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/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 "components/feedback/feedback_util.h"
  13 #include "content/public/browser/tracing_controller.h"
  14
  15 namespace {
  16 // Only once trace manager can exist at a time.
  17 TracingManager* g_tracing_manager = NULL;
  18 // Trace IDs start at 1 and increase.
  19 int g_next_trace_id = 1;
  20 // Name of the file to store the tracing data as.
  21 const base::FilePath::CharType kTracingFilename[] =
  22     FILE_PATH_LITERAL("tracing.json");
  23 }
  24
  25 TracingManager::TracingManager()
  26     : current_trace_id_(0),
  27       weak_ptr_factory_(this) {
  28   DCHECK(!g_tracing_manager);
  29   g_tracing_manager = this;
  30   StartTracing();
  31 }
  32
  33 TracingManager::~TracingManager() {
  34   DCHECK(g_tracing_manager == this);
  35   g_tracing_manager = NULL;
  36 }
  37
  38 int TracingManager::RequestTrace() {
  39   // Return the current trace if one is being collected.
  40   if (current_trace_id_)
  41     return current_trace_id_;
  42
  43   current_trace_id_ = g_next_trace_id;
  44   ++g_next_trace_id;
  45   content::TracingController::GetInstance()->DisableRecording(
  46       base::FilePath(),
  47       base::Bind(&TracingManager::OnTraceDataCollected,
  48                  weak_ptr_factory_.GetWeakPtr()));
  49   return current_trace_id_;
  50 }
  51
  52 bool TracingManager::GetTraceData(int id, const TraceDataCallback& callback) {
  53   // If a trace is being collected currently, send it via callback when
  54   // complete.
  55   if (current_trace_id_) {
  56     // Only allow one trace data request at a time.
  57     if (trace_callback_.is_null()) {
  58       trace_callback_ = callback;
  59       return true;
  60     } else {
  61       return false;
  62     }
  63   } else {
  64     std::map<int, scoped_refptr<base::RefCountedString> >::iterator data =
  65         trace_data_.find(id);
  66     if (data == trace_data_.end())
  67       return false;
  68
  69     // Always return the data asychronously, so the behavior is consistant.
  70     base::MessageLoopProxy::current()->PostTask(
  71         FROM_HERE,
  72         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::debug::CategoryFilter(),
  95       base::debug::TraceOptions(),
  96       content::TracingController::EnableRecordingDoneCallback());
  97 }
  98
  99 void TracingManager::OnTraceDataCollected(const base::FilePath& path) {
 100   if (!current_trace_id_)
 101     return;
 102
 103   std::string data;
 104   if (!base::ReadFileToString(path, &data)) {
 105     LOG(ERROR) << "Failed to read trace data from: " << path.value();
 106     return;
 107   }
 108   base::DeleteFile(path, false);
 109
 110   std::string output_val;
 111   feedback_util::ZipString(
 112       base::FilePath(kTracingFilename), data, &output_val);
 113
 114   scoped_refptr<base::RefCountedString> output(
 115       base::RefCountedString::TakeString(&output_val));
 116
 117   trace_data_[current_trace_id_] = output;
 118
 119   if (!trace_callback_.is_null()) {
 120     trace_callback_.Run(output);
 121     trace_callback_.Reset();
 122   }
 123
 124   current_trace_id_ = 0;
 125
 126   // Tracing has to be restarted asynchronous, so the TracingController can
 127   // clean up.
 128   base::MessageLoopProxy::current()->PostTask(
 129       FROM_HERE,
 130       base::Bind(&TracingManager::StartTracing,
 131                  weak_ptr_factory_.GetWeakPtr()));
 132 }
 133
 134 // static
 135 scoped_ptr<TracingManager> TracingManager::Create() {
 136   if (g_tracing_manager)
 137     return scoped_ptr<TracingManager>();
 138   return scoped_ptr<TracingManager>(new TracingManager());
 139 }
 140
 141 TracingManager* TracingManager::Get() {
 142   return g_tracing_manager;
 143 }