Unique code-completion strings. On Cocoa.h, this costs us about 4% in

speed but saves us about 25% of the memory usage for strings.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@124704 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 38 insertions, 0 deletions

diff --git a/include/clang/Sema/CodeCompleteConsumer.h b/include/clang/Sema/CodeCompleteConsumer.h
index 8cb8e75393..bd9a868101 100644
--- a/include/clang/Sema/CodeCompleteConsumer.h
+++ b/include/clang/Sema/CodeCompleteConsumer.h
@@ -15,7 +15,9 @@
 
 #include "clang/AST/Type.h"
 #include "clang/AST/CanonicalType.h"
+#include "llvm/ADT/DenseSet.h"
 #include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/StringRef.h"
 #include "llvm/Support/Allocator.h"
 #include "clang-c/Index.h"
@@ -421,11 +423,47 @@ public:
   std::string getAsString() const;   
 };
 
+/// \brief \c DenseMap information object for StringRefs.
+struct DenseMapStringRefInfo {
+  static inline llvm::StringRef getEmptyKey() {
+    return llvm::StringRef(reinterpret_cast<const char*>((intptr_t)-1), 0);
+  }
+  static inline llvm::StringRef getTombstoneKey() {
+    return llvm::StringRef(reinterpret_cast<const char *>((intptr_t)-2), 0);
+  }
+  static unsigned getHashValue(llvm::StringRef Str) {
+    return llvm::HashString(Str);
+  }
+  static bool isEqual(llvm::StringRef LHS, llvm::StringRef RHS) { 
+    if (LHS.size() == 0 && RHS.size() == 0) {
+      intptr_t LHSVal = reinterpret_cast<intptr_t>(LHS.data());
+      intptr_t RHSVal = reinterpret_cast<intptr_t>(RHS.data());
+      if (LHSVal == -1 || LHSVal == -2 || RHSVal == -1 || RHSVal == -2)
+        return LHSVal == RHSVal;
+      
+      return true;
+    }
+    
+    return LHS == RHS;
+  }
+};
+
 /// \brief An allocator used specifically for the purpose of code completion.
 class CodeCompletionAllocator : public llvm::BumpPtrAllocator { 
+  llvm::DenseSet<llvm::StringRef, DenseMapStringRefInfo> UniqueStrings;
+  unsigned StringBytesAllocated;
+  unsigned StringBytesUniqued;
+  unsigned StringsAllocated;
+  unsigned StringsUniqued;
+  
 public:
+  CodeCompletionAllocator();
+  ~CodeCompletionAllocator();
+  
   /// \brief Copy the given string into this allocator.
   const char *CopyString(llvm::StringRef String);
+  
+  void PrintStats();
 };
   
 /// \brief A builder class used to construct new code-completion strings.