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   base::Base64Encode(base::StringPiece(buffer, arraysize(buffer)),
  24                      &result);
  25   return result;
  26 }
  27
  28 }  // namespace
  29
  30 DesktopStreamsRegistry::DesktopStreamsRegistry() {}
  31 DesktopStreamsRegistry::~DesktopStreamsRegistry() {}
  32
  33 std::string DesktopStreamsRegistry::RegisterStream(
  34     int render_process_id,
  35     int render_view_id,
  36     const GURL& origin,
  37     const content::DesktopMediaID& source) {
  38   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
  39
  40   std::string id = GenerateRandomStreamId();
  41   ApprovedDesktopMediaStream& stream = approved_streams_[id];
  42   stream.render_process_id = render_process_id;
  43   stream.render_view_id = render_view_id;
  44   stream.origin = origin;
  45   stream.source = source;
  46
  47   content::BrowserThread::PostDelayedTask(
  48       content::BrowserThread::UI, FROM_HERE,
  49       base::Bind(&DesktopStreamsRegistry::CleanupStream,
  50                  base::Unretained(this), id),
  51       base::TimeDelta::FromSeconds(kApprovedStreamTimeToLiveSeconds));
  52
  53   return id;
  54 }
  55
  56 content::DesktopMediaID DesktopStreamsRegistry::RequestMediaForStreamId(
  57     const std::string& id,
  58     int render_process_id,
  59     int render_view_id,
  60     const GURL& origin) {
  61   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
  62
  63   StreamsMap::iterator it = approved_streams_.find(id);
  64
  65   // Verify that if there is a request with the specified ID it was created for
  66   // the same origin and the same renderer.
  67   if (it == approved_streams_.end() ||
  68       render_process_id != it->second.render_process_id ||
  69       render_view_id != it->second.render_view_id ||
  70       origin != it->second.origin) {
  71     return content::DesktopMediaID();
  72   }
  73
  74   content::DesktopMediaID result = it->second.source;
  75   approved_streams_.erase(it);
  76   return result;
  77 }
  78
  79 void DesktopStreamsRegistry::CleanupStream(const std::string& id) {
  80   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
  81   approved_streams_.erase(id);
  82 }