmniSharpHandler(OmniSharpEndpoints.ReAnalyze, LanguageNames.CSharp)]
+    public class ReAnalyzeService : IRequestHandler<ReAnalyzeRequest, ReanalyzeResponse>
+    {
+        private readonly ICsDiagnosticWorker _diagWorker;
+        private readonly OmniSharpWorkspace _workspace;
+        private readonly ILogger<ReAnalyzeService> _logger;
+
+        [ImportingConstructor]
+        public ReAnalyzeService(ICsDiagnosticWorker diagWorker, OmniSharpWorkspace workspace, ILoggerFactory loggerFactory)
+        {
+            _diagWorker = diagWorker;
+            _workspace = workspace;
+            _logger = loggerFactory.CreateLogger<ReAnalyzeService>();
+        }
+
+        public Task<ReanalyzeResponse> Handle(ReAnalyzeRequest request)
+        {
+
+            if(!string.IsNullOrEmpty(request.CurrentOpenFilePathAsContext))
+            {
+                var currentSolution = _workspace.CurrentSolution;
+
+                var projectIds = WhenRequestIsProjectFileItselfGetFilesFromIt(request.CurrentOpenFilePathAsContext, currentSolution)
+                    ?? GetDocumentsFromProjectWhereDocumentIs(request.CurrentOpenFilePathAsContext, currentSolution);
+
+                _logger.LogInformation($"Queue analysis for project(s) {string.Join(", ", projectIds)}");
+
+                _diagWorker.QueueDocumentsOfProjectsForDiagnostics(projectIds);
+            }
+            else
+            {
+                _logger.LogInformation($"Queue analysis for all projects.");
+                _diagWorker.QueueAllDocumentsForDiagnostics();
+            }
+
+            return Task.FromResult(new ReanalyzeResponse());
+        }
+
+        private ImmutableArray<ProjectId>? WhenRequestIsProjectFileItselfGetFilesFromIt(string currentOpenFilePathAsContext, Solution currentSolution)
+        {
+            var projects = currentSolution.Projects.Where(x => CompareProjectPath(currentOpenFilePathAsContext, x)).Select(x => x.Id).ToImmutableArray();
+
+            if(!projects.Any())
+                return null;
+
+            return projects;
+        }
+
+        private static bool CompareProjectPath(string currentOpenFilePathAsContext, Project x)
+        {
+            return String.Compare(
+                x.FilePath,
+                currentOpenFilePathAsContext,
+                StringComparison.InvariantCultureIgnoreCase) == 0;
+        }
+
+        private static ImmutableArray<ProjectId> GetDocumentsFromProjectWhereDocumentIs(string currentOpenFilePathAsContext, Solution currentSolution)
+        {
+            return currentSolution
+                .GetDocumentIdsWithFilePath(currentOpenFilePathAsContext)
+                .Select(docId => currentSolution.GetDocument(docId).Project.Id)
+                .ToImmutableArray();
+        }
+    }
+}

src/OmniSharp.Roslyn.CSharp/Workers/Diagnostics/AnalyzerWorkQueue.cs

@@ -12,98 +12,118 @@ namespace OmniSharp.Roslyn.CSharp.Workers.Diagnostics
 {
     public class AnalyzerWorkQueue
     {
-        private readonly int _throttlingMs = 300;
+        private class Queue
+        {
+            public Queue(TimeSpan throttling)
+            {
+                Throttling = throttling;
+            }
 
-        private readonly ConcurrentDictionary<DocumentId, (DateTime modified, CancellationTokenSource workDoneSource)> _workQueue =
-            new ConcurrentDictionary<DocumentId, (DateTime modified, CancellationTokenSource workDoneSource)>();
+            public ImmutableHashSet<DocumentId> WorkWaitingToExecute { get; set; } = ImmutableHashSet<DocumentId>.Empty;
+            public ImmutableHashSet<DocumentId> WorkExecuting { get; set; } = ImmutableHashSet<DocumentId>.Empty;
+            public DateTime LastThrottlingBegan { get; set; } = DateTime.UtcNow;
+            public TimeSpan Throttling { get; }
+            public CancellationTokenSource WorkPendingToken { get; set; }
+        }
 
