Added support to trace_event for passing static string arguments without copy

base/debug/trace_event.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/debug/trace_event.h"
 
 #include <algorithm>
 
 #if defined(OS_WIN)
 #include "base/debug/trace_event_win.h"
@@ skipping 65 matching lines @@
       *out += temp_string;
       break;
     case TRACE_TYPE_POINTER:
       base::snprintf(temp_string, arraysize(temp_string), "%llu",
                      static_cast<unsigned long long>(
                        reinterpret_cast<intptr_t>(
                          as_pointer())));
       *out += temp_string;
       break;
     case TRACE_TYPE_STRING:
+    case TRACE_TYPE_STATIC_STRING:
       *out += "\"";
       start_pos = out->size();
-      *out += as_string();
+      *out += as_string() ? as_string() : "NULL";
       // replace " character with '
       while ((start_pos = out->find_first_of('\"', start_pos)) !=
              std::string::npos)
         (*out)[start_pos] = '\'';
       *out += "\"";
       break;
     default:
       NOTREACHED() << "Don't know how to print this value";
       break;
   }
@@ skipping 70 matching lines @@
   arg_names_[1] = arg2_name;
   arg_values_[0] = arg1_val;
   arg_values_[1] = arg2_val;
 
   size_t alloc_size = 0;
   if (copy) {
     alloc_size += GetAllocLength(name);
     alloc_size += GetAllocLength(arg1_name);
     alloc_size += GetAllocLength(arg2_name);
   }
-  // We always take a copy of string arg_vals, even if |copy| was not set.
-  if (arg1_val.type() == TraceValue::TRACE_TYPE_STRING)
+
+  bool arg1_is_copy = (arg1_val.type() == TraceValue::TRACE_TYPE_STRING);
+  bool arg2_is_copy = (arg2_val.type() == TraceValue::TRACE_TYPE_STRING);
+
+  // We only take a copy of arg_vals if they are of type string (not static
+  // string), regardless of the |copy| flag.
+  if (arg1_is_copy)
     alloc_size += GetAllocLength(arg1_val.as_string());
-  if (arg2_val.type() == TraceValue::TRACE_TYPE_STRING)
+  if (arg2_is_copy)
     alloc_size += GetAllocLength(arg2_val.as_string());
 
   if (alloc_size) {
     parameter_copy_storage_ = new base::RefCountedString;
     parameter_copy_storage_->data().resize(alloc_size);
     char* ptr = string_as_array(&parameter_copy_storage_->data());
     const char* end = ptr + alloc_size;
     if (copy) {
       CopyTraceEventParameter(&ptr, &name_, end);
       CopyTraceEventParameter(&ptr, &arg_names_[0], end);
       CopyTraceEventParameter(&ptr, &arg_names_[1], end);
     }
-    if (arg_values_[0].type() == TraceValue::TRACE_TYPE_STRING)
+    if (arg1_is_copy)
       CopyTraceEventParameter(&ptr, arg_values_[0].as_assignable_string(), end);
-    if (arg_values_[1].type() == TraceValue::TRACE_TYPE_STRING)
+    if (arg2_is_copy)
       CopyTraceEventParameter(&ptr, arg_values_[1].as_assignable_string(), end);
     DCHECK_EQ(end, ptr) << "Overrun by " << ptr - end;
   }
 }
 
 TraceEvent::~TraceEvent() {
 }
 
 void TraceEvent::AppendEventsAsJSON(const std::vector<TraceEvent>& events,
                                     size_t start,
@@ skipping 147 matching lines @@
   }
 }
 
 int TraceLog::AddTraceEvent(TraceEventPhase phase,
                             const TraceCategory* category,
                             const char* name,
                             const char* arg1_name, TraceValue arg1_val,
                             const char* arg2_name, TraceValue arg2_val,
                             int threshold_begin_id,
                             int64 threshold,
-                            bool copy) {
+                            EventFlags flags) {
   DCHECK(name);
 #ifdef USE_UNRELIABLE_NOW
   TimeTicks now = TimeTicks::HighResNow();
 #else
   TimeTicks now = TimeTicks::Now();
 #endif
   BufferFullCallback buffer_full_callback_copy;
   int ret_begin_id = -1;
   {
     AutoLock lock(lock_);
@@ skipping 44 matching lines @@
         return -1;
       }
     }
     ret_begin_id = static_cast<int>(logged_events_.size());
     logged_events_.push_back(
         TraceEvent(static_cast<unsigned long>(base::GetCurrentProcId()),
                    thread_id,
                    now, phase, category, name,
                    arg1_name, arg1_val,
                    arg2_name, arg2_val,
-                   copy));
+                   flags & EVENT_FLAG_COPY));
 
