add classes trace_analyzer::Query and TraceAnalyzer to make it easy to search through trace data

base/debug/trace_event.cc

Index: base/debug/trace_event.cc
diff --git a/base/debug/trace_event.cc b/base/debug/trace_event.cc
index 879f3a978f9361900a8658b61c4ead4ef5f75f0b..3f321018417d5a9027d003c046418adf77547678 100644
--- a/base/debug/trace_event.cc
+++ b/base/debug/trace_event.cc
@@ -5,18 +5,22 @@
 #include "base/debug/trace_event.h"
 
 #include <algorithm>
+#include <math.h>
 
 #if defined(OS_WIN)
 #include "base/debug/trace_event_win.h"
 #endif
 #include "base/format_macros.h"
+#include "base/json/json_reader.h"
 #include "base/memory/ref_counted_memory.h"
+#include "base/memory/scoped_ptr.h"
 #include "base/process_util.h"
 #include "base/stringprintf.h"
 #include "base/threading/thread_local.h"
 #include "base/utf_string_conversions.h"
 #include "base/stl_util.h"
 #include "base/time.h"
+#include "base/values.h"
 
 #define USE_UNRELIABLE_NOW
 
@@ -126,6 +130,21 @@ const char* GetPhaseStr(TraceEventPhase phase) {
   }
 }
 
+TraceEventPhase GetPhaseFromStr(const char* phase) {
+  switch(*phase) {
+    case 'B':
+      return TRACE_EVENT_PHASE_BEGIN;
+    case 'I':
+      return TRACE_EVENT_PHASE_INSTANT;
+    case 'E':
+      return TRACE_EVENT_PHASE_END;
+    case 'M':
+      return TRACE_EVENT_PHASE_METADATA;
+    default:
+      return TRACE_EVENT_PHASE_BEGIN;
+  }
+}
+
 size_t GetAllocLength(const char* str) { return str ? strlen(str) + 1 : 0; }
 
 // Copies |*member| into |*buffer|, sets |*member| to point to this new
@@ -143,6 +162,112 @@ void CopyTraceEventParameter(char** buffer,
 
 }  // namespace
 
+TestTraceEvent::TestTraceEvent()
+    : pid_tid(0, 0),
+      timestamp(0),
+      phase(TRACE_EVENT_PHASE_BEGIN),
+      other_event(NULL) {
+}
+
+TestTraceEvent::TestTraceEvent(const base::Value* event_value)
+    : pid_tid(0, 0),
+      timestamp(0),
+      phase(TRACE_EVENT_PHASE_BEGIN),
+      other_event(NULL) {
+  if (event_value->GetType() != base::Value::TYPE_DICTIONARY)
+    return;
+  const base::DictionaryValue* dictionary =
+      static_cast<const base::DictionaryValue*>(event_value);
+
+  std::string phase_str;
+  base::DictionaryValue* args = NULL;
+
+  if (dictionary->GetInteger("pid", &pid_tid.pid) &&
+      dictionary->GetInteger("tid", &pid_tid.tid) &&
+      dictionary->GetDouble("ts", &timestamp) &&
+      dictionary->GetString("cat", &category) &&
+      dictionary->GetString("name", &name) &&
+      dictionary->GetString("ph", &phase_str) &&
+      dictionary->GetDictionary("args", &args)) {
+
+    phase = GetPhaseFromStr(phase_str.c_str());
+
+    // For each argument, copy the type and create a TraceValue.
+    base::DictionaryValue::key_iterator keyi = args->begin_keys();
+    for (; keyi != args->end_keys(); ++keyi) {
+      std::string str;
+      bool boolean = false;
+      int int_num = 0;
+      double double_num = 0.0;
+      Value* value = NULL;
+      if (args->GetWithoutPathExpansion(*keyi, &value)) {
+        if (value->GetAsString(&str))
+          arg_strings[*keyi] = str;
+        else if (value->GetAsInteger(&int_num))
+          arg_numbers[*keyi] = static_cast<double>(int_num);
+        else if (value->GetAsBoolean(&boolean))
+          arg_numbers[*keyi] = static_cast<double>(boolean ? 1 : 0);
+        else if (value->GetAsDouble(&double_num))
+          arg_numbers[*keyi] = double_num;
+      }
+    }
+  }
+}
+
+TestTraceEvent::~TestTraceEvent() {
+}
+
+bool TestTraceEvent::ParseEventsFromJson(const std::string& json,
+                                         std::vector<TestTraceEvent>* output) {
+  scoped_ptr<base::Value> root;
+  root.reset(base::JSONReader::Read(json, false));
+
+  ListValue* root_list = NULL;
+  if (!root.get() || !root->GetAsList(&root_list))
+    return false;
+
+  for (size_t i = 0; i < root_list->GetSize(); ++i) {
+    Value* item = NULL;
+    if (root_list->Get(i, &item))
+      output->push_back(TestTraceEvent(item));
+  }
+
+  return true;
+}
+
+bool TestTraceEvent::GetDuration(double* duration) const {
+  if (!other_event)
+    return false;
+
+  *duration = fabs(other_event->timestamp - timestamp);
+  return true;
+}
+
+bool TestTraceEvent::IsArg(const std::string& name) const {
+  return arg_numbers.find(name) != arg_numbers.end() ||
+         arg_strings.find(name) != arg_strings.end();
+}
+
+bool TestTraceEvent::GetArgAsString(const std::string& name,
+                                    std::string* arg) const {
+  std::map<std::string, std::string>::const_iterator i = arg_strings.find(name);
+  if (i != arg_strings.end()) {
+    *arg = i->second;
+    return true;
+  }
+  return false;
+}
+
+bool TestTraceEvent::GetArgAsNumber(const std::string& name,
+                                    double* arg) const {
+  std::map<std::string, double>::const_iterator i = arg_numbers.find(name);
+  if (i != arg_numbers.end()) {
+    *arg = i->second;
+    return true;
+  }
+  return false;
+}
+
 TraceEvent::TraceEvent()
     : process_id_(0),
       thread_id_(0),