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.

llvm-svn: 124704

1 files changed, 31 insertions, 0 deletions

diff --git a/clang/lib/Sema/CodeCompleteConsumer.cpp b/clang/lib/Sema/CodeCompleteConsumer.cpp
index cb2dd234b48..572c8dcbd0e 100644
--- a/clang/lib/Sema/CodeCompleteConsumer.cpp
+++ b/clang/lib/Sema/CodeCompleteConsumer.cpp
@@ -220,10 +220,41 @@ const char *CodeCompletionString::getTypedText() const {
   return 0;
 }
 
+CodeCompletionAllocator::CodeCompletionAllocator()
+  : llvm::BumpPtrAllocator(), StringBytesAllocated(0), StringBytesUniqued(0), 
+    StringsAllocated(0), StringsUniqued(0)
+{
+}
+
+CodeCompletionAllocator::~CodeCompletionAllocator() { }
+
+void CodeCompletionAllocator::PrintStats() {
+  llvm::errs() << "---Code completion memory allocation---\n" 
+    << "String bytes uniqued: " << StringBytesUniqued << "/"
+    << StringBytesAllocated << " (" 
+    << ((float)StringBytesUniqued*100/StringBytesAllocated)
+    << ")\nStrings uniqued: " << StringsUniqued << "/" << StringsAllocated
+    << " (" << ((float)StringsUniqued*100/StringsAllocated)
+  << ")\n";
+  
+  llvm::BumpPtrAllocator::PrintStats();
+}
+
 const char *CodeCompletionAllocator::CopyString(llvm::StringRef String) {
+  llvm::DenseSet<llvm::StringRef, DenseMapStringRefInfo>::iterator Uniqued
+    = UniqueStrings.find(String);
+  ++StringsAllocated;
+  StringBytesAllocated += String.size() + 1;
+  if (Uniqued != UniqueStrings.end()) {
+    StringBytesUniqued += String.size() + 1;
+    ++StringsUniqued;
+    return Uniqued->data();
+  }
+  
   char *Mem = (char *)Allocate(String.size() + 1, 1);
   std::copy(String.begin(), String.end(), Mem);
   Mem[String.size()] = 0;
+  UniqueStrings.insert(llvm::StringRef(Mem, String.size()));
   return Mem;
 }