     if (logged_events_.size() == kTraceEventBufferSize) {
       buffer_full_callback_copy = buffer_full_callback_;
     }
   } // release lock
 
   if (!buffer_full_callback_copy.is_null())
     buffer_full_callback_copy.Run();
 
   return ret_begin_id;
 }
 
 void TraceLog::AddTraceEventEtw(TraceEventPhase phase,
                                 const char* name,
                                 const void* id,
                                 const char* extra) {
-  // Legacy trace points on windows called to ETW
 #if defined(OS_WIN)
   TraceEventETWProvider::Trace(name, phase, id, extra);
 #endif
+  INTERNAL_TRACE_EVENT_ADD(phase,
+      "ETW Trace Event", name, "id", id, "extra", TRACE_STR_COPY(extra),
+      base::debug::TraceLog::EVENT_FLAG_NONE);
+}
 
-  // Also add new trace event behavior
-  static const TraceCategory* category = GetCategory("ETW Trace Event");
-  if (category->enabled) {
-    TraceLog* tracelog = TraceLog::GetInstance();
-    if (!tracelog)
-      return;
-    tracelog->AddTraceEvent(phase, category, name,
-                            "id", id,
-                            "extra", extra ? extra : "",
-                            -1, 0, false);
-  }
+void TraceLog::AddTraceEventEtw(TraceEventPhase phase,
+                                const char* name,
+                                const void* id,
+                                const std::string& extra)
+{
+#if defined(OS_WIN)
+  TraceEventETWProvider::Trace(name, phase, id, extra);
+#endif
+  INTERNAL_TRACE_EVENT_ADD(phase,
+      "ETW Trace Event", name, "id", id, "extra", extra,
+      base::debug::TraceLog::EVENT_FLAG_NONE);
 }
 
 void TraceLog::AddCurrentMetadataEvents() {
   lock_.AssertAcquired();
   for(base::hash_map<PlatformThreadId, std::string>::iterator it =
           thread_names_.begin();
       it != thread_names_.end();
       it++) {
     if (!it->second.empty())
       logged_events_.push_back(
           TraceEvent(static_cast<unsigned long>(base::GetCurrentProcId()),
                      it->first,
                      TimeTicks(), base::debug::TRACE_EVENT_PHASE_METADATA,
                      g_category_metadata, "thread_name",
-                     "name", it->second.c_str(),
+                     "name", it->second,
                      NULL, 0,
                      false));
   }
 }
 
 void TraceLog::Resurrect() {
   StaticMemorySingletonTraits<TraceLog>::Resurrect();
 }
 
 namespace internal {
 
 void TraceEndOnScopeClose::Initialize(const TraceCategory* category,
                                       const char* name) {
   data_.category = category;
   data_.name = name;
   p_data_ = &data_;
 }
 
 void TraceEndOnScopeClose::AddEventIfEnabled() {
   // Only called when p_data_ is non-null.
   if (p_data_->category->enabled) {
     base::debug::TraceLog::GetInstance()->AddTraceEvent(
         base::debug::TRACE_EVENT_PHASE_END,
         p_data_->category,
         p_data_->name,
         NULL, 0, NULL, 0,
-        -1, 0, false);
+        -1, 0, TraceLog::EVENT_FLAG_NONE);
   }
 }
 
 void TraceEndOnScopeCloseThreshold::Initialize(const TraceCategory* category,
                                                const char* name,
                                                int threshold_begin_id,
                                                int64 threshold) {
   data_.category = category;
   data_.name = name;
   data_.threshold_begin_id = threshold_begin_id;
   data_.threshold = threshold;
   p_data_ = &data_;
 }
 
 void TraceEndOnScopeCloseThreshold::AddEventIfEnabled() {
   // Only called when p_data_ is non-null.
   if (p_data_->category->enabled) {
     base::debug::TraceLog::GetInstance()->AddTraceEvent(
         base::debug::TRACE_EVENT_PHASE_END,
         p_data_->category,
         p_data_->name,
         NULL, 0, NULL, 0,
-        p_data_->threshold_begin_id, p_data_->threshold, false);
+        p_data_->threshold_begin_id, p_data_->threshold,
+        TraceLog::EVENT_FLAG_NONE);
   }
 }
 
 } // namespace internal
 
 }  // namespace debug
 }  // namespace base