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