Cache the file extension of files

Small optimisation, prevents it from having to be calculated often.

2 files changed, 6 insertions, 0 deletions

diff --git a/windirstat/item.cpp b/windirstat/item.cpp
index ef15071..f71f5be 100644
--- a/windirstat/item.cpp
+++ b/windirstat/item.cpp
@@ -909,6 +909,9 @@ CString CItem::GetName() const
 
 CString CItem::GetExtension() const
 {
+    if (m_extension != "")
+        return m_extension;
+
     CString ext;
 
     switch (GetType())
@@ -938,6 +941,8 @@ CString CItem::GetExtension() const
         ASSERT(0);
     }
 
+    m_extension = ext;
+
     return ext;
 }
 
diff --git a/windirstat/item.h b/windirstat/item.h
index e6e748f..e9778e9 100644
--- a/windirstat/item.h
+++ b/windirstat/item.h
@@ -221,6 +221,7 @@ private:
 
     ITEMTYPE m_type;            // Indicates our type. See ITEMTYPE.
     CString m_name;             // Display name
+    mutable CString m_extension;		// Cache of extension (it's used often)
     ULONGLONG m_size;           // OwnSize, if IT_FILE or IT_FREESPACE, or IT_UNKNOWN; SubtreeTotal else.
     ULONGLONG m_files;          // # Files in subtree
     ULONGLONG m_subdirs;        // # Folder in subtree