Home | History | Annotate | Download | only in browser 
      1 // Copyright (c) 2012 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 "content/browser/histogram_message_filter.h"
      6 
      7 #include "base/command_line.h"
      8 #include "base/metrics/histogram.h"
      9 #include "base/metrics/statistics_recorder.h"
     10 #include "content/browser/histogram_controller.h"
     11 #include "content/browser/tcmalloc_internals_request_job.h"
     12 #include "content/common/child_process_messages.h"
     13 #include "content/public/common/content_switches.h"
     14 
     15 namespace content {
     16 
     17 HistogramMessageFilter::HistogramMessageFilter()
     18     : BrowserMessageFilter(ChildProcessMsgStart) {}
     19 
     20 bool HistogramMessageFilter::OnMessageReceived(const IPC::Message& message) {
     21   bool handled = true;
     22   IPC_BEGIN_MESSAGE_MAP(HistogramMessageFilter, message)
     23     IPC_MESSAGE_HANDLER(ChildProcessHostMsg_ChildHistogramData,
     24                         OnChildHistogramData)
     25     IPC_MESSAGE_HANDLER(ChildProcessHostMsg_GetBrowserHistogram,
     26                         OnGetBrowserHistogram)
     27     IPC_MESSAGE_UNHANDLED(handled = false)
     28   IPC_END_MESSAGE_MAP()
     29   return handled;
     30 }
     31 
     32 HistogramMessageFilter::~HistogramMessageFilter() {}
     33 
     34 void HistogramMessageFilter::OnChildHistogramData(
     35     int sequence_number,
     36     const std::vector<std::string>& pickled_histograms) {
     37   HistogramController::GetInstance()->OnHistogramDataCollected(
     38       sequence_number, pickled_histograms);
     39 }
     40 
     41 void HistogramMessageFilter::OnGetBrowserHistogram(
     42     const std::string& name,
     43     std::string* histogram_json) {
     44   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::IO));
     45   // Security: Only allow access to browser histograms when running in the
     46   // context of a test.
     47   bool using_stats_collection_controller =
     48       CommandLine::ForCurrentProcess()->HasSwitch(
     49           switches::kStatsCollectionController);
     50   if (!using_stats_collection_controller) {
     51     LOG(ERROR) << "Attempt at reading browser histogram without specifying "
     52                << "--" << switches::kStatsCollectionController << " switch.";
     53     return;
     54   }
     55   base::HistogramBase* histogram =
     56       base::StatisticsRecorder::FindHistogram(name);
     57   if (!histogram) {
     58     *histogram_json = "{}";
     59   } else {
     60     histogram->WriteJSON(histogram_json);
     61   }
     62 }
     63 
     64 }  // namespace content
     65