-        private readonly ConcurrentDictionary<DocumentId, (DateTime modified,  CancellationTokenSource workDoneSource)> _currentWork =
-            new ConcurrentDictionary<DocumentId, (DateTime modified, CancellationTokenSource workDoneSource)>();
+        private readonly Dictionary<AnalyzerWorkType, Queue> _queues = null;
 
+        private readonly ILogger<AnalyzerWorkQueue> _logger;
         private readonly Func<DateTime> _utcNow;
         private readonly int _maximumDelayWhenWaitingForResults;
-        private readonly ILogger<AnalyzerWorkQueue> _logger;
+        private readonly object _queueLock = new Object();
 
-        public AnalyzerWorkQueue(ILoggerFactory loggerFactory, Func<DateTime> utcNow = null, int timeoutForPendingWorkMs = 15*1000)
+        public AnalyzerWorkQueue(ILoggerFactory loggerFactory, Func<DateTime> utcNow = null, int timeoutForPendingWorkMs = 15 * 1000)
         {
-            utcNow = utcNow ?? (() => DateTime.UtcNow);
+            _queues = new Dictionary<AnalyzerWorkType, Queue>
+            {
+                { AnalyzerWorkType.Foreground, new Queue(TimeSpan.FromMilliseconds(150)) },
+                { AnalyzerWorkType.Background, new Queue(TimeSpan.FromMilliseconds(1500)) }
+            };
+
             _logger = loggerFactory.CreateLogger<AnalyzerWorkQueue>();
-            _utcNow = utcNow;
+            _utcNow = utcNow ?? (() => DateTime.UtcNow);
             _maximumDelayWhenWaitingForResults = timeoutForPendingWorkMs;
         }
 
-        public void PutWork(DocumentId documentId)
+        public void PutWork(IReadOnlyCollection<DocumentId> documentIds, AnalyzerWorkType workType)
         {
-            _workQueue.AddOrUpdate(documentId,
-                (modified: DateTime.UtcNow, new CancellationTokenSource()),
-                (_, oldValue) => (modified: DateTime.UtcNow, oldValue.workDoneSource));
+            lock (_queueLock)
+            {
+                var queue = _queues[workType];
+
+                if (queue.WorkWaitingToExecute.IsEmpty)
+                    queue.LastThrottlingBegan = _utcNow();
+
+                if (queue.WorkPendingToken == null)
+                    queue.WorkPendingToken = new CancellationTokenSource();
+
+                queue.WorkWaitingToExecute = queue.WorkWaitingToExecute.Union(documentIds);
+            }
         }
 
-        public ImmutableArray<DocumentId> TakeWork()
+        public IReadOnlyCollection<DocumentId> TakeWork(AnalyzerWorkType workType)
         {
-            lock (_workQueue)
+            lock (_queueLock)
             {
-                var now = _utcNow();
-                var currentWork = _workQueue
-                    .Where(x => ThrottlingPeriodNotActive(x.Value.modified, now))
-                    .OrderByDescending(x => x.Value.modified)
-                    .Take(50)
-                    .ToImmutableArray();
-
-                foreach (var work in currentWork)
-                {
-                    _workQueue.TryRemove(work.Key, out _);
-                    _currentWork.TryAdd(work.Key, work.Value);
-                }
-
-                return currentWork.Select(x => x.Key).ToImmutableArray();
+                var queue = _queues[workType];
+
+                if (IsThrottlingActive(queue) || queue.WorkWaitingToExecute.IsEmpty)
+                    return ImmutableHashSet<DocumentId>.Empty;
+
+                queue.WorkExecuting = queue.WorkWaitingToExecute;
+                queue.WorkWaitingToExecute = ImmutableHashSet<DocumentId>.Empty;
+                return queue.WorkExecuting;
             }
         }
 
-        private bool ThrottlingPeriodNotActive(DateTime modified, DateTime now)
+        private bool IsThrottlingActive(Queue queue)
         {
-            return (now - modified).TotalMilliseconds >= _throttlingMs;
+            return (_utcNow() - queue.LastThrottlingBegan).TotalMilliseconds <= queue.Throttling.TotalMilliseconds;
         }
 
-        public void MarkWorkAsCompleteForDocumentId(DocumentId documentId)
+        public void WorkComplete(AnalyzerWorkType workType)
         {
-            if(_currentWork.TryGetValue(documentId, out var work))
+            lock (_queueLock)
             {
-                work.workDoneSource.Cancel();
-                _currentWork.TryRemove(documentId, out _);
+                if(_queues[workType].WorkExecuting.IsEmpty)
+                    return;
+
+                _queues[workType].WorkPendingToken?.Cancel();
+                _queues[workType].WorkPendingToken = null;
+                _queues[workType].WorkExecuting = ImmutableHashSet<DocumentId>.Empty;
             }
         }
 
