Clang: Fix delayed reparse of dirty and visible but not current documents

1. Open document foo.h
2. Create a split and open foo.cpp (#including "foo.h")
3. Edit foo.h (e.g. by introducing a syntax error, so that foo.cpp will
   indicate header errors in the toolbar or as info bar)
=> Actual: foo.cpp will be reparsed immediately.
 Expected: foo.cpp should be reparsed after a delay.

This saves resources (cpu time) and minimizes poping up of the header
info bar while editing header files in splits.

Regression introduced by

    commit 380d756a03
    Clang: Hook up supportive translation unit on first edit

Change-Id: Ib5fd90e49415dfc3aefacab7cd627b0e1937f5fc
Reviewed-by: David Schulz <david.schulz@qt.io>

src/tools/clangbackend/ipcsource/clangcodemodelserver.cpp

@@ -50,6 +50,8 @@
 #include <updatetranslationunitsforeditormessage.h>
 #include <updatevisibletranslationunitsmessage.h>
 
+#include <utils/qtcassert.h>
+
 #include <QCoreApplication>
 #include <QDebug>
 
@@ -57,16 +59,21 @@ namespace ClangBackEnd {
 
 ClangCodeModelServer::ClangCodeModelServer()
     : documents(projects, unsavedFiles)
-    , updateDocumentAnnotationsTimeOutInMs(1500)
 {
     updateDocumentAnnotationsTimer.setSingleShot(true);
-
     QObject::connect(&updateDocumentAnnotationsTimer,
                      &QTimer::timeout,
                      [this]() {
         processJobsForDirtyAndVisibleDocuments();
     });
 
+    updateVisibleButNotCurrentDocumentsTimer.setSingleShot(true);
+    QObject::connect(&updateVisibleButNotCurrentDocumentsTimer,
+                     &QTimer::timeout,
+                     [this]() {
+        processJobsForDirtyAndVisibleButNotCurrentDocuments();
+    });
+
     QObject::connect(documents.clangFileSystemWatcher(),
                      &ClangFileSystemWatcher::fileChanged,
                      [this](const Utf8String &filePath) {
@@ -265,16 +272,44 @@ bool ClangCodeModelServer::isTimerRunningForTestOnly() const
 
 void ClangCodeModelServer::processJobsForDirtyAndVisibleDocuments()
 {
-    for (const auto &document : documents.documents()) {
-        if (document.isNeedingReparse() && document.isVisibleInEditor()) {
+    processJobsForDirtyCurrentDocument();
+    processTimerForVisibleButNotCurrentDocuments();
+}
+
+void ClangCodeModelServer::processJobsForDirtyCurrentDocument()
+{
+    const auto currentDirtyDocuments = documents.filtered([](const Document &document) {
+        return document.isNeedingReparse() && document.isUsedByCurrentEditor();
+    });
+    QTC_CHECK(currentDirtyDocuments.size() <= 1);
+
+    addAndRunUpdateJobs(currentDirtyDocuments);
+}
+
+void ClangCodeModelServer::addAndRunUpdateJobs(const std::vector<Document> &documents)
+{
+    for (const auto &document : documents) {
         DocumentProcessor processor = documentProcessors().processor(document);
         processor.addJob(createJobRequest(document,
                                           JobRequest::Type::UpdateDocumentAnnotations,
                                           PreferredTranslationUnit::PreviouslyParsed));
+        processor.process();
     }
 }
 
-    documentProcessors().process();
+void ClangCodeModelServer::processTimerForVisibleButNotCurrentDocuments()
+{
+    if (documents.dirtyAndVisibleButNotCurrentDocuments().empty()) {
+        updateVisibleButNotCurrentDocumentsTimer.stop();
+    } else {
+        updateVisibleButNotCurrentDocumentsTimer.start(
+                    updateVisibleButNotCurrentDocumentsTimeOutInMs);
+    }
+}
+
+void ClangCodeModelServer::processJobsForDirtyAndVisibleButNotCurrentDocuments()
+{
+    addAndRunUpdateJobs(documents.dirtyAndVisibleButNotCurrentDocuments());
 }
 
 void ClangCodeModelServer::processInitialJobsForDocuments(const std::vector<Document> &documents)
@@ -332,6 +367,11 @@ void ClangCodeModelServer::setUpdateDocumentAnnotationsTimeOutInMsForTestsOnly(i
     updateDocumentAnnotationsTimeOutInMs = value;
 }
 
+void ClangCodeModelServer::setUpdateVisibleButNotCurrentDocumentsTimeOutInMsForTestsOnly(int value)
+{
+    updateVisibleButNotCurrentDocumentsTimeOutInMs = value;
+}
+
 DocumentProcessors &ClangCodeModelServer::documentProcessors()
 {
     if (!documentProcessors_) {

src/tools/clangbackend/ipcsource/clangcodemodelserver.h

@@ -65,16 +65,22 @@ public: // for tests
     int queueSizeForTestsOnly();
     bool isTimerRunningForTestOnly() const;
     void setUpdateDocumentAnnotationsTimeOutInMsForTestsOnly(int value);
+    void setUpdateVisibleButNotCurrentDocumentsTimeOutInMsForTestsOnly(int value);
     DocumentProcessors &documentProcessors();
 
 private:
-
     void startDocumentAnnotationsTimerIfFileIsNotOpenAsDocument(const Utf8String &filePath);
-    void addJobRequestsForDirtyAndVisibleDocuments();
-    void processJobsForDirtyAndVisibleDocuments();
+
     void processInitialJobsForDocuments(const std::vector<Document> &documents);
     void startInitializingSupportiveTranslationUnits(const std::vector<Document> &documents);
 
