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 15namespace content { 16 17HistogramMessageFilter::HistogramMessageFilter() 18 : BrowserMessageFilter(ChildProcessMsgStart) {} 19 20bool 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 32HistogramMessageFilter::~HistogramMessageFilter() {} 33 34void 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 41void 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 base::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