-        // Omnisharp V2 api expects that it can request current information of diagnostics any time,
+        // Omnisharp V2 api expects that it can request current information of diagnostics any time (single file/current document),
         // however analysis is worker based and is eventually ready. This method is used to make api look
         // like it's syncronous even that actual analysis may take a while.
-        public async Task WaitForResultsAsync(ImmutableArray<DocumentId> documentIds)
+        public Task WaitForegroundWorkComplete()
         {
-            var items = new List<(DateTime modified, CancellationTokenSource workDoneSource)>();
+            var queue = _queues[AnalyzerWorkType.Foreground];
+
+            if (queue.WorkPendingToken == null || (queue.WorkPendingToken == null && queue.WorkWaitingToExecute.IsEmpty))
+                return Task.CompletedTask;
 
-            foreach (var documentId in documentIds)
+            return Task.Delay(_maximumDelayWhenWaitingForResults, queue.WorkPendingToken.Token)
+                .ContinueWith(task => LogTimeouts(task));
+        }
+
+        public bool TryPromote(DocumentId id)
+        {
+
+            if (_queues[AnalyzerWorkType.Background].WorkWaitingToExecute.Contains(id) || _queues[AnalyzerWorkType.Background].WorkExecuting.Contains(id))
             {
-                if (_currentWork.ContainsKey(documentId))
-                {
-                    items.Add(_currentWork[documentId]);
-                }
-                else if (_workQueue.ContainsKey(documentId))
-                {
-                    items.Add(_workQueue[documentId]);
-                }
+                PutWork(new[] { id }, AnalyzerWorkType.Foreground);
+                return true;
             }
 
-            await Task.WhenAll(items.Select(item =>
-                                Task.Delay(_maximumDelayWhenWaitingForResults, item.workDoneSource.Token)
-                                .ContinueWith(task => LogTimeouts(task, documentIds))));
+            return false;
         }
 
-        // This logs wait's for documentId diagnostics that continue without getting current version from analyzer.
-        // This happens on larger solutions during initial load or situations where analysis slows down remarkably.
-        private void LogTimeouts(Task task, IEnumerable<DocumentId> documentIds)
+        private void LogTimeouts(Task task)
         {
-            if (!task.IsCanceled) _logger.LogDebug($"Timeout before work got ready for one of documents {string.Join(",", documentIds)}.");
+            if (!task.IsCanceled) _logger.LogWarning($"Timeout before work got ready for foreground analysis queue.");
         }
     }
-
 }

src/OmniSharp.Roslyn.CSharp/Workers/Diagnostics/AnalyzerWorkType.cs

@@ -0,0 +1,8 @@
+namespace OmniSharp.Roslyn.CSharp.Workers.Diagnostics
+{
+    public enum AnalyzerWorkType
+    {
+        Background, Foreground
+    }
+
+}

src/OmniSharp.Roslyn.CSharp/Workers/Diagnostics/CSharpDiagnosticWorker.cs

@@ -186,7 +186,14 @@ private static async Task<ImmutableArray<Diagnostic>> GetDiagnosticsForDocument(
 
         public ImmutableArray<DocumentId> QueueAllDocumentsForDiagnostics()
         {
-            var documents = _workspace.CurrentSolution.Projects.SelectMany(x => x.Documents).ToImmutableArray();
+            var documents = _workspace.CurrentSolution.Projects.SelectMany(x => x.Documents);
+            QueueForDiagnosis(documents.Select(x => x.FilePath).ToImmutableArray());
+            return documents.Select(x => x.Id).ToImmutableArray();
+        }
+
+        public ImmutableArray<DocumentId> QueueDocumentsOfProjectsForDiagnostics(ImmutableArray<ProjectId> projectIds)
+        {
+            var documents = projectIds.SelectMany(projectId => _workspace.CurrentSolution.GetProject(projectId).Documents);
             QueueForDiagnosis(documents.Select(x => x.FilePath).ToImmutableArray());
             return documents.Select(x => x.Id).ToImmutableArray();
         }