chrome/browser/feedback/tracing_manager.cc

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/browser/feedback/tracing_manager.h"
   6
   7 #include "base/bind.h"
   8 #include "base/file_util.h"
   9 #include "base/location.h"
  10 #include "base/memory/ref_counted_memory.h"
  11 #include "base/message_loop/message_loop_proxy.h"
  12 #include "base/prefs/pref_service.h"
  13 #include "chrome/browser/browser_process.h"
  14 #include "chrome/browser/feedback/feedback_util.h"
  15 #include "chrome/common/pref_names.h"
  16 #include "content/public/browser/tracing_controller.h"
  17
  18 namespace {
  19 // Only once trace manager can exist at a time.
  20 TracingManager* g_tracing_manager = NULL;
  21 // Trace IDs start at 1 and increase.
  22 int g_next_trace_id = 1;
  23 // Name of the file to store the tracing data as.
  24 const base::FilePath::CharType kTracingFilename[] =
  25     FILE_PATH_LITERAL("tracing.json");
  26 }
  27
  28 TracingManager::TracingManager()
  29     : current_trace_id_(0),
  30       weak_ptr_factory_(this) {
  31   DCHECK(!g_tracing_manager);
  32   g_tracing_manager = this;
  33   StartTracing();
  34 }
  35
  36 TracingManager::~TracingManager() {
  37   DCHECK(g_tracing_manager == this);
  38   g_tracing_manager = NULL;
  39 }
  40
  41 int TracingManager::RequestTrace() {
  42   // Return the current trace if one is being collected.
  43   if (current_trace_id_)
  44     return current_trace_id_;
  45
  46   current_trace_id_ = g_next_trace_id;
  47   ++g_next_trace_id;
  48   content::TracingController::GetInstance()->DisableRecording(
  49       base::FilePath(),
  50       base::Bind(&TracingManager::OnTraceDataCollected,
  51                  weak_ptr_factory_.GetWeakPtr()));
  52   return current_trace_id_;
  53 }
  54
  55 bool TracingManager::GetTraceData(int id, const TraceDataCallback& callback) {
  56   // If a trace is being collected currently, send it via callback when
  57   // complete.
  58   if (current_trace_id_) {
  59     // Only allow one trace data request at a time.
  60     if (trace_callback_.is_null()) {
  61       trace_callback_ = callback;
  62       return true;
  63     } else {
  64       return false;
  65     }
  66   } else {
  67     std::map<int, scoped_refptr<base::RefCountedString> >::iterator data =
  68         trace_data_.find(id);
  69     if (data == trace_data_.end())
  70       return false;
  71
  72     // Always return the data asychronously, so the behavior is consistant.
  73     base::MessageLoopProxy::current()->PostTask(
  74         FROM_HERE,
  75         base::Bind(callback, data->second));
  76     return true;
  77   }
  78 }
  79
  80 void TracingManager::DiscardTraceData(int id) {
  81   trace_data_.erase(id);
  82
  83   // If the trace is discarded before it is complete, clean up the accumulators.
  84   if (id == current_trace_id_) {
  85     current_trace_id_ = 0;
  86
  87     // If the trace has already been requested, provide an empty string.
  88     if (!trace_callback_.is_null()) {
  89       trace_callback_.Run(scoped_refptr<base::RefCountedString>());
  90       trace_callback_.Reset();
  91     }
  92   }
  93 }
  94
  95 void TracingManager::StartTracing() {
  96   content::TracingController::GetInstance()->EnableRecording(
  97       "", content::TracingController::DEFAULT_OPTIONS,
  98       content::TracingController::EnableRecordingDoneCallback());
  99 }
 100
 101 void TracingManager::OnTraceDataCollected(const base::FilePath& path) {
 102   if (!current_trace_id_)
 103     return;
 104
 105   std::string data;
 106   if (!base::ReadFileToString(path, &data)) {
 107     LOG(ERROR) << "Failed to read trace data from: " << path.value();
 108     return;
 109   }
 110   base::DeleteFile(path, false);
 111
 112   std::string output_val;
 113   feedback_util::ZipString(
 114       base::FilePath(kTracingFilename), data, &output_val);
 115
 116   scoped_refptr<base::RefCountedString> output(
 117       base::RefCountedString::TakeString(&output_val));
 118
 119   trace_data_[current_trace_id_] = output;
 120
 121   if (!trace_callback_.is_null()) {
 122     trace_callback_.Run(output);
 123     trace_callback_.Reset();
 124   }
 125
 126   current_trace_id_ = 0;
 127
 128   // Tracing has to be restarted asynchronous, so the TracingController can
 129   // clean up.
 130   base::MessageLoopProxy::current()->PostTask(
 131       FROM_HERE,
 132       base::Bind(&TracingManager::StartTracing,
 133                  weak_ptr_factory_.GetWeakPtr()));
 134 }
 135
 136 // static
 137 scoped_ptr<TracingManager> TracingManager::Create() {
 138   if (g_tracing_manager)
 139     return scoped_ptr<TracingManager>();
 140   return scoped_ptr<TracingManager>(new TracingManager());
 141 }
 142
 143 TracingManager* TracingManager::Get() {
 144   return g_tracing_manager;
 145 }