components/feedback/tracing_manager.cc

   1 // Copyright 2014 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 "components/feedback/tracing_manager.h"
   6
   7 #include "base/bind.h"
   8 #include "base/memory/ref_counted_memory.h"
   9 #include "base/message_loop/message_loop_proxy.h"
  10 #include "components/feedback/feedback_util.h"
  11 #include "content/public/browser/tracing_controller.h"
  12
  13 namespace {
  14
  15 // Only once trace manager can exist at a time.
  16 TracingManager* g_tracing_manager = NULL;
  17 // Trace IDs start at 1 and increase.
  18 int g_next_trace_id = 1;
  19 // Name of the file to store the tracing data as.
  20 const base::FilePath::CharType kTracingFilename[] =
  21     FILE_PATH_LITERAL("tracing.json");
  22 }
  23
  24 TracingManager::TracingManager()
  25     : current_trace_id_(0),
  26       weak_ptr_factory_(this) {
  27   DCHECK(!g_tracing_manager);
  28   g_tracing_manager = this;
  29   StartTracing();
  30 }
  31
  32 TracingManager::~TracingManager() {
  33   DCHECK(g_tracing_manager == this);
  34   g_tracing_manager = NULL;
  35 }
  36
  37 int TracingManager::RequestTrace() {
  38   // Return the current trace if one is being collected.
  39   if (current_trace_id_)
  40     return current_trace_id_;
  41
  42   current_trace_id_ = g_next_trace_id;
  43   ++g_next_trace_id;
  44   content::TracingController::GetInstance()->DisableRecording(
  45       content::TracingController::CreateStringSink(
  46           base::Bind(&TracingManager::OnTraceDataCollected,
  47                      weak_ptr_factory_.GetWeakPtr())));
  48   return current_trace_id_;
  49 }
  50
  51 bool TracingManager::GetTraceData(int id, const TraceDataCallback& callback) {
  52   // If a trace is being collected currently, send it via callback when
  53   // complete.
  54   if (current_trace_id_) {
  55     // Only allow one trace data request at a time.
  56     if (trace_callback_.is_null()) {
  57       trace_callback_ = callback;
  58       return true;
  59     } else {
  60       return false;
  61     }
  62   } else {
  63     std::map<int, scoped_refptr<base::RefCountedString> >::iterator data =
  64         trace_data_.find(id);
  65     if (data == trace_data_.end())
  66       return false;
  67
  68     // Always return the data asychronously, so the behavior is consistant.
  69     base::MessageLoopProxy::current()->PostTask(
  70         FROM_HERE,
  71         base::Bind(callback, data->second));
  72     return true;
  73   }
  74 }
  75
  76 void TracingManager::DiscardTraceData(int id) {
  77   trace_data_.erase(id);
  78
  79   // If the trace is discarded before it is complete, clean up the accumulators.
  80   if (id == current_trace_id_) {
  81     current_trace_id_ = 0;
  82
  83     // If the trace has already been requested, provide an empty string.
  84     if (!trace_callback_.is_null()) {
  85       trace_callback_.Run(scoped_refptr<base::RefCountedString>());
  86       trace_callback_.Reset();
  87     }
  88   }
  89 }
  90
  91 void TracingManager::StartTracing() {
  92   content::TracingController::GetInstance()->EnableRecording(
  93       base::trace_event::CategoryFilter(),
  94       base::trace_event::TraceOptions(),
  95       content::TracingController::EnableRecordingDoneCallback());
  96 }
  97
  98 void TracingManager::OnTraceDataCollected(base::RefCountedString* trace_data) {
  99   if (!current_trace_id_)
 100     return;
 101
 102   std::string output_val;
 103   feedback_util::ZipString(
 104       base::FilePath(kTracingFilename), trace_data->data(), &output_val);
 105
 106   scoped_refptr<base::RefCountedString> output(
 107       base::RefCountedString::TakeString(&output_val));
 108
 109   trace_data_[current_trace_id_] = output;
 110
 111   if (!trace_callback_.is_null()) {
 112     trace_callback_.Run(output);
 113     trace_callback_.Reset();
 114   }
 115
 116   current_trace_id_ = 0;
 117
 118   // Tracing has to be restarted asynchronous, so the TracingController can
 119   // clean up.
 120   base::MessageLoopProxy::current()->PostTask(
 121       FROM_HERE,
 122       base::Bind(&TracingManager::StartTracing,
 123                  weak_ptr_factory_.GetWeakPtr()));
 124 }
 125
 126 // static
 127 scoped_ptr<TracingManager> TracingManager::Create() {
 128   if (g_tracing_manager)
 129     return scoped_ptr<TracingManager>();
 130   return scoped_ptr<TracingManager>(new TracingManager());
 131 }
 132
 133 TracingManager* TracingManager::Get() {
 134   return g_tracing_manager;
 135 }