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     const std::string& extension_name) {
  39   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
  40
  41   std::string id = GenerateRandomStreamId();
  42   ApprovedDesktopMediaStream& stream = approved_streams_[id];
  43   stream.render_process_id = render_process_id;
  44   stream.render_view_id = render_view_id;
  45   stream.origin = origin;
  46   stream.source = source;
  47   stream.extension_name = extension_name;
  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     std::string* extension_name) {
  64   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
  65
  66   StreamsMap::iterator it = approved_streams_.find(id);
  67
  68   // Verify that if there is a request with the specified ID it was created for
  69   // the same origin and the same renderer.
  70   if (it == approved_streams_.end() ||
  71       render_process_id != it->second.render_process_id ||
  72       render_view_id != it->second.render_view_id ||
  73       origin != it->second.origin) {
  74     return content::DesktopMediaID();
  75   }
  76
  77   content::DesktopMediaID result = it->second.source;
  78   *extension_name = it->second.extension_name;
  79   approved_streams_.erase(it);
  80   return result;
  81 }
  82
  83 void DesktopStreamsRegistry::CleanupStream(const std::string& id) {
  84   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
  85   approved_streams_.erase(id);
  86 }
  87
  88 DesktopStreamsRegistry::ApprovedDesktopMediaStream::ApprovedDesktopMediaStream()
  89     : render_process_id(-1), render_view_id(-1) {}