C++: Release more documents.

- fix memory leak in find-usages
- do not retain snapshot in search history
- when an editor is invisible for more than 2 minutes, release the
  backing snapshot

Retaining snapshots will retain their documents, and if done for too
long, the memory consumption might grow. This is especially the case
when switching to a different kit (Qt version): in that case, the new
versions of headers will be indexed, while the old ones stay around.

Task-number: QTCREATORBUG-5583
Task-number: QTCREATORBUG-7645
Task-number: QTCREATORBUG-9842

Change-Id: I045eda1565e0a3fa702baeffaab9c12662f90289
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@digia.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/src/plugins/cpptools/cppsnapshotupdater.h b/src/plugins/cpptools/cppsnapshotupdater.h
index 98564357a7..739cb57d5a 100644
--- a/src/plugins/cpptools/cppsnapshotupdater.h
+++ b/src/plugins/cpptools/cppsnapshotupdater.h
@@ -52,6 +52,7 @@ public:
     { return m_fileInEditor; }
 
     void update(CppModelManagerInterface::WorkingCopy workingCopy);
+    void releaseSnapshot();
 
     CPlusPlus::Document::Ptr document() const;
     CPlusPlus::Snapshot snapshot() const;
@@ -81,6 +82,7 @@ private:
     CPlusPlus::Snapshot m_snapshot;
     CPlusPlus::DependencyTable m_deps;
     bool m_usePrecompiledHeaders;
+    bool m_forceSnapshotInvalidation;
 };
 
 } // namespace CppTools