+    void processJobsForDirtyAndVisibleDocuments();
+    void processJobsForDirtyCurrentDocument();
+    void processTimerForVisibleButNotCurrentDocuments();
+    void processJobsForDirtyAndVisibleButNotCurrentDocuments();
+
+    void addAndRunUpdateJobs(const std::vector<Document> &documents);
+
     JobRequest createJobRequest(const Document &document,
                                 JobRequest::Type type,
                                 PreferredTranslationUnit preferredTranslationUnit
@@ -88,7 +94,10 @@ private:
     QScopedPointer<DocumentProcessors> documentProcessors_; // Delayed initialization
 
     QTimer updateDocumentAnnotationsTimer;
-    int updateDocumentAnnotationsTimeOutInMs;
+    int updateDocumentAnnotationsTimeOutInMs = 1500;
+
+    QTimer updateVisibleButNotCurrentDocumentsTimer;
+    int updateVisibleButNotCurrentDocumentsTimeOutInMs = 2000;
 };
 
 } // namespace ClangBackEnd

src/tools/clangbackend/ipcsource/clangdocuments.cpp

@@ -33,6 +33,8 @@
 #include <skippedsourceranges.h>
 #include <unsavedfiles.h>
 
+#include <utils/algorithm.h>
+
 #include <QDebug>
 
 #include <algorithm>
@@ -143,6 +145,20 @@ const std::vector<Document> &Documents::documents() const
     return documents_;
 }
 
+const std::vector<Document> Documents::filtered(const IsMatchingDocument &isMatchingDocument) const
+{
+    return Utils::filtered(documents_, isMatchingDocument);
+}
+
+std::vector<Document> Documents::dirtyAndVisibleButNotCurrentDocuments() const
+{
+    return filtered([](const Document &document) {
+        return document.isNeedingReparse()
+            && document.isVisibleInEditor()
+            && !document.isUsedByCurrentEditor();
+    });
+}
+
 UnsavedFiles Documents::unsavedFiles() const
 {
     return unsavedFiles_;

src/tools/clangbackend/ipcsource/clangdocuments.h

@@ -32,6 +32,7 @@
 
 #include <QVector>
 
+#include <functional>
 #include <vector>
 
 namespace ClangBackEnd {
@@ -57,6 +58,9 @@ public:
     bool hasDocumentWithFilePath(const Utf8String &filePath) const;
 
     const std::vector<Document> &documents() const;
+    using IsMatchingDocument = std::function<bool(const Document &document)>;
+    const std::vector<Document> filtered(const IsMatchingDocument &isMatchingDocument) const;
+    std::vector<Document> dirtyAndVisibleButNotCurrentDocuments() const;
 
     UnsavedFiles unsavedFiles() const;
 

tests/unit/unittest/clangdocuments-test.cpp

@@ -289,6 +289,42 @@ TEST_F(Documents, HasNotDocument)
     ASSERT_FALSE(documents.hasDocument(filePath, projectPartId));
 }
 
+TEST_F(Documents, FilteredPositive)
+{
+    documents.create({{filePath, projectPartId}});
+    const auto isMatchingFilePath = [this](const Document &document) {
+        return document.filePath() == filePath;
+    };
+
+    const bool hasMatches = !documents.filtered(isMatchingFilePath).empty();
+
+    ASSERT_TRUE(hasMatches);
+}
+
+TEST_F(Documents, FilteredNegative)
+{
+    documents.create({{filePath, projectPartId}});
+    const auto isMatchingNothing = [](const Document &) {
+        return false;
+    };
+
+    const bool hasMatches = !documents.filtered(isMatchingNothing).empty();
+
+    ASSERT_FALSE(hasMatches);
+}
+
+TEST_F(Documents, DirtyAndVisibleButNotCurrentDocuments)
+{
+    documents.create({{filePath, projectPartId}});
+    documents.updateDocumentsWithChangedDependency(filePath);
+    documents.setVisibleInEditors({filePath});
+    documents.setUsedByCurrentEditor(Utf8String());
+
+    const bool hasMatches = !documents.dirtyAndVisibleButNotCurrentDocuments().empty();
+
+    ASSERT_TRUE(hasMatches);
+}
+
 TEST_F(Documents, isUsedByCurrentEditor)
 {
     documents.create({fileContainer});

tests/unit/unittest/clangipcserver-test.cpp

@@ -375,6 +375,7 @@ void ClangClangCodeModelServer::SetUp()
 {
     clangServer.setClient(&mockClangCodeModelClient);
     clangServer.setUpdateDocumentAnnotationsTimeOutInMsForTestsOnly(0);
+    clangServer.setUpdateVisibleButNotCurrentDocumentsTimeOutInMsForTestsOnly(0);
 }
 
 void ClangClangCodeModelServer::TearDown()