Always make a copy of a string when adding it to StringsStorage

src/profile-generator.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 23 matching lines @@
 #include "sampler.h"
 #include "global-handles.h"
 #include "scopeinfo.h"
 #include "unicode.h"
 #include "zone-inl.h"
 
 namespace v8 {
 namespace internal {
 
 
+bool StringsStorage::StringsMatch(void* key1, void* key2) {
+  return strcmp(reinterpret_cast<char*>(key1),
+                reinterpret_cast<char*>(key2)) == 0;
+}
+
+
 StringsStorage::StringsStorage(Heap* heap)
     : hash_seed_(heap->HashSeed()), names_(StringsMatch) {
 }
 
 
 StringsStorage::~StringsStorage() {
   for (HashMap::Entry* p = names_.Start();
        p != NULL;
        p = names_.Next(p)) {
     DeleteArray(reinterpret_cast<const char*>(p->value));
   }
 }
 
 
 const char* StringsStorage::GetCopy(const char* src) {
   int len = static_cast<int>(strlen(src));
-  Vector<char> dst = Vector<char>::New(len + 1);
-  OS::StrNCpy(dst, src, len);
-  dst[len] = '\0';
-  uint32_t hash =
-      StringHasher::HashSequentialString(dst.start(), len, hash_seed_);
-  return AddOrDisposeString(dst.start(), hash);
+  HashMap::Entry* entry = GetEntry(src, len);
+  if (entry->value == NULL) {
+    Vector<char> dst = Vector<char>::New(len + 1);
+    OS::StrNCpy(dst, src, len);
+    dst[len] = '\0';
+    entry->key = dst.start();
+    entry->value = entry->key;
+  }
+  return reinterpret_cast<const char*>(entry->value);
 }
 
 
 const char* StringsStorage::GetFormatted(const char* format, ...) {
   va_list args;
   va_start(args, format);
   const char* result = GetVFormatted(format, args);
   va_end(args);
   return result;
 }
 
 
-const char* StringsStorage::AddOrDisposeString(char* str, uint32_t hash) {
-  HashMap::Entry* cache_entry = names_.Lookup(str, hash, true);
-  if (cache_entry->value == NULL) {
+const char* StringsStorage::AddOrDisposeString(char* str, int len) {
+  HashMap::Entry* entry = GetEntry(str, len);
+  if (entry->value == NULL) {
     // New entry added.
-    cache_entry->value = str;
+    entry->key = str;
+    entry->value = str;
   } else {
     DeleteArray(str);
   }
-  return reinterpret_cast<const char*>(cache_entry->value);
+  return reinterpret_cast<const char*>(entry->value);
 }
 
 
 const char* StringsStorage::GetVFormatted(const char* format, va_list args) {
   Vector<char> str = Vector<char>::New(1024);
   int len = OS::VSNPrintF(str, format, args);
   if (len == -1) {
     DeleteArray(str.start());
-    return format;
+    return GetCopy(format);
   }
-  uint32_t hash = StringHasher::HashSequentialString(
-      str.start(), len, hash_seed_);
-  return AddOrDisposeString(str.start(), hash);
+  return AddOrDisposeString(str.start(), len);
 }
 
 
 const char* StringsStorage::GetName(Name* name) {
   if (name->IsString()) {
     String* str = String::cast(name);
     int length = Min(kMaxNameSize, str->length());
+    int actual_length = 0;
     SmartArrayPointer<char> data =
-        str->ToCString(DISALLOW_NULLS, ROBUST_STRING_TRAVERSAL, 0, length);
-    uint32_t hash = StringHasher::HashSequentialString(
-        *data, length, name->GetHeap()->HashSeed());
-    return AddOrDisposeString(data.Detach(), hash);
+        str->ToCString(DISALLOW_NULLS, ROBUST_STRING_TRAVERSAL, 0, length,
+                       &actual_length);
+    return AddOrDisposeString(data.Detach(), actual_length);
   } else if (name->IsSymbol()) {
     return "<symbol>";
   }
   return "";
 }
 
 
 const char* StringsStorage::GetName(int index) {
   return GetFormatted("%d", index);
 }
 
 
+const char* StringsStorage::GetFunctionName(Name* name) {
+  return BeautifyFunctionName(GetName(name));
+}
+
+
+const char* StringsStorage::GetFunctionName(const char* name) {
+  return BeautifyFunctionName(GetCopy(name));
+}
+
+
+const char* StringsStorage::BeautifyFunctionName(const char* name) {
+  return (*name == 0) ? ProfileGenerator::kAnonymousFunctionName : name;
+}
+
+
 size_t StringsStorage::GetUsedMemorySize() const {
   size_t size = sizeof(*this);
   size += sizeof(HashMap::Entry) * names_.capacity();
   for (HashMap::Entry* p = names_.Start(); p != NULL; p = names_.Next(p)) {
     size += strlen(reinterpret_cast<const char*>(p->value)) + 1;
   }
   return size;
 }
 
 
+HashMap::Entry* StringsStorage::GetEntry(const char* str, int len) {
+  uint32_t hash = StringHasher::HashSequentialString(str, len, hash_seed_);
+  return names_.Lookup(const_cast<char*>(str), hash, true);
+}
+
+
 const char* const CodeEntry::kEmptyNamePrefix = "";
 const char* const CodeEntry::kEmptyResourceName = "";
 const char* const CodeEntry::kEmptyBailoutReason = "";
 
 
 CodeEntry::~CodeEntry() {
   delete no_frame_ranges_;
 }
 
 
@@ skipping 521 matching lines @@
     case OTHER:
     case EXTERNAL:
       return program_entry_;
     case IDLE:
       return idle_entry_;
     default: return NULL;
   }
 }
 
 } }  // namespace v8::internal