assimp plugin: replace QMap with a C array

The keys are statically known, short, and few, so replace the
QMap<QByteArray, OpenMode> with a C array of a {char[2]; OpenMode}
struct, which occupies just 40B in read-only memory. We don't even
need to sort the list, as binary search in a list of ten entries is
slower than linear search (five comparisons each, on average, with the
linear scan having a predictable memory access pattern.

This is a port of dd1d8f51e67ec93031fdd7f7930d63761d1238e6 to the
other copy of this code, which shows that arguments like 'this is just
a tool, not a library' are ill-advised. Code _will_ be copied.

Change-Id: Ie04137f94e487ce998ec077daf655b09bcbbcfc7
Reviewed-by: Paul Lemire <paul.lemire@kdab.com>

1 files changed, 0 insertions, 6 deletions

diff --git a/src/plugins/sceneparsers/assimp/assimphelpers.h b/src/plugins/sceneparsers/assimp/assimphelpers.h
index 0db22ce7b..fd102213c 100644
--- a/src/plugins/sceneparsers/assimp/assimphelpers.h
+++ b/src/plugins/sceneparsers/assimp/assimphelpers.h
@@ -55,7 +55,6 @@
 #include <assimp/IOStream.hpp>
 #include <assimp/IOSystem.hpp>
 #include <QtCore/QIODevice>
-#include <QtCore/QMap>
 
 QT_BEGIN_NAMESPACE
 
@@ -84,15 +83,10 @@ private:
 class AssimpIOSystem : public Assimp::IOSystem
 {
 public :
-    AssimpIOSystem();
-    ~AssimpIOSystem();
     bool Exists(const char *pFile) const override;
     char getOsSeparator() const override;
     Assimp::IOStream *Open(const char *pFile, const char *pMode) override;
     void Close(Assimp::IOStream *pFile) override;
-
-private:
-    QMap<QByteArray, QIODevice::OpenMode> m_openModeMaps;
 };
 
 } // namespace AssimpHelper