src/chrome/browser/media/desktop_streams_registry.cc

   1 // Copyright 2013 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 "chrome/browser/media/desktop_streams_registry.h"
   6
   7 #include "base/base64.h"
   8 #include "base/location.h"
   9 #include "base/time/time.h"
  10 #include "content/public/browser/browser_thread.h"
  11 #include "crypto/random.h"
  12
  13 namespace {
  14
  15 const int kStreamIdLengthBytes = 16;
  16
  17 const int kApprovedStreamTimeToLiveSeconds = 10;
  18
  19 std::string GenerateRandomStreamId() {
  20   char buffer[kStreamIdLengthBytes];
  21   crypto::RandBytes(buffer, arraysize(buffer));
  22   std::string result;
  23   if (!base::Base64Encode(base::StringPiece(buffer, arraysize(buffer)),
  24                           &result)) {
  25     LOG(FATAL) << "Base64Encode failed.";
  26   }
  27   return result;
  28 }
  29
  30 }  // namespace
  31
  32 DesktopStreamsRegistry::DesktopStreamsRegistry() {}
  33 DesktopStreamsRegistry::~DesktopStreamsRegistry() {}
  34
  35 std::string DesktopStreamsRegistry::RegisterStream(
  36     int render_process_id,
  37     int render_view_id,
  38     const GURL& origin,
  39     const content::DesktopMediaID& source) {
  40   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
  41
  42   std::string id = GenerateRandomStreamId();
  43   ApprovedDesktopMediaStream& stream = approved_streams_[id];
  44   stream.render_process_id = render_process_id;
  45   stream.render_view_id = render_view_id;
  46   stream.origin = origin;
  47   stream.source = source;
  48
  49   content::BrowserThread::PostDelayedTask(
  50       content::BrowserThread::UI, FROM_HERE,
  51       base::Bind(&DesktopStreamsRegistry::CleanupStream,
  52                  base::Unretained(this), id),
  53       base::TimeDelta::FromSeconds(kApprovedStreamTimeToLiveSeconds));
  54
  55   return id;
  56 }
  57
  58 content::DesktopMediaID DesktopStreamsRegistry::RequestMediaForStreamId(
  59     const std::string& id,
  60     int render_process_id,
  61     int render_view_id,
  62     const GURL& origin) {
  63   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
  64
  65   StreamsMap::iterator it = approved_streams_.find(id);
  66
  67   // Verify that if there is a request with the specified ID it was created for
  68   // the same origin and the same renderer.
  69   if (it == approved_streams_.end() ||
  70       render_process_id != it->second.render_process_id ||
  71       render_view_id != it->second.render_view_id ||
  72       origin != it->second.origin) {
  73     return content::DesktopMediaID();
  74   }
  75
  76   content::DesktopMediaID result = it->second.source;
  77   approved_streams_.erase(it);
  78   return result;
  79 }
  80
  81 void DesktopStreamsRegistry::CleanupStream(const std::string& id) {
  82   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
  83   approved_streams_.erase(id);
  84 }